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| author |   Marc Zyngier <marc.zyngier@arm.com> | 2015-06-03 14:36:23 +0100 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2015-06-05 10:38:52 +0100 |
| commit | b0dd9c02d476162340ad60fc96befa817fa8fe9f (patch) | |
| tree | da38aa4858c587ef098f1097bcfb8796eefdfbcd /arch/arm64/kernel | |
| parent | arm64: insn: Add aarch64_{get,set}_branch_offset (diff) | |
| download | linux-dev-b0dd9c02d476162340ad60fc96befa817fa8fe9f.tar.xz linux-dev-b0dd9c02d476162340ad60fc96befa817fa8fe9f.zip | |
arm64: Rework alternate sequence for ARM erratum 845719
The workaround for erratum 845719 is currently using
a branch between two alternate sequences, which is
quite fragile, and that we are going to break as we
rework the alternative code.
This patch reworks the workaround to fit in a single
alternative sequence. The generated code itself is
unchanged.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/entry.S | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 959fe8733560..9fe1a85c2027 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -124,21 +124,24 @@ msr sp_el0, x23 #ifdef CONFIG_ARM64_ERRATUM_845719 - alternative_insn \ - "nop", \ - "tbz x22, #4, 1f", \ - ARM64_WORKAROUND_845719 + +#undef SEQUENCE_ORG +#undef SEQUENCE_ALT + #ifdef CONFIG_PID_IN_CONTEXTIDR - alternative_insn \ - "nop; nop", \ - "mrs x29, contextidr_el1; msr contextidr_el1, x29; 1:", \ - ARM64_WORKAROUND_845719 + +#define SEQUENCE_ORG "nop ; nop ; nop" +#define SEQUENCE_ALT "tbz x22, #4, 1f ; mrs x29, contextidr_el1; msr contextidr_el1, x29; 1:" + #else - alternative_insn \ - "nop", \ - "msr contextidr_el1, xzr; 1:", \ - ARM64_WORKAROUND_845719 + +#define SEQUENCE_ORG "nop ; nop" +#define SEQUENCE_ALT "tbz x22, #4, 1f ; msr contextidr_el1, xzr; 1:" + #endif + + alternative_insn SEQUENCE_ORG, SEQUENCE_ALT, ARM64_WORKAROUND_845719 + #endif .endif msr elr_el1, x21 // set up the return data |