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 [ v4.4: Removed cpufeature.h, included alternative.h, dropped entry.S changes and adapted to drop alternative_if_not ] Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- arch/arm64/include/asm/assembler.h | 18 ------------------ arch/arm64/mm/context.c | 10 ++++++++++ arch/arm64/mm/proc.S | 3 +-- 3 files changed, 11 insertions(+), 20 deletions(-)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 8ab46508e836..2b30363a3a89 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -23,7 +23,6 @@ #ifndef __ASM_ASSEMBLER_H #define __ASM_ASSEMBLER_H
-#include <asm/cpufeature.h> #include <asm/cputype.h> #include <asm/ptrace.h> #include <asm/thread_info.h> @@ -283,21 +282,4 @@ lr .req x30 // link register .Ldone@: .endm
-/* - * Errata workaround post TTBR0_EL1 update. - */ - .macro post_ttbr0_update_workaround -#ifdef CONFIG_CAVIUM_ERRATUM_27456 -alternative_if_not ARM64_WORKAROUND_CAVIUM_27456 - ret - nop - nop - nop -alternative_else - ic iallu - dsb nsh - isb -#endif - .endm - #endif /* __ASM_ASSEMBLER_H */ diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index e87f53ff5f58..492d2968fa8f 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -22,6 +22,7 @@ #include <linux/slab.h> #include <linux/mm.h>
+#include <asm/alternative.h> #include <asm/cpufeature.h> #include <asm/mmu_context.h> #include <asm/tlbflush.h> @@ -185,6 +186,15 @@ void check_and_switch_context(struct mm_struct *mm, unsigned int cpu) 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) { int fld = cpuid_feature_extract_field(read_cpuid(ID_AA64MMFR0_EL1), 4); diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 4eb1084e203a..a70b712ca94a 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -139,8 +139,7 @@ ENTRY(cpu_do_switch_mm) bfi x0, x1, #48, #16 // set the ASID msr ttbr0_el1, x0 // set TTBR0 isb - post_ttbr0_update_workaround - ret + b post_ttbr_update_workaround // Back to C code... ENDPROC(cpu_do_switch_mm)
.section ".text.init", #alloc, #execinstr