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-rw-r--r--arch/arm64/mm/init.c504
1 files changed, 504 insertions, 0 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
new file mode 100644
index 000000000..4b4651ee4
--- /dev/null
+++ b/arch/arm64/mm/init.c
@@ -0,0 +1,504 @@
+// 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.
+ *
+ * Memory reservation for crash kernel either done early or deferred
+ * depending on DMA memory zones configs (ZONE_DMA) --
+ *
+ * In absence of ZONE_DMA configs arm64_dma_phys_limit initialized
+ * here instead of max_zone_phys(). This lets early reservation of
+ * crash kernel memory which has a dependency on arm64_dma_phys_limit.
+ * Reserving memory early for crash kernel allows linear creation of block
+ * mappings (greater than page-granularity) for all the memory bank rangs.
+ * In this scheme a comparatively quicker boot is observed.
+ *
+ * If ZONE_DMA configs are defined, crash kernel memory reservation
+ * is delayed until DMA zone memory range size initialization performed in
+ * zone_sizes_init(). The defer is necessary to steer clear of DMA zone
+ * memory range to avoid overlap allocation. So crash kernel memory boundaries
+ * are not known when mapping all bank memory ranges, which otherwise means
+ * not possible to exclude crash kernel range from creating block mappings
+ * so page-granularity mappings are created for the entire memory range.
+ * Hence a slightly slower boot is observed.
+ *
+ * Note: Page-granularity mappings are necessary for crash kernel memory
+ * range for shrinking its size via /sys/kernel/kexec_crash_size interface.
+ */
+#if IS_ENABLED(CONFIG_ZONE_DMA) || IS_ENABLED(CONFIG_ZONE_DMA32)
+phys_addr_t __ro_after_init arm64_dma_phys_limit;
+#else
+phys_addr_t __ro_after_init arm64_dma_phys_limit = PHYS_MASK + 1;
+#endif
+
+/* 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)
+
+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_base, crash_size;
+ unsigned long long crash_low_size = 0;
+ unsigned long long crash_max = CRASH_ADDR_LOW_MAX;
+ char *cmdline = boot_command_line;
+ 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 && (ret != -ENOENT))
+ return;
+
+ crash_max = CRASH_ADDR_HIGH_MAX;
+ } 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)
+ crash_max = crash_base + crash_size;
+
+ crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
+ crash_base, crash_max);
+ if (!crash_base) {
+ 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
+ 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();
+
+ if (!defer_reserve_crashkernel())
+ reserve_crashkernel();
+
+ 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
+
+ dma_pernuma_cma_reserve();
+
+ 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.
+ */
+ if (defer_reserve_crashkernel())
+ 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)
+{
+ swiotlb_init(max_pfn > PFN_DOWN(arm64_dma_phys_limit), 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");
+ }
+}