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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 09:43:07 +0200
commita6830095680b0161a0dc47c67d14160f79479ed3 (patch)
treeccd2f06fde4482b6b651d7f318f26b3f78c0441a
parentd92fa5e18a42ef9d88473ff7fd99dce68b808a6c (diff)
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>
-rw-r--r--arch/arm64/include/asm/cachetype.h5
-rw-r--r--arch/arm64/kernel/cpu_errata.c7
-rw-r--r--arch/arm64/kernel/cpufeature.c4
3 files changed, 12 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/cachetype.h b/arch/arm64/include/asm/cachetype.h
index f5588692f1d4..877d4789dcb3 100644
--- a/arch/arm64/include/asm/cachetype.h
+++ b/arch/arm64/include/asm/cachetype.h
@@ -22,6 +22,11 @@
#define CTR_L1IP_MASK 3
#define CTR_CWG_SHIFT 24
#define CTR_CWG_MASK 15
+#define CTR_DMINLINE_SHIFT 16
+#define CTR_IMINLINE_SHIFT 0
+
+#define CTR_CACHE_MINLINE_MASK \
+ ((0xf << CTR_DMINLINE_SHIFT) | (0xf << CTR_IMINLINE_SHIFT))
#define ICACHE_POLICY_RESERVED 0
#define ICACHE_POLICY_AIVIVT 1
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 1db97ad7b58b..fe604bbf5cac 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -17,6 +17,7 @@
*/
#include <linux/types.h>
+#include <asm/cachetype.h>
#include <asm/cpu.h>
#include <asm/cputype.h>
#include <asm/cpufeature.h>
@@ -34,9 +35,11 @@ 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 ab15747a49d4..a3ab7dfad50a 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -152,7 +152,7 @@ static const struct arm64_ftr_bits ftr_ctr[] = {
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 3, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0), /* CWG */
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0), /* ERG */
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1), /* DminLine */
+ ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, CTR_DMINLINE_SHIFT, 4, 1),
/*
* Linux can handle differing I-cache policies. Userspace JITs will
* make use of *minLine.
@@ -160,7 +160,7 @@ static const struct arm64_ftr_bits ftr_ctr[] = {
*/
ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_AIVIVT), /* L1Ip */
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 10, 0), /* RAZ */
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* IminLine */
+ ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, CTR_IMINLINE_SHIFT, 4, 0),
ARM64_FTR_END,
};