diff options
| author | Marc Zyngier <marc.zyngier@arm.com> | 2015-11-16 10:28:18 +0000 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2015-11-24 17:58:14 +0100 |
| commit | 498cd5c32be6e32bc0f8efcad48ab094bb2bfdf3 (patch) | |
| tree | a82a2907c46684fcb8d15909de334dc48459a22e /arch | |
| parent | c0f0963464c24e034b858441205455bf2a5d93ad (diff) | |
| download | linux-498cd5c32be6e32bc0f8efcad48ab094bb2bfdf3.tar.bz2 | |
arm64: KVM: Add workaround for Cortex-A57 erratum 834220
Cortex-A57 parts up to r1p2 can misreport Stage 2 translation faults
when a Stage 1 permission fault or device alignment fault should
have been reported.
This patch implements the workaround (which is to validate that the
Stage-1 translation actually succeeds) by using code patching.
Cc: stable@vger.kernel.org
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/Kconfig | 21 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 3 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 9 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp.S | 6 |
4 files changed, 38 insertions, 1 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 9ac16a482ff1..e55848c1edf4 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -316,6 +316,27 @@ config ARM64_ERRATUM_832075 If unsure, say Y. +config ARM64_ERRATUM_834220 + bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" + depends on KVM + default y + help + This option adds an alternative code sequence to work around ARM + erratum 834220 on Cortex-A57 parts up to r1p2. + + Affected Cortex-A57 parts might report a Stage 2 translation + fault as the result of a Stage 1 fault for load crossing a + page boundary when there is a permission or device memory + alignment fault at Stage 1 and a translation fault at Stage 2. + + The workaround is to verify that the Stage 1 translation + doesn't generate a fault before handling the Stage 2 fault. + Please note that this does not necessarily enable the workaround, + as it depends on the alternative framework, which will only patch + the kernel if an affected CPU is detected. + + If unsure, say Y. + config ARM64_ERRATUM_845719 bool "Cortex-A53: 845719: a load might read incorrect data" depends on COMPAT diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 11d5bb0fdd54..52722ee73dba 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -29,8 +29,9 @@ #define ARM64_HAS_PAN 4 #define ARM64_HAS_LSE_ATOMICS 5 #define ARM64_WORKAROUND_CAVIUM_23154 6 +#define ARM64_WORKAROUND_834220 7 -#define ARM64_NCAPS 7 +#define ARM64_NCAPS 8 #ifndef __ASSEMBLY__ diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 24926f2504f7..feb6b4efa641 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -75,6 +75,15 @@ const struct arm64_cpu_capabilities arm64_errata[] = { (1 << MIDR_VARIANT_SHIFT) | 2), }, #endif +#ifdef CONFIG_ARM64_ERRATUM_834220 + { + /* Cortex-A57 r0p0 - r1p2 */ + .desc = "ARM erratum 834220", + .capability = ARM64_WORKAROUND_834220, + MIDR_RANGE(MIDR_CORTEX_A57, 0x00, + (1 << MIDR_VARIANT_SHIFT) | 2), + }, +#endif #ifdef CONFIG_ARM64_ERRATUM_845719 { /* Cortex-A53 r0p[01234] */ diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index 1599701ef044..ff2e038f0007 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -1015,9 +1015,15 @@ el1_trap: b.ne 1f // Not an abort we care about /* This is an abort. Check for permission fault */ +alternative_if_not ARM64_WORKAROUND_834220 and x2, x1, #ESR_ELx_FSC_TYPE cmp x2, #FSC_PERM b.ne 1f // Not a permission fault +alternative_else + nop // Use the permission fault path to + nop // check for a valid S1 translation, + nop // regardless of the ESR value. +alternative_endif /* * Check for Stage-1 page table walk, which is guaranteed |