4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Marc Zyngier <[email protected]> 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 <[email protected]> Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Catalin Marinas <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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(-) --- 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. --- 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 --- 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(); --- 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"
