[PATCH stable 2/2] arm64: Handle mismatched cache type

From: Suzuki K Poulose
Date: Mon Sep 03 2018 - 06:01:44 EST


commit 314d53d297980676011e6fd83dac60db4a01dc70 upstream

Track mismatches in the cache type register (CTR_EL0), other
than the D/I min line sizes and trap user accesses if there are any.

Fixes: be68a8aaf925 ("arm64: cpufeature: Fix CTR_EL0 field definitions")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.14
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
---
arch/arm64/include/asm/cpucaps.h | 3 ++-
arch/arm64/kernel/cpu_errata.c | 17 ++++++++++++++---
2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 76c0d23..7d6425d 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -44,7 +44,8 @@
#define ARM64_HARDEN_BRANCH_PREDICTOR 24
#define ARM64_HARDEN_BP_POST_GUEST_EXIT 25
#define ARM64_SSBD 26
+#define ARM64_MISMATCHED_CACHE_TYPE 27

-#define ARM64_NCAPS 27
+#define ARM64_NCAPS 28

#endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 3d1569c..762b1ad 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -45,11 +45,15 @@ is_kryo_midr(const struct arm64_cpu_capabilities *entry, int scope)
}

static bool
-has_mismatched_cache_line_size(const struct arm64_cpu_capabilities *entry,
- int scope)
+has_mismatched_cache_type(const struct arm64_cpu_capabilities *entry,
+ int scope)
{
u64 mask = CTR_CACHE_MINLINE_MASK;

+ /* Skip matching the min line sizes for cache type check */
+ if (entry->capability == ARM64_MISMATCHED_CACHE_TYPE)
+ mask ^= arm64_ftr_reg_ctrel0.strict_mask;
+
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
return (read_cpuid_cachetype() & mask) !=
(arm64_ftr_reg_ctrel0.sys_val & mask);
@@ -513,7 +517,14 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
{
.desc = "Mismatched cache line size",
.capability = ARM64_MISMATCHED_CACHE_LINE_SIZE,
- .matches = has_mismatched_cache_line_size,
+ .matches = has_mismatched_cache_type,
+ .def_scope = SCOPE_LOCAL_CPU,
+ .enable = cpu_enable_trap_ctr_access,
+ },
+ {
+ .desc = "Mismatched cache type",
+ .capability = ARM64_MISMATCHED_CACHE_TYPE,
+ .matches = has_mismatched_cache_type,
.def_scope = SCOPE_LOCAL_CPU,
.enable = cpu_enable_trap_ctr_access,
},
--
2.7.4