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Subject[PATCH v3 10/24] arm64: Consolidate CPU Sanity check to CPU Feature infrastructure
Date
This patch consolidates the CPU Sanity check to the new infrastructure.

Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
---
arch/arm64/include/asm/cpu.h | 3 +-
arch/arm64/kernel/cpufeature.c | 164 ++++++++++++++++++++++++++++++++--------
arch/arm64/kernel/cpuinfo.c | 113 +--------------------------
3 files changed, 134 insertions(+), 146 deletions(-)

diff --git a/arch/arm64/include/asm/cpu.h b/arch/arm64/include/asm/cpu.h
index 704c17b..b5e9cee 100644
--- a/arch/arm64/include/asm/cpu.h
+++ b/arch/arm64/include/asm/cpu.h
@@ -64,6 +64,7 @@ void cpuinfo_store_cpu(void);
void __init cpuinfo_store_boot_cpu(void);

void __init init_cpu_features(struct cpuinfo_arm64 *info);
-void update_cpu_features(struct cpuinfo_arm64 *info);
+void update_cpu_features(int cpu, struct cpuinfo_arm64 *info,
+ struct cpuinfo_arm64 *boot);

#endif /* __ASM_CPU_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 092bd83..70f1ae0 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -412,12 +412,9 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
update_mixed_endian_el0_support(info);
}

-static void update_cpu_ftr_reg(u32 sys_reg, u64 new)
+static void update_cpu_ftr_reg(struct arm64_ftr_reg *reg, u64 new)
{
struct arm64_ftr_bits *ftrp;
- struct arm64_ftr_reg *reg = get_arm64_sys_reg(sys_reg);
-
- BUG_ON(!reg);

for(ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
s64 ftr_cur = arm64_ftr_value(ftrp, reg->sys_val);
@@ -432,36 +429,137 @@ static void update_cpu_ftr_reg(u32 sys_reg, u64 new)

}

-/* Update CPU feature register from non-boot CPU */
-void update_cpu_features(struct cpuinfo_arm64 *info)
+static int check_update_ftr_reg(u32 sys_reg, int cpu, u64 val, u64 boot)
{
- update_cpu_ftr_reg(SYS_CTR_EL0, info->reg_ctr);
- update_cpu_ftr_reg(SYS_DCZID_EL0, info->reg_dczid);
- update_cpu_ftr_reg(SYS_CNTFRQ_EL0, info->reg_cntfrq);
- update_cpu_ftr_reg(SYS_ID_AA64DFR0_EL1, info->reg_id_aa64dfr0);
- update_cpu_ftr_reg(SYS_ID_AA64DFR1_EL1, info->reg_id_aa64dfr1);
- update_cpu_ftr_reg(SYS_ID_AA64ISAR0_EL1, info->reg_id_aa64isar0);
- update_cpu_ftr_reg(SYS_ID_AA64ISAR1_EL1, info->reg_id_aa64isar1);
- update_cpu_ftr_reg(SYS_ID_AA64MMFR0_EL1, info->reg_id_aa64mmfr0);
- update_cpu_ftr_reg(SYS_ID_AA64MMFR1_EL1, info->reg_id_aa64mmfr1);
- update_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
- update_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
- update_cpu_ftr_reg(SYS_ID_DFR0_EL1, info->reg_id_dfr0);
- update_cpu_ftr_reg(SYS_ID_ISAR0_EL1, info->reg_id_isar0);
- update_cpu_ftr_reg(SYS_ID_ISAR1_EL1, info->reg_id_isar1);
- update_cpu_ftr_reg(SYS_ID_ISAR2_EL1, info->reg_id_isar2);
- update_cpu_ftr_reg(SYS_ID_ISAR3_EL1, info->reg_id_isar3);
- update_cpu_ftr_reg(SYS_ID_ISAR4_EL1, info->reg_id_isar4);
- update_cpu_ftr_reg(SYS_ID_ISAR5_EL1, info->reg_id_isar5);
- update_cpu_ftr_reg(SYS_ID_MMFR0_EL1, info->reg_id_mmfr0);
- update_cpu_ftr_reg(SYS_ID_MMFR1_EL1, info->reg_id_mmfr1);
- update_cpu_ftr_reg(SYS_ID_MMFR2_EL1, info->reg_id_mmfr2);
- update_cpu_ftr_reg(SYS_ID_MMFR3_EL1, info->reg_id_mmfr3);
- update_cpu_ftr_reg(SYS_ID_PFR0_EL1, info->reg_id_pfr0);
- update_cpu_ftr_reg(SYS_ID_PFR1_EL1, info->reg_id_pfr1);
- update_cpu_ftr_reg(SYS_MVFR0_EL1, info->reg_mvfr0);
- update_cpu_ftr_reg(SYS_MVFR1_EL1, info->reg_mvfr1);
- update_cpu_ftr_reg(SYS_MVFR2_EL1, info->reg_mvfr2);
+ struct arm64_ftr_reg *regp = get_arm64_sys_reg(sys_reg);
+
+ BUG_ON(!regp);
+ update_cpu_ftr_reg(regp, val);
+ if ((boot & regp->strict_mask) == (val & regp->strict_mask))
+ return 0;
+ pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016llx, CPU%d: %#016llx\n",
+ regp->name, boot, cpu, val);
+ return 1;
+}
+
+/*
+ * Update system wide CPU feature registers with the values from a
+ * non-boot CPU. Also performs SANITY checks to make sure that there
+ * aren't any insane variations from that of the boot CPU.
+ */
+void update_cpu_features(int cpu,
+ struct cpuinfo_arm64 *info,
+ struct cpuinfo_arm64 *boot)
+{
+ int taint = 0;
+
+ /*
+ * The kernel can handle differing I-cache policies, but otherwise
+ * caches should look identical. Userspace JITs will make use of
+ * *minLine.
+ */
+ taint |= check_update_ftr_reg(SYS_CTR_EL0, cpu,
+ info->reg_ctr, boot->reg_ctr);
+
+ /*
+ * Userspace may perform DC ZVA instructions. Mismatched block sizes
+ * could result in too much or too little memory being zeroed if a
+ * process is preempted and migrated between CPUs.
+ */
+ taint |= check_update_ftr_reg(SYS_DCZID_EL0, cpu,
+ info->reg_dczid, boot->reg_dczid);
+
+ /* If different, timekeeping will be broken (especially with KVM) */
+ taint |= check_update_ftr_reg(SYS_CNTFRQ_EL0, cpu,
+ info->reg_cntfrq, boot->reg_cntfrq);
+
+ /*
+ * The kernel uses self-hosted debug features and expects CPUs to
+ * support identical debug features. We presently need CTX_CMPs, WRPs,
+ * and BRPs to be identical.
+ * ID_AA64DFR1 is currently RES0.
+ */
+ taint |= check_update_ftr_reg(SYS_ID_AA64DFR0_EL1, cpu,
+ info->reg_id_aa64dfr0, boot->reg_id_aa64dfr0);
+ taint |= check_update_ftr_reg(SYS_ID_AA64DFR1_EL1, cpu,
+ info->reg_id_aa64dfr1, boot->reg_id_aa64dfr1);
+ /*
+ * Even in big.LITTLE, processors should be identical instruction-set
+ * wise.
+ */
+ taint |= check_update_ftr_reg(SYS_ID_AA64ISAR0_EL1, cpu,
+ info->reg_id_aa64isar0, boot->reg_id_aa64isar0);
+ taint |= check_update_ftr_reg(SYS_ID_AA64ISAR1_EL1, cpu,
+ info->reg_id_aa64isar1, boot->reg_id_aa64isar1);
+
+ /*
+ * Differing PARange support is fine as long as all peripherals and
+ * memory are mapped within the minimum PARange of all CPUs.
+ * Linux should not care about secure memory.
+ */
+ taint |= check_update_ftr_reg(SYS_ID_AA64MMFR0_EL1, cpu,
+ info->reg_id_aa64mmfr0, boot->reg_id_aa64mmfr0);
+ taint |= check_update_ftr_reg(SYS_ID_AA64MMFR1_EL1, cpu,
+ info->reg_id_aa64mmfr1, boot->reg_id_aa64mmfr1);
+
+ /*
+ * EL3 is not our concern.
+ * ID_AA64PFR1 is currently RES0.
+ */
+ taint |= check_update_ftr_reg(SYS_ID_AA64PFR0_EL1, cpu,
+ info->reg_id_aa64pfr0, boot->reg_id_aa64pfr0);
+ taint |= check_update_ftr_reg(SYS_ID_AA64PFR1_EL1, cpu,
+ info->reg_id_aa64pfr1, boot->reg_id_aa64pfr1);
+
+ /*
+ * If we have AArch32, we care about 32-bit features for compat. These
+ * registers should be RES0 otherwise.
+ */
+ taint |= check_update_ftr_reg(SYS_ID_DFR0_EL1, cpu,
+ info->reg_id_dfr0, boot->reg_id_dfr0);
+ taint |= check_update_ftr_reg(SYS_ID_ISAR0_EL1, cpu,
+ info->reg_id_isar0, boot->reg_id_isar0);
+ taint |= check_update_ftr_reg(SYS_ID_ISAR1_EL1, cpu,
+ info->reg_id_isar1, boot->reg_id_isar1);
+ taint |= check_update_ftr_reg(SYS_ID_ISAR2_EL1, cpu,
+ info->reg_id_isar2, boot->reg_id_isar2);
+ taint |= check_update_ftr_reg(SYS_ID_ISAR3_EL1, cpu,
+ info->reg_id_isar3, boot->reg_id_isar3);
+ taint |= check_update_ftr_reg(SYS_ID_ISAR4_EL1, cpu,
+ info->reg_id_isar4, boot->reg_id_isar4);
+ taint |= check_update_ftr_reg(SYS_ID_ISAR5_EL1, cpu,
+ info->reg_id_isar5, boot->reg_id_isar5);
+
+ /*
+ * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
+ * ACTLR formats could differ across CPUs and therefore would have to
+ * be trapped for virtualization anyway.
+ */
+ taint |= check_update_ftr_reg(SYS_ID_MMFR0_EL1, cpu,
+ info->reg_id_mmfr0, boot->reg_id_mmfr0);
+ taint |= check_update_ftr_reg(SYS_ID_MMFR1_EL1, cpu,
+ info->reg_id_mmfr1, boot->reg_id_mmfr1);
+ taint |= check_update_ftr_reg(SYS_ID_MMFR2_EL1, cpu,
+ info->reg_id_mmfr2, boot->reg_id_mmfr2);
+ taint |= check_update_ftr_reg(SYS_ID_MMFR3_EL1, cpu,
+ info->reg_id_mmfr3, boot->reg_id_mmfr3);
+ taint |= check_update_ftr_reg(SYS_ID_PFR0_EL1, cpu,
+ info->reg_id_pfr0, boot->reg_id_pfr0);
+ taint |= check_update_ftr_reg(SYS_ID_PFR1_EL1, cpu,
+ info->reg_id_pfr1, boot->reg_id_pfr1);
+ taint |= check_update_ftr_reg(SYS_MVFR0_EL1, cpu,
+ info->reg_mvfr0, boot->reg_mvfr0);
+ taint |= check_update_ftr_reg(SYS_MVFR1_EL1, cpu,
+ info->reg_mvfr1, boot->reg_mvfr1);
+ taint |= check_update_ftr_reg(SYS_MVFR2_EL1, cpu,
+ info->reg_mvfr2, boot->reg_mvfr2);
+
+ /*
+ * Mismatched CPU features are a recipe for disaster. Don't even
+ * pretend to support them.
+ */
+ WARN_TAINT_ONCE(taint, TAINT_CPU_OUT_OF_SPEC,
+ "Unsupported CPU feature variation.\n");

update_mixed_endian_el0_support(info);
}
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 857aaf0..f25869e 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -192,116 +192,6 @@ static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
}

-static int check_reg_mask(char *name, u64 mask, u64 boot, u64 cur, int cpu)
-{
- if ((boot & mask) == (cur & mask))
- return 0;
-
- pr_warn("SANITY CHECK: Unexpected variation in %s. Boot CPU: %#016lx, CPU%d: %#016lx\n",
- name, (unsigned long)boot, cpu, (unsigned long)cur);
-
- return 1;
-}
-
-#define CHECK_MASK(field, mask, boot, cur, cpu) \
- check_reg_mask(#field, mask, (boot)->reg_ ## field, (cur)->reg_ ## field, cpu)
-
-#define CHECK(field, boot, cur, cpu) \
- CHECK_MASK(field, ~0ULL, boot, cur, cpu)
-
-/*
- * Verify that CPUs don't have unexpected differences that will cause problems.
- */
-static void cpuinfo_sanity_check(struct cpuinfo_arm64 *cur)
-{
- unsigned int cpu = smp_processor_id();
- struct cpuinfo_arm64 *boot = &boot_cpu_data;
- unsigned int diff = 0;
-
- /*
- * The kernel can handle differing I-cache policies, but otherwise
- * caches should look identical. Userspace JITs will make use of
- * *minLine.
- */
- diff |= CHECK_MASK(ctr, 0xffff3fff, boot, cur, cpu);
-
- /*
- * Userspace may perform DC ZVA instructions. Mismatched block sizes
- * could result in too much or too little memory being zeroed if a
- * process is preempted and migrated between CPUs.
- */
- diff |= CHECK(dczid, boot, cur, cpu);
-
- /* If different, timekeeping will be broken (especially with KVM) */
- diff |= CHECK(cntfrq, boot, cur, cpu);
-
- /*
- * The kernel uses self-hosted debug features and expects CPUs to
- * support identical debug features. We presently need CTX_CMPs, WRPs,
- * and BRPs to be identical.
- * ID_AA64DFR1 is currently RES0.
- */
- diff |= CHECK(id_aa64dfr0, boot, cur, cpu);
- diff |= CHECK(id_aa64dfr1, boot, cur, cpu);
-
- /*
- * Even in big.LITTLE, processors should be identical instruction-set
- * wise.
- */
- diff |= CHECK(id_aa64isar0, boot, cur, cpu);
- diff |= CHECK(id_aa64isar1, boot, cur, cpu);
-
- /*
- * Differing PARange support is fine as long as all peripherals and
- * memory are mapped within the minimum PARange of all CPUs.
- * Linux should not care about secure memory.
- * ID_AA64MMFR1 is currently RES0.
- */
- diff |= CHECK_MASK(id_aa64mmfr0, 0xffffffffffff0ff0, boot, cur, cpu);
- diff |= CHECK(id_aa64mmfr1, boot, cur, cpu);
-
- /*
- * EL3 is not our concern.
- * ID_AA64PFR1 is currently RES0.
- */
- diff |= CHECK_MASK(id_aa64pfr0, 0xffffffffffff0fff, boot, cur, cpu);
- diff |= CHECK(id_aa64pfr1, boot, cur, cpu);
-
- /*
- * If we have AArch32, we care about 32-bit features for compat. These
- * registers should be RES0 otherwise.
- */
- diff |= CHECK(id_dfr0, boot, cur, cpu);
- diff |= CHECK(id_isar0, boot, cur, cpu);
- diff |= CHECK(id_isar1, boot, cur, cpu);
- diff |= CHECK(id_isar2, boot, cur, cpu);
- diff |= CHECK(id_isar3, boot, cur, cpu);
- diff |= CHECK(id_isar4, boot, cur, cpu);
- diff |= CHECK(id_isar5, boot, cur, cpu);
- /*
- * Regardless of the value of the AuxReg field, the AIFSR, ADFSR, and
- * ACTLR formats could differ across CPUs and therefore would have to
- * be trapped for virtualization anyway.
- */
- diff |= CHECK_MASK(id_mmfr0, 0xff0fffff, boot, cur, cpu);
- diff |= CHECK(id_mmfr1, boot, cur, cpu);
- diff |= CHECK(id_mmfr2, boot, cur, cpu);
- diff |= CHECK(id_mmfr3, boot, cur, cpu);
- diff |= CHECK(id_pfr0, boot, cur, cpu);
- diff |= CHECK(id_pfr1, boot, cur, cpu);
-
- diff |= CHECK(mvfr0, boot, cur, cpu);
- diff |= CHECK(mvfr1, boot, cur, cpu);
- diff |= CHECK(mvfr2, boot, cur, cpu);
-
- /*
- * Mismatched CPU features are a recipe for disaster. Don't even
- * pretend to support them.
- */
- WARN_TAINT_ONCE(diff, TAINT_CPU_OUT_OF_SPEC,
- "Unsupported CPU feature variation.\n");
-}
-
static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
{
info->reg_cntfrq = arch_timer_get_cntfrq();
@@ -346,8 +236,7 @@ void cpuinfo_store_cpu(void)
{
struct cpuinfo_arm64 *info = this_cpu_ptr(&cpu_data);
__cpuinfo_store_cpu(info);
- cpuinfo_sanity_check(info);
- update_cpu_features(info);
+ update_cpu_features(smp_processor_id(), info, &boot_cpu_data);
}

void __init cpuinfo_store_boot_cpu(void)
--
1.7.9.5


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