4.9-stable review patch. If anyone has any objections, please let me know.
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From: Mark Rutland mark.rutland@arm.com
From: Marc Zyngier marc.zyngier@arm.com
commit 95e3de3590e3f2358bb13f013911bc1bfa5d3f53 upstream.
We will soon need to invoke a CPU-specific function pointer after changing page tables, so move post_ttbr_update_workaround out into C code to make this possible.
Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Mark Rutland mark.rutland@arm.com [v4.9 backport] Tested-by: Greg Hackmann ghackmann@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/include/asm/assembler.h | 13 ------------- arch/arm64/mm/context.c | 9 +++++++++ arch/arm64/mm/proc.S | 3 +-- 3 files changed, 10 insertions(+), 15 deletions(-)
--- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -435,17 +435,4 @@ alternative_endif and \phys, \pte, #(((1 << (48 - PAGE_SHIFT)) - 1) << PAGE_SHIFT) .endm
-/* - * Errata workaround post TTBR0_EL1 update. - */ - .macro post_ttbr0_update_workaround -#ifdef CONFIG_CAVIUM_ERRATUM_27456 -alternative_if ARM64_WORKAROUND_CAVIUM_27456 - ic iallu - dsb nsh - isb -alternative_else_nop_endif -#endif - .endm - #endif /* __ASM_ASSEMBLER_H */ --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -233,6 +233,15 @@ switch_mm_fastpath: cpu_switch_mm(mm->pgd, mm); }
+/* Errata workaround post TTBRx_EL1 update. */ +asmlinkage void post_ttbr_update_workaround(void) +{ + asm(ALTERNATIVE("nop; nop; nop", + "ic iallu; dsb nsh; isb", + ARM64_WORKAROUND_CAVIUM_27456, + CONFIG_CAVIUM_ERRATUM_27456)); +} + static int asids_init(void) { asid_bits = get_cpu_asid_bits(); --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -139,8 +139,7 @@ ENTRY(cpu_do_switch_mm) isb msr ttbr0_el1, x0 // now update TTBR0 isb - post_ttbr0_update_workaround - ret + b post_ttbr_update_workaround // Back to C code... ENDPROC(cpu_do_switch_mm)
.pushsection ".idmap.text", "awx"