4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mark Rutland <mark.rutland@xxxxxxx>
From: Marc Zyngier <marc.zyngier@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> [v4.9 backport]
Tested-by: Greg Hackmann <ghackmann@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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"