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-rw-r--r--arch/powerpc/lib/feature-fixups.c1012
1 files changed, 1012 insertions, 0 deletions
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
new file mode 100644
index 0000000000..4f82581ca2
--- /dev/null
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -0,0 +1,1012 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org)
+ *
+ * Modifications for ppc64:
+ * Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com>
+ *
+ * Copyright 2008 Michael Ellerman, IBM Corporation.
+ */
+
+#include <linux/types.h>
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/sched/mm.h>
+#include <linux/stop_machine.h>
+#include <asm/cputable.h>
+#include <asm/code-patching.h>
+#include <asm/interrupt.h>
+#include <asm/page.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/security_features.h>
+#include <asm/firmware.h>
+#include <asm/inst.h>
+
+struct fixup_entry {
+ unsigned long mask;
+ unsigned long value;
+ long start_off;
+ long end_off;
+ long alt_start_off;
+ long alt_end_off;
+};
+
+static u32 *calc_addr(struct fixup_entry *fcur, long offset)
+{
+ /*
+ * We store the offset to the code as a negative offset from
+ * the start of the alt_entry, to support the VDSO. This
+ * routine converts that back into an actual address.
+ */
+ return (u32 *)((unsigned long)fcur + offset);
+}
+
+static int patch_alt_instruction(u32 *src, u32 *dest, u32 *alt_start, u32 *alt_end)
+{
+ int err;
+ ppc_inst_t instr;
+
+ instr = ppc_inst_read(src);
+
+ if (instr_is_relative_branch(ppc_inst_read(src))) {
+ u32 *target = (u32 *)branch_target(src);
+
+ /* Branch within the section doesn't need translating */
+ if (target < alt_start || target > alt_end) {
+ err = translate_branch(&instr, dest, src);
+ if (err)
+ return 1;
+ }
+ }
+
+ raw_patch_instruction(dest, instr);
+
+ return 0;
+}
+
+static int patch_feature_section_mask(unsigned long value, unsigned long mask,
+ struct fixup_entry *fcur)
+{
+ u32 *start, *end, *alt_start, *alt_end, *src, *dest;
+
+ start = calc_addr(fcur, fcur->start_off);
+ end = calc_addr(fcur, fcur->end_off);
+ alt_start = calc_addr(fcur, fcur->alt_start_off);
+ alt_end = calc_addr(fcur, fcur->alt_end_off);
+
+ if ((alt_end - alt_start) > (end - start))
+ return 1;
+
+ if ((value & fcur->mask & mask) == (fcur->value & mask))
+ return 0;
+
+ src = alt_start;
+ dest = start;
+
+ for (; src < alt_end; src = ppc_inst_next(src, src),
+ dest = ppc_inst_next(dest, dest)) {
+ if (patch_alt_instruction(src, dest, alt_start, alt_end))
+ return 1;
+ }
+
+ for (; dest < end; dest++)
+ raw_patch_instruction(dest, ppc_inst(PPC_RAW_NOP()));
+
+ return 0;
+}
+
+static void do_feature_fixups_mask(unsigned long value, unsigned long mask,
+ void *fixup_start, void *fixup_end)
+{
+ struct fixup_entry *fcur, *fend;
+
+ fcur = fixup_start;
+ fend = fixup_end;
+
+ for (; fcur < fend; fcur++) {
+ if (patch_feature_section_mask(value, mask, fcur)) {
+ WARN_ON(1);
+ printk("Unable to patch feature section at %p - %p" \
+ " with %p - %p\n",
+ calc_addr(fcur, fcur->start_off),
+ calc_addr(fcur, fcur->end_off),
+ calc_addr(fcur, fcur->alt_start_off),
+ calc_addr(fcur, fcur->alt_end_off));
+ }
+ }
+}
+
+void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
+{
+ do_feature_fixups_mask(value, ~0, fixup_start, fixup_end);
+}
+
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
+static bool is_fixup_addr_valid(void *dest, size_t size)
+{
+ return system_state < SYSTEM_FREEING_INITMEM ||
+ !init_section_contains(dest, size);
+}
+
+static int do_patch_fixups(long *start, long *end, unsigned int *instrs, int num)
+{
+ int i;
+
+ for (i = 0; start < end; start++, i++) {
+ int j;
+ unsigned int *dest = (void *)start + *start;
+
+ if (!is_fixup_addr_valid(dest, sizeof(*instrs) * num))
+ continue;
+
+ pr_devel("patching dest %lx\n", (unsigned long)dest);
+
+ for (j = 0; j < num; j++)
+ patch_instruction(dest + j, ppc_inst(instrs[j]));
+ }
+ return i;
+}
+#endif
+
+#ifdef CONFIG_PPC_BOOK3S_64
+static int do_patch_entry_fixups(long *start, long *end, unsigned int *instrs,
+ bool do_fallback, void *fallback)
+{
+ int i;
+
+ for (i = 0; start < end; start++, i++) {
+ unsigned int *dest = (void *)start + *start;
+
+ if (!is_fixup_addr_valid(dest, sizeof(*instrs) * 3))
+ continue;
+
+ pr_devel("patching dest %lx\n", (unsigned long)dest);
+
+ // See comment in do_entry_flush_fixups() RE order of patching
+ if (do_fallback) {
+ patch_instruction(dest, ppc_inst(instrs[0]));
+ patch_instruction(dest + 2, ppc_inst(instrs[2]));
+ patch_branch(dest + 1, (unsigned long)fallback, BRANCH_SET_LINK);
+ } else {
+ patch_instruction(dest + 1, ppc_inst(instrs[1]));
+ patch_instruction(dest + 2, ppc_inst(instrs[2]));
+ patch_instruction(dest, ppc_inst(instrs[0]));
+ }
+ }
+ return i;
+}
+
+static void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
+{
+ unsigned int instrs[3];
+ long *start, *end;
+ int i;
+
+ start = PTRRELOC(&__start___stf_entry_barrier_fixup);
+ end = PTRRELOC(&__stop___stf_entry_barrier_fixup);
+
+ instrs[0] = PPC_RAW_NOP();
+ instrs[1] = PPC_RAW_NOP();
+ instrs[2] = PPC_RAW_NOP();
+
+ i = 0;
+ if (types & STF_BARRIER_FALLBACK) {
+ instrs[i++] = PPC_RAW_MFLR(_R10);
+ instrs[i++] = PPC_RAW_NOP(); /* branch patched below */
+ instrs[i++] = PPC_RAW_MTLR(_R10);
+ } else if (types & STF_BARRIER_EIEIO) {
+ instrs[i++] = PPC_RAW_EIEIO() | 0x02000000; /* eieio + bit 6 hint */
+ } else if (types & STF_BARRIER_SYNC_ORI) {
+ instrs[i++] = PPC_RAW_SYNC();
+ instrs[i++] = PPC_RAW_LD(_R10, _R13, 0);
+ instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
+ }
+
+ i = do_patch_entry_fixups(start, end, instrs, types & STF_BARRIER_FALLBACK,
+ &stf_barrier_fallback);
+
+ printk(KERN_DEBUG "stf-barrier: patched %d entry locations (%s barrier)\n", i,
+ (types == STF_BARRIER_NONE) ? "no" :
+ (types == STF_BARRIER_FALLBACK) ? "fallback" :
+ (types == STF_BARRIER_EIEIO) ? "eieio" :
+ (types == (STF_BARRIER_SYNC_ORI)) ? "hwsync"
+ : "unknown");
+}
+
+static void do_stf_exit_barrier_fixups(enum stf_barrier_type types)
+{
+ unsigned int instrs[6];
+ long *start, *end;
+ int i;
+
+ start = PTRRELOC(&__start___stf_exit_barrier_fixup);
+ end = PTRRELOC(&__stop___stf_exit_barrier_fixup);
+
+ instrs[0] = PPC_RAW_NOP();
+ instrs[1] = PPC_RAW_NOP();
+ instrs[2] = PPC_RAW_NOP();
+ instrs[3] = PPC_RAW_NOP();
+ instrs[4] = PPC_RAW_NOP();
+ instrs[5] = PPC_RAW_NOP();
+
+ i = 0;
+ if (types & STF_BARRIER_FALLBACK || types & STF_BARRIER_SYNC_ORI) {
+ if (cpu_has_feature(CPU_FTR_HVMODE)) {
+ instrs[i++] = PPC_RAW_MTSPR(SPRN_HSPRG1, _R13);
+ instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_HSPRG0);
+ } else {
+ instrs[i++] = PPC_RAW_MTSPR(SPRN_SPRG2, _R13);
+ instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_SPRG1);
+ }
+ instrs[i++] = PPC_RAW_SYNC();
+ instrs[i++] = PPC_RAW_LD(_R13, _R13, 0);
+ instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
+ if (cpu_has_feature(CPU_FTR_HVMODE))
+ instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_HSPRG1);
+ else
+ instrs[i++] = PPC_RAW_MFSPR(_R13, SPRN_SPRG2);
+ } else if (types & STF_BARRIER_EIEIO) {
+ instrs[i++] = PPC_RAW_EIEIO() | 0x02000000; /* eieio + bit 6 hint */
+ }
+
+ i = do_patch_fixups(start, end, instrs, ARRAY_SIZE(instrs));
+
+ printk(KERN_DEBUG "stf-barrier: patched %d exit locations (%s barrier)\n", i,
+ (types == STF_BARRIER_NONE) ? "no" :
+ (types == STF_BARRIER_FALLBACK) ? "fallback" :
+ (types == STF_BARRIER_EIEIO) ? "eieio" :
+ (types == (STF_BARRIER_SYNC_ORI)) ? "hwsync"
+ : "unknown");
+}
+
+static bool stf_exit_reentrant = false;
+static bool rfi_exit_reentrant = false;
+static DEFINE_MUTEX(exit_flush_lock);
+
+static int __do_stf_barrier_fixups(void *data)
+{
+ enum stf_barrier_type *types = data;
+
+ do_stf_entry_barrier_fixups(*types);
+ do_stf_exit_barrier_fixups(*types);
+
+ return 0;
+}
+
+void do_stf_barrier_fixups(enum stf_barrier_type types)
+{
+ /*
+ * The call to the fallback entry flush, and the fallback/sync-ori exit
+ * flush can not be safely patched in/out while other CPUs are
+ * executing them. So call __do_stf_barrier_fixups() on one CPU while
+ * all other CPUs spin in the stop machine core with interrupts hard
+ * disabled.
+ *
+ * The branch to mark interrupt exits non-reentrant is enabled first,
+ * then stop_machine runs which will ensure all CPUs are out of the
+ * low level interrupt exit code before patching. After the patching,
+ * if allowed, then flip the branch to allow fast exits.
+ */
+
+ // Prevent static key update races with do_rfi_flush_fixups()
+ mutex_lock(&exit_flush_lock);
+ static_branch_enable(&interrupt_exit_not_reentrant);
+
+ stop_machine(__do_stf_barrier_fixups, &types, NULL);
+
+ if ((types & STF_BARRIER_FALLBACK) || (types & STF_BARRIER_SYNC_ORI))
+ stf_exit_reentrant = false;
+ else
+ stf_exit_reentrant = true;
+
+ if (stf_exit_reentrant && rfi_exit_reentrant)
+ static_branch_disable(&interrupt_exit_not_reentrant);
+
+ mutex_unlock(&exit_flush_lock);
+}
+
+void do_uaccess_flush_fixups(enum l1d_flush_type types)
+{
+ unsigned int instrs[4];
+ long *start, *end;
+ int i;
+
+ start = PTRRELOC(&__start___uaccess_flush_fixup);
+ end = PTRRELOC(&__stop___uaccess_flush_fixup);
+
+ instrs[0] = PPC_RAW_NOP();
+ instrs[1] = PPC_RAW_NOP();
+ instrs[2] = PPC_RAW_NOP();
+ instrs[3] = PPC_RAW_BLR();
+
+ i = 0;
+ if (types == L1D_FLUSH_FALLBACK) {
+ instrs[3] = PPC_RAW_NOP();
+ /* fallthrough to fallback flush */
+ }
+
+ if (types & L1D_FLUSH_ORI) {
+ instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
+ instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
+ }
+
+ if (types & L1D_FLUSH_MTTRIG)
+ instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
+
+ i = do_patch_fixups(start, end, instrs, ARRAY_SIZE(instrs));
+
+ printk(KERN_DEBUG "uaccess-flush: patched %d locations (%s flush)\n", i,
+ (types == L1D_FLUSH_NONE) ? "no" :
+ (types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :
+ (types & L1D_FLUSH_ORI) ? (types & L1D_FLUSH_MTTRIG)
+ ? "ori+mttrig type"
+ : "ori type" :
+ (types & L1D_FLUSH_MTTRIG) ? "mttrig type"
+ : "unknown");
+}
+
+static int __do_entry_flush_fixups(void *data)
+{
+ enum l1d_flush_type types = *(enum l1d_flush_type *)data;
+ unsigned int instrs[3];
+ long *start, *end;
+ int i;
+
+ instrs[0] = PPC_RAW_NOP();
+ instrs[1] = PPC_RAW_NOP();
+ instrs[2] = PPC_RAW_NOP();
+
+ i = 0;
+ if (types == L1D_FLUSH_FALLBACK) {
+ instrs[i++] = PPC_RAW_MFLR(_R10);
+ instrs[i++] = PPC_RAW_NOP(); /* branch patched below */
+ instrs[i++] = PPC_RAW_MTLR(_R10);
+ }
+
+ if (types & L1D_FLUSH_ORI) {
+ instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
+ instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
+ }
+
+ if (types & L1D_FLUSH_MTTRIG)
+ instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
+
+ /*
+ * If we're patching in or out the fallback flush we need to be careful about the
+ * order in which we patch instructions. That's because it's possible we could
+ * take a page fault after patching one instruction, so the sequence of
+ * instructions must be safe even in a half patched state.
+ *
+ * To make that work, when patching in the fallback flush we patch in this order:
+ * - the mflr (dest)
+ * - the mtlr (dest + 2)
+ * - the branch (dest + 1)
+ *
+ * That ensures the sequence is safe to execute at any point. In contrast if we
+ * patch the mtlr last, it's possible we could return from the branch and not
+ * restore LR, leading to a crash later.
+ *
+ * When patching out the fallback flush (either with nops or another flush type),
+ * we patch in this order:
+ * - the branch (dest + 1)
+ * - the mtlr (dest + 2)
+ * - the mflr (dest)
+ *
+ * Note we are protected by stop_machine() from other CPUs executing the code in a
+ * semi-patched state.
+ */
+
+ start = PTRRELOC(&__start___entry_flush_fixup);
+ end = PTRRELOC(&__stop___entry_flush_fixup);
+ i = do_patch_entry_fixups(start, end, instrs, types == L1D_FLUSH_FALLBACK,
+ &entry_flush_fallback);
+
+ start = PTRRELOC(&__start___scv_entry_flush_fixup);
+ end = PTRRELOC(&__stop___scv_entry_flush_fixup);
+ i += do_patch_entry_fixups(start, end, instrs, types == L1D_FLUSH_FALLBACK,
+ &scv_entry_flush_fallback);
+
+ printk(KERN_DEBUG "entry-flush: patched %d locations (%s flush)\n", i,
+ (types == L1D_FLUSH_NONE) ? "no" :
+ (types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :
+ (types & L1D_FLUSH_ORI) ? (types & L1D_FLUSH_MTTRIG)
+ ? "ori+mttrig type"
+ : "ori type" :
+ (types & L1D_FLUSH_MTTRIG) ? "mttrig type"
+ : "unknown");
+
+ return 0;
+}
+
+void do_entry_flush_fixups(enum l1d_flush_type types)
+{
+ /*
+ * The call to the fallback flush can not be safely patched in/out while
+ * other CPUs are executing it. So call __do_entry_flush_fixups() on one
+ * CPU while all other CPUs spin in the stop machine core with interrupts
+ * hard disabled.
+ */
+ stop_machine(__do_entry_flush_fixups, &types, NULL);
+}
+
+static int __do_rfi_flush_fixups(void *data)
+{
+ enum l1d_flush_type types = *(enum l1d_flush_type *)data;
+ unsigned int instrs[3];
+ long *start, *end;
+ int i;
+
+ start = PTRRELOC(&__start___rfi_flush_fixup);
+ end = PTRRELOC(&__stop___rfi_flush_fixup);
+
+ instrs[0] = PPC_RAW_NOP();
+ instrs[1] = PPC_RAW_NOP();
+ instrs[2] = PPC_RAW_NOP();
+
+ if (types & L1D_FLUSH_FALLBACK)
+ /* b .+16 to fallback flush */
+ instrs[0] = PPC_RAW_BRANCH(16);
+
+ i = 0;
+ if (types & L1D_FLUSH_ORI) {
+ instrs[i++] = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
+ instrs[i++] = PPC_RAW_ORI(_R30, _R30, 0); /* L1d flush */
+ }
+
+ if (types & L1D_FLUSH_MTTRIG)
+ instrs[i++] = PPC_RAW_MTSPR(SPRN_TRIG2, _R0);
+
+ i = do_patch_fixups(start, end, instrs, ARRAY_SIZE(instrs));
+
+ printk(KERN_DEBUG "rfi-flush: patched %d locations (%s flush)\n", i,
+ (types == L1D_FLUSH_NONE) ? "no" :
+ (types == L1D_FLUSH_FALLBACK) ? "fallback displacement" :
+ (types & L1D_FLUSH_ORI) ? (types & L1D_FLUSH_MTTRIG)
+ ? "ori+mttrig type"
+ : "ori type" :
+ (types & L1D_FLUSH_MTTRIG) ? "mttrig type"
+ : "unknown");
+
+ return 0;
+}
+
+void do_rfi_flush_fixups(enum l1d_flush_type types)
+{
+ /*
+ * stop_machine gets all CPUs out of the interrupt exit handler same
+ * as do_stf_barrier_fixups. do_rfi_flush_fixups patching can run
+ * without stop_machine, so this could be achieved with a broadcast
+ * IPI instead, but this matches the stf sequence.
+ */
+
+ // Prevent static key update races with do_stf_barrier_fixups()
+ mutex_lock(&exit_flush_lock);
+ static_branch_enable(&interrupt_exit_not_reentrant);
+
+ stop_machine(__do_rfi_flush_fixups, &types, NULL);
+
+ if (types & L1D_FLUSH_FALLBACK)
+ rfi_exit_reentrant = false;
+ else
+ rfi_exit_reentrant = true;
+
+ if (stf_exit_reentrant && rfi_exit_reentrant)
+ static_branch_disable(&interrupt_exit_not_reentrant);
+
+ mutex_unlock(&exit_flush_lock);
+}
+
+void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
+{
+ unsigned int instr;
+ long *start, *end;
+ int i;
+
+ start = fixup_start;
+ end = fixup_end;
+
+ instr = PPC_RAW_NOP();
+
+ if (enable) {
+ pr_info("barrier-nospec: using ORI speculation barrier\n");
+ instr = PPC_RAW_ORI(_R31, _R31, 0); /* speculation barrier */
+ }
+
+ i = do_patch_fixups(start, end, &instr, 1);
+
+ printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
+}
+
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+#ifdef CONFIG_PPC_BARRIER_NOSPEC
+void do_barrier_nospec_fixups(bool enable)
+{
+ void *start, *end;
+
+ start = PTRRELOC(&__start___barrier_nospec_fixup);
+ end = PTRRELOC(&__stop___barrier_nospec_fixup);
+
+ do_barrier_nospec_fixups_range(enable, start, end);
+}
+#endif /* CONFIG_PPC_BARRIER_NOSPEC */
+
+#ifdef CONFIG_PPC_E500
+void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
+{
+ unsigned int instr[2];
+ long *start, *end;
+ int i;
+
+ start = fixup_start;
+ end = fixup_end;
+
+ instr[0] = PPC_RAW_NOP();
+ instr[1] = PPC_RAW_NOP();
+
+ if (enable) {
+ pr_info("barrier-nospec: using isync; sync as speculation barrier\n");
+ instr[0] = PPC_RAW_ISYNC();
+ instr[1] = PPC_RAW_SYNC();
+ }
+
+ i = do_patch_fixups(start, end, instr, ARRAY_SIZE(instr));
+
+ printk(KERN_DEBUG "barrier-nospec: patched %d locations\n", i);
+}
+
+static void __init patch_btb_flush_section(long *curr)
+{
+ unsigned int *start, *end;
+
+ start = (void *)curr + *curr;
+ end = (void *)curr + *(curr + 1);
+ for (; start < end; start++) {
+ pr_devel("patching dest %lx\n", (unsigned long)start);
+ patch_instruction(start, ppc_inst(PPC_RAW_NOP()));
+ }
+}
+
+void __init do_btb_flush_fixups(void)
+{
+ long *start, *end;
+
+ start = PTRRELOC(&__start__btb_flush_fixup);
+ end = PTRRELOC(&__stop__btb_flush_fixup);
+
+ for (; start < end; start += 2)
+ patch_btb_flush_section(start);
+}
+#endif /* CONFIG_PPC_E500 */
+
+void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
+{
+ long *start, *end;
+ u32 *dest;
+
+ if (!(value & CPU_FTR_LWSYNC))
+ return ;
+
+ start = fixup_start;
+ end = fixup_end;
+
+ for (; start < end; start++) {
+ dest = (void *)start + *start;
+ raw_patch_instruction(dest, ppc_inst(PPC_INST_LWSYNC));
+ }
+}
+
+static void __init do_final_fixups(void)
+{
+#if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
+ ppc_inst_t inst;
+ u32 *src, *dest, *end;
+
+ if (PHYSICAL_START == 0)
+ return;
+
+ src = (u32 *)(KERNELBASE + PHYSICAL_START);
+ dest = (u32 *)KERNELBASE;
+ end = (void *)src + (__end_interrupts - _stext);
+
+ while (src < end) {
+ inst = ppc_inst_read(src);
+ raw_patch_instruction(dest, inst);
+ src = ppc_inst_next(src, src);
+ dest = ppc_inst_next(dest, dest);
+ }
+#endif
+}
+
+static unsigned long __initdata saved_cpu_features;
+static unsigned int __initdata saved_mmu_features;
+#ifdef CONFIG_PPC64
+static unsigned long __initdata saved_firmware_features;
+#endif
+
+void __init apply_feature_fixups(void)
+{
+ struct cpu_spec *spec = PTRRELOC(*PTRRELOC(&cur_cpu_spec));
+
+ *PTRRELOC(&saved_cpu_features) = spec->cpu_features;
+ *PTRRELOC(&saved_mmu_features) = spec->mmu_features;
+
+ /*
+ * Apply the CPU-specific and firmware specific fixups to kernel text
+ * (nop out sections not relevant to this CPU or this firmware).
+ */
+ do_feature_fixups(spec->cpu_features,
+ PTRRELOC(&__start___ftr_fixup),
+ PTRRELOC(&__stop___ftr_fixup));
+
+ do_feature_fixups(spec->mmu_features,
+ PTRRELOC(&__start___mmu_ftr_fixup),
+ PTRRELOC(&__stop___mmu_ftr_fixup));
+
+ do_lwsync_fixups(spec->cpu_features,
+ PTRRELOC(&__start___lwsync_fixup),
+ PTRRELOC(&__stop___lwsync_fixup));
+
+#ifdef CONFIG_PPC64
+ saved_firmware_features = powerpc_firmware_features;
+ do_feature_fixups(powerpc_firmware_features,
+ &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
+#endif
+ do_final_fixups();
+}
+
+void __init update_mmu_feature_fixups(unsigned long mask)
+{
+ saved_mmu_features &= ~mask;
+ saved_mmu_features |= cur_cpu_spec->mmu_features & mask;
+
+ do_feature_fixups_mask(cur_cpu_spec->mmu_features, mask,
+ PTRRELOC(&__start___mmu_ftr_fixup),
+ PTRRELOC(&__stop___mmu_ftr_fixup));
+ mmu_feature_keys_init();
+}
+
+void __init setup_feature_keys(void)
+{
+ /*
+ * Initialise jump label. This causes all the cpu/mmu_has_feature()
+ * checks to take on their correct polarity based on the current set of
+ * CPU/MMU features.
+ */
+ jump_label_init();
+ cpu_feature_keys_init();
+ mmu_feature_keys_init();
+}
+
+static int __init check_features(void)
+{
+ WARN(saved_cpu_features != cur_cpu_spec->cpu_features,
+ "CPU features changed after feature patching!\n");
+ WARN(saved_mmu_features != cur_cpu_spec->mmu_features,
+ "MMU features changed after feature patching!\n");
+#ifdef CONFIG_PPC64
+ WARN(saved_firmware_features != powerpc_firmware_features,
+ "Firmware features changed after feature patching!\n");
+#endif
+
+ return 0;
+}
+late_initcall(check_features);
+
+#ifdef CONFIG_FTR_FIXUP_SELFTEST
+
+#define check(x) \
+ if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__);
+
+static int patch_feature_section(unsigned long value, struct fixup_entry *fcur)
+{
+ return patch_feature_section_mask(value, ~0, fcur);
+}
+
+/* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */
+static struct fixup_entry fixup;
+
+static long __init calc_offset(struct fixup_entry *entry, unsigned int *p)
+{
+ return (unsigned long)p - (unsigned long)entry;
+}
+
+static void __init test_basic_patching(void)
+{
+ extern unsigned int ftr_fixup_test1[];
+ extern unsigned int end_ftr_fixup_test1[];
+ extern unsigned int ftr_fixup_test1_orig[];
+ extern unsigned int ftr_fixup_test1_expected[];
+ int size = 4 * (end_ftr_fixup_test1 - ftr_fixup_test1);
+
+ fixup.value = fixup.mask = 8;
+ fixup.start_off = calc_offset(&fixup, ftr_fixup_test1 + 1);
+ fixup.end_off = calc_offset(&fixup, ftr_fixup_test1 + 2);
+ fixup.alt_start_off = fixup.alt_end_off = 0;
+
+ /* Sanity check */
+ check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
+
+ /* Check we don't patch if the value matches */
+ patch_feature_section(8, &fixup);
+ check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
+
+ /* Check we do patch if the value doesn't match */
+ patch_feature_section(0, &fixup);
+ check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
+
+ /* Check we do patch if the mask doesn't match */
+ memcpy(ftr_fixup_test1, ftr_fixup_test1_orig, size);
+ check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
+ patch_feature_section(~8, &fixup);
+ check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
+}
+
+static void __init test_alternative_patching(void)
+{
+ extern unsigned int ftr_fixup_test2[];
+ extern unsigned int end_ftr_fixup_test2[];
+ extern unsigned int ftr_fixup_test2_orig[];
+ extern unsigned int ftr_fixup_test2_alt[];
+ extern unsigned int ftr_fixup_test2_expected[];
+ int size = 4 * (end_ftr_fixup_test2 - ftr_fixup_test2);
+
+ fixup.value = fixup.mask = 0xF;
+ fixup.start_off = calc_offset(&fixup, ftr_fixup_test2 + 1);
+ fixup.end_off = calc_offset(&fixup, ftr_fixup_test2 + 2);
+ fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test2_alt);
+ fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test2_alt + 1);
+
+ /* Sanity check */
+ check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
+
+ /* Check we don't patch if the value matches */
+ patch_feature_section(0xF, &fixup);
+ check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
+
+ /* Check we do patch if the value doesn't match */
+ patch_feature_section(0, &fixup);
+ check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
+
+ /* Check we do patch if the mask doesn't match */
+ memcpy(ftr_fixup_test2, ftr_fixup_test2_orig, size);
+ check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
+ patch_feature_section(~0xF, &fixup);
+ check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
+}
+
+static void __init test_alternative_case_too_big(void)
+{
+ extern unsigned int ftr_fixup_test3[];
+ extern unsigned int end_ftr_fixup_test3[];
+ extern unsigned int ftr_fixup_test3_orig[];
+ extern unsigned int ftr_fixup_test3_alt[];
+ int size = 4 * (end_ftr_fixup_test3 - ftr_fixup_test3);
+
+ fixup.value = fixup.mask = 0xC;
+ fixup.start_off = calc_offset(&fixup, ftr_fixup_test3 + 1);
+ fixup.end_off = calc_offset(&fixup, ftr_fixup_test3 + 2);
+ fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test3_alt);
+ fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test3_alt + 2);
+
+ /* Sanity check */
+ check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
+
+ /* Expect nothing to be patched, and the error returned to us */
+ check(patch_feature_section(0xF, &fixup) == 1);
+ check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
+ check(patch_feature_section(0, &fixup) == 1);
+ check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
+ check(patch_feature_section(~0xF, &fixup) == 1);
+ check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
+}
+
+static void __init test_alternative_case_too_small(void)
+{
+ extern unsigned int ftr_fixup_test4[];
+ extern unsigned int end_ftr_fixup_test4[];
+ extern unsigned int ftr_fixup_test4_orig[];
+ extern unsigned int ftr_fixup_test4_alt[];
+ extern unsigned int ftr_fixup_test4_expected[];
+ int size = 4 * (end_ftr_fixup_test4 - ftr_fixup_test4);
+ unsigned long flag;
+
+ /* Check a high-bit flag */
+ flag = 1UL << ((sizeof(unsigned long) - 1) * 8);
+ fixup.value = fixup.mask = flag;
+ fixup.start_off = calc_offset(&fixup, ftr_fixup_test4 + 1);
+ fixup.end_off = calc_offset(&fixup, ftr_fixup_test4 + 5);
+ fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test4_alt);
+ fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test4_alt + 2);
+
+ /* Sanity check */
+ check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
+
+ /* Check we don't patch if the value matches */
+ patch_feature_section(flag, &fixup);
+ check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
+
+ /* Check we do patch if the value doesn't match */
+ patch_feature_section(0, &fixup);
+ check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
+
+ /* Check we do patch if the mask doesn't match */
+ memcpy(ftr_fixup_test4, ftr_fixup_test4_orig, size);
+ check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
+ patch_feature_section(~flag, &fixup);
+ check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
+}
+
+static void test_alternative_case_with_branch(void)
+{
+ extern unsigned int ftr_fixup_test5[];
+ extern unsigned int end_ftr_fixup_test5[];
+ extern unsigned int ftr_fixup_test5_expected[];
+ int size = 4 * (end_ftr_fixup_test5 - ftr_fixup_test5);
+
+ check(memcmp(ftr_fixup_test5, ftr_fixup_test5_expected, size) == 0);
+}
+
+static void __init test_alternative_case_with_external_branch(void)
+{
+ extern unsigned int ftr_fixup_test6[];
+ extern unsigned int end_ftr_fixup_test6[];
+ extern unsigned int ftr_fixup_test6_expected[];
+ int size = 4 * (end_ftr_fixup_test6 - ftr_fixup_test6);
+
+ check(memcmp(ftr_fixup_test6, ftr_fixup_test6_expected, size) == 0);
+}
+
+static void __init test_alternative_case_with_branch_to_end(void)
+{
+ extern unsigned int ftr_fixup_test7[];
+ extern unsigned int end_ftr_fixup_test7[];
+ extern unsigned int ftr_fixup_test7_expected[];
+ int size = 4 * (end_ftr_fixup_test7 - ftr_fixup_test7);
+
+ check(memcmp(ftr_fixup_test7, ftr_fixup_test7_expected, size) == 0);
+}
+
+static void __init test_cpu_macros(void)
+{
+ extern u8 ftr_fixup_test_FTR_macros[];
+ extern u8 ftr_fixup_test_FTR_macros_expected[];
+ unsigned long size = ftr_fixup_test_FTR_macros_expected -
+ ftr_fixup_test_FTR_macros;
+
+ /* The fixups have already been done for us during boot */
+ check(memcmp(ftr_fixup_test_FTR_macros,
+ ftr_fixup_test_FTR_macros_expected, size) == 0);
+}
+
+static void __init test_fw_macros(void)
+{
+#ifdef CONFIG_PPC64
+ extern u8 ftr_fixup_test_FW_FTR_macros[];
+ extern u8 ftr_fixup_test_FW_FTR_macros_expected[];
+ unsigned long size = ftr_fixup_test_FW_FTR_macros_expected -
+ ftr_fixup_test_FW_FTR_macros;
+
+ /* The fixups have already been done for us during boot */
+ check(memcmp(ftr_fixup_test_FW_FTR_macros,
+ ftr_fixup_test_FW_FTR_macros_expected, size) == 0);
+#endif
+}
+
+static void __init test_lwsync_macros(void)
+{
+ extern u8 lwsync_fixup_test[];
+ extern u8 end_lwsync_fixup_test[];
+ extern u8 lwsync_fixup_test_expected_LWSYNC[];
+ extern u8 lwsync_fixup_test_expected_SYNC[];
+ unsigned long size = end_lwsync_fixup_test -
+ lwsync_fixup_test;
+
+ /* The fixups have already been done for us during boot */
+ if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) {
+ check(memcmp(lwsync_fixup_test,
+ lwsync_fixup_test_expected_LWSYNC, size) == 0);
+ } else {
+ check(memcmp(lwsync_fixup_test,
+ lwsync_fixup_test_expected_SYNC, size) == 0);
+ }
+}
+
+#ifdef CONFIG_PPC64
+static void __init test_prefix_patching(void)
+{
+ extern unsigned int ftr_fixup_prefix1[];
+ extern unsigned int end_ftr_fixup_prefix1[];
+ extern unsigned int ftr_fixup_prefix1_orig[];
+ extern unsigned int ftr_fixup_prefix1_expected[];
+ int size = sizeof(unsigned int) * (end_ftr_fixup_prefix1 - ftr_fixup_prefix1);
+
+ fixup.value = fixup.mask = 8;
+ fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix1 + 1);
+ fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix1 + 3);
+ fixup.alt_start_off = fixup.alt_end_off = 0;
+
+ /* Sanity check */
+ check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_orig, size) == 0);
+
+ patch_feature_section(0, &fixup);
+ check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_expected, size) == 0);
+ check(memcmp(ftr_fixup_prefix1, ftr_fixup_prefix1_orig, size) != 0);
+}
+
+static void __init test_prefix_alt_patching(void)
+{
+ extern unsigned int ftr_fixup_prefix2[];
+ extern unsigned int end_ftr_fixup_prefix2[];
+ extern unsigned int ftr_fixup_prefix2_orig[];
+ extern unsigned int ftr_fixup_prefix2_expected[];
+ extern unsigned int ftr_fixup_prefix2_alt[];
+ int size = sizeof(unsigned int) * (end_ftr_fixup_prefix2 - ftr_fixup_prefix2);
+
+ fixup.value = fixup.mask = 8;
+ fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix2 + 1);
+ fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix2 + 3);
+ fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_prefix2_alt);
+ fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_prefix2_alt + 2);
+ /* Sanity check */
+ check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_orig, size) == 0);
+
+ patch_feature_section(0, &fixup);
+ check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_expected, size) == 0);
+ check(memcmp(ftr_fixup_prefix2, ftr_fixup_prefix2_orig, size) != 0);
+}
+
+static void __init test_prefix_word_alt_patching(void)
+{
+ extern unsigned int ftr_fixup_prefix3[];
+ extern unsigned int end_ftr_fixup_prefix3[];
+ extern unsigned int ftr_fixup_prefix3_orig[];
+ extern unsigned int ftr_fixup_prefix3_expected[];
+ extern unsigned int ftr_fixup_prefix3_alt[];
+ int size = sizeof(unsigned int) * (end_ftr_fixup_prefix3 - ftr_fixup_prefix3);
+
+ fixup.value = fixup.mask = 8;
+ fixup.start_off = calc_offset(&fixup, ftr_fixup_prefix3 + 1);
+ fixup.end_off = calc_offset(&fixup, ftr_fixup_prefix3 + 4);
+ fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_prefix3_alt);
+ fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_prefix3_alt + 3);
+ /* Sanity check */
+ check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_orig, size) == 0);
+
+ patch_feature_section(0, &fixup);
+ check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_expected, size) == 0);
+ patch_feature_section(0, &fixup);
+ check(memcmp(ftr_fixup_prefix3, ftr_fixup_prefix3_orig, size) != 0);
+}
+#else
+static inline void test_prefix_patching(void) {}
+static inline void test_prefix_alt_patching(void) {}
+static inline void test_prefix_word_alt_patching(void) {}
+#endif /* CONFIG_PPC64 */
+
+static int __init test_feature_fixups(void)
+{
+ printk(KERN_DEBUG "Running feature fixup self-tests ...\n");
+
+ test_basic_patching();
+ test_alternative_patching();
+ test_alternative_case_too_big();
+ test_alternative_case_too_small();
+ test_alternative_case_with_branch();
+ test_alternative_case_with_external_branch();
+ test_alternative_case_with_branch_to_end();
+ test_cpu_macros();
+ test_fw_macros();
+ test_lwsync_macros();
+ test_prefix_patching();
+ test_prefix_alt_patching();
+ test_prefix_word_alt_patching();
+
+ return 0;
+}
+late_initcall(test_feature_fixups);
+
+#endif /* CONFIG_FTR_FIXUP_SELFTEST */