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authorSuzuki K Poulose <suzuki.poulose@arm.com>2018-07-04 23:07:45 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-15 09:45:36 +0200
commit469c89aa5d7e1a616a174d89d085011de5d75b75 (patch)
tree8311e8d57c03635bb935f3e6f1d31f9e82368391 /arch
parent0d2e80411a1a24cc39be3449e62d5621db57bed8 (diff)
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arm64: Fix mismatched cache line size detection
commit 4c4a39dd5fe2d13e2d2fa5fceb8ef95d19fc389a upstream. If there is a mismatch in the I/D min line size, we must always use the system wide safe value both in applications and in the kernel, while performing cache operations. However, we have been checking more bits than just the min line sizes, which triggers false negatives. We may need to trap the user accesses in such cases, but not necessarily patch the kernel. This patch fixes the check to do the right thing as advertised. A new capability will be added to check mismatches in other fields and ensure we trap the CTR accesses. Fixes: be68a8aaf925 ("arm64: cpufeature: Fix CTR_EL0 field definitions") Cc: <stable@vger.kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/cache.h5
-rw-r--r--arch/arm64/kernel/cpu_errata.c6
-rw-r--r--arch/arm64/kernel/cpufeature.c4
3 files changed, 11 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h
index ea9bb4e0e9bb..e40f8a2df545 100644
--- a/arch/arm64/include/asm/cache.h
+++ b/arch/arm64/include/asm/cache.h
@@ -20,9 +20,14 @@
#define CTR_L1IP_SHIFT 14
#define CTR_L1IP_MASK 3
+#define CTR_DMINLINE_SHIFT 16
+#define CTR_IMINLINE_SHIFT 0
#define CTR_CWG_SHIFT 24
#define CTR_CWG_MASK 15
+#define CTR_CACHE_MINLINE_MASK \
+ (0xf << CTR_DMINLINE_SHIFT | 0xf << CTR_IMINLINE_SHIFT)
+
#define CTR_L1IP(ctr) (((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK)
#define ICACHE_POLICY_VPIPT 0
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 4bdf72bd79de..81016cc59d59 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -50,9 +50,11 @@ static bool
has_mismatched_cache_line_size(const struct arm64_cpu_capabilities *entry,
int scope)
{
+ u64 mask = CTR_CACHE_MINLINE_MASK;
+
WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
- return (read_cpuid_cachetype() & arm64_ftr_reg_ctrel0.strict_mask) !=
- (arm64_ftr_reg_ctrel0.sys_val & arm64_ftr_reg_ctrel0.strict_mask);
+ return (read_cpuid_cachetype() & mask) !=
+ (arm64_ftr_reg_ctrel0.sys_val & mask);
}
static int cpu_enable_trap_ctr_access(void *__unused)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 376cf12edf0c..003dd39225a0 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -180,14 +180,14 @@ static const struct arm64_ftr_bits ftr_ctr[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 28, 1, 1), /* IDC */
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0), /* CWG */
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, 20, 4, 0), /* ERG */
- ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1), /* DminLine */
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
/*
* Linux can handle differing I-cache policies. Userspace JITs will
* make use of *minLine.
* If we have differing I-cache policies, report it as the weakest - VIPT.
*/
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_VIPT), /* L1Ip */
- ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* IminLine */
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0),
ARM64_FTR_END,
};