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| author | Suzuki K Poulose <suzuki.poulose@arm.com> | 2018-10-09 16:47:07 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-10-16 13:53:34 +0300 |
| commit | 4afe8e79da920bdf6698b01bc668fffc6758f37b (patch) | |
| tree | d2c1918b8acb95d4b5b36c103c82057cac9cd4a1 | |
| parent | 1602df02f33f61fe0de1bbfeba0d1c97c14bff19 (diff) | |
| download | linux-4afe8e79da920bdf6698b01bc668fffc6758f37b.tar.xz | |
arm64: cpufeature: Trap CTR_EL0 access only where it is necessary
When there is a mismatch in the CTR_EL0 field, we trap
access to CTR from EL0 on all CPUs to expose the safe
value. However, we could skip trapping on a CPU which
matches the safe value.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 3deb01c6ed49..9af8df96ec49 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -99,7 +99,12 @@ has_mismatched_cache_type(const struct arm64_cpu_capabilities *entry, static void cpu_enable_trap_ctr_access(const struct arm64_cpu_capabilities *__unused) { - sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0); + u64 mask = arm64_ftr_reg_ctrel0.strict_mask; + + /* Trap CTR_EL0 access on this CPU, only if it has a mismatch */ + if ((read_cpuid_cachetype() & mask) != + (arm64_ftr_reg_ctrel0.sys_val & mask)) + sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0); } atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); |