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authorMark Rutland <mark.rutland@arm.com>2018-04-12 12:11:12 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-20 08:20:44 +0200
commit20bcfe09d404df14c2a3b0e3fa3ce56326bd8ced (patch)
tree2820b080d6725a9bf5cf7673d59c7991011facfc
parent965924ee9a73ee7509f0f3a261978931e33ef375 (diff)
arm64: Move post_ttbr_update_workaround to C code
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>
-rw-r--r--arch/arm64/include/asm/assembler.h13
-rw-r--r--arch/arm64/mm/context.c9
-rw-r--r--arch/arm64/mm/proc.S3
3 files changed, 10 insertions, 15 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index c9bd4ad4db82..e60375ce0dd2 100644
--- 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 */
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index f00f5eeb556f..b9b087564bac 100644
--- 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();
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 135a698ce946..619da1cbd32b 100644
--- 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"