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-rw-r--r--arch/arm64/mm/Makefile16
-rw-r--r--arch/arm64/mm/cache.S197
-rw-r--r--arch/arm64/mm/context.c422
-rw-r--r--arch/arm64/mm/copypage.c42
-rw-r--r--arch/arm64/mm/dma-mapping.c65
-rw-r--r--arch/arm64/mm/extable.c78
-rw-r--r--arch/arm64/mm/fault.c962
-rw-r--r--arch/arm64/mm/fixmap.c203
-rw-r--r--arch/arm64/mm/flush.c102
-rw-r--r--arch/arm64/mm/hugetlbpage.c566
-rw-r--r--arch/arm64/mm/init.c549
-rw-r--r--arch/arm64/mm/ioremap.c37
-rw-r--r--arch/arm64/mm/kasan_init.c308
-rw-r--r--arch/arm64/mm/mmap.c103
-rw-r--r--arch/arm64/mm/mmu.c1489
-rw-r--r--arch/arm64/mm/mteswap.c85
-rw-r--r--arch/arm64/mm/pageattr.c249
-rw-r--r--arch/arm64/mm/pgd.c56
-rw-r--r--arch/arm64/mm/physaddr.c31
-rw-r--r--arch/arm64/mm/proc.S480
-rw-r--r--arch/arm64/mm/ptdump.c386
-rw-r--r--arch/arm64/mm/ptdump_debugfs.c22
-rw-r--r--arch/arm64/mm/trans_pgd-asm.S65
-rw-r--r--arch/arm64/mm/trans_pgd.c292
24 files changed, 6805 insertions, 0 deletions
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
new file mode 100644
index 0000000000..dbd1bc9596
--- /dev/null
+++ b/arch/arm64/mm/Makefile
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y := dma-mapping.o extable.o fault.o init.o \
+ cache.o copypage.o flush.o \
+ ioremap.o mmap.o pgd.o mmu.o \
+ context.o proc.o pageattr.o fixmap.o
+obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
+obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
+obj-$(CONFIG_PTDUMP_DEBUGFS) += ptdump_debugfs.o
+obj-$(CONFIG_TRANS_TABLE) += trans_pgd.o
+obj-$(CONFIG_TRANS_TABLE) += trans_pgd-asm.o
+obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o
+obj-$(CONFIG_ARM64_MTE) += mteswap.o
+KASAN_SANITIZE_physaddr.o += n
+
+obj-$(CONFIG_KASAN) += kasan_init.o
+KASAN_SANITIZE_kasan_init.o := n
diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
new file mode 100644
index 0000000000..503567c864
--- /dev/null
+++ b/arch/arm64/mm/cache.S
@@ -0,0 +1,197 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Cache maintenance
+ *
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/errno.h>
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+#include <asm/cpufeature.h>
+#include <asm/alternative.h>
+#include <asm/asm-uaccess.h>
+
+/*
+ * caches_clean_inval_pou_macro(start,end) [fixup]
+ *
+ * Ensure that the I and D caches are coherent within specified region.
+ * This is typically used when code has been written to a memory region,
+ * and will be executed.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ * - fixup - optional label to branch to on user fault
+ */
+.macro caches_clean_inval_pou_macro, fixup
+alternative_if ARM64_HAS_CACHE_IDC
+ dsb ishst
+ b .Ldc_skip_\@
+alternative_else_nop_endif
+ mov x2, x0
+ mov x3, x1
+ dcache_by_line_op cvau, ish, x2, x3, x4, x5, \fixup
+.Ldc_skip_\@:
+alternative_if ARM64_HAS_CACHE_DIC
+ isb
+ b .Lic_skip_\@
+alternative_else_nop_endif
+ invalidate_icache_by_line x0, x1, x2, x3, \fixup
+.Lic_skip_\@:
+.endm
+
+/*
+ * caches_clean_inval_pou(start,end)
+ *
+ * Ensure that the I and D caches are coherent within specified region.
+ * This is typically used when code has been written to a memory region,
+ * and will be executed.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+SYM_FUNC_START(caches_clean_inval_pou)
+ caches_clean_inval_pou_macro
+ ret
+SYM_FUNC_END(caches_clean_inval_pou)
+SYM_FUNC_ALIAS(__pi_caches_clean_inval_pou, caches_clean_inval_pou)
+
+/*
+ * caches_clean_inval_user_pou(start,end)
+ *
+ * Ensure that the I and D caches are coherent within specified region.
+ * This is typically used when code has been written to a memory region,
+ * and will be executed.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+SYM_FUNC_START(caches_clean_inval_user_pou)
+ uaccess_ttbr0_enable x2, x3, x4
+
+ caches_clean_inval_pou_macro 2f
+ mov x0, xzr
+1:
+ uaccess_ttbr0_disable x1, x2
+ ret
+2:
+ mov x0, #-EFAULT
+ b 1b
+SYM_FUNC_END(caches_clean_inval_user_pou)
+
+/*
+ * icache_inval_pou(start,end)
+ *
+ * Ensure that the I cache is invalid within specified region.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+SYM_FUNC_START(icache_inval_pou)
+alternative_if ARM64_HAS_CACHE_DIC
+ isb
+ ret
+alternative_else_nop_endif
+
+ invalidate_icache_by_line x0, x1, x2, x3
+ ret
+SYM_FUNC_END(icache_inval_pou)
+
+/*
+ * dcache_clean_inval_poc(start, end)
+ *
+ * Ensure that any D-cache lines for the interval [start, end)
+ * are cleaned and invalidated to the PoC.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+SYM_FUNC_START(__pi_dcache_clean_inval_poc)
+ dcache_by_line_op civac, sy, x0, x1, x2, x3
+ ret
+SYM_FUNC_END(__pi_dcache_clean_inval_poc)
+SYM_FUNC_ALIAS(dcache_clean_inval_poc, __pi_dcache_clean_inval_poc)
+
+/*
+ * dcache_clean_pou(start, end)
+ *
+ * Ensure that any D-cache lines for the interval [start, end)
+ * are cleaned to the PoU.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+SYM_FUNC_START(dcache_clean_pou)
+alternative_if ARM64_HAS_CACHE_IDC
+ dsb ishst
+ ret
+alternative_else_nop_endif
+ dcache_by_line_op cvau, ish, x0, x1, x2, x3
+ ret
+SYM_FUNC_END(dcache_clean_pou)
+
+/*
+ * dcache_inval_poc(start, end)
+ *
+ * Ensure that any D-cache lines for the interval [start, end)
+ * are invalidated. Any partial lines at the ends of the interval are
+ * also cleaned to PoC to prevent data loss.
+ *
+ * - start - kernel start address of region
+ * - end - kernel end address of region
+ */
+SYM_FUNC_START(__pi_dcache_inval_poc)
+ dcache_line_size x2, x3
+ sub x3, x2, #1
+ tst x1, x3 // end cache line aligned?
+ bic x1, x1, x3
+ b.eq 1f
+ dc civac, x1 // clean & invalidate D / U line
+1: tst x0, x3 // start cache line aligned?
+ bic x0, x0, x3
+ b.eq 2f
+ dc civac, x0 // clean & invalidate D / U line
+ b 3f
+2: dc ivac, x0 // invalidate D / U line
+3: add x0, x0, x2
+ cmp x0, x1
+ b.lo 2b
+ dsb sy
+ ret
+SYM_FUNC_END(__pi_dcache_inval_poc)
+SYM_FUNC_ALIAS(dcache_inval_poc, __pi_dcache_inval_poc)
+
+/*
+ * dcache_clean_poc(start, end)
+ *
+ * Ensure that any D-cache lines for the interval [start, end)
+ * are cleaned to the PoC.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+SYM_FUNC_START(__pi_dcache_clean_poc)
+ dcache_by_line_op cvac, sy, x0, x1, x2, x3
+ ret
+SYM_FUNC_END(__pi_dcache_clean_poc)
+SYM_FUNC_ALIAS(dcache_clean_poc, __pi_dcache_clean_poc)
+
+/*
+ * dcache_clean_pop(start, end)
+ *
+ * Ensure that any D-cache lines for the interval [start, end)
+ * are cleaned to the PoP.
+ *
+ * - start - virtual start address of region
+ * - end - virtual end address of region
+ */
+SYM_FUNC_START(__pi_dcache_clean_pop)
+ alternative_if_not ARM64_HAS_DCPOP
+ b dcache_clean_poc
+ alternative_else_nop_endif
+ dcache_by_line_op cvap, sy, x0, x1, x2, x3
+ ret
+SYM_FUNC_END(__pi_dcache_clean_pop)
+SYM_FUNC_ALIAS(dcache_clean_pop, __pi_dcache_clean_pop)
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
new file mode 100644
index 0000000000..188197590f
--- /dev/null
+++ b/arch/arm64/mm/context.c
@@ -0,0 +1,422 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/mm/context.c
+ *
+ * Copyright (C) 2002-2003 Deep Blue Solutions Ltd, all rights reserved.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+
+#include <asm/cpufeature.h>
+#include <asm/mmu_context.h>
+#include <asm/smp.h>
+#include <asm/tlbflush.h>
+
+static u32 asid_bits;
+static DEFINE_RAW_SPINLOCK(cpu_asid_lock);
+
+static atomic64_t asid_generation;
+static unsigned long *asid_map;
+
+static DEFINE_PER_CPU(atomic64_t, active_asids);
+static DEFINE_PER_CPU(u64, reserved_asids);
+static cpumask_t tlb_flush_pending;
+
+static unsigned long max_pinned_asids;
+static unsigned long nr_pinned_asids;
+static unsigned long *pinned_asid_map;
+
+#define ASID_MASK (~GENMASK(asid_bits - 1, 0))
+#define ASID_FIRST_VERSION (1UL << asid_bits)
+
+#define NUM_USER_ASIDS ASID_FIRST_VERSION
+#define ctxid2asid(asid) ((asid) & ~ASID_MASK)
+#define asid2ctxid(asid, genid) ((asid) | (genid))
+
+/* Get the ASIDBits supported by the current CPU */
+static u32 get_cpu_asid_bits(void)
+{
+ u32 asid;
+ int fld = cpuid_feature_extract_unsigned_field(read_cpuid(ID_AA64MMFR0_EL1),
+ ID_AA64MMFR0_EL1_ASIDBITS_SHIFT);
+
+ switch (fld) {
+ default:
+ pr_warn("CPU%d: Unknown ASID size (%d); assuming 8-bit\n",
+ smp_processor_id(), fld);
+ fallthrough;
+ case ID_AA64MMFR0_EL1_ASIDBITS_8:
+ asid = 8;
+ break;
+ case ID_AA64MMFR0_EL1_ASIDBITS_16:
+ asid = 16;
+ }
+
+ return asid;
+}
+
+/* Check if the current cpu's ASIDBits is compatible with asid_bits */
+void verify_cpu_asid_bits(void)
+{
+ u32 asid = get_cpu_asid_bits();
+
+ if (asid < asid_bits) {
+ /*
+ * We cannot decrease the ASID size at runtime, so panic if we support
+ * fewer ASID bits than the boot CPU.
+ */
+ pr_crit("CPU%d: smaller ASID size(%u) than boot CPU (%u)\n",
+ smp_processor_id(), asid, asid_bits);
+ cpu_panic_kernel();
+ }
+}
+
+static void set_kpti_asid_bits(unsigned long *map)
+{
+ unsigned int len = BITS_TO_LONGS(NUM_USER_ASIDS) * sizeof(unsigned long);
+ /*
+ * In case of KPTI kernel/user ASIDs are allocated in
+ * pairs, the bottom bit distinguishes the two: if it
+ * is set, then the ASID will map only userspace. Thus
+ * mark even as reserved for kernel.
+ */
+ memset(map, 0xaa, len);
+}
+
+static void set_reserved_asid_bits(void)
+{
+ if (pinned_asid_map)
+ bitmap_copy(asid_map, pinned_asid_map, NUM_USER_ASIDS);
+ else if (arm64_kernel_unmapped_at_el0())
+ set_kpti_asid_bits(asid_map);
+ else
+ bitmap_clear(asid_map, 0, NUM_USER_ASIDS);
+}
+
+#define asid_gen_match(asid) \
+ (!(((asid) ^ atomic64_read(&asid_generation)) >> asid_bits))
+
+static void flush_context(void)
+{
+ int i;
+ u64 asid;
+
+ /* Update the list of reserved ASIDs and the ASID bitmap. */
+ set_reserved_asid_bits();
+
+ for_each_possible_cpu(i) {
+ asid = atomic64_xchg_relaxed(&per_cpu(active_asids, i), 0);
+ /*
+ * If this CPU has already been through a
+ * rollover, but hasn't run another task in
+ * the meantime, we must preserve its reserved
+ * ASID, as this is the only trace we have of
+ * the process it is still running.
+ */
+ if (asid == 0)
+ asid = per_cpu(reserved_asids, i);
+ __set_bit(ctxid2asid(asid), asid_map);
+ per_cpu(reserved_asids, i) = asid;
+ }
+
+ /*
+ * Queue a TLB invalidation for each CPU to perform on next
+ * context-switch
+ */
+ cpumask_setall(&tlb_flush_pending);
+}
+
+static bool check_update_reserved_asid(u64 asid, u64 newasid)
+{
+ int cpu;
+ bool hit = false;
+
+ /*
+ * Iterate over the set of reserved ASIDs looking for a match.
+ * If we find one, then we can update our mm to use newasid
+ * (i.e. the same ASID in the current generation) but we can't
+ * exit the loop early, since we need to ensure that all copies
+ * of the old ASID are updated to reflect the mm. Failure to do
+ * so could result in us missing the reserved ASID in a future
+ * generation.
+ */
+ for_each_possible_cpu(cpu) {
+ if (per_cpu(reserved_asids, cpu) == asid) {
+ hit = true;
+ per_cpu(reserved_asids, cpu) = newasid;
+ }
+ }
+
+ return hit;
+}
+
+static u64 new_context(struct mm_struct *mm)
+{
+ static u32 cur_idx = 1;
+ u64 asid = atomic64_read(&mm->context.id);
+ u64 generation = atomic64_read(&asid_generation);
+
+ if (asid != 0) {
+ u64 newasid = asid2ctxid(ctxid2asid(asid), generation);
+
+ /*
+ * If our current ASID was active during a rollover, we
+ * can continue to use it and this was just a false alarm.
+ */
+ if (check_update_reserved_asid(asid, newasid))
+ return newasid;
+
+ /*
+ * If it is pinned, we can keep using it. Note that reserved
+ * takes priority, because even if it is also pinned, we need to
+ * update the generation into the reserved_asids.
+ */
+ if (refcount_read(&mm->context.pinned))
+ return newasid;
+
+ /*
+ * We had a valid ASID in a previous life, so try to re-use
+ * it if possible.
+ */
+ if (!__test_and_set_bit(ctxid2asid(asid), asid_map))
+ return newasid;
+ }
+
+ /*
+ * Allocate a free ASID. If we can't find one, take a note of the
+ * currently active ASIDs and mark the TLBs as requiring flushes. We
+ * always count from ASID #2 (index 1), as we use ASID #0 when setting
+ * a reserved TTBR0 for the init_mm and we allocate ASIDs in even/odd
+ * pairs.
+ */
+ asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, cur_idx);
+ if (asid != NUM_USER_ASIDS)
+ goto set_asid;
+
+ /* We're out of ASIDs, so increment the global generation count */
+ generation = atomic64_add_return_relaxed(ASID_FIRST_VERSION,
+ &asid_generation);
+ flush_context();
+
+ /* We have more ASIDs than CPUs, so this will always succeed */
+ asid = find_next_zero_bit(asid_map, NUM_USER_ASIDS, 1);
+
+set_asid:
+ __set_bit(asid, asid_map);
+ cur_idx = asid;
+ return asid2ctxid(asid, generation);
+}
+
+void check_and_switch_context(struct mm_struct *mm)
+{
+ unsigned long flags;
+ unsigned int cpu;
+ u64 asid, old_active_asid;
+
+ if (system_supports_cnp())
+ cpu_set_reserved_ttbr0();
+
+ asid = atomic64_read(&mm->context.id);
+
+ /*
+ * The memory ordering here is subtle.
+ * If our active_asids is non-zero and the ASID matches the current
+ * generation, then we update the active_asids entry with a relaxed
+ * cmpxchg. Racing with a concurrent rollover means that either:
+ *
+ * - We get a zero back from the cmpxchg and end up waiting on the
+ * lock. Taking the lock synchronises with the rollover and so
+ * we are forced to see the updated generation.
+ *
+ * - We get a valid ASID back from the cmpxchg, which means the
+ * relaxed xchg in flush_context will treat us as reserved
+ * because atomic RmWs are totally ordered for a given location.
+ */
+ old_active_asid = atomic64_read(this_cpu_ptr(&active_asids));
+ if (old_active_asid && asid_gen_match(asid) &&
+ atomic64_cmpxchg_relaxed(this_cpu_ptr(&active_asids),
+ old_active_asid, asid))
+ goto switch_mm_fastpath;
+
+ raw_spin_lock_irqsave(&cpu_asid_lock, flags);
+ /* Check that our ASID belongs to the current generation. */
+ asid = atomic64_read(&mm->context.id);
+ if (!asid_gen_match(asid)) {
+ asid = new_context(mm);
+ atomic64_set(&mm->context.id, asid);
+ }
+
+ cpu = smp_processor_id();
+ if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending))
+ local_flush_tlb_all();
+
+ atomic64_set(this_cpu_ptr(&active_asids), asid);
+ raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
+
+switch_mm_fastpath:
+
+ arm64_apply_bp_hardening();
+
+ /*
+ * Defer TTBR0_EL1 setting for user threads to uaccess_enable() when
+ * emulating PAN.
+ */
+ if (!system_uses_ttbr0_pan())
+ cpu_switch_mm(mm->pgd, mm);
+}
+
+unsigned long arm64_mm_context_get(struct mm_struct *mm)
+{
+ unsigned long flags;
+ u64 asid;
+
+ if (!pinned_asid_map)
+ return 0;
+
+ raw_spin_lock_irqsave(&cpu_asid_lock, flags);
+
+ asid = atomic64_read(&mm->context.id);
+
+ if (refcount_inc_not_zero(&mm->context.pinned))
+ goto out_unlock;
+
+ if (nr_pinned_asids >= max_pinned_asids) {
+ asid = 0;
+ goto out_unlock;
+ }
+
+ if (!asid_gen_match(asid)) {
+ /*
+ * We went through one or more rollover since that ASID was
+ * used. Ensure that it is still valid, or generate a new one.
+ */
+ asid = new_context(mm);
+ atomic64_set(&mm->context.id, asid);
+ }
+
+ nr_pinned_asids++;
+ __set_bit(ctxid2asid(asid), pinned_asid_map);
+ refcount_set(&mm->context.pinned, 1);
+
+out_unlock:
+ raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
+
+ asid = ctxid2asid(asid);
+
+ /* Set the equivalent of USER_ASID_BIT */
+ if (asid && arm64_kernel_unmapped_at_el0())
+ asid |= 1;
+
+ return asid;
+}
+EXPORT_SYMBOL_GPL(arm64_mm_context_get);
+
+void arm64_mm_context_put(struct mm_struct *mm)
+{
+ unsigned long flags;
+ u64 asid = atomic64_read(&mm->context.id);
+
+ if (!pinned_asid_map)
+ return;
+
+ raw_spin_lock_irqsave(&cpu_asid_lock, flags);
+
+ if (refcount_dec_and_test(&mm->context.pinned)) {
+ __clear_bit(ctxid2asid(asid), pinned_asid_map);
+ nr_pinned_asids--;
+ }
+
+ raw_spin_unlock_irqrestore(&cpu_asid_lock, flags);
+}
+EXPORT_SYMBOL_GPL(arm64_mm_context_put);
+
+/* Errata workaround post TTBRx_EL1 update. */
+asmlinkage void post_ttbr_update_workaround(void)
+{
+ if (!IS_ENABLED(CONFIG_CAVIUM_ERRATUM_27456))
+ return;
+
+ asm(ALTERNATIVE("nop; nop; nop",
+ "ic iallu; dsb nsh; isb",
+ ARM64_WORKAROUND_CAVIUM_27456));
+}
+
+void cpu_do_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm)
+{
+ unsigned long ttbr1 = read_sysreg(ttbr1_el1);
+ unsigned long asid = ASID(mm);
+ unsigned long ttbr0 = phys_to_ttbr(pgd_phys);
+
+ /* Skip CNP for the reserved ASID */
+ if (system_supports_cnp() && asid)
+ ttbr0 |= TTBR_CNP_BIT;
+
+ /* SW PAN needs a copy of the ASID in TTBR0 for entry */
+ if (IS_ENABLED(CONFIG_ARM64_SW_TTBR0_PAN))
+ ttbr0 |= FIELD_PREP(TTBR_ASID_MASK, asid);
+
+ /* Set ASID in TTBR1 since TCR.A1 is set */
+ ttbr1 &= ~TTBR_ASID_MASK;
+ ttbr1 |= FIELD_PREP(TTBR_ASID_MASK, asid);
+
+ cpu_set_reserved_ttbr0_nosync();
+ write_sysreg(ttbr1, ttbr1_el1);
+ write_sysreg(ttbr0, ttbr0_el1);
+ isb();
+ post_ttbr_update_workaround();
+}
+
+static int asids_update_limit(void)
+{
+ unsigned long num_available_asids = NUM_USER_ASIDS;
+
+ if (arm64_kernel_unmapped_at_el0()) {
+ num_available_asids /= 2;
+ if (pinned_asid_map)
+ set_kpti_asid_bits(pinned_asid_map);
+ }
+ /*
+ * Expect allocation after rollover to fail if we don't have at least
+ * one more ASID than CPUs. ASID #0 is reserved for init_mm.
+ */
+ WARN_ON(num_available_asids - 1 <= num_possible_cpus());
+ pr_info("ASID allocator initialised with %lu entries\n",
+ num_available_asids);
+
+ /*
+ * There must always be an ASID available after rollover. Ensure that,
+ * even if all CPUs have a reserved ASID and the maximum number of ASIDs
+ * are pinned, there still is at least one empty slot in the ASID map.
+ */
+ max_pinned_asids = num_available_asids - num_possible_cpus() - 2;
+ return 0;
+}
+arch_initcall(asids_update_limit);
+
+static int asids_init(void)
+{
+ asid_bits = get_cpu_asid_bits();
+ atomic64_set(&asid_generation, ASID_FIRST_VERSION);
+ asid_map = bitmap_zalloc(NUM_USER_ASIDS, GFP_KERNEL);
+ if (!asid_map)
+ panic("Failed to allocate bitmap for %lu ASIDs\n",
+ NUM_USER_ASIDS);
+
+ pinned_asid_map = bitmap_zalloc(NUM_USER_ASIDS, GFP_KERNEL);
+ nr_pinned_asids = 0;
+
+ /*
+ * We cannot call set_reserved_asid_bits() here because CPU
+ * caps are not finalized yet, so it is safer to assume KPTI
+ * and reserve kernel ASID's from beginning.
+ */
+ if (IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0))
+ set_kpti_asid_bits(asid_map);
+ return 0;
+}
+early_initcall(asids_init);
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
new file mode 100644
index 0000000000..a7bb20055c
--- /dev/null
+++ b/arch/arm64/mm/copypage.c
@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/mm/copypage.c
+ *
+ * Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/bitops.h>
+#include <linux/mm.h>
+
+#include <asm/page.h>
+#include <asm/cacheflush.h>
+#include <asm/cpufeature.h>
+#include <asm/mte.h>
+
+void copy_highpage(struct page *to, struct page *from)
+{
+ void *kto = page_address(to);
+ void *kfrom = page_address(from);
+
+ copy_page(kto, kfrom);
+
+ if (kasan_hw_tags_enabled())
+ page_kasan_tag_reset(to);
+
+ if (system_supports_mte() && page_mte_tagged(from)) {
+ /* It's a new page, shouldn't have been tagged yet */
+ WARN_ON_ONCE(!try_page_mte_tagging(to));
+ mte_copy_page_tags(kto, kfrom);
+ set_page_mte_tagged(to);
+ }
+}
+EXPORT_SYMBOL(copy_highpage);
+
+void copy_user_highpage(struct page *to, struct page *from,
+ unsigned long vaddr, struct vm_area_struct *vma)
+{
+ copy_highpage(to, from);
+ flush_dcache_page(to);
+}
+EXPORT_SYMBOL_GPL(copy_user_highpage);
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
new file mode 100644
index 0000000000..3cb101e8cb
--- /dev/null
+++ b/arch/arm64/mm/dma-mapping.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Catalin Marinas <catalin.marinas@arm.com>
+ */
+
+#include <linux/gfp.h>
+#include <linux/cache.h>
+#include <linux/dma-map-ops.h>
+#include <linux/iommu.h>
+#include <xen/xen.h>
+
+#include <asm/cacheflush.h>
+#include <asm/xen/xen-ops.h>
+
+void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
+ enum dma_data_direction dir)
+{
+ unsigned long start = (unsigned long)phys_to_virt(paddr);
+
+ dcache_clean_poc(start, start + size);
+}
+
+void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
+ enum dma_data_direction dir)
+{
+ unsigned long start = (unsigned long)phys_to_virt(paddr);
+
+ if (dir == DMA_TO_DEVICE)
+ return;
+
+ dcache_inval_poc(start, start + size);
+}
+
+void arch_dma_prep_coherent(struct page *page, size_t size)
+{
+ unsigned long start = (unsigned long)page_address(page);
+
+ dcache_clean_poc(start, start + size);
+}
+
+#ifdef CONFIG_IOMMU_DMA
+void arch_teardown_dma_ops(struct device *dev)
+{
+ dev->dma_ops = NULL;
+}
+#endif
+
+void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+ const struct iommu_ops *iommu, bool coherent)
+{
+ int cls = cache_line_size_of_cpu();
+
+ WARN_TAINT(!coherent && cls > ARCH_DMA_MINALIGN,
+ TAINT_CPU_OUT_OF_SPEC,
+ "%s %s: ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (%d < %d)",
+ dev_driver_string(dev), dev_name(dev),
+ ARCH_DMA_MINALIGN, cls);
+
+ dev->dma_coherent = coherent;
+ if (iommu)
+ iommu_setup_dma_ops(dev, dma_base, dma_base + size - 1);
+
+ xen_setup_dma_ops(dev);
+}
diff --git a/arch/arm64/mm/extable.c b/arch/arm64/mm/extable.c
new file mode 100644
index 0000000000..228d681a87
--- /dev/null
+++ b/arch/arm64/mm/extable.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Based on arch/arm/mm/extable.c
+ */
+
+#include <linux/bitfield.h>
+#include <linux/extable.h>
+#include <linux/uaccess.h>
+
+#include <asm/asm-extable.h>
+#include <asm/ptrace.h>
+
+static inline unsigned long
+get_ex_fixup(const struct exception_table_entry *ex)
+{
+ return ((unsigned long)&ex->fixup + ex->fixup);
+}
+
+static bool ex_handler_uaccess_err_zero(const struct exception_table_entry *ex,
+ struct pt_regs *regs)
+{
+ int reg_err = FIELD_GET(EX_DATA_REG_ERR, ex->data);
+ int reg_zero = FIELD_GET(EX_DATA_REG_ZERO, ex->data);
+
+ pt_regs_write_reg(regs, reg_err, -EFAULT);
+ pt_regs_write_reg(regs, reg_zero, 0);
+
+ regs->pc = get_ex_fixup(ex);
+ return true;
+}
+
+static bool
+ex_handler_load_unaligned_zeropad(const struct exception_table_entry *ex,
+ struct pt_regs *regs)
+{
+ int reg_data = FIELD_GET(EX_DATA_REG_DATA, ex->data);
+ int reg_addr = FIELD_GET(EX_DATA_REG_ADDR, ex->data);
+ unsigned long data, addr, offset;
+
+ addr = pt_regs_read_reg(regs, reg_addr);
+
+ offset = addr & 0x7UL;
+ addr &= ~0x7UL;
+
+ data = *(unsigned long*)addr;
+
+#ifndef __AARCH64EB__
+ data >>= 8 * offset;
+#else
+ data <<= 8 * offset;
+#endif
+
+ pt_regs_write_reg(regs, reg_data, data);
+
+ regs->pc = get_ex_fixup(ex);
+ return true;
+}
+
+bool fixup_exception(struct pt_regs *regs)
+{
+ const struct exception_table_entry *ex;
+
+ ex = search_exception_tables(instruction_pointer(regs));
+ if (!ex)
+ return false;
+
+ switch (ex->type) {
+ case EX_TYPE_BPF:
+ return ex_handler_bpf(ex, regs);
+ case EX_TYPE_UACCESS_ERR_ZERO:
+ case EX_TYPE_KACCESS_ERR_ZERO:
+ return ex_handler_uaccess_err_zero(ex, regs);
+ case EX_TYPE_LOAD_UNALIGNED_ZEROPAD:
+ return ex_handler_load_unaligned_zeropad(ex, regs);
+ }
+
+ BUG();
+}
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
new file mode 100644
index 0000000000..2e5d1e238a
--- /dev/null
+++ b/arch/arm64/mm/fault.c
@@ -0,0 +1,962 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/mm/fault.c
+ *
+ * Copyright (C) 1995 Linus Torvalds
+ * Copyright (C) 1995-2004 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/extable.h>
+#include <linux/kfence.h>
+#include <linux/signal.h>
+#include <linux/mm.h>
+#include <linux/hardirq.h>
+#include <linux/init.h>
+#include <linux/kasan.h>
+#include <linux/kprobes.h>
+#include <linux/uaccess.h>
+#include <linux/page-flags.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/debug.h>
+#include <linux/highmem.h>
+#include <linux/perf_event.h>
+#include <linux/preempt.h>
+#include <linux/hugetlb.h>
+
+#include <asm/acpi.h>
+#include <asm/bug.h>
+#include <asm/cmpxchg.h>
+#include <asm/cpufeature.h>
+#include <asm/efi.h>
+#include <asm/exception.h>
+#include <asm/daifflags.h>
+#include <asm/debug-monitors.h>
+#include <asm/esr.h>
+#include <asm/kprobes.h>
+#include <asm/mte.h>
+#include <asm/processor.h>
+#include <asm/sysreg.h>
+#include <asm/system_misc.h>
+#include <asm/tlbflush.h>
+#include <asm/traps.h>
+
+struct fault_info {
+ int (*fn)(unsigned long far, unsigned long esr,
+ struct pt_regs *regs);
+ int sig;
+ int code;
+ const char *name;
+};
+
+static const struct fault_info fault_info[];
+static struct fault_info debug_fault_info[];
+
+static inline const struct fault_info *esr_to_fault_info(unsigned long esr)
+{
+ return fault_info + (esr & ESR_ELx_FSC);
+}
+
+static inline const struct fault_info *esr_to_debug_fault_info(unsigned long esr)
+{
+ return debug_fault_info + DBG_ESR_EVT(esr);
+}
+
+static void data_abort_decode(unsigned long esr)
+{
+ unsigned long iss2 = ESR_ELx_ISS2(esr);
+
+ pr_alert("Data abort info:\n");
+
+ if (esr & ESR_ELx_ISV) {
+ pr_alert(" Access size = %u byte(s)\n",
+ 1U << ((esr & ESR_ELx_SAS) >> ESR_ELx_SAS_SHIFT));
+ pr_alert(" SSE = %lu, SRT = %lu\n",
+ (esr & ESR_ELx_SSE) >> ESR_ELx_SSE_SHIFT,
+ (esr & ESR_ELx_SRT_MASK) >> ESR_ELx_SRT_SHIFT);
+ pr_alert(" SF = %lu, AR = %lu\n",
+ (esr & ESR_ELx_SF) >> ESR_ELx_SF_SHIFT,
+ (esr & ESR_ELx_AR) >> ESR_ELx_AR_SHIFT);
+ } else {
+ pr_alert(" ISV = 0, ISS = 0x%08lx, ISS2 = 0x%08lx\n",
+ esr & ESR_ELx_ISS_MASK, iss2);
+ }
+
+ pr_alert(" CM = %lu, WnR = %lu, TnD = %lu, TagAccess = %lu\n",
+ (esr & ESR_ELx_CM) >> ESR_ELx_CM_SHIFT,
+ (esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT,
+ (iss2 & ESR_ELx_TnD) >> ESR_ELx_TnD_SHIFT,
+ (iss2 & ESR_ELx_TagAccess) >> ESR_ELx_TagAccess_SHIFT);
+
+ pr_alert(" GCS = %ld, Overlay = %lu, DirtyBit = %lu, Xs = %llu\n",
+ (iss2 & ESR_ELx_GCS) >> ESR_ELx_GCS_SHIFT,
+ (iss2 & ESR_ELx_Overlay) >> ESR_ELx_Overlay_SHIFT,
+ (iss2 & ESR_ELx_DirtyBit) >> ESR_ELx_DirtyBit_SHIFT,
+ (iss2 & ESR_ELx_Xs_MASK) >> ESR_ELx_Xs_SHIFT);
+}
+
+static void mem_abort_decode(unsigned long esr)
+{
+ pr_alert("Mem abort info:\n");
+
+ pr_alert(" ESR = 0x%016lx\n", esr);
+ pr_alert(" EC = 0x%02lx: %s, IL = %u bits\n",
+ ESR_ELx_EC(esr), esr_get_class_string(esr),
+ (esr & ESR_ELx_IL) ? 32 : 16);
+ pr_alert(" SET = %lu, FnV = %lu\n",
+ (esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT,
+ (esr & ESR_ELx_FnV) >> ESR_ELx_FnV_SHIFT);
+ pr_alert(" EA = %lu, S1PTW = %lu\n",
+ (esr & ESR_ELx_EA) >> ESR_ELx_EA_SHIFT,
+ (esr & ESR_ELx_S1PTW) >> ESR_ELx_S1PTW_SHIFT);
+ pr_alert(" FSC = 0x%02lx: %s\n", (esr & ESR_ELx_FSC),
+ esr_to_fault_info(esr)->name);
+
+ if (esr_is_data_abort(esr))
+ data_abort_decode(esr);
+}
+
+static inline unsigned long mm_to_pgd_phys(struct mm_struct *mm)
+{
+ /* Either init_pg_dir or swapper_pg_dir */
+ if (mm == &init_mm)
+ return __pa_symbol(mm->pgd);
+
+ return (unsigned long)virt_to_phys(mm->pgd);
+}
+
+/*
+ * Dump out the page tables associated with 'addr' in the currently active mm.
+ */
+static void show_pte(unsigned long addr)
+{
+ struct mm_struct *mm;
+ pgd_t *pgdp;
+ pgd_t pgd;
+
+ if (is_ttbr0_addr(addr)) {
+ /* TTBR0 */
+ mm = current->active_mm;
+ if (mm == &init_mm) {
+ pr_alert("[%016lx] user address but active_mm is swapper\n",
+ addr);
+ return;
+ }
+ } else if (is_ttbr1_addr(addr)) {
+ /* TTBR1 */
+ mm = &init_mm;
+ } else {
+ pr_alert("[%016lx] address between user and kernel address ranges\n",
+ addr);
+ return;
+ }
+
+ pr_alert("%s pgtable: %luk pages, %llu-bit VAs, pgdp=%016lx\n",
+ mm == &init_mm ? "swapper" : "user", PAGE_SIZE / SZ_1K,
+ vabits_actual, mm_to_pgd_phys(mm));
+ pgdp = pgd_offset(mm, addr);
+ pgd = READ_ONCE(*pgdp);
+ pr_alert("[%016lx] pgd=%016llx", addr, pgd_val(pgd));
+
+ do {
+ p4d_t *p4dp, p4d;
+ pud_t *pudp, pud;
+ pmd_t *pmdp, pmd;
+ pte_t *ptep, pte;
+
+ if (pgd_none(pgd) || pgd_bad(pgd))
+ break;
+
+ p4dp = p4d_offset(pgdp, addr);
+ p4d = READ_ONCE(*p4dp);
+ pr_cont(", p4d=%016llx", p4d_val(p4d));
+ if (p4d_none(p4d) || p4d_bad(p4d))
+ break;
+
+ pudp = pud_offset(p4dp, addr);
+ pud = READ_ONCE(*pudp);
+ pr_cont(", pud=%016llx", pud_val(pud));
+ if (pud_none(pud) || pud_bad(pud))
+ break;
+
+ pmdp = pmd_offset(pudp, addr);
+ pmd = READ_ONCE(*pmdp);
+ pr_cont(", pmd=%016llx", pmd_val(pmd));
+ if (pmd_none(pmd) || pmd_bad(pmd))
+ break;
+
+ ptep = pte_offset_map(pmdp, addr);
+ if (!ptep)
+ break;
+
+ pte = READ_ONCE(*ptep);
+ pr_cont(", pte=%016llx", pte_val(pte));
+ pte_unmap(ptep);
+ } while(0);
+
+ pr_cont("\n");
+}
+
+/*
+ * This function sets the access flags (dirty, accessed), as well as write
+ * permission, and only to a more permissive setting.
+ *
+ * It needs to cope with hardware update of the accessed/dirty state by other
+ * agents in the system and can safely skip the __sync_icache_dcache() call as,
+ * like set_pte_at(), the PTE is never changed from no-exec to exec here.
+ *
+ * Returns whether or not the PTE actually changed.
+ */
+int ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep,
+ pte_t entry, int dirty)
+{
+ pteval_t old_pteval, pteval;
+ pte_t pte = READ_ONCE(*ptep);
+
+ if (pte_same(pte, entry))
+ return 0;
+
+ /* only preserve the access flags and write permission */
+ pte_val(entry) &= PTE_RDONLY | PTE_AF | PTE_WRITE | PTE_DIRTY;
+
+ /*
+ * Setting the flags must be done atomically to avoid racing with the
+ * hardware update of the access/dirty state. The PTE_RDONLY bit must
+ * be set to the most permissive (lowest value) of *ptep and entry
+ * (calculated as: a & b == ~(~a | ~b)).
+ */
+ pte_val(entry) ^= PTE_RDONLY;
+ pteval = pte_val(pte);
+ do {
+ old_pteval = pteval;
+ pteval ^= PTE_RDONLY;
+ pteval |= pte_val(entry);
+ pteval ^= PTE_RDONLY;
+ pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
+ } while (pteval != old_pteval);
+
+ /* Invalidate a stale read-only entry */
+ if (dirty)
+ flush_tlb_page(vma, address);
+ return 1;
+}
+
+static bool is_el1_instruction_abort(unsigned long esr)
+{
+ return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR;
+}
+
+static bool is_el1_data_abort(unsigned long esr)
+{
+ return ESR_ELx_EC(esr) == ESR_ELx_EC_DABT_CUR;
+}
+
+static inline bool is_el1_permission_fault(unsigned long addr, unsigned long esr,
+ struct pt_regs *regs)
+{
+ unsigned long fsc_type = esr & ESR_ELx_FSC_TYPE;
+
+ if (!is_el1_data_abort(esr) && !is_el1_instruction_abort(esr))
+ return false;
+
+ if (fsc_type == ESR_ELx_FSC_PERM)
+ return true;
+
+ if (is_ttbr0_addr(addr) && system_uses_ttbr0_pan())
+ return fsc_type == ESR_ELx_FSC_FAULT &&
+ (regs->pstate & PSR_PAN_BIT);
+
+ return false;
+}
+
+static bool __kprobes is_spurious_el1_translation_fault(unsigned long addr,
+ unsigned long esr,
+ struct pt_regs *regs)
+{
+ unsigned long flags;
+ u64 par, dfsc;
+
+ if (!is_el1_data_abort(esr) ||
+ (esr & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT)
+ return false;
+
+ local_irq_save(flags);
+ asm volatile("at s1e1r, %0" :: "r" (addr));
+ isb();
+ par = read_sysreg_par();
+ local_irq_restore(flags);
+
+ /*
+ * If we now have a valid translation, treat the translation fault as
+ * spurious.
+ */
+ if (!(par & SYS_PAR_EL1_F))
+ return true;
+
+ /*
+ * If we got a different type of fault from the AT instruction,
+ * treat the translation fault as spurious.
+ */
+ dfsc = FIELD_GET(SYS_PAR_EL1_FST, par);
+ return (dfsc & ESR_ELx_FSC_TYPE) != ESR_ELx_FSC_FAULT;
+}
+
+static void die_kernel_fault(const char *msg, unsigned long addr,
+ unsigned long esr, struct pt_regs *regs)
+{
+ bust_spinlocks(1);
+
+ pr_alert("Unable to handle kernel %s at virtual address %016lx\n", msg,
+ addr);
+
+ kasan_non_canonical_hook(addr);
+
+ mem_abort_decode(esr);
+
+ show_pte(addr);
+ die("Oops", regs, esr);
+ bust_spinlocks(0);
+ make_task_dead(SIGKILL);
+}
+
+#ifdef CONFIG_KASAN_HW_TAGS
+static void report_tag_fault(unsigned long addr, unsigned long esr,
+ struct pt_regs *regs)
+{
+ /*
+ * SAS bits aren't set for all faults reported in EL1, so we can't
+ * find out access size.
+ */
+ bool is_write = !!(esr & ESR_ELx_WNR);
+ kasan_report((void *)addr, 0, is_write, regs->pc);
+}
+#else
+/* Tag faults aren't enabled without CONFIG_KASAN_HW_TAGS. */
+static inline void report_tag_fault(unsigned long addr, unsigned long esr,
+ struct pt_regs *regs) { }
+#endif
+
+static void do_tag_recovery(unsigned long addr, unsigned long esr,
+ struct pt_regs *regs)
+{
+
+ report_tag_fault(addr, esr, regs);
+
+ /*
+ * Disable MTE Tag Checking on the local CPU for the current EL.
+ * It will be done lazily on the other CPUs when they will hit a
+ * tag fault.
+ */
+ sysreg_clear_set(sctlr_el1, SCTLR_EL1_TCF_MASK,
+ SYS_FIELD_PREP_ENUM(SCTLR_EL1, TCF, NONE));
+ isb();
+}
+
+static bool is_el1_mte_sync_tag_check_fault(unsigned long esr)
+{
+ unsigned long fsc = esr & ESR_ELx_FSC;
+
+ if (!is_el1_data_abort(esr))
+ return false;
+
+ if (fsc == ESR_ELx_FSC_MTE)
+ return true;
+
+ return false;
+}
+
+static bool is_translation_fault(unsigned long esr)
+{
+ return (esr & ESR_ELx_FSC_TYPE) == ESR_ELx_FSC_FAULT;
+}
+
+static void __do_kernel_fault(unsigned long addr, unsigned long esr,
+ struct pt_regs *regs)
+{
+ const char *msg;
+
+ /*
+ * Are we prepared to handle this kernel fault?
+ * We are almost certainly not prepared to handle instruction faults.
+ */
+ if (!is_el1_instruction_abort(esr) && fixup_exception(regs))
+ return;
+
+ if (WARN_RATELIMIT(is_spurious_el1_translation_fault(addr, esr, regs),
+ "Ignoring spurious kernel translation fault at virtual address %016lx\n", addr))
+ return;
+
+ if (is_el1_mte_sync_tag_check_fault(esr)) {
+ do_tag_recovery(addr, esr, regs);
+
+ return;
+ }
+
+ if (is_el1_permission_fault(addr, esr, regs)) {
+ if (esr & ESR_ELx_WNR)
+ msg = "write to read-only memory";
+ else if (is_el1_instruction_abort(esr))
+ msg = "execute from non-executable memory";
+ else
+ msg = "read from unreadable memory";
+ } else if (addr < PAGE_SIZE) {
+ msg = "NULL pointer dereference";
+ } else {
+ if (is_translation_fault(esr) &&
+ kfence_handle_page_fault(addr, esr & ESR_ELx_WNR, regs))
+ return;
+
+ msg = "paging request";
+ }
+
+ if (efi_runtime_fixup_exception(regs, msg))
+ return;
+
+ die_kernel_fault(msg, addr, esr, regs);
+}
+
+static void set_thread_esr(unsigned long address, unsigned long esr)
+{
+ current->thread.fault_address = address;
+
+ /*
+ * If the faulting address is in the kernel, we must sanitize the ESR.
+ * From userspace's point of view, kernel-only mappings don't exist
+ * at all, so we report them as level 0 translation faults.
+ * (This is not quite the way that "no mapping there at all" behaves:
+ * an alignment fault not caused by the memory type would take
+ * precedence over translation fault for a real access to empty
+ * space. Unfortunately we can't easily distinguish "alignment fault
+ * not caused by memory type" from "alignment fault caused by memory
+ * type", so we ignore this wrinkle and just return the translation
+ * fault.)
+ */
+ if (!is_ttbr0_addr(current->thread.fault_address)) {
+ switch (ESR_ELx_EC(esr)) {
+ case ESR_ELx_EC_DABT_LOW:
+ /*
+ * These bits provide only information about the
+ * faulting instruction, which userspace knows already.
+ * We explicitly clear bits which are architecturally
+ * RES0 in case they are given meanings in future.
+ * We always report the ESR as if the fault was taken
+ * to EL1 and so ISV and the bits in ISS[23:14] are
+ * clear. (In fact it always will be a fault to EL1.)
+ */
+ esr &= ESR_ELx_EC_MASK | ESR_ELx_IL |
+ ESR_ELx_CM | ESR_ELx_WNR;
+ esr |= ESR_ELx_FSC_FAULT;
+ break;
+ case ESR_ELx_EC_IABT_LOW:
+ /*
+ * Claim a level 0 translation fault.
+ * All other bits are architecturally RES0 for faults
+ * reported with that DFSC value, so we clear them.
+ */
+ esr &= ESR_ELx_EC_MASK | ESR_ELx_IL;
+ esr |= ESR_ELx_FSC_FAULT;
+ break;
+ default:
+ /*
+ * This should never happen (entry.S only brings us
+ * into this code for insn and data aborts from a lower
+ * exception level). Fail safe by not providing an ESR
+ * context record at all.
+ */
+ WARN(1, "ESR 0x%lx is not DABT or IABT from EL0\n", esr);
+ esr = 0;
+ break;
+ }
+ }
+
+ current->thread.fault_code = esr;
+}
+
+static void do_bad_area(unsigned long far, unsigned long esr,
+ struct pt_regs *regs)
+{
+ unsigned long addr = untagged_addr(far);
+
+ /*
+ * If we are in kernel mode at this point, we have no context to
+ * handle this fault with.
+ */
+ if (user_mode(regs)) {
+ const struct fault_info *inf = esr_to_fault_info(esr);
+
+ set_thread_esr(addr, esr);
+ arm64_force_sig_fault(inf->sig, inf->code, far, inf->name);
+ } else {
+ __do_kernel_fault(addr, esr, regs);
+ }
+}
+
+#define VM_FAULT_BADMAP ((__force vm_fault_t)0x010000)
+#define VM_FAULT_BADACCESS ((__force vm_fault_t)0x020000)
+
+static vm_fault_t __do_page_fault(struct mm_struct *mm,
+ struct vm_area_struct *vma, unsigned long addr,
+ unsigned int mm_flags, unsigned long vm_flags,
+ struct pt_regs *regs)
+{
+ /*
+ * Ok, we have a good vm_area for this memory access, so we can handle
+ * it.
+ * Check that the permissions on the VMA allow for the fault which
+ * occurred.
+ */
+ if (!(vma->vm_flags & vm_flags))
+ return VM_FAULT_BADACCESS;
+ return handle_mm_fault(vma, addr, mm_flags, regs);
+}
+
+static bool is_el0_instruction_abort(unsigned long esr)
+{
+ return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW;
+}
+
+/*
+ * Note: not valid for EL1 DC IVAC, but we never use that such that it
+ * should fault. EL0 cannot issue DC IVAC (undef).
+ */
+static bool is_write_abort(unsigned long esr)
+{
+ return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM);
+}
+
+static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
+ struct pt_regs *regs)
+{
+ const struct fault_info *inf;
+ struct mm_struct *mm = current->mm;
+ vm_fault_t fault;
+ unsigned long vm_flags;
+ unsigned int mm_flags = FAULT_FLAG_DEFAULT;
+ unsigned long addr = untagged_addr(far);
+ struct vm_area_struct *vma;
+
+ if (kprobe_page_fault(regs, esr))
+ return 0;
+
+ /*
+ * If we're in an interrupt or have no user context, we must not take
+ * the fault.
+ */
+ if (faulthandler_disabled() || !mm)
+ goto no_context;
+
+ if (user_mode(regs))
+ mm_flags |= FAULT_FLAG_USER;
+
+ /*
+ * vm_flags tells us what bits we must have in vma->vm_flags
+ * for the fault to be benign, __do_page_fault() would check
+ * vma->vm_flags & vm_flags and returns an error if the
+ * intersection is empty
+ */
+ if (is_el0_instruction_abort(esr)) {
+ /* It was exec fault */
+ vm_flags = VM_EXEC;
+ mm_flags |= FAULT_FLAG_INSTRUCTION;
+ } else if (is_write_abort(esr)) {
+ /* It was write fault */
+ vm_flags = VM_WRITE;
+ mm_flags |= FAULT_FLAG_WRITE;
+ } else {
+ /* It was read fault */
+ vm_flags = VM_READ;
+ /* Write implies read */
+ vm_flags |= VM_WRITE;
+ /* If EPAN is absent then exec implies read */
+ if (!cpus_have_const_cap(ARM64_HAS_EPAN))
+ vm_flags |= VM_EXEC;
+ }
+
+ if (is_ttbr0_addr(addr) && is_el1_permission_fault(addr, esr, regs)) {
+ if (is_el1_instruction_abort(esr))
+ die_kernel_fault("execution of user memory",
+ addr, esr, regs);
+
+ if (!search_exception_tables(regs->pc))
+ die_kernel_fault("access to user memory outside uaccess routines",
+ addr, esr, regs);
+ }
+
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
+
+ if (!(mm_flags & FAULT_FLAG_USER))
+ goto lock_mmap;
+
+ vma = lock_vma_under_rcu(mm, addr);
+ if (!vma)
+ goto lock_mmap;
+
+ if (!(vma->vm_flags & vm_flags)) {
+ vma_end_read(vma);
+ goto lock_mmap;
+ }
+ fault = handle_mm_fault(vma, addr, mm_flags | FAULT_FLAG_VMA_LOCK, regs);
+ if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))
+ vma_end_read(vma);
+
+ if (!(fault & VM_FAULT_RETRY)) {
+ count_vm_vma_lock_event(VMA_LOCK_SUCCESS);
+ goto done;
+ }
+ count_vm_vma_lock_event(VMA_LOCK_RETRY);
+
+ /* Quick path to respond to signals */
+ if (fault_signal_pending(fault, regs)) {
+ if (!user_mode(regs))
+ goto no_context;
+ return 0;
+ }
+lock_mmap:
+
+retry:
+ vma = lock_mm_and_find_vma(mm, addr, regs);
+ if (unlikely(!vma)) {
+ fault = VM_FAULT_BADMAP;
+ goto done;
+ }
+
+ fault = __do_page_fault(mm, vma, addr, mm_flags, vm_flags, regs);
+
+ /* Quick path to respond to signals */
+ if (fault_signal_pending(fault, regs)) {
+ if (!user_mode(regs))
+ goto no_context;
+ return 0;
+ }
+
+ /* The fault is fully completed (including releasing mmap lock) */
+ if (fault & VM_FAULT_COMPLETED)
+ return 0;
+
+ if (fault & VM_FAULT_RETRY) {
+ mm_flags |= FAULT_FLAG_TRIED;
+ goto retry;
+ }
+ mmap_read_unlock(mm);
+
+done:
+ /*
+ * Handle the "normal" (no error) case first.
+ */
+ if (likely(!(fault & (VM_FAULT_ERROR | VM_FAULT_BADMAP |
+ VM_FAULT_BADACCESS))))
+ return 0;
+
+ /*
+ * If we are in kernel mode at this point, we have no context to
+ * handle this fault with.
+ */
+ if (!user_mode(regs))
+ goto no_context;
+
+ if (fault & VM_FAULT_OOM) {
+ /*
+ * We ran out of memory, call the OOM killer, and return to
+ * userspace (which will retry the fault, or kill us if we got
+ * oom-killed).
+ */
+ pagefault_out_of_memory();
+ return 0;
+ }
+
+ inf = esr_to_fault_info(esr);
+ set_thread_esr(addr, esr);
+ if (fault & VM_FAULT_SIGBUS) {
+ /*
+ * We had some memory, but were unable to successfully fix up
+ * this page fault.
+ */
+ arm64_force_sig_fault(SIGBUS, BUS_ADRERR, far, inf->name);
+ } else if (fault & (VM_FAULT_HWPOISON_LARGE | VM_FAULT_HWPOISON)) {
+ unsigned int lsb;
+
+ lsb = PAGE_SHIFT;
+ if (fault & VM_FAULT_HWPOISON_LARGE)
+ lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault));
+
+ arm64_force_sig_mceerr(BUS_MCEERR_AR, far, lsb, inf->name);
+ } else {
+ /*
+ * Something tried to access memory that isn't in our memory
+ * map.
+ */
+ arm64_force_sig_fault(SIGSEGV,
+ fault == VM_FAULT_BADACCESS ? SEGV_ACCERR : SEGV_MAPERR,
+ far, inf->name);
+ }
+
+ return 0;
+
+no_context:
+ __do_kernel_fault(addr, esr, regs);
+ return 0;
+}
+
+static int __kprobes do_translation_fault(unsigned long far,
+ unsigned long esr,
+ struct pt_regs *regs)
+{
+ unsigned long addr = untagged_addr(far);
+
+ if (is_ttbr0_addr(addr))
+ return do_page_fault(far, esr, regs);
+
+ do_bad_area(far, esr, regs);
+ return 0;
+}
+
+static int do_alignment_fault(unsigned long far, unsigned long esr,
+ struct pt_regs *regs)
+{
+ if (IS_ENABLED(CONFIG_COMPAT_ALIGNMENT_FIXUPS) &&
+ compat_user_mode(regs))
+ return do_compat_alignment_fixup(far, regs);
+ do_bad_area(far, esr, regs);
+ return 0;
+}
+
+static int do_bad(unsigned long far, unsigned long esr, struct pt_regs *regs)
+{
+ return 1; /* "fault" */
+}
+
+static int do_sea(unsigned long far, unsigned long esr, struct pt_regs *regs)
+{
+ const struct fault_info *inf;
+ unsigned long siaddr;
+
+ inf = esr_to_fault_info(esr);
+
+ if (user_mode(regs) && apei_claim_sea(regs) == 0) {
+ /*
+ * APEI claimed this as a firmware-first notification.
+ * Some processing deferred to task_work before ret_to_user().
+ */
+ return 0;
+ }
+
+ if (esr & ESR_ELx_FnV) {
+ siaddr = 0;
+ } else {
+ /*
+ * The architecture specifies that the tag bits of FAR_EL1 are
+ * UNKNOWN for synchronous external aborts. Mask them out now
+ * so that userspace doesn't see them.
+ */
+ siaddr = untagged_addr(far);
+ }
+ arm64_notify_die(inf->name, regs, inf->sig, inf->code, siaddr, esr);
+
+ return 0;
+}
+
+static int do_tag_check_fault(unsigned long far, unsigned long esr,
+ struct pt_regs *regs)
+{
+ /*
+ * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN
+ * for tag check faults. Set them to corresponding bits in the untagged
+ * address.
+ */
+ far = (__untagged_addr(far) & ~MTE_TAG_MASK) | (far & MTE_TAG_MASK);
+ do_bad_area(far, esr, regs);
+ return 0;
+}
+
+static const struct fault_info fault_info[] = {
+ { do_bad, SIGKILL, SI_KERNEL, "ttbr address size fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "level 1 address size fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "level 2 address size fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "level 3 address size fault" },
+ { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 0 translation fault" },
+ { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 1 translation fault" },
+ { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 2 translation fault" },
+ { do_translation_fault, SIGSEGV, SEGV_MAPERR, "level 3 translation fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 8" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 access flag fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 access flag fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 12" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" },
+ { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" },
+ { do_sea, SIGBUS, BUS_OBJERR, "synchronous external abort" },
+ { do_tag_check_fault, SIGSEGV, SEGV_MTESERR, "synchronous tag check fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 18" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 19" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 0 (translation table walk)" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 1 (translation table walk)" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 2 (translation table walk)" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 3 (translation table walk)" },
+ { do_sea, SIGBUS, BUS_OBJERR, "synchronous parity or ECC error" }, // Reserved when RAS is implemented
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 25" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 26" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 27" },
+ { do_sea, SIGKILL, SI_KERNEL, "level 0 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
+ { do_sea, SIGKILL, SI_KERNEL, "level 1 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
+ { do_sea, SIGKILL, SI_KERNEL, "level 2 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
+ { do_sea, SIGKILL, SI_KERNEL, "level 3 synchronous parity error (translation table walk)" }, // Reserved when RAS is implemented
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 32" },
+ { do_alignment_fault, SIGBUS, BUS_ADRALN, "alignment fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 34" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 35" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 36" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 37" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 38" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 39" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 40" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 41" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 42" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 43" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 44" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 45" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 46" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 47" },
+ { do_bad, SIGKILL, SI_KERNEL, "TLB conflict abort" },
+ { do_bad, SIGKILL, SI_KERNEL, "Unsupported atomic hardware update fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 50" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 51" },
+ { do_bad, SIGKILL, SI_KERNEL, "implementation fault (lockdown abort)" },
+ { do_bad, SIGBUS, BUS_OBJERR, "implementation fault (unsupported exclusive)" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 54" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 55" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 56" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 57" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 58" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 59" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 60" },
+ { do_bad, SIGKILL, SI_KERNEL, "section domain fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "page domain fault" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 63" },
+};
+
+void do_mem_abort(unsigned long far, unsigned long esr, struct pt_regs *regs)
+{
+ const struct fault_info *inf = esr_to_fault_info(esr);
+ unsigned long addr = untagged_addr(far);
+
+ if (!inf->fn(far, esr, regs))
+ return;
+
+ if (!user_mode(regs))
+ die_kernel_fault(inf->name, addr, esr, regs);
+
+ /*
+ * At this point we have an unrecognized fault type whose tag bits may
+ * have been defined as UNKNOWN. Therefore we only expose the untagged
+ * address to the signal handler.
+ */
+ arm64_notify_die(inf->name, regs, inf->sig, inf->code, addr, esr);
+}
+NOKPROBE_SYMBOL(do_mem_abort);
+
+void do_sp_pc_abort(unsigned long addr, unsigned long esr, struct pt_regs *regs)
+{
+ arm64_notify_die("SP/PC alignment exception", regs, SIGBUS, BUS_ADRALN,
+ addr, esr);
+}
+NOKPROBE_SYMBOL(do_sp_pc_abort);
+
+/*
+ * __refdata because early_brk64 is __init, but the reference to it is
+ * clobbered at arch_initcall time.
+ * See traps.c and debug-monitors.c:debug_traps_init().
+ */
+static struct fault_info __refdata debug_fault_info[] = {
+ { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware breakpoint" },
+ { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware single-step" },
+ { do_bad, SIGTRAP, TRAP_HWBKPT, "hardware watchpoint" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 3" },
+ { do_bad, SIGTRAP, TRAP_BRKPT, "aarch32 BKPT" },
+ { do_bad, SIGKILL, SI_KERNEL, "aarch32 vector catch" },
+ { early_brk64, SIGTRAP, TRAP_BRKPT, "aarch64 BRK" },
+ { do_bad, SIGKILL, SI_KERNEL, "unknown 7" },
+};
+
+void __init hook_debug_fault_code(int nr,
+ int (*fn)(unsigned long, unsigned long, struct pt_regs *),
+ int sig, int code, const char *name)
+{
+ BUG_ON(nr < 0 || nr >= ARRAY_SIZE(debug_fault_info));
+
+ debug_fault_info[nr].fn = fn;
+ debug_fault_info[nr].sig = sig;
+ debug_fault_info[nr].code = code;
+ debug_fault_info[nr].name = name;
+}
+
+/*
+ * In debug exception context, we explicitly disable preemption despite
+ * having interrupts disabled.
+ * This serves two purposes: it makes it much less likely that we would
+ * accidentally schedule in exception context and it will force a warning
+ * if we somehow manage to schedule by accident.
+ */
+static void debug_exception_enter(struct pt_regs *regs)
+{
+ preempt_disable();
+
+ /* This code is a bit fragile. Test it. */
+ RCU_LOCKDEP_WARN(!rcu_is_watching(), "exception_enter didn't work");
+}
+NOKPROBE_SYMBOL(debug_exception_enter);
+
+static void debug_exception_exit(struct pt_regs *regs)
+{
+ preempt_enable_no_resched();
+}
+NOKPROBE_SYMBOL(debug_exception_exit);
+
+void do_debug_exception(unsigned long addr_if_watchpoint, unsigned long esr,
+ struct pt_regs *regs)
+{
+ const struct fault_info *inf = esr_to_debug_fault_info(esr);
+ unsigned long pc = instruction_pointer(regs);
+
+ debug_exception_enter(regs);
+
+ if (user_mode(regs) && !is_ttbr0_addr(pc))
+ arm64_apply_bp_hardening();
+
+ if (inf->fn(addr_if_watchpoint, esr, regs)) {
+ arm64_notify_die(inf->name, regs, inf->sig, inf->code, pc, esr);
+ }
+
+ debug_exception_exit(regs);
+}
+NOKPROBE_SYMBOL(do_debug_exception);
+
+/*
+ * Used during anonymous page fault handling.
+ */
+struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma,
+ unsigned long vaddr)
+{
+ gfp_t flags = GFP_HIGHUSER_MOVABLE | __GFP_ZERO;
+
+ /*
+ * If the page is mapped with PROT_MTE, initialise the tags at the
+ * point of allocation and page zeroing as this is usually faster than
+ * separate DC ZVA and STGM.
+ */
+ if (vma->vm_flags & VM_MTE)
+ flags |= __GFP_ZEROTAGS;
+
+ return vma_alloc_folio(flags, 0, vma, vaddr, false);
+}
+
+void tag_clear_highpage(struct page *page)
+{
+ /* Newly allocated page, shouldn't have been tagged yet */
+ WARN_ON_ONCE(!try_page_mte_tagging(page));
+ mte_zero_clear_page_tags(page_address(page));
+ set_page_mte_tagged(page);
+}
diff --git a/arch/arm64/mm/fixmap.c b/arch/arm64/mm/fixmap.c
new file mode 100644
index 0000000000..c0a3301203
--- /dev/null
+++ b/arch/arm64/mm/fixmap.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Fixmap manipulation code
+ */
+
+#include <linux/bug.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/libfdt.h>
+#include <linux/memory.h>
+#include <linux/mm.h>
+#include <linux/sizes.h>
+
+#include <asm/fixmap.h>
+#include <asm/kernel-pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+
+#define NR_BM_PTE_TABLES \
+ SPAN_NR_ENTRIES(FIXADDR_TOT_START, FIXADDR_TOP, PMD_SHIFT)
+#define NR_BM_PMD_TABLES \
+ SPAN_NR_ENTRIES(FIXADDR_TOT_START, FIXADDR_TOP, PUD_SHIFT)
+
+static_assert(NR_BM_PMD_TABLES == 1);
+
+#define __BM_TABLE_IDX(addr, shift) \
+ (((addr) >> (shift)) - (FIXADDR_TOT_START >> (shift)))
+
+#define BM_PTE_TABLE_IDX(addr) __BM_TABLE_IDX(addr, PMD_SHIFT)
+
+static pte_t bm_pte[NR_BM_PTE_TABLES][PTRS_PER_PTE] __page_aligned_bss;
+static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused;
+static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
+
+static inline pte_t *fixmap_pte(unsigned long addr)
+{
+ return &bm_pte[BM_PTE_TABLE_IDX(addr)][pte_index(addr)];
+}
+
+static void __init early_fixmap_init_pte(pmd_t *pmdp, unsigned long addr)
+{
+ pmd_t pmd = READ_ONCE(*pmdp);
+ pte_t *ptep;
+
+ if (pmd_none(pmd)) {
+ ptep = bm_pte[BM_PTE_TABLE_IDX(addr)];
+ __pmd_populate(pmdp, __pa_symbol(ptep), PMD_TYPE_TABLE);
+ }
+}
+
+static void __init early_fixmap_init_pmd(pud_t *pudp, unsigned long addr,
+ unsigned long end)
+{
+ unsigned long next;
+ pud_t pud = READ_ONCE(*pudp);
+ pmd_t *pmdp;
+
+ if (pud_none(pud))
+ __pud_populate(pudp, __pa_symbol(bm_pmd), PUD_TYPE_TABLE);
+
+ pmdp = pmd_offset_kimg(pudp, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ early_fixmap_init_pte(pmdp, addr);
+ } while (pmdp++, addr = next, addr != end);
+}
+
+
+static void __init early_fixmap_init_pud(p4d_t *p4dp, unsigned long addr,
+ unsigned long end)
+{
+ p4d_t p4d = READ_ONCE(*p4dp);
+ pud_t *pudp;
+
+ if (CONFIG_PGTABLE_LEVELS > 3 && !p4d_none(p4d) &&
+ p4d_page_paddr(p4d) != __pa_symbol(bm_pud)) {
+ /*
+ * We only end up here if the kernel mapping and the fixmap
+ * share the top level pgd entry, which should only happen on
+ * 16k/4 levels configurations.
+ */
+ BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
+ }
+
+ if (p4d_none(p4d))
+ __p4d_populate(p4dp, __pa_symbol(bm_pud), P4D_TYPE_TABLE);
+
+ pudp = pud_offset_kimg(p4dp, addr);
+ early_fixmap_init_pmd(pudp, addr, end);
+}
+
+/*
+ * The p*d_populate functions call virt_to_phys implicitly so they can't be used
+ * directly on kernel symbols (bm_p*d). This function is called too early to use
+ * lm_alias so __p*d_populate functions must be used to populate with the
+ * physical address from __pa_symbol.
+ */
+void __init early_fixmap_init(void)
+{
+ unsigned long addr = FIXADDR_TOT_START;
+ unsigned long end = FIXADDR_TOP;
+
+ pgd_t *pgdp = pgd_offset_k(addr);
+ p4d_t *p4dp = p4d_offset(pgdp, addr);
+
+ early_fixmap_init_pud(p4dp, addr, end);
+}
+
+/*
+ * Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we
+ * ever need to use IPIs for TLB broadcasting, then we're in trouble here.
+ */
+void __set_fixmap(enum fixed_addresses idx,
+ phys_addr_t phys, pgprot_t flags)
+{
+ unsigned long addr = __fix_to_virt(idx);
+ pte_t *ptep;
+
+ BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
+
+ ptep = fixmap_pte(addr);
+
+ if (pgprot_val(flags)) {
+ set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags));
+ } else {
+ pte_clear(&init_mm, addr, ptep);
+ flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
+ }
+}
+
+void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
+{
+ const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
+ phys_addr_t dt_phys_base;
+ int offset;
+ void *dt_virt;
+
+ /*
+ * Check whether the physical FDT address is set and meets the minimum
+ * alignment requirement. Since we are relying on MIN_FDT_ALIGN to be
+ * at least 8 bytes so that we can always access the magic and size
+ * fields of the FDT header after mapping the first chunk, double check
+ * here if that is indeed the case.
+ */
+ BUILD_BUG_ON(MIN_FDT_ALIGN < 8);
+ if (!dt_phys || dt_phys % MIN_FDT_ALIGN)
+ return NULL;
+
+ dt_phys_base = round_down(dt_phys, PAGE_SIZE);
+ offset = dt_phys % PAGE_SIZE;
+ dt_virt = (void *)dt_virt_base + offset;
+
+ /* map the first chunk so we can read the size from the header */
+ create_mapping_noalloc(dt_phys_base, dt_virt_base, PAGE_SIZE, prot);
+
+ if (fdt_magic(dt_virt) != FDT_MAGIC)
+ return NULL;
+
+ *size = fdt_totalsize(dt_virt);
+ if (*size > MAX_FDT_SIZE)
+ return NULL;
+
+ if (offset + *size > PAGE_SIZE) {
+ create_mapping_noalloc(dt_phys_base, dt_virt_base,
+ offset + *size, prot);
+ }
+
+ return dt_virt;
+}
+
+/*
+ * Copy the fixmap region into a new pgdir.
+ */
+void __init fixmap_copy(pgd_t *pgdir)
+{
+ if (!READ_ONCE(pgd_val(*pgd_offset_pgd(pgdir, FIXADDR_TOT_START)))) {
+ /*
+ * The fixmap falls in a separate pgd to the kernel, and doesn't
+ * live in the carveout for the swapper_pg_dir. We can simply
+ * re-use the existing dir for the fixmap.
+ */
+ set_pgd(pgd_offset_pgd(pgdir, FIXADDR_TOT_START),
+ READ_ONCE(*pgd_offset_k(FIXADDR_TOT_START)));
+ } else if (CONFIG_PGTABLE_LEVELS > 3) {
+ pgd_t *bm_pgdp;
+ p4d_t *bm_p4dp;
+ pud_t *bm_pudp;
+ /*
+ * The fixmap shares its top level pgd entry with the kernel
+ * mapping. This can really only occur when we are running
+ * with 16k/4 levels, so we can simply reuse the pud level
+ * entry instead.
+ */
+ BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
+ bm_pgdp = pgd_offset_pgd(pgdir, FIXADDR_TOT_START);
+ bm_p4dp = p4d_offset(bm_pgdp, FIXADDR_TOT_START);
+ bm_pudp = pud_set_fixmap_offset(bm_p4dp, FIXADDR_TOT_START);
+ pud_populate(&init_mm, bm_pudp, lm_alias(bm_pmd));
+ pud_clear_fixmap();
+ } else {
+ BUG();
+ }
+}
diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
new file mode 100644
index 0000000000..013eead9b6
--- /dev/null
+++ b/arch/arm64/mm/flush.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/mm/flush.c
+ *
+ * Copyright (C) 1995-2002 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/libnvdimm.h>
+#include <linux/pagemap.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cache.h>
+#include <asm/tlbflush.h>
+
+void sync_icache_aliases(unsigned long start, unsigned long end)
+{
+ if (icache_is_aliasing()) {
+ dcache_clean_pou(start, end);
+ icache_inval_all_pou();
+ } else {
+ /*
+ * Don't issue kick_all_cpus_sync() after I-cache invalidation
+ * for user mappings.
+ */
+ caches_clean_inval_pou(start, end);
+ }
+}
+
+static void flush_ptrace_access(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end)
+{
+ if (vma->vm_flags & VM_EXEC)
+ sync_icache_aliases(start, end);
+}
+
+/*
+ * Copy user data from/to a page which is mapped into a different processes
+ * address space. Really, we want to allow our "user space" model to handle
+ * this.
+ */
+void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
+ unsigned long uaddr, void *dst, const void *src,
+ unsigned long len)
+{
+ memcpy(dst, src, len);
+ flush_ptrace_access(vma, (unsigned long)dst, (unsigned long)dst + len);
+}
+
+void __sync_icache_dcache(pte_t pte)
+{
+ struct folio *folio = page_folio(pte_page(pte));
+
+ if (!test_bit(PG_dcache_clean, &folio->flags)) {
+ sync_icache_aliases((unsigned long)folio_address(folio),
+ (unsigned long)folio_address(folio) +
+ folio_size(folio));
+ set_bit(PG_dcache_clean, &folio->flags);
+ }
+}
+EXPORT_SYMBOL_GPL(__sync_icache_dcache);
+
+/*
+ * This function is called when a page has been modified by the kernel. Mark
+ * it as dirty for later flushing when mapped in user space (if executable,
+ * see __sync_icache_dcache).
+ */
+void flush_dcache_folio(struct folio *folio)
+{
+ if (test_bit(PG_dcache_clean, &folio->flags))
+ clear_bit(PG_dcache_clean, &folio->flags);
+}
+EXPORT_SYMBOL(flush_dcache_folio);
+
+void flush_dcache_page(struct page *page)
+{
+ flush_dcache_folio(page_folio(page));
+}
+EXPORT_SYMBOL(flush_dcache_page);
+
+/*
+ * Additional functions defined in assembly.
+ */
+EXPORT_SYMBOL(caches_clean_inval_pou);
+
+#ifdef CONFIG_ARCH_HAS_PMEM_API
+void arch_wb_cache_pmem(void *addr, size_t size)
+{
+ /* Ensure order against any prior non-cacheable writes */
+ dmb(osh);
+ dcache_clean_pop((unsigned long)addr, (unsigned long)addr + size);
+}
+EXPORT_SYMBOL_GPL(arch_wb_cache_pmem);
+
+void arch_invalidate_pmem(void *addr, size_t size)
+{
+ dcache_inval_poc((unsigned long)addr, (unsigned long)addr + size);
+}
+EXPORT_SYMBOL_GPL(arch_invalidate_pmem);
+#endif
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
new file mode 100644
index 0000000000..13fd592228
--- /dev/null
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -0,0 +1,566 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch/arm64/mm/hugetlbpage.c
+ *
+ * Copyright (C) 2013 Linaro Ltd.
+ *
+ * Based on arch/x86/mm/hugetlbpage.c.
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.h>
+#include <linux/err.h>
+#include <linux/sysctl.h>
+#include <asm/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+/*
+ * HugeTLB Support Matrix
+ *
+ * ---------------------------------------------------
+ * | Page Size | CONT PTE | PMD | CONT PMD | PUD |
+ * ---------------------------------------------------
+ * | 4K | 64K | 2M | 32M | 1G |
+ * | 16K | 2M | 32M | 1G | |
+ * | 64K | 2M | 512M | 16G | |
+ * ---------------------------------------------------
+ */
+
+/*
+ * Reserve CMA areas for the largest supported gigantic
+ * huge page when requested. Any other smaller gigantic
+ * huge pages could still be served from those areas.
+ */
+#ifdef CONFIG_CMA
+void __init arm64_hugetlb_cma_reserve(void)
+{
+ int order;
+
+ if (pud_sect_supported())
+ order = PUD_SHIFT - PAGE_SHIFT;
+ else
+ order = CONT_PMD_SHIFT - PAGE_SHIFT;
+
+ /*
+ * HugeTLB CMA reservation is required for gigantic
+ * huge pages which could not be allocated via the
+ * page allocator. Just warn if there is any change
+ * breaking this assumption.
+ */
+ WARN_ON(order <= MAX_ORDER);
+ hugetlb_cma_reserve(order);
+}
+#endif /* CONFIG_CMA */
+
+static bool __hugetlb_valid_size(unsigned long size)
+{
+ switch (size) {
+#ifndef __PAGETABLE_PMD_FOLDED
+ case PUD_SIZE:
+ return pud_sect_supported();
+#endif
+ case CONT_PMD_SIZE:
+ case PMD_SIZE:
+ case CONT_PTE_SIZE:
+ return true;
+ }
+
+ return false;
+}
+
+#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
+bool arch_hugetlb_migration_supported(struct hstate *h)
+{
+ size_t pagesize = huge_page_size(h);
+
+ if (!__hugetlb_valid_size(pagesize)) {
+ pr_warn("%s: unrecognized huge page size 0x%lx\n",
+ __func__, pagesize);
+ return false;
+ }
+ return true;
+}
+#endif
+
+int pmd_huge(pmd_t pmd)
+{
+ return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
+}
+
+int pud_huge(pud_t pud)
+{
+#ifndef __PAGETABLE_PMD_FOLDED
+ return pud_val(pud) && !(pud_val(pud) & PUD_TABLE_BIT);
+#else
+ return 0;
+#endif
+}
+
+static int find_num_contig(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, size_t *pgsize)
+{
+ pgd_t *pgdp = pgd_offset(mm, addr);
+ p4d_t *p4dp;
+ pud_t *pudp;
+ pmd_t *pmdp;
+
+ *pgsize = PAGE_SIZE;
+ p4dp = p4d_offset(pgdp, addr);
+ pudp = pud_offset(p4dp, addr);
+ pmdp = pmd_offset(pudp, addr);
+ if ((pte_t *)pmdp == ptep) {
+ *pgsize = PMD_SIZE;
+ return CONT_PMDS;
+ }
+ return CONT_PTES;
+}
+
+static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
+{
+ int contig_ptes = 0;
+
+ *pgsize = size;
+
+ switch (size) {
+#ifndef __PAGETABLE_PMD_FOLDED
+ case PUD_SIZE:
+ if (pud_sect_supported())
+ contig_ptes = 1;
+ break;
+#endif
+ case PMD_SIZE:
+ contig_ptes = 1;
+ break;
+ case CONT_PMD_SIZE:
+ *pgsize = PMD_SIZE;
+ contig_ptes = CONT_PMDS;
+ break;
+ case CONT_PTE_SIZE:
+ *pgsize = PAGE_SIZE;
+ contig_ptes = CONT_PTES;
+ break;
+ }
+
+ return contig_ptes;
+}
+
+pte_t huge_ptep_get(pte_t *ptep)
+{
+ int ncontig, i;
+ size_t pgsize;
+ pte_t orig_pte = ptep_get(ptep);
+
+ if (!pte_present(orig_pte) || !pte_cont(orig_pte))
+ return orig_pte;
+
+ ncontig = num_contig_ptes(page_size(pte_page(orig_pte)), &pgsize);
+ for (i = 0; i < ncontig; i++, ptep++) {
+ pte_t pte = ptep_get(ptep);
+
+ if (pte_dirty(pte))
+ orig_pte = pte_mkdirty(orig_pte);
+
+ if (pte_young(pte))
+ orig_pte = pte_mkyoung(orig_pte);
+ }
+ return orig_pte;
+}
+
+/*
+ * Changing some bits of contiguous entries requires us to follow a
+ * Break-Before-Make approach, breaking the whole contiguous set
+ * before we can change any entries. See ARM DDI 0487A.k_iss10775,
+ * "Misprogramming of the Contiguous bit", page D4-1762.
+ *
+ * This helper performs the break step.
+ */
+static pte_t get_clear_contig(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pgsize,
+ unsigned long ncontig)
+{
+ pte_t orig_pte = ptep_get(ptep);
+ unsigned long i;
+
+ for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
+ pte_t pte = ptep_get_and_clear(mm, addr, ptep);
+
+ /*
+ * If HW_AFDBM is enabled, then the HW could turn on
+ * the dirty or accessed bit for any page in the set,
+ * so check them all.
+ */
+ if (pte_dirty(pte))
+ orig_pte = pte_mkdirty(orig_pte);
+
+ if (pte_young(pte))
+ orig_pte = pte_mkyoung(orig_pte);
+ }
+ return orig_pte;
+}
+
+static pte_t get_clear_contig_flush(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pgsize,
+ unsigned long ncontig)
+{
+ pte_t orig_pte = get_clear_contig(mm, addr, ptep, pgsize, ncontig);
+ struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
+
+ flush_tlb_range(&vma, addr, addr + (pgsize * ncontig));
+ return orig_pte;
+}
+
+/*
+ * Changing some bits of contiguous entries requires us to follow a
+ * Break-Before-Make approach, breaking the whole contiguous set
+ * before we can change any entries. See ARM DDI 0487A.k_iss10775,
+ * "Misprogramming of the Contiguous bit", page D4-1762.
+ *
+ * This helper performs the break step for use cases where the
+ * original pte is not needed.
+ */
+static void clear_flush(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pgsize,
+ unsigned long ncontig)
+{
+ struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
+ unsigned long i, saddr = addr;
+
+ for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
+ ptep_clear(mm, addr, ptep);
+
+ flush_tlb_range(&vma, saddr, addr);
+}
+
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned long sz)
+{
+ size_t pgsize;
+ int i;
+ int ncontig;
+ unsigned long pfn, dpfn;
+ pgprot_t hugeprot;
+
+ ncontig = num_contig_ptes(sz, &pgsize);
+
+ if (!pte_present(pte)) {
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
+ set_pte_at(mm, addr, ptep, pte);
+ return;
+ }
+
+ if (!pte_cont(pte)) {
+ set_pte_at(mm, addr, ptep, pte);
+ return;
+ }
+
+ pfn = pte_pfn(pte);
+ dpfn = pgsize >> PAGE_SHIFT;
+ hugeprot = pte_pgprot(pte);
+
+ clear_flush(mm, addr, ptep, pgsize, ncontig);
+
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
+ set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
+}
+
+pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, unsigned long sz)
+{
+ pgd_t *pgdp;
+ p4d_t *p4dp;
+ pud_t *pudp;
+ pmd_t *pmdp;
+ pte_t *ptep = NULL;
+
+ pgdp = pgd_offset(mm, addr);
+ p4dp = p4d_offset(pgdp, addr);
+ pudp = pud_alloc(mm, p4dp, addr);
+ if (!pudp)
+ return NULL;
+
+ if (sz == PUD_SIZE) {
+ ptep = (pte_t *)pudp;
+ } else if (sz == (CONT_PTE_SIZE)) {
+ pmdp = pmd_alloc(mm, pudp, addr);
+ if (!pmdp)
+ return NULL;
+
+ WARN_ON(addr & (sz - 1));
+ ptep = pte_alloc_huge(mm, pmdp, addr);
+ } else if (sz == PMD_SIZE) {
+ if (want_pmd_share(vma, addr) && pud_none(READ_ONCE(*pudp)))
+ ptep = huge_pmd_share(mm, vma, addr, pudp);
+ else
+ ptep = (pte_t *)pmd_alloc(mm, pudp, addr);
+ } else if (sz == (CONT_PMD_SIZE)) {
+ pmdp = pmd_alloc(mm, pudp, addr);
+ WARN_ON(addr & (sz - 1));
+ return (pte_t *)pmdp;
+ }
+
+ return ptep;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm,
+ unsigned long addr, unsigned long sz)
+{
+ pgd_t *pgdp;
+ p4d_t *p4dp;
+ pud_t *pudp, pud;
+ pmd_t *pmdp, pmd;
+
+ pgdp = pgd_offset(mm, addr);
+ if (!pgd_present(READ_ONCE(*pgdp)))
+ return NULL;
+
+ p4dp = p4d_offset(pgdp, addr);
+ if (!p4d_present(READ_ONCE(*p4dp)))
+ return NULL;
+
+ pudp = pud_offset(p4dp, addr);
+ pud = READ_ONCE(*pudp);
+ if (sz != PUD_SIZE && pud_none(pud))
+ return NULL;
+ /* hugepage or swap? */
+ if (pud_huge(pud) || !pud_present(pud))
+ return (pte_t *)pudp;
+ /* table; check the next level */
+
+ if (sz == CONT_PMD_SIZE)
+ addr &= CONT_PMD_MASK;
+
+ pmdp = pmd_offset(pudp, addr);
+ pmd = READ_ONCE(*pmdp);
+ if (!(sz == PMD_SIZE || sz == CONT_PMD_SIZE) &&
+ pmd_none(pmd))
+ return NULL;
+ if (pmd_huge(pmd) || !pmd_present(pmd))
+ return (pte_t *)pmdp;
+
+ if (sz == CONT_PTE_SIZE)
+ return pte_offset_huge(pmdp, (addr & CONT_PTE_MASK));
+
+ return NULL;
+}
+
+unsigned long hugetlb_mask_last_page(struct hstate *h)
+{
+ unsigned long hp_size = huge_page_size(h);
+
+ switch (hp_size) {
+#ifndef __PAGETABLE_PMD_FOLDED
+ case PUD_SIZE:
+ return PGDIR_SIZE - PUD_SIZE;
+#endif
+ case CONT_PMD_SIZE:
+ return PUD_SIZE - CONT_PMD_SIZE;
+ case PMD_SIZE:
+ return PUD_SIZE - PMD_SIZE;
+ case CONT_PTE_SIZE:
+ return PMD_SIZE - CONT_PTE_SIZE;
+ default:
+ break;
+ }
+
+ return 0UL;
+}
+
+pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
+{
+ size_t pagesize = 1UL << shift;
+
+ entry = pte_mkhuge(entry);
+ if (pagesize == CONT_PTE_SIZE) {
+ entry = pte_mkcont(entry);
+ } else if (pagesize == CONT_PMD_SIZE) {
+ entry = pmd_pte(pmd_mkcont(pte_pmd(entry)));
+ } else if (pagesize != PUD_SIZE && pagesize != PMD_SIZE) {
+ pr_warn("%s: unrecognized huge page size 0x%lx\n",
+ __func__, pagesize);
+ }
+ return entry;
+}
+
+void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, unsigned long sz)
+{
+ int i, ncontig;
+ size_t pgsize;
+
+ ncontig = num_contig_ptes(sz, &pgsize);
+
+ for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
+ pte_clear(mm, addr, ptep);
+}
+
+pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ int ncontig;
+ size_t pgsize;
+ pte_t orig_pte = ptep_get(ptep);
+
+ if (!pte_cont(orig_pte))
+ return ptep_get_and_clear(mm, addr, ptep);
+
+ ncontig = find_num_contig(mm, addr, ptep, &pgsize);
+
+ return get_clear_contig(mm, addr, ptep, pgsize, ncontig);
+}
+
+/*
+ * huge_ptep_set_access_flags will update access flags (dirty, accesssed)
+ * and write permission.
+ *
+ * For a contiguous huge pte range we need to check whether or not write
+ * permission has to change only on the first pte in the set. Then for
+ * all the contiguous ptes we need to check whether or not there is a
+ * discrepancy between dirty or young.
+ */
+static int __cont_access_flags_changed(pte_t *ptep, pte_t pte, int ncontig)
+{
+ int i;
+
+ if (pte_write(pte) != pte_write(ptep_get(ptep)))
+ return 1;
+
+ for (i = 0; i < ncontig; i++) {
+ pte_t orig_pte = ptep_get(ptep + i);
+
+ if (pte_dirty(pte) != pte_dirty(orig_pte))
+ return 1;
+
+ if (pte_young(pte) != pte_young(orig_pte))
+ return 1;
+ }
+
+ return 0;
+}
+
+int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t pte, int dirty)
+{
+ int ncontig, i;
+ size_t pgsize = 0;
+ unsigned long pfn = pte_pfn(pte), dpfn;
+ struct mm_struct *mm = vma->vm_mm;
+ pgprot_t hugeprot;
+ pte_t orig_pte;
+
+ if (!pte_cont(pte))
+ return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
+
+ ncontig = find_num_contig(mm, addr, ptep, &pgsize);
+ dpfn = pgsize >> PAGE_SHIFT;
+
+ if (!__cont_access_flags_changed(ptep, pte, ncontig))
+ return 0;
+
+ orig_pte = get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
+
+ /* Make sure we don't lose the dirty or young state */
+ if (pte_dirty(orig_pte))
+ pte = pte_mkdirty(pte);
+
+ if (pte_young(orig_pte))
+ pte = pte_mkyoung(pte);
+
+ hugeprot = pte_pgprot(pte);
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
+ set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
+
+ return 1;
+}
+
+void huge_ptep_set_wrprotect(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ unsigned long pfn, dpfn;
+ pgprot_t hugeprot;
+ int ncontig, i;
+ size_t pgsize;
+ pte_t pte;
+
+ if (!pte_cont(READ_ONCE(*ptep))) {
+ ptep_set_wrprotect(mm, addr, ptep);
+ return;
+ }
+
+ ncontig = find_num_contig(mm, addr, ptep, &pgsize);
+ dpfn = pgsize >> PAGE_SHIFT;
+
+ pte = get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
+ pte = pte_wrprotect(pte);
+
+ hugeprot = pte_pgprot(pte);
+ pfn = pte_pfn(pte);
+
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
+ set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
+}
+
+pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ size_t pgsize;
+ int ncontig;
+
+ if (!pte_cont(READ_ONCE(*ptep)))
+ return ptep_clear_flush(vma, addr, ptep);
+
+ ncontig = find_num_contig(mm, addr, ptep, &pgsize);
+ return get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
+}
+
+static int __init hugetlbpage_init(void)
+{
+ if (pud_sect_supported())
+ hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
+
+ hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT);
+ hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
+ hugetlb_add_hstate(CONT_PTE_SHIFT - PAGE_SHIFT);
+
+ return 0;
+}
+arch_initcall(hugetlbpage_init);
+
+bool __init arch_hugetlb_valid_size(unsigned long size)
+{
+ return __hugetlb_valid_size(size);
+}
+
+pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
+{
+ if (IS_ENABLED(CONFIG_ARM64_ERRATUM_2645198) &&
+ cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
+ /*
+ * Break-before-make (BBM) is required for all user space mappings
+ * when the permission changes from executable to non-executable
+ * in cases where cpu is affected with errata #2645198.
+ */
+ if (pte_user_exec(READ_ONCE(*ptep)))
+ return huge_ptep_clear_flush(vma, addr, ptep);
+ }
+ return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+}
+
+void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
+ pte_t old_pte, pte_t pte)
+{
+ unsigned long psize = huge_page_size(hstate_vma(vma));
+
+ set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
+}
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
new file mode 100644
index 0000000000..8a0f860434
--- /dev/null
+++ b/arch/arm64/mm/init.c
@@ -0,0 +1,549 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/mm/init.c
+ *
+ * Copyright (C) 1995-2005 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/swap.h>
+#include <linux/init.h>
+#include <linux/cache.h>
+#include <linux/mman.h>
+#include <linux/nodemask.h>
+#include <linux/initrd.h>
+#include <linux/gfp.h>
+#include <linux/memblock.h>
+#include <linux/sort.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/dma-direct.h>
+#include <linux/dma-map-ops.h>
+#include <linux/efi.h>
+#include <linux/swiotlb.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/kexec.h>
+#include <linux/crash_dump.h>
+#include <linux/hugetlb.h>
+#include <linux/acpi_iort.h>
+#include <linux/kmemleak.h>
+
+#include <asm/boot.h>
+#include <asm/fixmap.h>
+#include <asm/kasan.h>
+#include <asm/kernel-pgtable.h>
+#include <asm/kvm_host.h>
+#include <asm/memory.h>
+#include <asm/numa.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <linux/sizes.h>
+#include <asm/tlb.h>
+#include <asm/alternative.h>
+#include <asm/xen/swiotlb-xen.h>
+
+/*
+ * We need to be able to catch inadvertent references to memstart_addr
+ * that occur (potentially in generic code) before arm64_memblock_init()
+ * executes, which assigns it its actual value. So use a default value
+ * that cannot be mistaken for a real physical address.
+ */
+s64 memstart_addr __ro_after_init = -1;
+EXPORT_SYMBOL(memstart_addr);
+
+/*
+ * If the corresponding config options are enabled, we create both ZONE_DMA
+ * and ZONE_DMA32. By default ZONE_DMA covers the 32-bit addressable memory
+ * unless restricted on specific platforms (e.g. 30-bit on Raspberry Pi 4).
+ * In such case, ZONE_DMA32 covers the rest of the 32-bit addressable memory,
+ * otherwise it is empty.
+ */
+phys_addr_t __ro_after_init arm64_dma_phys_limit;
+
+/* Current arm64 boot protocol requires 2MB alignment */
+#define CRASH_ALIGN SZ_2M
+
+#define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit
+#define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1)
+#define CRASH_HIGH_SEARCH_BASE SZ_4G
+
+#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20)
+
+/*
+ * To make optimal use of block mappings when laying out the linear
+ * mapping, round down the base of physical memory to a size that can
+ * be mapped efficiently, i.e., either PUD_SIZE (4k granule) or PMD_SIZE
+ * (64k granule), or a multiple that can be mapped using contiguous bits
+ * in the page tables: 32 * PMD_SIZE (16k granule)
+ */
+#if defined(CONFIG_ARM64_4K_PAGES)
+#define ARM64_MEMSTART_SHIFT PUD_SHIFT
+#elif defined(CONFIG_ARM64_16K_PAGES)
+#define ARM64_MEMSTART_SHIFT CONT_PMD_SHIFT
+#else
+#define ARM64_MEMSTART_SHIFT PMD_SHIFT
+#endif
+
+/*
+ * sparsemem vmemmap imposes an additional requirement on the alignment of
+ * memstart_addr, due to the fact that the base of the vmemmap region
+ * has a direct correspondence, and needs to appear sufficiently aligned
+ * in the virtual address space.
+ */
+#if ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS
+#define ARM64_MEMSTART_ALIGN (1UL << SECTION_SIZE_BITS)
+#else
+#define ARM64_MEMSTART_ALIGN (1UL << ARM64_MEMSTART_SHIFT)
+#endif
+
+static int __init reserve_crashkernel_low(unsigned long long low_size)
+{
+ unsigned long long low_base;
+
+ low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX);
+ if (!low_base) {
+ pr_err("cannot allocate crashkernel low memory (size:0x%llx).\n", low_size);
+ return -ENOMEM;
+ }
+
+ pr_info("crashkernel low memory reserved: 0x%08llx - 0x%08llx (%lld MB)\n",
+ low_base, low_base + low_size, low_size >> 20);
+
+ crashk_low_res.start = low_base;
+ crashk_low_res.end = low_base + low_size - 1;
+ insert_resource(&iomem_resource, &crashk_low_res);
+
+ return 0;
+}
+
+/*
+ * reserve_crashkernel() - reserves memory for crash kernel
+ *
+ * This function reserves memory area given in "crashkernel=" kernel command
+ * line parameter. The memory reserved is used by dump capture kernel when
+ * primary kernel is crashing.
+ */
+static void __init reserve_crashkernel(void)
+{
+ unsigned long long crash_low_size = 0, search_base = 0;
+ unsigned long long crash_max = CRASH_ADDR_LOW_MAX;
+ unsigned long long crash_base, crash_size;
+ char *cmdline = boot_command_line;
+ bool fixed_base = false;
+ bool high = false;
+ int ret;
+
+ if (!IS_ENABLED(CONFIG_KEXEC_CORE))
+ return;
+
+ /* crashkernel=X[@offset] */
+ ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
+ &crash_size, &crash_base);
+ if (ret == -ENOENT) {
+ ret = parse_crashkernel_high(cmdline, 0, &crash_size, &crash_base);
+ if (ret || !crash_size)
+ return;
+
+ /*
+ * crashkernel=Y,low can be specified or not, but invalid value
+ * is not allowed.
+ */
+ ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base);
+ if (ret == -ENOENT)
+ crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
+ else if (ret)
+ return;
+
+ search_base = CRASH_HIGH_SEARCH_BASE;
+ crash_max = CRASH_ADDR_HIGH_MAX;
+ high = true;
+ } else if (ret || !crash_size) {
+ /* The specified value is invalid */
+ return;
+ }
+
+ crash_size = PAGE_ALIGN(crash_size);
+
+ /* User specifies base address explicitly. */
+ if (crash_base) {
+ fixed_base = true;
+ search_base = crash_base;
+ crash_max = crash_base + crash_size;
+ }
+
+retry:
+ crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
+ search_base, crash_max);
+ if (!crash_base) {
+ /*
+ * For crashkernel=size[KMG]@offset[KMG], print out failure
+ * message if can't reserve the specified region.
+ */
+ if (fixed_base) {
+ pr_warn("crashkernel reservation failed - memory is in use.\n");
+ return;
+ }
+
+ /*
+ * For crashkernel=size[KMG], if the first attempt was for
+ * low memory, fall back to high memory, the minimum required
+ * low memory will be reserved later.
+ */
+ if (!high && crash_max == CRASH_ADDR_LOW_MAX) {
+ crash_max = CRASH_ADDR_HIGH_MAX;
+ search_base = CRASH_ADDR_LOW_MAX;
+ crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
+ goto retry;
+ }
+
+ /*
+ * For crashkernel=size[KMG],high, if the first attempt was
+ * for high memory, fall back to low memory.
+ */
+ if (high && crash_max == CRASH_ADDR_HIGH_MAX) {
+ crash_max = CRASH_ADDR_LOW_MAX;
+ search_base = 0;
+ goto retry;
+ }
+ pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
+ crash_size);
+ return;
+ }
+
+ if ((crash_base >= CRASH_ADDR_LOW_MAX) && crash_low_size &&
+ reserve_crashkernel_low(crash_low_size)) {
+ memblock_phys_free(crash_base, crash_size);
+ return;
+ }
+
+ pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
+ crash_base, crash_base + crash_size, crash_size >> 20);
+
+ /*
+ * The crashkernel memory will be removed from the kernel linear
+ * map. Inform kmemleak so that it won't try to access it.
+ */
+ kmemleak_ignore_phys(crash_base);
+ if (crashk_low_res.end)
+ kmemleak_ignore_phys(crashk_low_res.start);
+
+ crashk_res.start = crash_base;
+ crashk_res.end = crash_base + crash_size - 1;
+ insert_resource(&iomem_resource, &crashk_res);
+}
+
+/*
+ * Return the maximum physical address for a zone accessible by the given bits
+ * limit. If DRAM starts above 32-bit, expand the zone to the maximum
+ * available memory, otherwise cap it at 32-bit.
+ */
+static phys_addr_t __init max_zone_phys(unsigned int zone_bits)
+{
+ phys_addr_t zone_mask = DMA_BIT_MASK(zone_bits);
+ phys_addr_t phys_start = memblock_start_of_DRAM();
+
+ if (phys_start > U32_MAX)
+ zone_mask = PHYS_ADDR_MAX;
+ else if (phys_start > zone_mask)
+ zone_mask = U32_MAX;
+
+ return min(zone_mask, memblock_end_of_DRAM() - 1) + 1;
+}
+
+static void __init zone_sizes_init(void)
+{
+ unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
+ unsigned int __maybe_unused acpi_zone_dma_bits;
+ unsigned int __maybe_unused dt_zone_dma_bits;
+ phys_addr_t __maybe_unused dma32_phys_limit = max_zone_phys(32);
+
+#ifdef CONFIG_ZONE_DMA
+ acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address());
+ dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL));
+ zone_dma_bits = min3(32U, dt_zone_dma_bits, acpi_zone_dma_bits);
+ arm64_dma_phys_limit = max_zone_phys(zone_dma_bits);
+ max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit);
+#endif
+#ifdef CONFIG_ZONE_DMA32
+ max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
+ if (!arm64_dma_phys_limit)
+ arm64_dma_phys_limit = dma32_phys_limit;
+#endif
+ if (!arm64_dma_phys_limit)
+ arm64_dma_phys_limit = PHYS_MASK + 1;
+ max_zone_pfns[ZONE_NORMAL] = max_pfn;
+
+ free_area_init(max_zone_pfns);
+}
+
+int pfn_is_map_memory(unsigned long pfn)
+{
+ phys_addr_t addr = PFN_PHYS(pfn);
+
+ /* avoid false positives for bogus PFNs, see comment in pfn_valid() */
+ if (PHYS_PFN(addr) != pfn)
+ return 0;
+
+ return memblock_is_map_memory(addr);
+}
+EXPORT_SYMBOL(pfn_is_map_memory);
+
+static phys_addr_t memory_limit __ro_after_init = PHYS_ADDR_MAX;
+
+/*
+ * Limit the memory size that was specified via FDT.
+ */
+static int __init early_mem(char *p)
+{
+ if (!p)
+ return 1;
+
+ memory_limit = memparse(p, &p) & PAGE_MASK;
+ pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
+
+ return 0;
+}
+early_param("mem", early_mem);
+
+void __init arm64_memblock_init(void)
+{
+ s64 linear_region_size = PAGE_END - _PAGE_OFFSET(vabits_actual);
+
+ /*
+ * Corner case: 52-bit VA capable systems running KVM in nVHE mode may
+ * be limited in their ability to support a linear map that exceeds 51
+ * bits of VA space, depending on the placement of the ID map. Given
+ * that the placement of the ID map may be randomized, let's simply
+ * limit the kernel's linear map to 51 bits as well if we detect this
+ * configuration.
+ */
+ if (IS_ENABLED(CONFIG_KVM) && vabits_actual == 52 &&
+ is_hyp_mode_available() && !is_kernel_in_hyp_mode()) {
+ pr_info("Capping linear region to 51 bits for KVM in nVHE mode on LVA capable hardware.\n");
+ linear_region_size = min_t(u64, linear_region_size, BIT(51));
+ }
+
+ /* Remove memory above our supported physical address size */
+ memblock_remove(1ULL << PHYS_MASK_SHIFT, ULLONG_MAX);
+
+ /*
+ * Select a suitable value for the base of physical memory.
+ */
+ memstart_addr = round_down(memblock_start_of_DRAM(),
+ ARM64_MEMSTART_ALIGN);
+
+ if ((memblock_end_of_DRAM() - memstart_addr) > linear_region_size)
+ pr_warn("Memory doesn't fit in the linear mapping, VA_BITS too small\n");
+
+ /*
+ * Remove the memory that we will not be able to cover with the
+ * linear mapping. Take care not to clip the kernel which may be
+ * high in memory.
+ */
+ memblock_remove(max_t(u64, memstart_addr + linear_region_size,
+ __pa_symbol(_end)), ULLONG_MAX);
+ if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) {
+ /* ensure that memstart_addr remains sufficiently aligned */
+ memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size,
+ ARM64_MEMSTART_ALIGN);
+ memblock_remove(0, memstart_addr);
+ }
+
+ /*
+ * If we are running with a 52-bit kernel VA config on a system that
+ * does not support it, we have to place the available physical
+ * memory in the 48-bit addressable part of the linear region, i.e.,
+ * we have to move it upward. Since memstart_addr represents the
+ * physical address of PAGE_OFFSET, we have to *subtract* from it.
+ */
+ if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52))
+ memstart_addr -= _PAGE_OFFSET(48) - _PAGE_OFFSET(52);
+
+ /*
+ * Apply the memory limit if it was set. Since the kernel may be loaded
+ * high up in memory, add back the kernel region that must be accessible
+ * via the linear mapping.
+ */
+ if (memory_limit != PHYS_ADDR_MAX) {
+ memblock_mem_limit_remove_map(memory_limit);
+ memblock_add(__pa_symbol(_text), (u64)(_end - _text));
+ }
+
+ if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) {
+ /*
+ * Add back the memory we just removed if it results in the
+ * initrd to become inaccessible via the linear mapping.
+ * Otherwise, this is a no-op
+ */
+ u64 base = phys_initrd_start & PAGE_MASK;
+ u64 size = PAGE_ALIGN(phys_initrd_start + phys_initrd_size) - base;
+
+ /*
+ * We can only add back the initrd memory if we don't end up
+ * with more memory than we can address via the linear mapping.
+ * It is up to the bootloader to position the kernel and the
+ * initrd reasonably close to each other (i.e., within 32 GB of
+ * each other) so that all granule/#levels combinations can
+ * always access both.
+ */
+ if (WARN(base < memblock_start_of_DRAM() ||
+ base + size > memblock_start_of_DRAM() +
+ linear_region_size,
+ "initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) {
+ phys_initrd_size = 0;
+ } else {
+ memblock_add(base, size);
+ memblock_clear_nomap(base, size);
+ memblock_reserve(base, size);
+ }
+ }
+
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
+ extern u16 memstart_offset_seed;
+ u64 mmfr0 = read_cpuid(ID_AA64MMFR0_EL1);
+ int parange = cpuid_feature_extract_unsigned_field(
+ mmfr0, ID_AA64MMFR0_EL1_PARANGE_SHIFT);
+ s64 range = linear_region_size -
+ BIT(id_aa64mmfr0_parange_to_phys_shift(parange));
+
+ /*
+ * If the size of the linear region exceeds, by a sufficient
+ * margin, the size of the region that the physical memory can
+ * span, randomize the linear region as well.
+ */
+ if (memstart_offset_seed > 0 && range >= (s64)ARM64_MEMSTART_ALIGN) {
+ range /= ARM64_MEMSTART_ALIGN;
+ memstart_addr -= ARM64_MEMSTART_ALIGN *
+ ((range * memstart_offset_seed) >> 16);
+ }
+ }
+
+ /*
+ * Register the kernel text, kernel data, initrd, and initial
+ * pagetables with memblock.
+ */
+ memblock_reserve(__pa_symbol(_stext), _end - _stext);
+ if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) {
+ /* the generic initrd code expects virtual addresses */
+ initrd_start = __phys_to_virt(phys_initrd_start);
+ initrd_end = initrd_start + phys_initrd_size;
+ }
+
+ early_init_fdt_scan_reserved_mem();
+
+ high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
+}
+
+void __init bootmem_init(void)
+{
+ unsigned long min, max;
+
+ min = PFN_UP(memblock_start_of_DRAM());
+ max = PFN_DOWN(memblock_end_of_DRAM());
+
+ early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
+
+ max_pfn = max_low_pfn = max;
+ min_low_pfn = min;
+
+ arch_numa_init();
+
+ /*
+ * must be done after arch_numa_init() which calls numa_init() to
+ * initialize node_online_map that gets used in hugetlb_cma_reserve()
+ * while allocating required CMA size across online nodes.
+ */
+#if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_CMA)
+ arm64_hugetlb_cma_reserve();
+#endif
+
+ kvm_hyp_reserve();
+
+ /*
+ * sparse_init() tries to allocate memory from memblock, so must be
+ * done after the fixed reservations
+ */
+ sparse_init();
+ zone_sizes_init();
+
+ /*
+ * Reserve the CMA area after arm64_dma_phys_limit was initialised.
+ */
+ dma_contiguous_reserve(arm64_dma_phys_limit);
+
+ /*
+ * request_standard_resources() depends on crashkernel's memory being
+ * reserved, so do it here.
+ */
+ reserve_crashkernel();
+
+ memblock_dump_all();
+}
+
+/*
+ * mem_init() marks the free areas in the mem_map and tells us how much memory
+ * is free. This is done after various parts of the system have claimed their
+ * memory after the kernel image.
+ */
+void __init mem_init(void)
+{
+ bool swiotlb = max_pfn > PFN_DOWN(arm64_dma_phys_limit);
+
+ if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC))
+ swiotlb = true;
+
+ swiotlb_init(swiotlb, SWIOTLB_VERBOSE);
+
+ /* this will put all unused low memory onto the freelists */
+ memblock_free_all();
+
+ /*
+ * Check boundaries twice: Some fundamental inconsistencies can be
+ * detected at build time already.
+ */
+#ifdef CONFIG_COMPAT
+ BUILD_BUG_ON(TASK_SIZE_32 > DEFAULT_MAP_WINDOW_64);
+#endif
+
+ /*
+ * Selected page table levels should match when derived from
+ * scratch using the virtual address range and page size.
+ */
+ BUILD_BUG_ON(ARM64_HW_PGTABLE_LEVELS(CONFIG_ARM64_VA_BITS) !=
+ CONFIG_PGTABLE_LEVELS);
+
+ if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
+ extern int sysctl_overcommit_memory;
+ /*
+ * On a machine this small we won't get anywhere without
+ * overcommit, so turn it on by default.
+ */
+ sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
+ }
+}
+
+void free_initmem(void)
+{
+ free_reserved_area(lm_alias(__init_begin),
+ lm_alias(__init_end),
+ POISON_FREE_INITMEM, "unused kernel");
+ /*
+ * Unmap the __init region but leave the VM area in place. This
+ * prevents the region from being reused for kernel modules, which
+ * is not supported by kallsyms.
+ */
+ vunmap_range((u64)__init_begin, (u64)__init_end);
+}
+
+void dump_mem_limit(void)
+{
+ if (memory_limit != PHYS_ADDR_MAX) {
+ pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20);
+ } else {
+ pr_emerg("Memory Limit: none\n");
+ }
+}
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
new file mode 100644
index 0000000000..269f2f63ab
--- /dev/null
+++ b/arch/arm64/mm/ioremap.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/mm.h>
+#include <linux/io.h>
+
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+ unsigned long prot)
+{
+ unsigned long last_addr = phys_addr + size - 1;
+
+ /* Don't allow outside PHYS_MASK */
+ if (last_addr & ~PHYS_MASK)
+ return NULL;
+
+ /* Don't allow RAM to be mapped. */
+ if (WARN_ON(pfn_is_map_memory(__phys_to_pfn(phys_addr))))
+ return NULL;
+
+ return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
+}
+EXPORT_SYMBOL(ioremap_prot);
+
+/*
+ * Must be called after early_fixmap_init
+ */
+void __init early_ioremap_init(void)
+{
+ early_ioremap_setup();
+}
+
+bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
+ unsigned long flags)
+{
+ unsigned long pfn = PHYS_PFN(offset);
+
+ return pfn_is_map_memory(pfn);
+}
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
new file mode 100644
index 0000000000..f17d066e85
--- /dev/null
+++ b/arch/arm64/mm/kasan_init.c
@@ -0,0 +1,308 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file contains kasan initialization code for ARM64.
+ *
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
+ */
+
+#define pr_fmt(fmt) "kasan: " fmt
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/sched/task.h>
+#include <linux/memblock.h>
+#include <linux/start_kernel.h>
+#include <linux/mm.h>
+
+#include <asm/mmu_context.h>
+#include <asm/kernel-pgtable.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+#include <asm/tlbflush.h>
+
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+
+static pgd_t tmp_pg_dir[PTRS_PER_PGD] __initdata __aligned(PGD_SIZE);
+
+/*
+ * The p*d_populate functions call virt_to_phys implicitly so they can't be used
+ * directly on kernel symbols (bm_p*d). All the early functions are called too
+ * early to use lm_alias so __p*d_populate functions must be used to populate
+ * with the physical address from __pa_symbol.
+ */
+
+static phys_addr_t __init kasan_alloc_zeroed_page(int node)
+{
+ void *p = memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE,
+ __pa(MAX_DMA_ADDRESS),
+ MEMBLOCK_ALLOC_NOLEAKTRACE, node);
+ if (!p)
+ panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%llx\n",
+ __func__, PAGE_SIZE, PAGE_SIZE, node,
+ __pa(MAX_DMA_ADDRESS));
+
+ return __pa(p);
+}
+
+static phys_addr_t __init kasan_alloc_raw_page(int node)
+{
+ void *p = memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE,
+ __pa(MAX_DMA_ADDRESS),
+ MEMBLOCK_ALLOC_NOLEAKTRACE,
+ node);
+ if (!p)
+ panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%llx\n",
+ __func__, PAGE_SIZE, PAGE_SIZE, node,
+ __pa(MAX_DMA_ADDRESS));
+
+ return __pa(p);
+}
+
+static pte_t *__init kasan_pte_offset(pmd_t *pmdp, unsigned long addr, int node,
+ bool early)
+{
+ if (pmd_none(READ_ONCE(*pmdp))) {
+ phys_addr_t pte_phys = early ?
+ __pa_symbol(kasan_early_shadow_pte)
+ : kasan_alloc_zeroed_page(node);
+ __pmd_populate(pmdp, pte_phys, PMD_TYPE_TABLE);
+ }
+
+ return early ? pte_offset_kimg(pmdp, addr)
+ : pte_offset_kernel(pmdp, addr);
+}
+
+static pmd_t *__init kasan_pmd_offset(pud_t *pudp, unsigned long addr, int node,
+ bool early)
+{
+ if (pud_none(READ_ONCE(*pudp))) {
+ phys_addr_t pmd_phys = early ?
+ __pa_symbol(kasan_early_shadow_pmd)
+ : kasan_alloc_zeroed_page(node);
+ __pud_populate(pudp, pmd_phys, PUD_TYPE_TABLE);
+ }
+
+ return early ? pmd_offset_kimg(pudp, addr) : pmd_offset(pudp, addr);
+}
+
+static pud_t *__init kasan_pud_offset(p4d_t *p4dp, unsigned long addr, int node,
+ bool early)
+{
+ if (p4d_none(READ_ONCE(*p4dp))) {
+ phys_addr_t pud_phys = early ?
+ __pa_symbol(kasan_early_shadow_pud)
+ : kasan_alloc_zeroed_page(node);
+ __p4d_populate(p4dp, pud_phys, P4D_TYPE_TABLE);
+ }
+
+ return early ? pud_offset_kimg(p4dp, addr) : pud_offset(p4dp, addr);
+}
+
+static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr,
+ unsigned long end, int node, bool early)
+{
+ unsigned long next;
+ pte_t *ptep = kasan_pte_offset(pmdp, addr, node, early);
+
+ do {
+ phys_addr_t page_phys = early ?
+ __pa_symbol(kasan_early_shadow_page)
+ : kasan_alloc_raw_page(node);
+ if (!early)
+ memset(__va(page_phys), KASAN_SHADOW_INIT, PAGE_SIZE);
+ next = addr + PAGE_SIZE;
+ set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL));
+ } while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep)));
+}
+
+static void __init kasan_pmd_populate(pud_t *pudp, unsigned long addr,
+ unsigned long end, int node, bool early)
+{
+ unsigned long next;
+ pmd_t *pmdp = kasan_pmd_offset(pudp, addr, node, early);
+
+ do {
+ next = pmd_addr_end(addr, end);
+ kasan_pte_populate(pmdp, addr, next, node, early);
+ } while (pmdp++, addr = next, addr != end && pmd_none(READ_ONCE(*pmdp)));
+}
+
+static void __init kasan_pud_populate(p4d_t *p4dp, unsigned long addr,
+ unsigned long end, int node, bool early)
+{
+ unsigned long next;
+ pud_t *pudp = kasan_pud_offset(p4dp, addr, node, early);
+
+ do {
+ next = pud_addr_end(addr, end);
+ kasan_pmd_populate(pudp, addr, next, node, early);
+ } while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp)));
+}
+
+static void __init kasan_p4d_populate(pgd_t *pgdp, unsigned long addr,
+ unsigned long end, int node, bool early)
+{
+ unsigned long next;
+ p4d_t *p4dp = p4d_offset(pgdp, addr);
+
+ do {
+ next = p4d_addr_end(addr, end);
+ kasan_pud_populate(p4dp, addr, next, node, early);
+ } while (p4dp++, addr = next, addr != end);
+}
+
+static void __init kasan_pgd_populate(unsigned long addr, unsigned long end,
+ int node, bool early)
+{
+ unsigned long next;
+ pgd_t *pgdp;
+
+ pgdp = pgd_offset_k(addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ kasan_p4d_populate(pgdp, addr, next, node, early);
+ } while (pgdp++, addr = next, addr != end);
+}
+
+/* The early shadow maps everything to a single page of zeroes */
+asmlinkage void __init kasan_early_init(void)
+{
+ BUILD_BUG_ON(KASAN_SHADOW_OFFSET !=
+ KASAN_SHADOW_END - (1UL << (64 - KASAN_SHADOW_SCALE_SHIFT)));
+ BUILD_BUG_ON(!IS_ALIGNED(_KASAN_SHADOW_START(VA_BITS), PGDIR_SIZE));
+ BUILD_BUG_ON(!IS_ALIGNED(_KASAN_SHADOW_START(VA_BITS_MIN), PGDIR_SIZE));
+ BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE));
+ kasan_pgd_populate(KASAN_SHADOW_START, KASAN_SHADOW_END, NUMA_NO_NODE,
+ true);
+}
+
+/* Set up full kasan mappings, ensuring that the mapped pages are zeroed */
+static void __init kasan_map_populate(unsigned long start, unsigned long end,
+ int node)
+{
+ kasan_pgd_populate(start & PAGE_MASK, PAGE_ALIGN(end), node, false);
+}
+
+/*
+ * Copy the current shadow region into a new pgdir.
+ */
+void __init kasan_copy_shadow(pgd_t *pgdir)
+{
+ pgd_t *pgdp, *pgdp_new, *pgdp_end;
+
+ pgdp = pgd_offset_k(KASAN_SHADOW_START);
+ pgdp_end = pgd_offset_k(KASAN_SHADOW_END);
+ pgdp_new = pgd_offset_pgd(pgdir, KASAN_SHADOW_START);
+ do {
+ set_pgd(pgdp_new, READ_ONCE(*pgdp));
+ } while (pgdp++, pgdp_new++, pgdp != pgdp_end);
+}
+
+static void __init clear_pgds(unsigned long start,
+ unsigned long end)
+{
+ /*
+ * Remove references to kasan page tables from
+ * swapper_pg_dir. pgd_clear() can't be used
+ * here because it's nop on 2,3-level pagetable setups
+ */
+ for (; start < end; start += PGDIR_SIZE)
+ set_pgd(pgd_offset_k(start), __pgd(0));
+}
+
+static void __init kasan_init_shadow(void)
+{
+ u64 kimg_shadow_start, kimg_shadow_end;
+ u64 mod_shadow_start;
+ u64 vmalloc_shadow_end;
+ phys_addr_t pa_start, pa_end;
+ u64 i;
+
+ kimg_shadow_start = (u64)kasan_mem_to_shadow(KERNEL_START) & PAGE_MASK;
+ kimg_shadow_end = PAGE_ALIGN((u64)kasan_mem_to_shadow(KERNEL_END));
+
+ mod_shadow_start = (u64)kasan_mem_to_shadow((void *)MODULES_VADDR);
+
+ vmalloc_shadow_end = (u64)kasan_mem_to_shadow((void *)VMALLOC_END);
+
+ /*
+ * We are going to perform proper setup of shadow memory.
+ * At first we should unmap early shadow (clear_pgds() call below).
+ * However, instrumented code couldn't execute without shadow memory.
+ * tmp_pg_dir used to keep early shadow mapped until full shadow
+ * setup will be finished.
+ */
+ memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(tmp_pg_dir));
+ dsb(ishst);
+ cpu_replace_ttbr1(lm_alias(tmp_pg_dir), idmap_pg_dir);
+
+ clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ kasan_map_populate(kimg_shadow_start, kimg_shadow_end,
+ early_pfn_to_nid(virt_to_pfn(lm_alias(KERNEL_START))));
+
+ kasan_populate_early_shadow(kasan_mem_to_shadow((void *)PAGE_END),
+ (void *)mod_shadow_start);
+
+ BUILD_BUG_ON(VMALLOC_START != MODULES_END);
+ kasan_populate_early_shadow((void *)vmalloc_shadow_end,
+ (void *)KASAN_SHADOW_END);
+
+ for_each_mem_range(i, &pa_start, &pa_end) {
+ void *start = (void *)__phys_to_virt(pa_start);
+ void *end = (void *)__phys_to_virt(pa_end);
+
+ if (start >= end)
+ break;
+
+ kasan_map_populate((unsigned long)kasan_mem_to_shadow(start),
+ (unsigned long)kasan_mem_to_shadow(end),
+ early_pfn_to_nid(virt_to_pfn(start)));
+ }
+
+ /*
+ * KAsan may reuse the contents of kasan_early_shadow_pte directly,
+ * so we should make sure that it maps the zero page read-only.
+ */
+ for (i = 0; i < PTRS_PER_PTE; i++)
+ set_pte(&kasan_early_shadow_pte[i],
+ pfn_pte(sym_to_pfn(kasan_early_shadow_page),
+ PAGE_KERNEL_RO));
+
+ memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE);
+ cpu_replace_ttbr1(lm_alias(swapper_pg_dir), idmap_pg_dir);
+}
+
+static void __init kasan_init_depth(void)
+{
+ init_task.kasan_depth = 0;
+}
+
+#ifdef CONFIG_KASAN_VMALLOC
+void __init kasan_populate_early_vm_area_shadow(void *start, unsigned long size)
+{
+ unsigned long shadow_start, shadow_end;
+
+ if (!is_vmalloc_or_module_addr(start))
+ return;
+
+ shadow_start = (unsigned long)kasan_mem_to_shadow(start);
+ shadow_start = ALIGN_DOWN(shadow_start, PAGE_SIZE);
+ shadow_end = (unsigned long)kasan_mem_to_shadow(start + size);
+ shadow_end = ALIGN(shadow_end, PAGE_SIZE);
+ kasan_map_populate(shadow_start, shadow_end, NUMA_NO_NODE);
+}
+#endif
+
+void __init kasan_init(void)
+{
+ kasan_init_shadow();
+ kasan_init_depth();
+#if defined(CONFIG_KASAN_GENERIC)
+ /* CONFIG_KASAN_SW_TAGS also requires kasan_init_sw_tags(). */
+ pr_info("KernelAddressSanitizer initialized (generic)\n");
+#endif
+}
+
+#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
new file mode 100644
index 0000000000..8f5b7ce857
--- /dev/null
+++ b/arch/arm64/mm/mmap.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/mm/mmap.c
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/io.h>
+#include <linux/memblock.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+
+#include <asm/cpufeature.h>
+#include <asm/page.h>
+
+static pgprot_t protection_map[16] __ro_after_init = {
+ [VM_NONE] = PAGE_NONE,
+ [VM_READ] = PAGE_READONLY,
+ [VM_WRITE] = PAGE_READONLY,
+ [VM_WRITE | VM_READ] = PAGE_READONLY,
+ /* PAGE_EXECONLY if Enhanced PAN */
+ [VM_EXEC] = PAGE_READONLY_EXEC,
+ [VM_EXEC | VM_READ] = PAGE_READONLY_EXEC,
+ [VM_EXEC | VM_WRITE] = PAGE_READONLY_EXEC,
+ [VM_EXEC | VM_WRITE | VM_READ] = PAGE_READONLY_EXEC,
+ [VM_SHARED] = PAGE_NONE,
+ [VM_SHARED | VM_READ] = PAGE_READONLY,
+ [VM_SHARED | VM_WRITE] = PAGE_SHARED,
+ [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
+ /* PAGE_EXECONLY if Enhanced PAN */
+ [VM_SHARED | VM_EXEC] = PAGE_READONLY_EXEC,
+ [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_EXEC,
+ [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC,
+ [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC
+};
+
+/*
+ * You really shouldn't be using read() or write() on /dev/mem. This might go
+ * away in the future.
+ */
+int valid_phys_addr_range(phys_addr_t addr, size_t size)
+{
+ /*
+ * Check whether addr is covered by a memory region without the
+ * MEMBLOCK_NOMAP attribute, and whether that region covers the
+ * entire range. In theory, this could lead to false negatives
+ * if the range is covered by distinct but adjacent memory regions
+ * that only differ in other attributes. However, few of such
+ * attributes have been defined, and it is debatable whether it
+ * follows that /dev/mem read() calls should be able traverse
+ * such boundaries.
+ */
+ return memblock_is_region_memory(addr, size) &&
+ memblock_is_map_memory(addr);
+}
+
+/*
+ * Do not allow /dev/mem mappings beyond the supported physical range.
+ */
+int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
+{
+ return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK);
+}
+
+static int __init adjust_protection_map(void)
+{
+ /*
+ * With Enhanced PAN we can honour the execute-only permissions as
+ * there is no PAN override with such mappings.
+ */
+ if (cpus_have_const_cap(ARM64_HAS_EPAN)) {
+ protection_map[VM_EXEC] = PAGE_EXECONLY;
+ protection_map[VM_EXEC | VM_SHARED] = PAGE_EXECONLY;
+ }
+
+ return 0;
+}
+arch_initcall(adjust_protection_map);
+
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+ pteval_t prot = pgprot_val(protection_map[vm_flags &
+ (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
+
+ if (vm_flags & VM_ARM64_BTI)
+ prot |= PTE_GP;
+
+ /*
+ * There are two conditions required for returning a Normal Tagged
+ * memory type: (1) the user requested it via PROT_MTE passed to
+ * mmap() or mprotect() and (2) the corresponding vma supports MTE. We
+ * register (1) as VM_MTE in the vma->vm_flags and (2) as
+ * VM_MTE_ALLOWED. Note that the latter can only be set during the
+ * mmap() call since mprotect() does not accept MAP_* flags.
+ * Checking for VM_MTE only is sufficient since arch_validate_flags()
+ * does not permit (VM_MTE & !VM_MTE_ALLOWED).
+ */
+ if (vm_flags & VM_MTE)
+ prot |= PTE_ATTRINDX(MT_NORMAL_TAGGED);
+
+ return __pgprot(prot);
+}
+EXPORT_SYMBOL(vm_get_page_prot);
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
new file mode 100644
index 0000000000..47781bec61
--- /dev/null
+++ b/arch/arm64/mm/mmu.c
@@ -0,0 +1,1489 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/mm/mmu.c
+ *
+ * Copyright (C) 1995-2005 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/cache.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/kexec.h>
+#include <linux/libfdt.h>
+#include <linux/mman.h>
+#include <linux/nodemask.h>
+#include <linux/memblock.h>
+#include <linux/memremap.h>
+#include <linux/memory.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <linux/set_memory.h>
+#include <linux/kfence.h>
+
+#include <asm/barrier.h>
+#include <asm/cputype.h>
+#include <asm/fixmap.h>
+#include <asm/kasan.h>
+#include <asm/kernel-pgtable.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <linux/sizes.h>
+#include <asm/tlb.h>
+#include <asm/mmu_context.h>
+#include <asm/ptdump.h>
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+#include <asm/kfence.h>
+
+#define NO_BLOCK_MAPPINGS BIT(0)
+#define NO_CONT_MAPPINGS BIT(1)
+#define NO_EXEC_MAPPINGS BIT(2) /* assumes FEAT_HPDS is not used */
+
+int idmap_t0sz __ro_after_init;
+
+#if VA_BITS > 48
+u64 vabits_actual __ro_after_init = VA_BITS_MIN;
+EXPORT_SYMBOL(vabits_actual);
+#endif
+
+u64 kimage_vaddr __ro_after_init = (u64)&_text;
+EXPORT_SYMBOL(kimage_vaddr);
+
+u64 kimage_voffset __ro_after_init;
+EXPORT_SYMBOL(kimage_voffset);
+
+u32 __boot_cpu_mode[] = { BOOT_CPU_MODE_EL2, BOOT_CPU_MODE_EL1 };
+
+/*
+ * The booting CPU updates the failed status @__early_cpu_boot_status,
+ * with MMU turned off.
+ */
+long __section(".mmuoff.data.write") __early_cpu_boot_status;
+
+/*
+ * Empty_zero_page is a special page that is used for zero-initialized data
+ * and COW.
+ */
+unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
+EXPORT_SYMBOL(empty_zero_page);
+
+static DEFINE_SPINLOCK(swapper_pgdir_lock);
+static DEFINE_MUTEX(fixmap_lock);
+
+void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd)
+{
+ pgd_t *fixmap_pgdp;
+
+ spin_lock(&swapper_pgdir_lock);
+ fixmap_pgdp = pgd_set_fixmap(__pa_symbol(pgdp));
+ WRITE_ONCE(*fixmap_pgdp, pgd);
+ /*
+ * We need dsb(ishst) here to ensure the page-table-walker sees
+ * our new entry before set_p?d() returns. The fixmap's
+ * flush_tlb_kernel_range() via clear_fixmap() does this for us.
+ */
+ pgd_clear_fixmap();
+ spin_unlock(&swapper_pgdir_lock);
+}
+
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot)
+{
+ if (!pfn_is_map_memory(pfn))
+ return pgprot_noncached(vma_prot);
+ else if (file->f_flags & O_SYNC)
+ return pgprot_writecombine(vma_prot);
+ return vma_prot;
+}
+EXPORT_SYMBOL(phys_mem_access_prot);
+
+static phys_addr_t __init early_pgtable_alloc(int shift)
+{
+ phys_addr_t phys;
+ void *ptr;
+
+ phys = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0,
+ MEMBLOCK_ALLOC_NOLEAKTRACE);
+ if (!phys)
+ panic("Failed to allocate page table page\n");
+
+ /*
+ * The FIX_{PGD,PUD,PMD} slots may be in active use, but the FIX_PTE
+ * slot will be free, so we can (ab)use the FIX_PTE slot to initialise
+ * any level of table.
+ */
+ ptr = pte_set_fixmap(phys);
+
+ memset(ptr, 0, PAGE_SIZE);
+
+ /*
+ * Implicit barriers also ensure the zeroed page is visible to the page
+ * table walker
+ */
+ pte_clear_fixmap();
+
+ return phys;
+}
+
+bool pgattr_change_is_safe(u64 old, u64 new)
+{
+ /*
+ * The following mapping attributes may be updated in live
+ * kernel mappings without the need for break-before-make.
+ */
+ pteval_t mask = PTE_PXN | PTE_RDONLY | PTE_WRITE | PTE_NG;
+
+ /* creating or taking down mappings is always safe */
+ if (!pte_valid(__pte(old)) || !pte_valid(__pte(new)))
+ return true;
+
+ /* A live entry's pfn should not change */
+ if (pte_pfn(__pte(old)) != pte_pfn(__pte(new)))
+ return false;
+
+ /* live contiguous mappings may not be manipulated at all */
+ if ((old | new) & PTE_CONT)
+ return false;
+
+ /* Transitioning from Non-Global to Global is unsafe */
+ if (old & ~new & PTE_NG)
+ return false;
+
+ /*
+ * Changing the memory type between Normal and Normal-Tagged is safe
+ * since Tagged is considered a permission attribute from the
+ * mismatched attribute aliases perspective.
+ */
+ if (((old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) ||
+ (old & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)) &&
+ ((new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL) ||
+ (new & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL_TAGGED)))
+ mask |= PTE_ATTRINDX_MASK;
+
+ return ((old ^ new) & ~mask) == 0;
+}
+
+static void init_pte(pmd_t *pmdp, unsigned long addr, unsigned long end,
+ phys_addr_t phys, pgprot_t prot)
+{
+ pte_t *ptep;
+
+ ptep = pte_set_fixmap_offset(pmdp, addr);
+ do {
+ pte_t old_pte = READ_ONCE(*ptep);
+
+ set_pte(ptep, pfn_pte(__phys_to_pfn(phys), prot));
+
+ /*
+ * After the PTE entry has been populated once, we
+ * only allow updates to the permission attributes.
+ */
+ BUG_ON(!pgattr_change_is_safe(pte_val(old_pte),
+ READ_ONCE(pte_val(*ptep))));
+
+ phys += PAGE_SIZE;
+ } while (ptep++, addr += PAGE_SIZE, addr != end);
+
+ pte_clear_fixmap();
+}
+
+static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr,
+ unsigned long end, phys_addr_t phys,
+ pgprot_t prot,
+ phys_addr_t (*pgtable_alloc)(int),
+ int flags)
+{
+ unsigned long next;
+ pmd_t pmd = READ_ONCE(*pmdp);
+
+ BUG_ON(pmd_sect(pmd));
+ if (pmd_none(pmd)) {
+ pmdval_t pmdval = PMD_TYPE_TABLE | PMD_TABLE_UXN;
+ phys_addr_t pte_phys;
+
+ if (flags & NO_EXEC_MAPPINGS)
+ pmdval |= PMD_TABLE_PXN;
+ BUG_ON(!pgtable_alloc);
+ pte_phys = pgtable_alloc(PAGE_SHIFT);
+ __pmd_populate(pmdp, pte_phys, pmdval);
+ pmd = READ_ONCE(*pmdp);
+ }
+ BUG_ON(pmd_bad(pmd));
+
+ do {
+ pgprot_t __prot = prot;
+
+ next = pte_cont_addr_end(addr, end);
+
+ /* use a contiguous mapping if the range is suitably aligned */
+ if ((((addr | next | phys) & ~CONT_PTE_MASK) == 0) &&
+ (flags & NO_CONT_MAPPINGS) == 0)
+ __prot = __pgprot(pgprot_val(prot) | PTE_CONT);
+
+ init_pte(pmdp, addr, next, phys, __prot);
+
+ phys += next - addr;
+ } while (addr = next, addr != end);
+}
+
+static void init_pmd(pud_t *pudp, unsigned long addr, unsigned long end,
+ phys_addr_t phys, pgprot_t prot,
+ phys_addr_t (*pgtable_alloc)(int), int flags)
+{
+ unsigned long next;
+ pmd_t *pmdp;
+
+ pmdp = pmd_set_fixmap_offset(pudp, addr);
+ do {
+ pmd_t old_pmd = READ_ONCE(*pmdp);
+
+ next = pmd_addr_end(addr, end);
+
+ /* try section mapping first */
+ if (((addr | next | phys) & ~PMD_MASK) == 0 &&
+ (flags & NO_BLOCK_MAPPINGS) == 0) {
+ pmd_set_huge(pmdp, phys, prot);
+
+ /*
+ * After the PMD entry has been populated once, we
+ * only allow updates to the permission attributes.
+ */
+ BUG_ON(!pgattr_change_is_safe(pmd_val(old_pmd),
+ READ_ONCE(pmd_val(*pmdp))));
+ } else {
+ alloc_init_cont_pte(pmdp, addr, next, phys, prot,
+ pgtable_alloc, flags);
+
+ BUG_ON(pmd_val(old_pmd) != 0 &&
+ pmd_val(old_pmd) != READ_ONCE(pmd_val(*pmdp)));
+ }
+ phys += next - addr;
+ } while (pmdp++, addr = next, addr != end);
+
+ pmd_clear_fixmap();
+}
+
+static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr,
+ unsigned long end, phys_addr_t phys,
+ pgprot_t prot,
+ phys_addr_t (*pgtable_alloc)(int), int flags)
+{
+ unsigned long next;
+ pud_t pud = READ_ONCE(*pudp);
+
+ /*
+ * Check for initial section mappings in the pgd/pud.
+ */
+ BUG_ON(pud_sect(pud));
+ if (pud_none(pud)) {
+ pudval_t pudval = PUD_TYPE_TABLE | PUD_TABLE_UXN;
+ phys_addr_t pmd_phys;
+
+ if (flags & NO_EXEC_MAPPINGS)
+ pudval |= PUD_TABLE_PXN;
+ BUG_ON(!pgtable_alloc);
+ pmd_phys = pgtable_alloc(PMD_SHIFT);
+ __pud_populate(pudp, pmd_phys, pudval);
+ pud = READ_ONCE(*pudp);
+ }
+ BUG_ON(pud_bad(pud));
+
+ do {
+ pgprot_t __prot = prot;
+
+ next = pmd_cont_addr_end(addr, end);
+
+ /* use a contiguous mapping if the range is suitably aligned */
+ if ((((addr | next | phys) & ~CONT_PMD_MASK) == 0) &&
+ (flags & NO_CONT_MAPPINGS) == 0)
+ __prot = __pgprot(pgprot_val(prot) | PTE_CONT);
+
+ init_pmd(pudp, addr, next, phys, __prot, pgtable_alloc, flags);
+
+ phys += next - addr;
+ } while (addr = next, addr != end);
+}
+
+static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
+ phys_addr_t phys, pgprot_t prot,
+ phys_addr_t (*pgtable_alloc)(int),
+ int flags)
+{
+ unsigned long next;
+ pud_t *pudp;
+ p4d_t *p4dp = p4d_offset(pgdp, addr);
+ p4d_t p4d = READ_ONCE(*p4dp);
+
+ if (p4d_none(p4d)) {
+ p4dval_t p4dval = P4D_TYPE_TABLE | P4D_TABLE_UXN;
+ phys_addr_t pud_phys;
+
+ if (flags & NO_EXEC_MAPPINGS)
+ p4dval |= P4D_TABLE_PXN;
+ BUG_ON(!pgtable_alloc);
+ pud_phys = pgtable_alloc(PUD_SHIFT);
+ __p4d_populate(p4dp, pud_phys, p4dval);
+ p4d = READ_ONCE(*p4dp);
+ }
+ BUG_ON(p4d_bad(p4d));
+
+ pudp = pud_set_fixmap_offset(p4dp, addr);
+ do {
+ pud_t old_pud = READ_ONCE(*pudp);
+
+ next = pud_addr_end(addr, end);
+
+ /*
+ * For 4K granule only, attempt to put down a 1GB block
+ */
+ if (pud_sect_supported() &&
+ ((addr | next | phys) & ~PUD_MASK) == 0 &&
+ (flags & NO_BLOCK_MAPPINGS) == 0) {
+ pud_set_huge(pudp, phys, prot);
+
+ /*
+ * After the PUD entry has been populated once, we
+ * only allow updates to the permission attributes.
+ */
+ BUG_ON(!pgattr_change_is_safe(pud_val(old_pud),
+ READ_ONCE(pud_val(*pudp))));
+ } else {
+ alloc_init_cont_pmd(pudp, addr, next, phys, prot,
+ pgtable_alloc, flags);
+
+ BUG_ON(pud_val(old_pud) != 0 &&
+ pud_val(old_pud) != READ_ONCE(pud_val(*pudp)));
+ }
+ phys += next - addr;
+ } while (pudp++, addr = next, addr != end);
+
+ pud_clear_fixmap();
+}
+
+static void __create_pgd_mapping_locked(pgd_t *pgdir, phys_addr_t phys,
+ unsigned long virt, phys_addr_t size,
+ pgprot_t prot,
+ phys_addr_t (*pgtable_alloc)(int),
+ int flags)
+{
+ unsigned long addr, end, next;
+ pgd_t *pgdp = pgd_offset_pgd(pgdir, virt);
+
+ /*
+ * If the virtual and physical address don't have the same offset
+ * within a page, we cannot map the region as the caller expects.
+ */
+ if (WARN_ON((phys ^ virt) & ~PAGE_MASK))
+ return;
+
+ phys &= PAGE_MASK;
+ addr = virt & PAGE_MASK;
+ end = PAGE_ALIGN(virt + size);
+
+ do {
+ next = pgd_addr_end(addr, end);
+ alloc_init_pud(pgdp, addr, next, phys, prot, pgtable_alloc,
+ flags);
+ phys += next - addr;
+ } while (pgdp++, addr = next, addr != end);
+}
+
+static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
+ unsigned long virt, phys_addr_t size,
+ pgprot_t prot,
+ phys_addr_t (*pgtable_alloc)(int),
+ int flags)
+{
+ mutex_lock(&fixmap_lock);
+ __create_pgd_mapping_locked(pgdir, phys, virt, size, prot,
+ pgtable_alloc, flags);
+ mutex_unlock(&fixmap_lock);
+}
+
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+extern __alias(__create_pgd_mapping_locked)
+void create_kpti_ng_temp_pgd(pgd_t *pgdir, phys_addr_t phys, unsigned long virt,
+ phys_addr_t size, pgprot_t prot,
+ phys_addr_t (*pgtable_alloc)(int), int flags);
+#endif
+
+static phys_addr_t __pgd_pgtable_alloc(int shift)
+{
+ void *ptr = (void *)__get_free_page(GFP_PGTABLE_KERNEL);
+ BUG_ON(!ptr);
+
+ /* Ensure the zeroed page is visible to the page table walker */
+ dsb(ishst);
+ return __pa(ptr);
+}
+
+static phys_addr_t pgd_pgtable_alloc(int shift)
+{
+ phys_addr_t pa = __pgd_pgtable_alloc(shift);
+ struct ptdesc *ptdesc = page_ptdesc(phys_to_page(pa));
+
+ /*
+ * Call proper page table ctor in case later we need to
+ * call core mm functions like apply_to_page_range() on
+ * this pre-allocated page table.
+ *
+ * We don't select ARCH_ENABLE_SPLIT_PMD_PTLOCK if pmd is
+ * folded, and if so pagetable_pte_ctor() becomes nop.
+ */
+ if (shift == PAGE_SHIFT)
+ BUG_ON(!pagetable_pte_ctor(ptdesc));
+ else if (shift == PMD_SHIFT)
+ BUG_ON(!pagetable_pmd_ctor(ptdesc));
+
+ return pa;
+}
+
+/*
+ * This function can only be used to modify existing table entries,
+ * without allocating new levels of table. Note that this permits the
+ * creation of new section or page entries.
+ */
+void __init create_mapping_noalloc(phys_addr_t phys, unsigned long virt,
+ phys_addr_t size, pgprot_t prot)
+{
+ if (virt < PAGE_OFFSET) {
+ pr_warn("BUG: not creating mapping for %pa at 0x%016lx - outside kernel range\n",
+ &phys, virt);
+ return;
+ }
+ __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
+ NO_CONT_MAPPINGS);
+}
+
+void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
+ unsigned long virt, phys_addr_t size,
+ pgprot_t prot, bool page_mappings_only)
+{
+ int flags = 0;
+
+ BUG_ON(mm == &init_mm);
+
+ if (page_mappings_only)
+ flags = NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
+
+ __create_pgd_mapping(mm->pgd, phys, virt, size, prot,
+ pgd_pgtable_alloc, flags);
+}
+
+static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
+ phys_addr_t size, pgprot_t prot)
+{
+ if (virt < PAGE_OFFSET) {
+ pr_warn("BUG: not updating mapping for %pa at 0x%016lx - outside kernel range\n",
+ &phys, virt);
+ return;
+ }
+
+ __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL,
+ NO_CONT_MAPPINGS);
+
+ /* flush the TLBs after updating live kernel mappings */
+ flush_tlb_kernel_range(virt, virt + size);
+}
+
+static void __init __map_memblock(pgd_t *pgdp, phys_addr_t start,
+ phys_addr_t end, pgprot_t prot, int flags)
+{
+ __create_pgd_mapping(pgdp, start, __phys_to_virt(start), end - start,
+ prot, early_pgtable_alloc, flags);
+}
+
+void __init mark_linear_text_alias_ro(void)
+{
+ /*
+ * Remove the write permissions from the linear alias of .text/.rodata
+ */
+ update_mapping_prot(__pa_symbol(_stext), (unsigned long)lm_alias(_stext),
+ (unsigned long)__init_begin - (unsigned long)_stext,
+ PAGE_KERNEL_RO);
+}
+
+#ifdef CONFIG_KFENCE
+
+bool __ro_after_init kfence_early_init = !!CONFIG_KFENCE_SAMPLE_INTERVAL;
+
+/* early_param() will be parsed before map_mem() below. */
+static int __init parse_kfence_early_init(char *arg)
+{
+ int val;
+
+ if (get_option(&arg, &val))
+ kfence_early_init = !!val;
+ return 0;
+}
+early_param("kfence.sample_interval", parse_kfence_early_init);
+
+static phys_addr_t __init arm64_kfence_alloc_pool(void)
+{
+ phys_addr_t kfence_pool;
+
+ if (!kfence_early_init)
+ return 0;
+
+ kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE);
+ if (!kfence_pool) {
+ pr_err("failed to allocate kfence pool\n");
+ kfence_early_init = false;
+ return 0;
+ }
+
+ /* Temporarily mark as NOMAP. */
+ memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE);
+
+ return kfence_pool;
+}
+
+static void __init arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp)
+{
+ if (!kfence_pool)
+ return;
+
+ /* KFENCE pool needs page-level mapping. */
+ __map_memblock(pgdp, kfence_pool, kfence_pool + KFENCE_POOL_SIZE,
+ pgprot_tagged(PAGE_KERNEL),
+ NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
+ memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE);
+ __kfence_pool = phys_to_virt(kfence_pool);
+}
+#else /* CONFIG_KFENCE */
+
+static inline phys_addr_t arm64_kfence_alloc_pool(void) { return 0; }
+static inline void arm64_kfence_map_pool(phys_addr_t kfence_pool, pgd_t *pgdp) { }
+
+#endif /* CONFIG_KFENCE */
+
+static void __init map_mem(pgd_t *pgdp)
+{
+ static const u64 direct_map_end = _PAGE_END(VA_BITS_MIN);
+ phys_addr_t kernel_start = __pa_symbol(_stext);
+ phys_addr_t kernel_end = __pa_symbol(__init_begin);
+ phys_addr_t start, end;
+ phys_addr_t early_kfence_pool;
+ int flags = NO_EXEC_MAPPINGS;
+ u64 i;
+
+ /*
+ * Setting hierarchical PXNTable attributes on table entries covering
+ * the linear region is only possible if it is guaranteed that no table
+ * entries at any level are being shared between the linear region and
+ * the vmalloc region. Check whether this is true for the PGD level, in
+ * which case it is guaranteed to be true for all other levels as well.
+ */
+ BUILD_BUG_ON(pgd_index(direct_map_end - 1) == pgd_index(direct_map_end));
+
+ early_kfence_pool = arm64_kfence_alloc_pool();
+
+ if (can_set_direct_map())
+ flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
+
+ /*
+ * Take care not to create a writable alias for the
+ * read-only text and rodata sections of the kernel image.
+ * So temporarily mark them as NOMAP to skip mappings in
+ * the following for-loop
+ */
+ memblock_mark_nomap(kernel_start, kernel_end - kernel_start);
+
+ /* map all the memory banks */
+ for_each_mem_range(i, &start, &end) {
+ if (start >= end)
+ break;
+ /*
+ * The linear map must allow allocation tags reading/writing
+ * if MTE is present. Otherwise, it has the same attributes as
+ * PAGE_KERNEL.
+ */
+ __map_memblock(pgdp, start, end, pgprot_tagged(PAGE_KERNEL),
+ flags);
+ }
+
+ /*
+ * Map the linear alias of the [_stext, __init_begin) interval
+ * as non-executable now, and remove the write permission in
+ * mark_linear_text_alias_ro() below (which will be called after
+ * alternative patching has completed). This makes the contents
+ * of the region accessible to subsystems such as hibernate,
+ * but protects it from inadvertent modification or execution.
+ * Note that contiguous mappings cannot be remapped in this way,
+ * so we should avoid them here.
+ */
+ __map_memblock(pgdp, kernel_start, kernel_end,
+ PAGE_KERNEL, NO_CONT_MAPPINGS);
+ memblock_clear_nomap(kernel_start, kernel_end - kernel_start);
+ arm64_kfence_map_pool(early_kfence_pool, pgdp);
+}
+
+void mark_rodata_ro(void)
+{
+ unsigned long section_size;
+
+ /*
+ * mark .rodata as read only. Use __init_begin rather than __end_rodata
+ * to cover NOTES and EXCEPTION_TABLE.
+ */
+ section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata;
+ update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata,
+ section_size, PAGE_KERNEL_RO);
+
+ debug_checkwx();
+}
+
+static void __init map_kernel_segment(pgd_t *pgdp, void *va_start, void *va_end,
+ pgprot_t prot, struct vm_struct *vma,
+ int flags, unsigned long vm_flags)
+{
+ phys_addr_t pa_start = __pa_symbol(va_start);
+ unsigned long size = va_end - va_start;
+
+ BUG_ON(!PAGE_ALIGNED(pa_start));
+ BUG_ON(!PAGE_ALIGNED(size));
+
+ __create_pgd_mapping(pgdp, pa_start, (unsigned long)va_start, size, prot,
+ early_pgtable_alloc, flags);
+
+ if (!(vm_flags & VM_NO_GUARD))
+ size += PAGE_SIZE;
+
+ vma->addr = va_start;
+ vma->phys_addr = pa_start;
+ vma->size = size;
+ vma->flags = VM_MAP | vm_flags;
+ vma->caller = __builtin_return_address(0);
+
+ vm_area_add_early(vma);
+}
+
+static pgprot_t kernel_exec_prot(void)
+{
+ return rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
+}
+
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+static int __init map_entry_trampoline(void)
+{
+ int i;
+
+ pgprot_t prot = kernel_exec_prot();
+ phys_addr_t pa_start = __pa_symbol(__entry_tramp_text_start);
+
+ /* The trampoline is always mapped and can therefore be global */
+ pgprot_val(prot) &= ~PTE_NG;
+
+ /* Map only the text into the trampoline page table */
+ memset(tramp_pg_dir, 0, PGD_SIZE);
+ __create_pgd_mapping(tramp_pg_dir, pa_start, TRAMP_VALIAS,
+ entry_tramp_text_size(), prot,
+ __pgd_pgtable_alloc, NO_BLOCK_MAPPINGS);
+
+ /* Map both the text and data into the kernel page table */
+ for (i = 0; i < DIV_ROUND_UP(entry_tramp_text_size(), PAGE_SIZE); i++)
+ __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i,
+ pa_start + i * PAGE_SIZE, prot);
+
+ if (IS_ENABLED(CONFIG_RELOCATABLE))
+ __set_fixmap(FIX_ENTRY_TRAMP_TEXT1 - i,
+ pa_start + i * PAGE_SIZE, PAGE_KERNEL_RO);
+
+ return 0;
+}
+core_initcall(map_entry_trampoline);
+#endif
+
+/*
+ * Open coded check for BTI, only for use to determine configuration
+ * for early mappings for before the cpufeature code has run.
+ */
+static bool arm64_early_this_cpu_has_bti(void)
+{
+ u64 pfr1;
+
+ if (!IS_ENABLED(CONFIG_ARM64_BTI_KERNEL))
+ return false;
+
+ pfr1 = __read_sysreg_by_encoding(SYS_ID_AA64PFR1_EL1);
+ return cpuid_feature_extract_unsigned_field(pfr1,
+ ID_AA64PFR1_EL1_BT_SHIFT);
+}
+
+/*
+ * Create fine-grained mappings for the kernel.
+ */
+static void __init map_kernel(pgd_t *pgdp)
+{
+ static struct vm_struct vmlinux_text, vmlinux_rodata, vmlinux_inittext,
+ vmlinux_initdata, vmlinux_data;
+
+ /*
+ * External debuggers may need to write directly to the text
+ * mapping to install SW breakpoints. Allow this (only) when
+ * explicitly requested with rodata=off.
+ */
+ pgprot_t text_prot = kernel_exec_prot();
+
+ /*
+ * If we have a CPU that supports BTI and a kernel built for
+ * BTI then mark the kernel executable text as guarded pages
+ * now so we don't have to rewrite the page tables later.
+ */
+ if (arm64_early_this_cpu_has_bti())
+ text_prot = __pgprot_modify(text_prot, PTE_GP, PTE_GP);
+
+ /*
+ * Only rodata will be remapped with different permissions later on,
+ * all other segments are allowed to use contiguous mappings.
+ */
+ map_kernel_segment(pgdp, _stext, _etext, text_prot, &vmlinux_text, 0,
+ VM_NO_GUARD);
+ map_kernel_segment(pgdp, __start_rodata, __inittext_begin, PAGE_KERNEL,
+ &vmlinux_rodata, NO_CONT_MAPPINGS, VM_NO_GUARD);
+ map_kernel_segment(pgdp, __inittext_begin, __inittext_end, text_prot,
+ &vmlinux_inittext, 0, VM_NO_GUARD);
+ map_kernel_segment(pgdp, __initdata_begin, __initdata_end, PAGE_KERNEL,
+ &vmlinux_initdata, 0, VM_NO_GUARD);
+ map_kernel_segment(pgdp, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0);
+
+ fixmap_copy(pgdp);
+ kasan_copy_shadow(pgdp);
+}
+
+static void __init create_idmap(void)
+{
+ u64 start = __pa_symbol(__idmap_text_start);
+ u64 size = __pa_symbol(__idmap_text_end) - start;
+ pgd_t *pgd = idmap_pg_dir;
+ u64 pgd_phys;
+
+ /* check if we need an additional level of translation */
+ if (VA_BITS < 48 && idmap_t0sz < (64 - VA_BITS_MIN)) {
+ pgd_phys = early_pgtable_alloc(PAGE_SHIFT);
+ set_pgd(&idmap_pg_dir[start >> VA_BITS],
+ __pgd(pgd_phys | P4D_TYPE_TABLE));
+ pgd = __va(pgd_phys);
+ }
+ __create_pgd_mapping(pgd, start, start, size, PAGE_KERNEL_ROX,
+ early_pgtable_alloc, 0);
+
+ if (IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) {
+ extern u32 __idmap_kpti_flag;
+ u64 pa = __pa_symbol(&__idmap_kpti_flag);
+
+ /*
+ * The KPTI G-to-nG conversion code needs a read-write mapping
+ * of its synchronization flag in the ID map.
+ */
+ __create_pgd_mapping(pgd, pa, pa, sizeof(u32), PAGE_KERNEL,
+ early_pgtable_alloc, 0);
+ }
+}
+
+void __init paging_init(void)
+{
+ pgd_t *pgdp = pgd_set_fixmap(__pa_symbol(swapper_pg_dir));
+ extern pgd_t init_idmap_pg_dir[];
+
+ idmap_t0sz = 63UL - __fls(__pa_symbol(_end) | GENMASK(VA_BITS_MIN - 1, 0));
+
+ map_kernel(pgdp);
+ map_mem(pgdp);
+
+ pgd_clear_fixmap();
+
+ cpu_replace_ttbr1(lm_alias(swapper_pg_dir), init_idmap_pg_dir);
+ init_mm.pgd = swapper_pg_dir;
+
+ memblock_phys_free(__pa_symbol(init_pg_dir),
+ __pa_symbol(init_pg_end) - __pa_symbol(init_pg_dir));
+
+ memblock_allow_resize();
+
+ create_idmap();
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static void free_hotplug_page_range(struct page *page, size_t size,
+ struct vmem_altmap *altmap)
+{
+ if (altmap) {
+ vmem_altmap_free(altmap, size >> PAGE_SHIFT);
+ } else {
+ WARN_ON(PageReserved(page));
+ free_pages((unsigned long)page_address(page), get_order(size));
+ }
+}
+
+static void free_hotplug_pgtable_page(struct page *page)
+{
+ free_hotplug_page_range(page, PAGE_SIZE, NULL);
+}
+
+static bool pgtable_range_aligned(unsigned long start, unsigned long end,
+ unsigned long floor, unsigned long ceiling,
+ unsigned long mask)
+{
+ start &= mask;
+ if (start < floor)
+ return false;
+
+ if (ceiling) {
+ ceiling &= mask;
+ if (!ceiling)
+ return false;
+ }
+
+ if (end - 1 > ceiling - 1)
+ return false;
+ return true;
+}
+
+static void unmap_hotplug_pte_range(pmd_t *pmdp, unsigned long addr,
+ unsigned long end, bool free_mapped,
+ struct vmem_altmap *altmap)
+{
+ pte_t *ptep, pte;
+
+ do {
+ ptep = pte_offset_kernel(pmdp, addr);
+ pte = READ_ONCE(*ptep);
+ if (pte_none(pte))
+ continue;
+
+ WARN_ON(!pte_present(pte));
+ pte_clear(&init_mm, addr, ptep);
+ flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+ if (free_mapped)
+ free_hotplug_page_range(pte_page(pte),
+ PAGE_SIZE, altmap);
+ } while (addr += PAGE_SIZE, addr < end);
+}
+
+static void unmap_hotplug_pmd_range(pud_t *pudp, unsigned long addr,
+ unsigned long end, bool free_mapped,
+ struct vmem_altmap *altmap)
+{
+ unsigned long next;
+ pmd_t *pmdp, pmd;
+
+ do {
+ next = pmd_addr_end(addr, end);
+ pmdp = pmd_offset(pudp, addr);
+ pmd = READ_ONCE(*pmdp);
+ if (pmd_none(pmd))
+ continue;
+
+ WARN_ON(!pmd_present(pmd));
+ if (pmd_sect(pmd)) {
+ pmd_clear(pmdp);
+
+ /*
+ * One TLBI should be sufficient here as the PMD_SIZE
+ * range is mapped with a single block entry.
+ */
+ flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+ if (free_mapped)
+ free_hotplug_page_range(pmd_page(pmd),
+ PMD_SIZE, altmap);
+ continue;
+ }
+ WARN_ON(!pmd_table(pmd));
+ unmap_hotplug_pte_range(pmdp, addr, next, free_mapped, altmap);
+ } while (addr = next, addr < end);
+}
+
+static void unmap_hotplug_pud_range(p4d_t *p4dp, unsigned long addr,
+ unsigned long end, bool free_mapped,
+ struct vmem_altmap *altmap)
+{
+ unsigned long next;
+ pud_t *pudp, pud;
+
+ do {
+ next = pud_addr_end(addr, end);
+ pudp = pud_offset(p4dp, addr);
+ pud = READ_ONCE(*pudp);
+ if (pud_none(pud))
+ continue;
+
+ WARN_ON(!pud_present(pud));
+ if (pud_sect(pud)) {
+ pud_clear(pudp);
+
+ /*
+ * One TLBI should be sufficient here as the PUD_SIZE
+ * range is mapped with a single block entry.
+ */
+ flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+ if (free_mapped)
+ free_hotplug_page_range(pud_page(pud),
+ PUD_SIZE, altmap);
+ continue;
+ }
+ WARN_ON(!pud_table(pud));
+ unmap_hotplug_pmd_range(pudp, addr, next, free_mapped, altmap);
+ } while (addr = next, addr < end);
+}
+
+static void unmap_hotplug_p4d_range(pgd_t *pgdp, unsigned long addr,
+ unsigned long end, bool free_mapped,
+ struct vmem_altmap *altmap)
+{
+ unsigned long next;
+ p4d_t *p4dp, p4d;
+
+ do {
+ next = p4d_addr_end(addr, end);
+ p4dp = p4d_offset(pgdp, addr);
+ p4d = READ_ONCE(*p4dp);
+ if (p4d_none(p4d))
+ continue;
+
+ WARN_ON(!p4d_present(p4d));
+ unmap_hotplug_pud_range(p4dp, addr, next, free_mapped, altmap);
+ } while (addr = next, addr < end);
+}
+
+static void unmap_hotplug_range(unsigned long addr, unsigned long end,
+ bool free_mapped, struct vmem_altmap *altmap)
+{
+ unsigned long next;
+ pgd_t *pgdp, pgd;
+
+ /*
+ * altmap can only be used as vmemmap mapping backing memory.
+ * In case the backing memory itself is not being freed, then
+ * altmap is irrelevant. Warn about this inconsistency when
+ * encountered.
+ */
+ WARN_ON(!free_mapped && altmap);
+
+ do {
+ next = pgd_addr_end(addr, end);
+ pgdp = pgd_offset_k(addr);
+ pgd = READ_ONCE(*pgdp);
+ if (pgd_none(pgd))
+ continue;
+
+ WARN_ON(!pgd_present(pgd));
+ unmap_hotplug_p4d_range(pgdp, addr, next, free_mapped, altmap);
+ } while (addr = next, addr < end);
+}
+
+static void free_empty_pte_table(pmd_t *pmdp, unsigned long addr,
+ unsigned long end, unsigned long floor,
+ unsigned long ceiling)
+{
+ pte_t *ptep, pte;
+ unsigned long i, start = addr;
+
+ do {
+ ptep = pte_offset_kernel(pmdp, addr);
+ pte = READ_ONCE(*ptep);
+
+ /*
+ * This is just a sanity check here which verifies that
+ * pte clearing has been done by earlier unmap loops.
+ */
+ WARN_ON(!pte_none(pte));
+ } while (addr += PAGE_SIZE, addr < end);
+
+ if (!pgtable_range_aligned(start, end, floor, ceiling, PMD_MASK))
+ return;
+
+ /*
+ * Check whether we can free the pte page if the rest of the
+ * entries are empty. Overlap with other regions have been
+ * handled by the floor/ceiling check.
+ */
+ ptep = pte_offset_kernel(pmdp, 0UL);
+ for (i = 0; i < PTRS_PER_PTE; i++) {
+ if (!pte_none(READ_ONCE(ptep[i])))
+ return;
+ }
+
+ pmd_clear(pmdp);
+ __flush_tlb_kernel_pgtable(start);
+ free_hotplug_pgtable_page(virt_to_page(ptep));
+}
+
+static void free_empty_pmd_table(pud_t *pudp, unsigned long addr,
+ unsigned long end, unsigned long floor,
+ unsigned long ceiling)
+{
+ pmd_t *pmdp, pmd;
+ unsigned long i, next, start = addr;
+
+ do {
+ next = pmd_addr_end(addr, end);
+ pmdp = pmd_offset(pudp, addr);
+ pmd = READ_ONCE(*pmdp);
+ if (pmd_none(pmd))
+ continue;
+
+ WARN_ON(!pmd_present(pmd) || !pmd_table(pmd) || pmd_sect(pmd));
+ free_empty_pte_table(pmdp, addr, next, floor, ceiling);
+ } while (addr = next, addr < end);
+
+ if (CONFIG_PGTABLE_LEVELS <= 2)
+ return;
+
+ if (!pgtable_range_aligned(start, end, floor, ceiling, PUD_MASK))
+ return;
+
+ /*
+ * Check whether we can free the pmd page if the rest of the
+ * entries are empty. Overlap with other regions have been
+ * handled by the floor/ceiling check.
+ */
+ pmdp = pmd_offset(pudp, 0UL);
+ for (i = 0; i < PTRS_PER_PMD; i++) {
+ if (!pmd_none(READ_ONCE(pmdp[i])))
+ return;
+ }
+
+ pud_clear(pudp);
+ __flush_tlb_kernel_pgtable(start);
+ free_hotplug_pgtable_page(virt_to_page(pmdp));
+}
+
+static void free_empty_pud_table(p4d_t *p4dp, unsigned long addr,
+ unsigned long end, unsigned long floor,
+ unsigned long ceiling)
+{
+ pud_t *pudp, pud;
+ unsigned long i, next, start = addr;
+
+ do {
+ next = pud_addr_end(addr, end);
+ pudp = pud_offset(p4dp, addr);
+ pud = READ_ONCE(*pudp);
+ if (pud_none(pud))
+ continue;
+
+ WARN_ON(!pud_present(pud) || !pud_table(pud) || pud_sect(pud));
+ free_empty_pmd_table(pudp, addr, next, floor, ceiling);
+ } while (addr = next, addr < end);
+
+ if (CONFIG_PGTABLE_LEVELS <= 3)
+ return;
+
+ if (!pgtable_range_aligned(start, end, floor, ceiling, PGDIR_MASK))
+ return;
+
+ /*
+ * Check whether we can free the pud page if the rest of the
+ * entries are empty. Overlap with other regions have been
+ * handled by the floor/ceiling check.
+ */
+ pudp = pud_offset(p4dp, 0UL);
+ for (i = 0; i < PTRS_PER_PUD; i++) {
+ if (!pud_none(READ_ONCE(pudp[i])))
+ return;
+ }
+
+ p4d_clear(p4dp);
+ __flush_tlb_kernel_pgtable(start);
+ free_hotplug_pgtable_page(virt_to_page(pudp));
+}
+
+static void free_empty_p4d_table(pgd_t *pgdp, unsigned long addr,
+ unsigned long end, unsigned long floor,
+ unsigned long ceiling)
+{
+ unsigned long next;
+ p4d_t *p4dp, p4d;
+
+ do {
+ next = p4d_addr_end(addr, end);
+ p4dp = p4d_offset(pgdp, addr);
+ p4d = READ_ONCE(*p4dp);
+ if (p4d_none(p4d))
+ continue;
+
+ WARN_ON(!p4d_present(p4d));
+ free_empty_pud_table(p4dp, addr, next, floor, ceiling);
+ } while (addr = next, addr < end);
+}
+
+static void free_empty_tables(unsigned long addr, unsigned long end,
+ unsigned long floor, unsigned long ceiling)
+{
+ unsigned long next;
+ pgd_t *pgdp, pgd;
+
+ do {
+ next = pgd_addr_end(addr, end);
+ pgdp = pgd_offset_k(addr);
+ pgd = READ_ONCE(*pgdp);
+ if (pgd_none(pgd))
+ continue;
+
+ WARN_ON(!pgd_present(pgd));
+ free_empty_p4d_table(pgdp, addr, next, floor, ceiling);
+ } while (addr = next, addr < end);
+}
+#endif
+
+void __meminit vmemmap_set_pmd(pmd_t *pmdp, void *p, int node,
+ unsigned long addr, unsigned long next)
+{
+ pmd_set_huge(pmdp, __pa(p), __pgprot(PROT_SECT_NORMAL));
+}
+
+int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node,
+ unsigned long addr, unsigned long next)
+{
+ vmemmap_verify((pte_t *)pmdp, node, addr, next);
+ return 1;
+}
+
+int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
+ struct vmem_altmap *altmap)
+{
+ WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END));
+
+ if (!IS_ENABLED(CONFIG_ARM64_4K_PAGES))
+ return vmemmap_populate_basepages(start, end, node, altmap);
+ else
+ return vmemmap_populate_hugepages(start, end, node, altmap);
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+void vmemmap_free(unsigned long start, unsigned long end,
+ struct vmem_altmap *altmap)
+{
+ WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END));
+
+ unmap_hotplug_range(start, end, true, altmap);
+ free_empty_tables(start, end, VMEMMAP_START, VMEMMAP_END);
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot)
+{
+ pud_t new_pud = pfn_pud(__phys_to_pfn(phys), mk_pud_sect_prot(prot));
+
+ /* Only allow permission changes for now */
+ if (!pgattr_change_is_safe(READ_ONCE(pud_val(*pudp)),
+ pud_val(new_pud)))
+ return 0;
+
+ VM_BUG_ON(phys & ~PUD_MASK);
+ set_pud(pudp, new_pud);
+ return 1;
+}
+
+int pmd_set_huge(pmd_t *pmdp, phys_addr_t phys, pgprot_t prot)
+{
+ pmd_t new_pmd = pfn_pmd(__phys_to_pfn(phys), mk_pmd_sect_prot(prot));
+
+ /* Only allow permission changes for now */
+ if (!pgattr_change_is_safe(READ_ONCE(pmd_val(*pmdp)),
+ pmd_val(new_pmd)))
+ return 0;
+
+ VM_BUG_ON(phys & ~PMD_MASK);
+ set_pmd(pmdp, new_pmd);
+ return 1;
+}
+
+int pud_clear_huge(pud_t *pudp)
+{
+ if (!pud_sect(READ_ONCE(*pudp)))
+ return 0;
+ pud_clear(pudp);
+ return 1;
+}
+
+int pmd_clear_huge(pmd_t *pmdp)
+{
+ if (!pmd_sect(READ_ONCE(*pmdp)))
+ return 0;
+ pmd_clear(pmdp);
+ return 1;
+}
+
+int pmd_free_pte_page(pmd_t *pmdp, unsigned long addr)
+{
+ pte_t *table;
+ pmd_t pmd;
+
+ pmd = READ_ONCE(*pmdp);
+
+ if (!pmd_table(pmd)) {
+ VM_WARN_ON(1);
+ return 1;
+ }
+
+ table = pte_offset_kernel(pmdp, addr);
+ pmd_clear(pmdp);
+ __flush_tlb_kernel_pgtable(addr);
+ pte_free_kernel(NULL, table);
+ return 1;
+}
+
+int pud_free_pmd_page(pud_t *pudp, unsigned long addr)
+{
+ pmd_t *table;
+ pmd_t *pmdp;
+ pud_t pud;
+ unsigned long next, end;
+
+ pud = READ_ONCE(*pudp);
+
+ if (!pud_table(pud)) {
+ VM_WARN_ON(1);
+ return 1;
+ }
+
+ table = pmd_offset(pudp, addr);
+ pmdp = table;
+ next = addr;
+ end = addr + PUD_SIZE;
+ do {
+ pmd_free_pte_page(pmdp, next);
+ } while (pmdp++, next += PMD_SIZE, next != end);
+
+ pud_clear(pudp);
+ __flush_tlb_kernel_pgtable(addr);
+ pmd_free(NULL, table);
+ return 1;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static void __remove_pgd_mapping(pgd_t *pgdir, unsigned long start, u64 size)
+{
+ unsigned long end = start + size;
+
+ WARN_ON(pgdir != init_mm.pgd);
+ WARN_ON((start < PAGE_OFFSET) || (end > PAGE_END));
+
+ unmap_hotplug_range(start, end, false, NULL);
+ free_empty_tables(start, end, PAGE_OFFSET, PAGE_END);
+}
+
+struct range arch_get_mappable_range(void)
+{
+ struct range mhp_range;
+ u64 start_linear_pa = __pa(_PAGE_OFFSET(vabits_actual));
+ u64 end_linear_pa = __pa(PAGE_END - 1);
+
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
+ /*
+ * Check for a wrap, it is possible because of randomized linear
+ * mapping the start physical address is actually bigger than
+ * the end physical address. In this case set start to zero
+ * because [0, end_linear_pa] range must still be able to cover
+ * all addressable physical addresses.
+ */
+ if (start_linear_pa > end_linear_pa)
+ start_linear_pa = 0;
+ }
+
+ WARN_ON(start_linear_pa > end_linear_pa);
+
+ /*
+ * Linear mapping region is the range [PAGE_OFFSET..(PAGE_END - 1)]
+ * accommodating both its ends but excluding PAGE_END. Max physical
+ * range which can be mapped inside this linear mapping range, must
+ * also be derived from its end points.
+ */
+ mhp_range.start = start_linear_pa;
+ mhp_range.end = end_linear_pa;
+
+ return mhp_range;
+}
+
+int arch_add_memory(int nid, u64 start, u64 size,
+ struct mhp_params *params)
+{
+ int ret, flags = NO_EXEC_MAPPINGS;
+
+ VM_BUG_ON(!mhp_range_allowed(start, size, true));
+
+ if (can_set_direct_map())
+ flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS;
+
+ __create_pgd_mapping(swapper_pg_dir, start, __phys_to_virt(start),
+ size, params->pgprot, __pgd_pgtable_alloc,
+ flags);
+
+ memblock_clear_nomap(start, size);
+
+ ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT,
+ params);
+ if (ret)
+ __remove_pgd_mapping(swapper_pg_dir,
+ __phys_to_virt(start), size);
+ else {
+ max_pfn = PFN_UP(start + size);
+ max_low_pfn = max_pfn;
+ }
+
+ return ret;
+}
+
+void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap)
+{
+ unsigned long start_pfn = start >> PAGE_SHIFT;
+ unsigned long nr_pages = size >> PAGE_SHIFT;
+
+ __remove_pages(start_pfn, nr_pages, altmap);
+ __remove_pgd_mapping(swapper_pg_dir, __phys_to_virt(start), size);
+}
+
+/*
+ * This memory hotplug notifier helps prevent boot memory from being
+ * inadvertently removed as it blocks pfn range offlining process in
+ * __offline_pages(). Hence this prevents both offlining as well as
+ * removal process for boot memory which is initially always online.
+ * In future if and when boot memory could be removed, this notifier
+ * should be dropped and free_hotplug_page_range() should handle any
+ * reserved pages allocated during boot.
+ */
+static int prevent_bootmem_remove_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct mem_section *ms;
+ struct memory_notify *arg = data;
+ unsigned long end_pfn = arg->start_pfn + arg->nr_pages;
+ unsigned long pfn = arg->start_pfn;
+
+ if ((action != MEM_GOING_OFFLINE) && (action != MEM_OFFLINE))
+ return NOTIFY_OK;
+
+ for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ unsigned long start = PFN_PHYS(pfn);
+ unsigned long end = start + (1UL << PA_SECTION_SHIFT);
+
+ ms = __pfn_to_section(pfn);
+ if (!early_section(ms))
+ continue;
+
+ if (action == MEM_GOING_OFFLINE) {
+ /*
+ * Boot memory removal is not supported. Prevent
+ * it via blocking any attempted offline request
+ * for the boot memory and just report it.
+ */
+ pr_warn("Boot memory [%lx %lx] offlining attempted\n", start, end);
+ return NOTIFY_BAD;
+ } else if (action == MEM_OFFLINE) {
+ /*
+ * This should have never happened. Boot memory
+ * offlining should have been prevented by this
+ * very notifier. Probably some memory removal
+ * procedure might have changed which would then
+ * require further debug.
+ */
+ pr_err("Boot memory [%lx %lx] offlined\n", start, end);
+
+ /*
+ * Core memory hotplug does not process a return
+ * code from the notifier for MEM_OFFLINE events.
+ * The error condition has been reported. Return
+ * from here as if ignored.
+ */
+ return NOTIFY_DONE;
+ }
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block prevent_bootmem_remove_nb = {
+ .notifier_call = prevent_bootmem_remove_notifier,
+};
+
+/*
+ * This ensures that boot memory sections on the platform are online
+ * from early boot. Memory sections could not be prevented from being
+ * offlined, unless for some reason they are not online to begin with.
+ * This helps validate the basic assumption on which the above memory
+ * event notifier works to prevent boot memory section offlining and
+ * its possible removal.
+ */
+static void validate_bootmem_online(void)
+{
+ phys_addr_t start, end, addr;
+ struct mem_section *ms;
+ u64 i;
+
+ /*
+ * Scanning across all memblock might be expensive
+ * on some big memory systems. Hence enable this
+ * validation only with DEBUG_VM.
+ */
+ if (!IS_ENABLED(CONFIG_DEBUG_VM))
+ return;
+
+ for_each_mem_range(i, &start, &end) {
+ for (addr = start; addr < end; addr += (1UL << PA_SECTION_SHIFT)) {
+ ms = __pfn_to_section(PHYS_PFN(addr));
+
+ /*
+ * All memory ranges in the system at this point
+ * should have been marked as early sections.
+ */
+ WARN_ON(!early_section(ms));
+
+ /*
+ * Memory notifier mechanism here to prevent boot
+ * memory offlining depends on the fact that each
+ * early section memory on the system is initially
+ * online. Otherwise a given memory section which
+ * is already offline will be overlooked and can
+ * be removed completely. Call out such sections.
+ */
+ if (!online_section(ms))
+ pr_err("Boot memory [%llx %llx] is offline, can be removed\n",
+ addr, addr + (1UL << PA_SECTION_SHIFT));
+ }
+ }
+}
+
+static int __init prevent_bootmem_remove_init(void)
+{
+ int ret = 0;
+
+ if (!IS_ENABLED(CONFIG_MEMORY_HOTREMOVE))
+ return ret;
+
+ validate_bootmem_online();
+ ret = register_memory_notifier(&prevent_bootmem_remove_nb);
+ if (ret)
+ pr_err("%s: Notifier registration failed %d\n", __func__, ret);
+
+ return ret;
+}
+early_initcall(prevent_bootmem_remove_init);
+#endif
+
+pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
+{
+ if (IS_ENABLED(CONFIG_ARM64_ERRATUM_2645198) &&
+ cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
+ /*
+ * Break-before-make (BBM) is required for all user space mappings
+ * when the permission changes from executable to non-executable
+ * in cases where cpu is affected with errata #2645198.
+ */
+ if (pte_user_exec(READ_ONCE(*ptep)))
+ return ptep_clear_flush(vma, addr, ptep);
+ }
+ return ptep_get_and_clear(vma->vm_mm, addr, ptep);
+}
+
+void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
+ pte_t old_pte, pte_t pte)
+{
+ set_pte_at(vma->vm_mm, addr, ptep, pte);
+}
diff --git a/arch/arm64/mm/mteswap.c b/arch/arm64/mm/mteswap.c
new file mode 100644
index 0000000000..a31833e3dd
--- /dev/null
+++ b/arch/arm64/mm/mteswap.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/pagemap.h>
+#include <linux/xarray.h>
+#include <linux/slab.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <asm/mte.h>
+
+static DEFINE_XARRAY(mte_pages);
+
+void *mte_allocate_tag_storage(void)
+{
+ /* tags granule is 16 bytes, 2 tags stored per byte */
+ return kmalloc(MTE_PAGE_TAG_STORAGE, GFP_KERNEL);
+}
+
+void mte_free_tag_storage(char *storage)
+{
+ kfree(storage);
+}
+
+int mte_save_tags(struct page *page)
+{
+ void *tag_storage, *ret;
+
+ if (!page_mte_tagged(page))
+ return 0;
+
+ tag_storage = mte_allocate_tag_storage();
+ if (!tag_storage)
+ return -ENOMEM;
+
+ mte_save_page_tags(page_address(page), tag_storage);
+
+ /* lookup the swap entry.val from the page */
+ ret = xa_store(&mte_pages, page_swap_entry(page).val, tag_storage,
+ GFP_KERNEL);
+ if (WARN(xa_is_err(ret), "Failed to store MTE tags")) {
+ mte_free_tag_storage(tag_storage);
+ return xa_err(ret);
+ } else if (ret) {
+ /* Entry is being replaced, free the old entry */
+ mte_free_tag_storage(ret);
+ }
+
+ return 0;
+}
+
+void mte_restore_tags(swp_entry_t entry, struct page *page)
+{
+ void *tags = xa_load(&mte_pages, entry.val);
+
+ if (!tags)
+ return;
+
+ if (try_page_mte_tagging(page)) {
+ mte_restore_page_tags(page_address(page), tags);
+ set_page_mte_tagged(page);
+ }
+}
+
+void mte_invalidate_tags(int type, pgoff_t offset)
+{
+ swp_entry_t entry = swp_entry(type, offset);
+ void *tags = xa_erase(&mte_pages, entry.val);
+
+ mte_free_tag_storage(tags);
+}
+
+void mte_invalidate_tags_area(int type)
+{
+ swp_entry_t entry = swp_entry(type, 0);
+ swp_entry_t last_entry = swp_entry(type + 1, 0);
+ void *tags;
+
+ XA_STATE(xa_state, &mte_pages, entry.val);
+
+ xa_lock(&mte_pages);
+ xas_for_each(&xa_state, tags, last_entry.val - 1) {
+ __xa_erase(&mte_pages, xa_state.xa_index);
+ mte_free_tag_storage(tags);
+ }
+ xa_unlock(&mte_pages);
+}
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
new file mode 100644
index 0000000000..924843f1f6
--- /dev/null
+++ b/arch/arm64/mm/pageattr.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ */
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/vmalloc.h>
+
+#include <asm/cacheflush.h>
+#include <asm/set_memory.h>
+#include <asm/tlbflush.h>
+#include <asm/kfence.h>
+
+struct page_change_data {
+ pgprot_t set_mask;
+ pgprot_t clear_mask;
+};
+
+bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED);
+
+bool can_set_direct_map(void)
+{
+ /*
+ * rodata_full and DEBUG_PAGEALLOC require linear map to be
+ * mapped at page granularity, so that it is possible to
+ * protect/unprotect single pages.
+ *
+ * KFENCE pool requires page-granular mapping if initialized late.
+ */
+ return rodata_full || debug_pagealloc_enabled() ||
+ arm64_kfence_can_set_direct_map();
+}
+
+static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
+{
+ struct page_change_data *cdata = data;
+ pte_t pte = READ_ONCE(*ptep);
+
+ pte = clear_pte_bit(pte, cdata->clear_mask);
+ pte = set_pte_bit(pte, cdata->set_mask);
+
+ set_pte(ptep, pte);
+ return 0;
+}
+
+/*
+ * This function assumes that the range is mapped with PAGE_SIZE pages.
+ */
+static int __change_memory_common(unsigned long start, unsigned long size,
+ pgprot_t set_mask, pgprot_t clear_mask)
+{
+ struct page_change_data data;
+ int ret;
+
+ data.set_mask = set_mask;
+ data.clear_mask = clear_mask;
+
+ ret = apply_to_page_range(&init_mm, start, size, change_page_range,
+ &data);
+
+ flush_tlb_kernel_range(start, start + size);
+ return ret;
+}
+
+static int change_memory_common(unsigned long addr, int numpages,
+ pgprot_t set_mask, pgprot_t clear_mask)
+{
+ unsigned long start = addr;
+ unsigned long size = PAGE_SIZE * numpages;
+ unsigned long end = start + size;
+ struct vm_struct *area;
+ int i;
+
+ if (!PAGE_ALIGNED(addr)) {
+ start &= PAGE_MASK;
+ end = start + size;
+ WARN_ON_ONCE(1);
+ }
+
+ /*
+ * Kernel VA mappings are always live, and splitting live section
+ * mappings into page mappings may cause TLB conflicts. This means
+ * we have to ensure that changing the permission bits of the range
+ * we are operating on does not result in such splitting.
+ *
+ * Let's restrict ourselves to mappings created by vmalloc (or vmap).
+ * Those are guaranteed to consist entirely of page mappings, and
+ * splitting is never needed.
+ *
+ * So check whether the [addr, addr + size) interval is entirely
+ * covered by precisely one VM area that has the VM_ALLOC flag set.
+ */
+ area = find_vm_area((void *)addr);
+ if (!area ||
+ end > (unsigned long)kasan_reset_tag(area->addr) + area->size ||
+ !(area->flags & VM_ALLOC))
+ return -EINVAL;
+
+ if (!numpages)
+ return 0;
+
+ /*
+ * If we are manipulating read-only permissions, apply the same
+ * change to the linear mapping of the pages that back this VM area.
+ */
+ if (rodata_full && (pgprot_val(set_mask) == PTE_RDONLY ||
+ pgprot_val(clear_mask) == PTE_RDONLY)) {
+ for (i = 0; i < area->nr_pages; i++) {
+ __change_memory_common((u64)page_address(area->pages[i]),
+ PAGE_SIZE, set_mask, clear_mask);
+ }
+ }
+
+ /*
+ * Get rid of potentially aliasing lazily unmapped vm areas that may
+ * have permissions set that deviate from the ones we are setting here.
+ */
+ vm_unmap_aliases();
+
+ return __change_memory_common(start, size, set_mask, clear_mask);
+}
+
+int set_memory_ro(unsigned long addr, int numpages)
+{
+ return change_memory_common(addr, numpages,
+ __pgprot(PTE_RDONLY),
+ __pgprot(PTE_WRITE));
+}
+
+int set_memory_rw(unsigned long addr, int numpages)
+{
+ return change_memory_common(addr, numpages,
+ __pgprot(PTE_WRITE),
+ __pgprot(PTE_RDONLY));
+}
+
+int set_memory_nx(unsigned long addr, int numpages)
+{
+ return change_memory_common(addr, numpages,
+ __pgprot(PTE_PXN),
+ __pgprot(PTE_MAYBE_GP));
+}
+
+int set_memory_x(unsigned long addr, int numpages)
+{
+ return change_memory_common(addr, numpages,
+ __pgprot(PTE_MAYBE_GP),
+ __pgprot(PTE_PXN));
+}
+
+int set_memory_valid(unsigned long addr, int numpages, int enable)
+{
+ if (enable)
+ return __change_memory_common(addr, PAGE_SIZE * numpages,
+ __pgprot(PTE_VALID),
+ __pgprot(0));
+ else
+ return __change_memory_common(addr, PAGE_SIZE * numpages,
+ __pgprot(0),
+ __pgprot(PTE_VALID));
+}
+
+int set_direct_map_invalid_noflush(struct page *page)
+{
+ struct page_change_data data = {
+ .set_mask = __pgprot(0),
+ .clear_mask = __pgprot(PTE_VALID),
+ };
+
+ if (!can_set_direct_map())
+ return 0;
+
+ return apply_to_page_range(&init_mm,
+ (unsigned long)page_address(page),
+ PAGE_SIZE, change_page_range, &data);
+}
+
+int set_direct_map_default_noflush(struct page *page)
+{
+ struct page_change_data data = {
+ .set_mask = __pgprot(PTE_VALID | PTE_WRITE),
+ .clear_mask = __pgprot(PTE_RDONLY),
+ };
+
+ if (!can_set_direct_map())
+ return 0;
+
+ return apply_to_page_range(&init_mm,
+ (unsigned long)page_address(page),
+ PAGE_SIZE, change_page_range, &data);
+}
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+void __kernel_map_pages(struct page *page, int numpages, int enable)
+{
+ if (!can_set_direct_map())
+ return;
+
+ set_memory_valid((unsigned long)page_address(page), numpages, enable);
+}
+#endif /* CONFIG_DEBUG_PAGEALLOC */
+
+/*
+ * This function is used to determine if a linear map page has been marked as
+ * not-valid. Walk the page table and check the PTE_VALID bit.
+ *
+ * Because this is only called on the kernel linear map, p?d_sect() implies
+ * p?d_present(). When debug_pagealloc is enabled, sections mappings are
+ * disabled.
+ */
+bool kernel_page_present(struct page *page)
+{
+ pgd_t *pgdp;
+ p4d_t *p4dp;
+ pud_t *pudp, pud;
+ pmd_t *pmdp, pmd;
+ pte_t *ptep;
+ unsigned long addr = (unsigned long)page_address(page);
+
+ if (!can_set_direct_map())
+ return true;
+
+ pgdp = pgd_offset_k(addr);
+ if (pgd_none(READ_ONCE(*pgdp)))
+ return false;
+
+ p4dp = p4d_offset(pgdp, addr);
+ if (p4d_none(READ_ONCE(*p4dp)))
+ return false;
+
+ pudp = pud_offset(p4dp, addr);
+ pud = READ_ONCE(*pudp);
+ if (pud_none(pud))
+ return false;
+ if (pud_sect(pud))
+ return true;
+
+ pmdp = pmd_offset(pudp, addr);
+ pmd = READ_ONCE(*pmdp);
+ if (pmd_none(pmd))
+ return false;
+ if (pmd_sect(pmd))
+ return true;
+
+ ptep = pte_offset_kernel(pmdp, addr);
+ return pte_valid(READ_ONCE(*ptep));
+}
diff --git a/arch/arm64/mm/pgd.c b/arch/arm64/mm/pgd.c
new file mode 100644
index 0000000000..4a64089e57
--- /dev/null
+++ b/arch/arm64/mm/pgd.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PGD allocation/freeing
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Catalin Marinas <catalin.marinas@arm.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+
+#include <asm/pgalloc.h>
+#include <asm/page.h>
+#include <asm/tlbflush.h>
+
+static struct kmem_cache *pgd_cache __ro_after_init;
+
+pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+ gfp_t gfp = GFP_PGTABLE_USER;
+
+ if (PGD_SIZE == PAGE_SIZE)
+ return (pgd_t *)__get_free_page(gfp);
+ else
+ return kmem_cache_alloc(pgd_cache, gfp);
+}
+
+void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+ if (PGD_SIZE == PAGE_SIZE)
+ free_page((unsigned long)pgd);
+ else
+ kmem_cache_free(pgd_cache, pgd);
+}
+
+void __init pgtable_cache_init(void)
+{
+ if (PGD_SIZE == PAGE_SIZE)
+ return;
+
+#ifdef CONFIG_ARM64_PA_BITS_52
+ /*
+ * With 52-bit physical addresses, the architecture requires the
+ * top-level table to be aligned to at least 64 bytes.
+ */
+ BUILD_BUG_ON(PGD_SIZE < 64);
+#endif
+
+ /*
+ * Naturally aligned pgds required by the architecture.
+ */
+ pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_SIZE,
+ SLAB_PANIC, NULL);
+}
diff --git a/arch/arm64/mm/physaddr.c b/arch/arm64/mm/physaddr.c
new file mode 100644
index 0000000000..cde44c13dd
--- /dev/null
+++ b/arch/arm64/mm/physaddr.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bug.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/mmdebug.h>
+#include <linux/mm.h>
+
+#include <asm/memory.h>
+
+phys_addr_t __virt_to_phys(unsigned long x)
+{
+ WARN(!__is_lm_address(__tag_reset(x)),
+ "virt_to_phys used for non-linear address: %pK (%pS)\n",
+ (void *)x,
+ (void *)x);
+
+ return __virt_to_phys_nodebug(x);
+}
+EXPORT_SYMBOL(__virt_to_phys);
+
+phys_addr_t __phys_addr_symbol(unsigned long x)
+{
+ /*
+ * This is bounds checking against the kernel image only.
+ * __pa_symbol should only be used on kernel symbol addresses.
+ */
+ VIRTUAL_BUG_ON(x < (unsigned long) KERNEL_START ||
+ x > (unsigned long) KERNEL_END);
+ return __pa_symbol_nodebug(x);
+}
+EXPORT_SYMBOL(__phys_addr_symbol);
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
new file mode 100644
index 0000000000..14fdf645ed
--- /dev/null
+++ b/arch/arm64/mm/proc.S
@@ -0,0 +1,480 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Based on arch/arm/mm/proc.S
+ *
+ * Copyright (C) 2001 Deep Blue Solutions Ltd.
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Catalin Marinas <catalin.marinas@arm.com>
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/pgtable.h>
+#include <linux/cfi_types.h>
+#include <asm/assembler.h>
+#include <asm/asm-offsets.h>
+#include <asm/asm_pointer_auth.h>
+#include <asm/hwcap.h>
+#include <asm/kernel-pgtable.h>
+#include <asm/pgtable-hwdef.h>
+#include <asm/cpufeature.h>
+#include <asm/alternative.h>
+#include <asm/smp.h>
+#include <asm/sysreg.h>
+
+#ifdef CONFIG_ARM64_64K_PAGES
+#define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K
+#elif defined(CONFIG_ARM64_16K_PAGES)
+#define TCR_TG_FLAGS TCR_TG0_16K | TCR_TG1_16K
+#else /* CONFIG_ARM64_4K_PAGES */
+#define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K
+#endif
+
+#ifdef CONFIG_RANDOMIZE_BASE
+#define TCR_KASLR_FLAGS TCR_NFD1
+#else
+#define TCR_KASLR_FLAGS 0
+#endif
+
+#define TCR_SMP_FLAGS TCR_SHARED
+
+/* PTWs cacheable, inner/outer WBWA */
+#define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA
+
+#ifdef CONFIG_KASAN_SW_TAGS
+#define TCR_KASAN_SW_FLAGS TCR_TBI1 | TCR_TBID1
+#else
+#define TCR_KASAN_SW_FLAGS 0
+#endif
+
+#ifdef CONFIG_KASAN_HW_TAGS
+#define TCR_MTE_FLAGS TCR_TCMA1 | TCR_TBI1 | TCR_TBID1
+#elif defined(CONFIG_ARM64_MTE)
+/*
+ * The mte_zero_clear_page_tags() implementation uses DC GZVA, which relies on
+ * TBI being enabled at EL1.
+ */
+#define TCR_MTE_FLAGS TCR_TBI1 | TCR_TBID1
+#else
+#define TCR_MTE_FLAGS 0
+#endif
+
+/*
+ * Default MAIR_EL1. MT_NORMAL_TAGGED is initially mapped as Normal memory and
+ * changed during mte_cpu_setup to Normal Tagged if the system supports MTE.
+ */
+#define MAIR_EL1_SET \
+ (MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRnE, MT_DEVICE_nGnRnE) | \
+ MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRE, MT_DEVICE_nGnRE) | \
+ MAIR_ATTRIDX(MAIR_ATTR_NORMAL_NC, MT_NORMAL_NC) | \
+ MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL) | \
+ MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL_TAGGED))
+
+#ifdef CONFIG_CPU_PM
+/**
+ * cpu_do_suspend - save CPU registers context
+ *
+ * x0: virtual address of context pointer
+ *
+ * This must be kept in sync with struct cpu_suspend_ctx in <asm/suspend.h>.
+ */
+SYM_FUNC_START(cpu_do_suspend)
+ mrs x2, tpidr_el0
+ mrs x3, tpidrro_el0
+ mrs x4, contextidr_el1
+ mrs x5, osdlr_el1
+ mrs x6, cpacr_el1
+ mrs x7, tcr_el1
+ mrs x8, vbar_el1
+ mrs x9, mdscr_el1
+ mrs x10, oslsr_el1
+ mrs x11, sctlr_el1
+ get_this_cpu_offset x12
+ mrs x13, sp_el0
+ stp x2, x3, [x0]
+ stp x4, x5, [x0, #16]
+ stp x6, x7, [x0, #32]
+ stp x8, x9, [x0, #48]
+ stp x10, x11, [x0, #64]
+ stp x12, x13, [x0, #80]
+ /*
+ * Save x18 as it may be used as a platform register, e.g. by shadow
+ * call stack.
+ */
+ str x18, [x0, #96]
+ ret
+SYM_FUNC_END(cpu_do_suspend)
+
+/**
+ * cpu_do_resume - restore CPU register context
+ *
+ * x0: Address of context pointer
+ */
+SYM_FUNC_START(cpu_do_resume)
+ ldp x2, x3, [x0]
+ ldp x4, x5, [x0, #16]
+ ldp x6, x8, [x0, #32]
+ ldp x9, x10, [x0, #48]
+ ldp x11, x12, [x0, #64]
+ ldp x13, x14, [x0, #80]
+ /*
+ * Restore x18, as it may be used as a platform register, and clear
+ * the buffer to minimize the risk of exposure when used for shadow
+ * call stack.
+ */
+ ldr x18, [x0, #96]
+ str xzr, [x0, #96]
+ msr tpidr_el0, x2
+ msr tpidrro_el0, x3
+ msr contextidr_el1, x4
+ msr cpacr_el1, x6
+
+ /* Don't change t0sz here, mask those bits when restoring */
+ mrs x7, tcr_el1
+ bfi x8, x7, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
+
+ msr tcr_el1, x8
+ msr vbar_el1, x9
+
+ /*
+ * __cpu_setup() cleared MDSCR_EL1.MDE and friends, before unmasking
+ * debug exceptions. By restoring MDSCR_EL1 here, we may take a debug
+ * exception. Mask them until local_daif_restore() in cpu_suspend()
+ * resets them.
+ */
+ disable_daif
+ msr mdscr_el1, x10
+
+ msr sctlr_el1, x12
+ set_this_cpu_offset x13
+ msr sp_el0, x14
+ /*
+ * Restore oslsr_el1 by writing oslar_el1
+ */
+ msr osdlr_el1, x5
+ ubfx x11, x11, #1, #1
+ msr oslar_el1, x11
+ reset_pmuserenr_el0 x0 // Disable PMU access from EL0
+ reset_amuserenr_el0 x0 // Disable AMU access from EL0
+
+alternative_if ARM64_HAS_RAS_EXTN
+ msr_s SYS_DISR_EL1, xzr
+alternative_else_nop_endif
+
+ ptrauth_keys_install_kernel_nosync x14, x1, x2, x3
+ isb
+ ret
+SYM_FUNC_END(cpu_do_resume)
+#endif
+
+ .pushsection ".idmap.text", "a"
+
+.macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2
+ adrp \tmp1, reserved_pg_dir
+ phys_to_ttbr \tmp2, \tmp1
+ offset_ttbr1 \tmp2, \tmp1
+ msr ttbr1_el1, \tmp2
+ isb
+ tlbi vmalle1
+ dsb nsh
+ isb
+.endm
+
+/*
+ * void idmap_cpu_replace_ttbr1(phys_addr_t ttbr1)
+ *
+ * This is the low-level counterpart to cpu_replace_ttbr1, and should not be
+ * called by anything else. It can only be executed from a TTBR0 mapping.
+ */
+SYM_TYPED_FUNC_START(idmap_cpu_replace_ttbr1)
+ __idmap_cpu_set_reserved_ttbr1 x1, x3
+
+ offset_ttbr1 x0, x3
+ msr ttbr1_el1, x0
+ isb
+
+ ret
+SYM_FUNC_END(idmap_cpu_replace_ttbr1)
+ .popsection
+
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+
+#define KPTI_NG_PTE_FLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS | PTE_WRITE)
+
+ .pushsection ".idmap.text", "a"
+
+ .macro kpti_mk_tbl_ng, type, num_entries
+ add end_\type\()p, cur_\type\()p, #\num_entries * 8
+.Ldo_\type:
+ ldr \type, [cur_\type\()p] // Load the entry
+ tbz \type, #0, .Lnext_\type // Skip invalid and
+ tbnz \type, #11, .Lnext_\type // non-global entries
+ orr \type, \type, #PTE_NG // Same bit for blocks and pages
+ str \type, [cur_\type\()p] // Update the entry
+ .ifnc \type, pte
+ tbnz \type, #1, .Lderef_\type
+ .endif
+.Lnext_\type:
+ add cur_\type\()p, cur_\type\()p, #8
+ cmp cur_\type\()p, end_\type\()p
+ b.ne .Ldo_\type
+ .endm
+
+ /*
+ * Dereference the current table entry and map it into the temporary
+ * fixmap slot associated with the current level.
+ */
+ .macro kpti_map_pgtbl, type, level
+ str xzr, [temp_pte, #8 * (\level + 1)] // break before make
+ dsb nshst
+ add pte, temp_pte, #PAGE_SIZE * (\level + 1)
+ lsr pte, pte, #12
+ tlbi vaae1, pte
+ dsb nsh
+ isb
+
+ phys_to_pte pte, cur_\type\()p
+ add cur_\type\()p, temp_pte, #PAGE_SIZE * (\level + 1)
+ orr pte, pte, pte_flags
+ str pte, [temp_pte, #8 * (\level + 1)]
+ dsb nshst
+ .endm
+
+/*
+ * void __kpti_install_ng_mappings(int cpu, int num_secondaries, phys_addr_t temp_pgd,
+ * unsigned long temp_pte_va)
+ *
+ * Called exactly once from stop_machine context by each CPU found during boot.
+ */
+ .pushsection ".data", "aw", %progbits
+SYM_DATA(__idmap_kpti_flag, .long 1)
+ .popsection
+
+SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings)
+ cpu .req w0
+ temp_pte .req x0
+ num_cpus .req w1
+ pte_flags .req x1
+ temp_pgd_phys .req x2
+ swapper_ttb .req x3
+ flag_ptr .req x4
+ cur_pgdp .req x5
+ end_pgdp .req x6
+ pgd .req x7
+ cur_pudp .req x8
+ end_pudp .req x9
+ cur_pmdp .req x11
+ end_pmdp .req x12
+ cur_ptep .req x14
+ end_ptep .req x15
+ pte .req x16
+ valid .req x17
+
+ mov x5, x3 // preserve temp_pte arg
+ mrs swapper_ttb, ttbr1_el1
+ adr_l flag_ptr, __idmap_kpti_flag
+
+ cbnz cpu, __idmap_kpti_secondary
+
+ /* We're the boot CPU. Wait for the others to catch up */
+ sevl
+1: wfe
+ ldaxr w17, [flag_ptr]
+ eor w17, w17, num_cpus
+ cbnz w17, 1b
+
+ /* Switch to the temporary page tables on this CPU only */
+ __idmap_cpu_set_reserved_ttbr1 x8, x9
+ offset_ttbr1 temp_pgd_phys, x8
+ msr ttbr1_el1, temp_pgd_phys
+ isb
+
+ mov temp_pte, x5
+ mov_q pte_flags, KPTI_NG_PTE_FLAGS
+
+ /* Everybody is enjoying the idmap, so we can rewrite swapper. */
+ /* PGD */
+ adrp cur_pgdp, swapper_pg_dir
+ kpti_map_pgtbl pgd, 0
+ kpti_mk_tbl_ng pgd, PTRS_PER_PGD
+
+ /* Ensure all the updated entries are visible to secondary CPUs */
+ dsb ishst
+
+ /* We're done: fire up swapper_pg_dir again */
+ __idmap_cpu_set_reserved_ttbr1 x8, x9
+ msr ttbr1_el1, swapper_ttb
+ isb
+
+ /* Set the flag to zero to indicate that we're all done */
+ str wzr, [flag_ptr]
+ ret
+
+.Lderef_pgd:
+ /* PUD */
+ .if CONFIG_PGTABLE_LEVELS > 3
+ pud .req x10
+ pte_to_phys cur_pudp, pgd
+ kpti_map_pgtbl pud, 1
+ kpti_mk_tbl_ng pud, PTRS_PER_PUD
+ b .Lnext_pgd
+ .else /* CONFIG_PGTABLE_LEVELS <= 3 */
+ pud .req pgd
+ .set .Lnext_pud, .Lnext_pgd
+ .endif
+
+.Lderef_pud:
+ /* PMD */
+ .if CONFIG_PGTABLE_LEVELS > 2
+ pmd .req x13
+ pte_to_phys cur_pmdp, pud
+ kpti_map_pgtbl pmd, 2
+ kpti_mk_tbl_ng pmd, PTRS_PER_PMD
+ b .Lnext_pud
+ .else /* CONFIG_PGTABLE_LEVELS <= 2 */
+ pmd .req pgd
+ .set .Lnext_pmd, .Lnext_pgd
+ .endif
+
+.Lderef_pmd:
+ /* PTE */
+ pte_to_phys cur_ptep, pmd
+ kpti_map_pgtbl pte, 3
+ kpti_mk_tbl_ng pte, PTRS_PER_PTE
+ b .Lnext_pmd
+
+ .unreq cpu
+ .unreq temp_pte
+ .unreq num_cpus
+ .unreq pte_flags
+ .unreq temp_pgd_phys
+ .unreq cur_pgdp
+ .unreq end_pgdp
+ .unreq pgd
+ .unreq cur_pudp
+ .unreq end_pudp
+ .unreq pud
+ .unreq cur_pmdp
+ .unreq end_pmdp
+ .unreq pmd
+ .unreq cur_ptep
+ .unreq end_ptep
+ .unreq pte
+ .unreq valid
+
+ /* Secondary CPUs end up here */
+__idmap_kpti_secondary:
+ /* Uninstall swapper before surgery begins */
+ __idmap_cpu_set_reserved_ttbr1 x16, x17
+
+ /* Increment the flag to let the boot CPU we're ready */
+1: ldxr w16, [flag_ptr]
+ add w16, w16, #1
+ stxr w17, w16, [flag_ptr]
+ cbnz w17, 1b
+
+ /* Wait for the boot CPU to finish messing around with swapper */
+ sevl
+1: wfe
+ ldxr w16, [flag_ptr]
+ cbnz w16, 1b
+
+ /* All done, act like nothing happened */
+ msr ttbr1_el1, swapper_ttb
+ isb
+ ret
+
+ .unreq swapper_ttb
+ .unreq flag_ptr
+SYM_FUNC_END(idmap_kpti_install_ng_mappings)
+ .popsection
+#endif
+
+/*
+ * __cpu_setup
+ *
+ * Initialise the processor for turning the MMU on.
+ *
+ * Input:
+ * x0 - actual number of VA bits (ignored unless VA_BITS > 48)
+ * Output:
+ * Return in x0 the value of the SCTLR_EL1 register.
+ */
+ .pushsection ".idmap.text", "a"
+SYM_FUNC_START(__cpu_setup)
+ tlbi vmalle1 // Invalidate local TLB
+ dsb nsh
+
+ mov x1, #3 << 20
+ msr cpacr_el1, x1 // Enable FP/ASIMD
+ mov x1, #1 << 12 // Reset mdscr_el1 and disable
+ msr mdscr_el1, x1 // access to the DCC from EL0
+ isb // Unmask debug exceptions now,
+ enable_dbg // since this is per-cpu
+ reset_pmuserenr_el0 x1 // Disable PMU access from EL0
+ reset_amuserenr_el0 x1 // Disable AMU access from EL0
+
+ /*
+ * Default values for VMSA control registers. These will be adjusted
+ * below depending on detected CPU features.
+ */
+ mair .req x17
+ tcr .req x16
+ mov_q mair, MAIR_EL1_SET
+ mov_q tcr, TCR_TxSZ(VA_BITS) | TCR_CACHE_FLAGS | TCR_SMP_FLAGS | \
+ TCR_TG_FLAGS | TCR_KASLR_FLAGS | TCR_ASID16 | \
+ TCR_TBI0 | TCR_A1 | TCR_KASAN_SW_FLAGS | TCR_MTE_FLAGS
+
+ tcr_clear_errata_bits tcr, x9, x5
+
+#ifdef CONFIG_ARM64_VA_BITS_52
+ sub x9, xzr, x0
+ add x9, x9, #64
+ tcr_set_t1sz tcr, x9
+#else
+ idmap_get_t0sz x9
+#endif
+ tcr_set_t0sz tcr, x9
+
+ /*
+ * Set the IPS bits in TCR_EL1.
+ */
+ tcr_compute_pa_size tcr, #TCR_IPS_SHIFT, x5, x6
+#ifdef CONFIG_ARM64_HW_AFDBM
+ /*
+ * Enable hardware update of the Access Flags bit.
+ * Hardware dirty bit management is enabled later,
+ * via capabilities.
+ */
+ mrs x9, ID_AA64MMFR1_EL1
+ and x9, x9, ID_AA64MMFR1_EL1_HAFDBS_MASK
+ cbz x9, 1f
+ orr tcr, tcr, #TCR_HA // hardware Access flag update
+1:
+#endif /* CONFIG_ARM64_HW_AFDBM */
+ msr mair_el1, mair
+ msr tcr_el1, tcr
+
+ mrs_s x1, SYS_ID_AA64MMFR3_EL1
+ ubfx x1, x1, #ID_AA64MMFR3_EL1_S1PIE_SHIFT, #4
+ cbz x1, .Lskip_indirection
+
+ mov_q x0, PIE_E0
+ msr REG_PIRE0_EL1, x0
+ mov_q x0, PIE_E1
+ msr REG_PIR_EL1, x0
+
+ mov x0, TCR2_EL1x_PIE
+ msr REG_TCR2_EL1, x0
+
+.Lskip_indirection:
+
+ /*
+ * Prepare SCTLR
+ */
+ mov_q x0, INIT_SCTLR_EL1_MMU_ON
+ ret // return to head.S
+
+ .unreq mair
+ .unreq tcr
+SYM_FUNC_END(__cpu_setup)
diff --git a/arch/arm64/mm/ptdump.c b/arch/arm64/mm/ptdump.c
new file mode 100644
index 0000000000..e305b6593c
--- /dev/null
+++ b/arch/arm64/mm/ptdump.c
@@ -0,0 +1,386 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ * Debug helper to dump the current kernel pagetables of the system
+ * so that we can see what the various memory ranges are set to.
+ *
+ * Derived from x86 and arm implementation:
+ * (C) Copyright 2008 Intel Corporation
+ *
+ * Author: Arjan van de Ven <arjan@linux.intel.com>
+ */
+#include <linux/debugfs.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/ptdump.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+
+#include <asm/fixmap.h>
+#include <asm/kasan.h>
+#include <asm/memory.h>
+#include <asm/pgtable-hwdef.h>
+#include <asm/ptdump.h>
+
+
+enum address_markers_idx {
+ PAGE_OFFSET_NR = 0,
+ PAGE_END_NR,
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+ KASAN_START_NR,
+#endif
+};
+
+static struct addr_marker address_markers[] = {
+ { PAGE_OFFSET, "Linear Mapping start" },
+ { 0 /* PAGE_END */, "Linear Mapping end" },
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+ { 0 /* KASAN_SHADOW_START */, "Kasan shadow start" },
+ { KASAN_SHADOW_END, "Kasan shadow end" },
+#endif
+ { MODULES_VADDR, "Modules start" },
+ { MODULES_END, "Modules end" },
+ { VMALLOC_START, "vmalloc() area" },
+ { VMALLOC_END, "vmalloc() end" },
+ { FIXADDR_TOT_START, "Fixmap start" },
+ { FIXADDR_TOP, "Fixmap end" },
+ { PCI_IO_START, "PCI I/O start" },
+ { PCI_IO_END, "PCI I/O end" },
+ { VMEMMAP_START, "vmemmap start" },
+ { VMEMMAP_START + VMEMMAP_SIZE, "vmemmap end" },
+ { -1, NULL },
+};
+
+#define pt_dump_seq_printf(m, fmt, args...) \
+({ \
+ if (m) \
+ seq_printf(m, fmt, ##args); \
+})
+
+#define pt_dump_seq_puts(m, fmt) \
+({ \
+ if (m) \
+ seq_printf(m, fmt); \
+})
+
+/*
+ * The page dumper groups page table entries of the same type into a single
+ * description. It uses pg_state to track the range information while
+ * iterating over the pte entries. When the continuity is broken it then
+ * dumps out a description of the range.
+ */
+struct pg_state {
+ struct ptdump_state ptdump;
+ struct seq_file *seq;
+ const struct addr_marker *marker;
+ unsigned long start_address;
+ int level;
+ u64 current_prot;
+ bool check_wx;
+ unsigned long wx_pages;
+ unsigned long uxn_pages;
+};
+
+struct prot_bits {
+ u64 mask;
+ u64 val;
+ const char *set;
+ const char *clear;
+};
+
+static const struct prot_bits pte_bits[] = {
+ {
+ .mask = PTE_VALID,
+ .val = PTE_VALID,
+ .set = " ",
+ .clear = "F",
+ }, {
+ .mask = PTE_USER,
+ .val = PTE_USER,
+ .set = "USR",
+ .clear = " ",
+ }, {
+ .mask = PTE_RDONLY,
+ .val = PTE_RDONLY,
+ .set = "ro",
+ .clear = "RW",
+ }, {
+ .mask = PTE_PXN,
+ .val = PTE_PXN,
+ .set = "NX",
+ .clear = "x ",
+ }, {
+ .mask = PTE_SHARED,
+ .val = PTE_SHARED,
+ .set = "SHD",
+ .clear = " ",
+ }, {
+ .mask = PTE_AF,
+ .val = PTE_AF,
+ .set = "AF",
+ .clear = " ",
+ }, {
+ .mask = PTE_NG,
+ .val = PTE_NG,
+ .set = "NG",
+ .clear = " ",
+ }, {
+ .mask = PTE_CONT,
+ .val = PTE_CONT,
+ .set = "CON",
+ .clear = " ",
+ }, {
+ .mask = PTE_TABLE_BIT,
+ .val = PTE_TABLE_BIT,
+ .set = " ",
+ .clear = "BLK",
+ }, {
+ .mask = PTE_UXN,
+ .val = PTE_UXN,
+ .set = "UXN",
+ .clear = " ",
+ }, {
+ .mask = PTE_GP,
+ .val = PTE_GP,
+ .set = "GP",
+ .clear = " ",
+ }, {
+ .mask = PTE_ATTRINDX_MASK,
+ .val = PTE_ATTRINDX(MT_DEVICE_nGnRnE),
+ .set = "DEVICE/nGnRnE",
+ }, {
+ .mask = PTE_ATTRINDX_MASK,
+ .val = PTE_ATTRINDX(MT_DEVICE_nGnRE),
+ .set = "DEVICE/nGnRE",
+ }, {
+ .mask = PTE_ATTRINDX_MASK,
+ .val = PTE_ATTRINDX(MT_NORMAL_NC),
+ .set = "MEM/NORMAL-NC",
+ }, {
+ .mask = PTE_ATTRINDX_MASK,
+ .val = PTE_ATTRINDX(MT_NORMAL),
+ .set = "MEM/NORMAL",
+ }, {
+ .mask = PTE_ATTRINDX_MASK,
+ .val = PTE_ATTRINDX(MT_NORMAL_TAGGED),
+ .set = "MEM/NORMAL-TAGGED",
+ }
+};
+
+struct pg_level {
+ const struct prot_bits *bits;
+ const char *name;
+ size_t num;
+ u64 mask;
+};
+
+static struct pg_level pg_level[] = {
+ { /* pgd */
+ .name = "PGD",
+ .bits = pte_bits,
+ .num = ARRAY_SIZE(pte_bits),
+ }, { /* p4d */
+ .name = "P4D",
+ .bits = pte_bits,
+ .num = ARRAY_SIZE(pte_bits),
+ }, { /* pud */
+ .name = (CONFIG_PGTABLE_LEVELS > 3) ? "PUD" : "PGD",
+ .bits = pte_bits,
+ .num = ARRAY_SIZE(pte_bits),
+ }, { /* pmd */
+ .name = (CONFIG_PGTABLE_LEVELS > 2) ? "PMD" : "PGD",
+ .bits = pte_bits,
+ .num = ARRAY_SIZE(pte_bits),
+ }, { /* pte */
+ .name = "PTE",
+ .bits = pte_bits,
+ .num = ARRAY_SIZE(pte_bits),
+ },
+};
+
+static void dump_prot(struct pg_state *st, const struct prot_bits *bits,
+ size_t num)
+{
+ unsigned i;
+
+ for (i = 0; i < num; i++, bits++) {
+ const char *s;
+
+ if ((st->current_prot & bits->mask) == bits->val)
+ s = bits->set;
+ else
+ s = bits->clear;
+
+ if (s)
+ pt_dump_seq_printf(st->seq, " %s", s);
+ }
+}
+
+static void note_prot_uxn(struct pg_state *st, unsigned long addr)
+{
+ if (!st->check_wx)
+ return;
+
+ if ((st->current_prot & PTE_UXN) == PTE_UXN)
+ return;
+
+ WARN_ONCE(1, "arm64/mm: Found non-UXN mapping at address %p/%pS\n",
+ (void *)st->start_address, (void *)st->start_address);
+
+ st->uxn_pages += (addr - st->start_address) / PAGE_SIZE;
+}
+
+static void note_prot_wx(struct pg_state *st, unsigned long addr)
+{
+ if (!st->check_wx)
+ return;
+ if ((st->current_prot & PTE_RDONLY) == PTE_RDONLY)
+ return;
+ if ((st->current_prot & PTE_PXN) == PTE_PXN)
+ return;
+
+ WARN_ONCE(1, "arm64/mm: Found insecure W+X mapping at address %p/%pS\n",
+ (void *)st->start_address, (void *)st->start_address);
+
+ st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
+}
+
+static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
+ u64 val)
+{
+ struct pg_state *st = container_of(pt_st, struct pg_state, ptdump);
+ static const char units[] = "KMGTPE";
+ u64 prot = 0;
+
+ if (level >= 0)
+ prot = val & pg_level[level].mask;
+
+ if (st->level == -1) {
+ st->level = level;
+ st->current_prot = prot;
+ st->start_address = addr;
+ pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
+ } else if (prot != st->current_prot || level != st->level ||
+ addr >= st->marker[1].start_address) {
+ const char *unit = units;
+ unsigned long delta;
+
+ if (st->current_prot) {
+ note_prot_uxn(st, addr);
+ note_prot_wx(st, addr);
+ }
+
+ pt_dump_seq_printf(st->seq, "0x%016lx-0x%016lx ",
+ st->start_address, addr);
+
+ delta = (addr - st->start_address) >> 10;
+ while (!(delta & 1023) && unit[1]) {
+ delta >>= 10;
+ unit++;
+ }
+ pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
+ pg_level[st->level].name);
+ if (st->current_prot && pg_level[st->level].bits)
+ dump_prot(st, pg_level[st->level].bits,
+ pg_level[st->level].num);
+ pt_dump_seq_puts(st->seq, "\n");
+
+ if (addr >= st->marker[1].start_address) {
+ st->marker++;
+ pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
+ }
+
+ st->start_address = addr;
+ st->current_prot = prot;
+ st->level = level;
+ }
+
+ if (addr >= st->marker[1].start_address) {
+ st->marker++;
+ pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
+ }
+
+}
+
+void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
+{
+ unsigned long end = ~0UL;
+ struct pg_state st;
+
+ if (info->base_addr < TASK_SIZE_64)
+ end = TASK_SIZE_64;
+
+ st = (struct pg_state){
+ .seq = s,
+ .marker = info->markers,
+ .level = -1,
+ .ptdump = {
+ .note_page = note_page,
+ .range = (struct ptdump_range[]){
+ {info->base_addr, end},
+ {0, 0}
+ }
+ }
+ };
+
+ ptdump_walk_pgd(&st.ptdump, info->mm, NULL);
+}
+
+static void __init ptdump_initialize(void)
+{
+ unsigned i, j;
+
+ for (i = 0; i < ARRAY_SIZE(pg_level); i++)
+ if (pg_level[i].bits)
+ for (j = 0; j < pg_level[i].num; j++)
+ pg_level[i].mask |= pg_level[i].bits[j].mask;
+}
+
+static struct ptdump_info kernel_ptdump_info = {
+ .mm = &init_mm,
+ .markers = address_markers,
+ .base_addr = PAGE_OFFSET,
+};
+
+void ptdump_check_wx(void)
+{
+ struct pg_state st = {
+ .seq = NULL,
+ .marker = (struct addr_marker[]) {
+ { 0, NULL},
+ { -1, NULL},
+ },
+ .level = -1,
+ .check_wx = true,
+ .ptdump = {
+ .note_page = note_page,
+ .range = (struct ptdump_range[]) {
+ {PAGE_OFFSET, ~0UL},
+ {0, 0}
+ }
+ }
+ };
+
+ ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
+
+ if (st.wx_pages || st.uxn_pages)
+ pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found, %lu non-UXN pages found\n",
+ st.wx_pages, st.uxn_pages);
+ else
+ pr_info("Checked W+X mappings: passed, no W+X pages found\n");
+}
+
+static int __init ptdump_init(void)
+{
+ address_markers[PAGE_END_NR].start_address = PAGE_END;
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+ address_markers[KASAN_START_NR].start_address = KASAN_SHADOW_START;
+#endif
+ ptdump_initialize();
+ ptdump_debugfs_register(&kernel_ptdump_info, "kernel_page_tables");
+ return 0;
+}
+device_initcall(ptdump_init);
diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c
new file mode 100644
index 0000000000..68bf1a1255
--- /dev/null
+++ b/arch/arm64/mm/ptdump_debugfs.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/debugfs.h>
+#include <linux/memory_hotplug.h>
+#include <linux/seq_file.h>
+
+#include <asm/ptdump.h>
+
+static int ptdump_show(struct seq_file *m, void *v)
+{
+ struct ptdump_info *info = m->private;
+
+ get_online_mems();
+ ptdump_walk(m, info);
+ put_online_mems();
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(ptdump);
+
+void __init ptdump_debugfs_register(struct ptdump_info *info, const char *name)
+{
+ debugfs_create_file(name, 0400, NULL, info, &ptdump_fops);
+}
diff --git a/arch/arm64/mm/trans_pgd-asm.S b/arch/arm64/mm/trans_pgd-asm.S
new file mode 100644
index 0000000000..021c31573b
--- /dev/null
+++ b/arch/arm64/mm/trans_pgd-asm.S
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/*
+ * Copyright (c) 2021, Microsoft Corporation.
+ * Pasha Tatashin <pasha.tatashin@soleen.com>
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+#include <asm/kvm_asm.h>
+
+.macro invalid_vector label
+SYM_CODE_START_LOCAL(\label)
+ .align 7
+ b \label
+SYM_CODE_END(\label)
+.endm
+
+.macro el1_sync_vector
+SYM_CODE_START_LOCAL(el1_sync)
+ .align 7
+ cmp x0, #HVC_SET_VECTORS /* Called from hibernate */
+ b.ne 1f
+ msr vbar_el2, x1
+ mov x0, xzr
+ eret
+1: cmp x0, #HVC_SOFT_RESTART /* Called from kexec */
+ b.ne 2f
+ mov x0, x2
+ mov x2, x4
+ mov x4, x1
+ mov x1, x3
+ br x4
+2: /* Unexpected argument, set an error */
+ mov_q x0, HVC_STUB_ERR
+ eret
+SYM_CODE_END(el1_sync)
+.endm
+
+SYM_CODE_START(trans_pgd_stub_vectors)
+ invalid_vector hyp_stub_el2t_sync_invalid // Synchronous EL2t
+ invalid_vector hyp_stub_el2t_irq_invalid // IRQ EL2t
+ invalid_vector hyp_stub_el2t_fiq_invalid // FIQ EL2t
+ invalid_vector hyp_stub_el2t_error_invalid // Error EL2t
+
+ invalid_vector hyp_stub_el2h_sync_invalid // Synchronous EL2h
+ invalid_vector hyp_stub_el2h_irq_invalid // IRQ EL2h
+ invalid_vector hyp_stub_el2h_fiq_invalid // FIQ EL2h
+ invalid_vector hyp_stub_el2h_error_invalid // Error EL2h
+
+ el1_sync_vector // Synchronous 64-bit EL1
+ invalid_vector hyp_stub_el1_irq_invalid // IRQ 64-bit EL1
+ invalid_vector hyp_stub_el1_fiq_invalid // FIQ 64-bit EL1
+ invalid_vector hyp_stub_el1_error_invalid // Error 64-bit EL1
+
+ invalid_vector hyp_stub_32b_el1_sync_invalid // Synchronous 32-bit EL1
+ invalid_vector hyp_stub_32b_el1_irq_invalid // IRQ 32-bit EL1
+ invalid_vector hyp_stub_32b_el1_fiq_invalid // FIQ 32-bit EL1
+ invalid_vector hyp_stub_32b_el1_error_invalid // Error 32-bit EL1
+ .align 11
+SYM_INNER_LABEL(__trans_pgd_stub_vectors_end, SYM_L_LOCAL)
+SYM_CODE_END(trans_pgd_stub_vectors)
+
+# Check the trans_pgd_stub_vectors didn't overflow
+.org . - (__trans_pgd_stub_vectors_end - trans_pgd_stub_vectors) + SZ_2K
diff --git a/arch/arm64/mm/trans_pgd.c b/arch/arm64/mm/trans_pgd.c
new file mode 100644
index 0000000000..7b14df3c64
--- /dev/null
+++ b/arch/arm64/mm/trans_pgd.c
@@ -0,0 +1,292 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Transitional page tables for kexec and hibernate
+ *
+ * This file derived from: arch/arm64/kernel/hibernate.c
+ *
+ * Copyright (c) 2021, Microsoft Corporation.
+ * Pasha Tatashin <pasha.tatashin@soleen.com>
+ *
+ */
+
+/*
+ * Transitional tables are used during system transferring from one world to
+ * another: such as during hibernate restore, and kexec reboots. During these
+ * phases one cannot rely on page table not being overwritten. This is because
+ * hibernate and kexec can overwrite the current page tables during transition.
+ */
+
+#include <asm/trans_pgd.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <linux/suspend.h>
+#include <linux/bug.h>
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/kfence.h>
+
+static void *trans_alloc(struct trans_pgd_info *info)
+{
+ return info->trans_alloc_page(info->trans_alloc_arg);
+}
+
+static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr)
+{
+ pte_t pte = READ_ONCE(*src_ptep);
+
+ if (pte_valid(pte)) {
+ /*
+ * Resume will overwrite areas that may be marked
+ * read only (code, rodata). Clear the RDONLY bit from
+ * the temporary mappings we use during restore.
+ */
+ set_pte(dst_ptep, pte_mkwrite_novma(pte));
+ } else if ((debug_pagealloc_enabled() ||
+ is_kfence_address((void *)addr)) && !pte_none(pte)) {
+ /*
+ * debug_pagealloc will removed the PTE_VALID bit if
+ * the page isn't in use by the resume kernel. It may have
+ * been in use by the original kernel, in which case we need
+ * to put it back in our copy to do the restore.
+ *
+ * Before marking this entry valid, check the pfn should
+ * be mapped.
+ */
+ BUG_ON(!pfn_valid(pte_pfn(pte)));
+
+ set_pte(dst_ptep, pte_mkpresent(pte_mkwrite_novma(pte)));
+ }
+}
+
+static int copy_pte(struct trans_pgd_info *info, pmd_t *dst_pmdp,
+ pmd_t *src_pmdp, unsigned long start, unsigned long end)
+{
+ pte_t *src_ptep;
+ pte_t *dst_ptep;
+ unsigned long addr = start;
+
+ dst_ptep = trans_alloc(info);
+ if (!dst_ptep)
+ return -ENOMEM;
+ pmd_populate_kernel(NULL, dst_pmdp, dst_ptep);
+ dst_ptep = pte_offset_kernel(dst_pmdp, start);
+
+ src_ptep = pte_offset_kernel(src_pmdp, start);
+ do {
+ _copy_pte(dst_ptep, src_ptep, addr);
+ } while (dst_ptep++, src_ptep++, addr += PAGE_SIZE, addr != end);
+
+ return 0;
+}
+
+static int copy_pmd(struct trans_pgd_info *info, pud_t *dst_pudp,
+ pud_t *src_pudp, unsigned long start, unsigned long end)
+{
+ pmd_t *src_pmdp;
+ pmd_t *dst_pmdp;
+ unsigned long next;
+ unsigned long addr = start;
+
+ if (pud_none(READ_ONCE(*dst_pudp))) {
+ dst_pmdp = trans_alloc(info);
+ if (!dst_pmdp)
+ return -ENOMEM;
+ pud_populate(NULL, dst_pudp, dst_pmdp);
+ }
+ dst_pmdp = pmd_offset(dst_pudp, start);
+
+ src_pmdp = pmd_offset(src_pudp, start);
+ do {
+ pmd_t pmd = READ_ONCE(*src_pmdp);
+
+ next = pmd_addr_end(addr, end);
+ if (pmd_none(pmd))
+ continue;
+ if (pmd_table(pmd)) {
+ if (copy_pte(info, dst_pmdp, src_pmdp, addr, next))
+ return -ENOMEM;
+ } else {
+ set_pmd(dst_pmdp,
+ __pmd(pmd_val(pmd) & ~PMD_SECT_RDONLY));
+ }
+ } while (dst_pmdp++, src_pmdp++, addr = next, addr != end);
+
+ return 0;
+}
+
+static int copy_pud(struct trans_pgd_info *info, p4d_t *dst_p4dp,
+ p4d_t *src_p4dp, unsigned long start,
+ unsigned long end)
+{
+ pud_t *dst_pudp;
+ pud_t *src_pudp;
+ unsigned long next;
+ unsigned long addr = start;
+
+ if (p4d_none(READ_ONCE(*dst_p4dp))) {
+ dst_pudp = trans_alloc(info);
+ if (!dst_pudp)
+ return -ENOMEM;
+ p4d_populate(NULL, dst_p4dp, dst_pudp);
+ }
+ dst_pudp = pud_offset(dst_p4dp, start);
+
+ src_pudp = pud_offset(src_p4dp, start);
+ do {
+ pud_t pud = READ_ONCE(*src_pudp);
+
+ next = pud_addr_end(addr, end);
+ if (pud_none(pud))
+ continue;
+ if (pud_table(pud)) {
+ if (copy_pmd(info, dst_pudp, src_pudp, addr, next))
+ return -ENOMEM;
+ } else {
+ set_pud(dst_pudp,
+ __pud(pud_val(pud) & ~PUD_SECT_RDONLY));
+ }
+ } while (dst_pudp++, src_pudp++, addr = next, addr != end);
+
+ return 0;
+}
+
+static int copy_p4d(struct trans_pgd_info *info, pgd_t *dst_pgdp,
+ pgd_t *src_pgdp, unsigned long start,
+ unsigned long end)
+{
+ p4d_t *dst_p4dp;
+ p4d_t *src_p4dp;
+ unsigned long next;
+ unsigned long addr = start;
+
+ dst_p4dp = p4d_offset(dst_pgdp, start);
+ src_p4dp = p4d_offset(src_pgdp, start);
+ do {
+ next = p4d_addr_end(addr, end);
+ if (p4d_none(READ_ONCE(*src_p4dp)))
+ continue;
+ if (copy_pud(info, dst_p4dp, src_p4dp, addr, next))
+ return -ENOMEM;
+ } while (dst_p4dp++, src_p4dp++, addr = next, addr != end);
+
+ return 0;
+}
+
+static int copy_page_tables(struct trans_pgd_info *info, pgd_t *dst_pgdp,
+ unsigned long start, unsigned long end)
+{
+ unsigned long next;
+ unsigned long addr = start;
+ pgd_t *src_pgdp = pgd_offset_k(start);
+
+ dst_pgdp = pgd_offset_pgd(dst_pgdp, start);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none(READ_ONCE(*src_pgdp)))
+ continue;
+ if (copy_p4d(info, dst_pgdp, src_pgdp, addr, next))
+ return -ENOMEM;
+ } while (dst_pgdp++, src_pgdp++, addr = next, addr != end);
+
+ return 0;
+}
+
+/*
+ * Create trans_pgd and copy linear map.
+ * info: contains allocator and its argument
+ * dst_pgdp: new page table that is created, and to which map is copied.
+ * start: Start of the interval (inclusive).
+ * end: End of the interval (exclusive).
+ *
+ * Returns 0 on success, and -ENOMEM on failure.
+ */
+int trans_pgd_create_copy(struct trans_pgd_info *info, pgd_t **dst_pgdp,
+ unsigned long start, unsigned long end)
+{
+ int rc;
+ pgd_t *trans_pgd = trans_alloc(info);
+
+ if (!trans_pgd) {
+ pr_err("Failed to allocate memory for temporary page tables.\n");
+ return -ENOMEM;
+ }
+
+ rc = copy_page_tables(info, trans_pgd, start, end);
+ if (!rc)
+ *dst_pgdp = trans_pgd;
+
+ return rc;
+}
+
+/*
+ * The page we want to idmap may be outside the range covered by VA_BITS that
+ * can be built using the kernel's p?d_populate() helpers. As a one off, for a
+ * single page, we build these page tables bottom up and just assume that will
+ * need the maximum T0SZ.
+ *
+ * Returns 0 on success, and -ENOMEM on failure.
+ * On success trans_ttbr0 contains page table with idmapped page, t0sz is set to
+ * maximum T0SZ for this page.
+ */
+int trans_pgd_idmap_page(struct trans_pgd_info *info, phys_addr_t *trans_ttbr0,
+ unsigned long *t0sz, void *page)
+{
+ phys_addr_t dst_addr = virt_to_phys(page);
+ unsigned long pfn = __phys_to_pfn(dst_addr);
+ int max_msb = (dst_addr & GENMASK(52, 48)) ? 51 : 47;
+ int bits_mapped = PAGE_SHIFT - 4;
+ unsigned long level_mask, prev_level_entry, *levels[4];
+ int this_level, index, level_lsb, level_msb;
+
+ dst_addr &= PAGE_MASK;
+ prev_level_entry = pte_val(pfn_pte(pfn, PAGE_KERNEL_ROX));
+
+ for (this_level = 3; this_level >= 0; this_level--) {
+ levels[this_level] = trans_alloc(info);
+ if (!levels[this_level])
+ return -ENOMEM;
+
+ level_lsb = ARM64_HW_PGTABLE_LEVEL_SHIFT(this_level);
+ level_msb = min(level_lsb + bits_mapped, max_msb);
+ level_mask = GENMASK_ULL(level_msb, level_lsb);
+
+ index = (dst_addr & level_mask) >> level_lsb;
+ *(levels[this_level] + index) = prev_level_entry;
+
+ pfn = virt_to_pfn(levels[this_level]);
+ prev_level_entry = pte_val(pfn_pte(pfn,
+ __pgprot(PMD_TYPE_TABLE)));
+
+ if (level_msb == max_msb)
+ break;
+ }
+
+ *trans_ttbr0 = phys_to_ttbr(__pfn_to_phys(pfn));
+ *t0sz = TCR_T0SZ(max_msb + 1);
+
+ return 0;
+}
+
+/*
+ * Create a copy of the vector table so we can call HVC_SET_VECTORS or
+ * HVC_SOFT_RESTART from contexts where the table may be overwritten.
+ */
+int trans_pgd_copy_el2_vectors(struct trans_pgd_info *info,
+ phys_addr_t *el2_vectors)
+{
+ void *hyp_stub = trans_alloc(info);
+
+ if (!hyp_stub)
+ return -ENOMEM;
+ *el2_vectors = virt_to_phys(hyp_stub);
+ memcpy(hyp_stub, &trans_pgd_stub_vectors, ARM64_VECTOR_TABLE_LEN);
+ caches_clean_inval_pou((unsigned long)hyp_stub,
+ (unsigned long)hyp_stub +
+ ARM64_VECTOR_TABLE_LEN);
+ dcache_clean_inval_poc((unsigned long)hyp_stub,
+ (unsigned long)hyp_stub +
+ ARM64_VECTOR_TABLE_LEN);
+
+ return 0;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-03 04:43:29 +0000