From: Marc Zyngier <marc.zyngier@xxxxxxx>
Commit 95e3de3590e3 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: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm64/include/asm/assembler.h | 13 -------------
arch/arm64/kernel/entry.S | 2 +-
arch/arm64/mm/context.c | 9 +++++++++
arch/arm64/mm/proc.S | 3 +--
4 files changed, 11 insertions(+), 16 deletions(-)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 6d951a82e656..463619dcadd4 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -481,19 +481,6 @@ alternative_endif
mrs \rd, sp_el0
.endm
-/*
- * Errata workaround post TTBRx_EL1 update.
- */
- .macro post_ttbr_update_workaround
-#ifdef CONFIG_CAVIUM_ERRATUM_27456
-alternative_if ARM64_WORKAROUND_CAVIUM_27456
- ic iallu
- dsb nsh
- isb
-alternative_else_nop_endif
-#endif
- .endm
-
/**
* Errata workaround prior to disable MMU. Insert an ISB immediately prior
* to executing the MSR that will change SCTLR_ELn[M] from a value of 1 to 0.
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index f786e8d3d5be..185c87a53fe3 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -275,7 +275,7 @@ alternative_else_nop_endif
* Cavium erratum 27456 (broadcast TLBI instructions may cause I-cache
* corruption).
*/
- post_ttbr_update_workaround
+ bl post_ttbr_update_workaround
.endif
1:
.if \el != 0
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
index db28958d9e4f..23498d032c82 100644
--- a/arch/arm64/mm/context.c
+++ b/arch/arm64/mm/context.c
@@ -235,6 +235,15 @@ 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)
{
asid_bits = get_cpu_asid_bits();
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index c25e58bc2910..27058f3fd132 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -148,8 +148,7 @@ ENTRY(cpu_do_switch_mm)
isb
msr ttbr0_el1, x0 // now update TTBR0
isb
- post_ttbr_update_workaround
- ret
+ b post_ttbr_update_workaround // Back to C code...
ENDPROC(cpu_do_switch_mm)
.pushsection ".idmap.text", "awx"
--
2.11.0