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authorMarc Zyngier <marc.zyngier@arm.com>2018-01-02 21:19:39 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-16 22:22:53 +0300
commitc10e4aa77814063ac459fab673a5a392b7334b42 (patch)
treeffd6811249594e33c001fa04256a84141888b591 /arch/arm64
parentf91f190708b25df0a5675800bcabae13bf2aa882 (diff)
downloadlinux-c10e4aa77814063ac459fab673a5a392b7334b42.tar.xz
arm64: Move post_ttbr_update_workaround to C code
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@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/assembler.h13
-rw-r--r--arch/arm64/kernel/entry.S2
-rw-r--r--arch/arm64/mm/context.c9
-rw-r--r--arch/arm64/mm/proc.S3
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 @@ 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 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"