From 85d13c001497b481b4a8cc5d7db243cc44ac2bd8 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 10 Aug 2017 13:29:06 +0100 Subject: [PATCH] arm64: mm: Remove pre_ttbr0_update_workaround for Falkor erratum #E1003 The pre_ttbr0_update_workaround hook is called prior to context-switching TTBR0 because Falkor erratum E1003 can cause TLB allocation with the wrong ASID if both the ASID and the base address of the TTBR are updated at the same time. With the ASID sitting safely in TTBR1, we no longer update things atomically, so we can remove the pre_ttbr0_update_workaround macro as it's no longer required. The erratum infrastructure and documentation is left around for #E1003, as it will be required by the entry trampoline code in a future patch. Reviewed-by: Mark Rutland Tested-by: Laura Abbott Tested-by: Shanker Donthineni Signed-off-by: Will Deacon --- arch/arm64/include/asm/assembler.h | 22 ---------------------- arch/arm64/include/asm/mmu_context.h | 2 -- arch/arm64/mm/context.c | 11 ----------- arch/arm64/mm/proc.S | 1 - 4 files changed, 36 deletions(-) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index aef72d886677..e1fa5db858b7 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -26,7 +26,6 @@ #include #include #include -#include #include #include #include @@ -478,27 +477,6 @@ alternative_endif .endm /* - * Errata workaround prior to TTBR0_EL1 update - * - * val: TTBR value with new BADDR, preserved - * tmp0: temporary register, clobbered - * tmp1: other temporary register, clobbered - */ - .macro pre_ttbr0_update_workaround, val, tmp0, tmp1 -#ifdef CONFIG_QCOM_FALKOR_ERRATUM_1003 -alternative_if ARM64_WORKAROUND_QCOM_FALKOR_E1003 - mrs \tmp0, ttbr0_el1 - mov \tmp1, #FALKOR_RESERVED_ASID - bfi \tmp0, \tmp1, #48, #16 // reserved ASID + old BADDR - msr ttbr0_el1, \tmp0 - isb - bfi \tmp0, \val, #0, #48 // reserved ASID + new BADDR - msr ttbr0_el1, \tmp0 - isb -alternative_else_nop_endif -#endif - .endm - /* * Errata workaround post TTBR0_EL1 update. */ diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index aa39c126c0d0..da29766a181c 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -19,8 +19,6 @@ #ifndef __ASM_MMU_CONTEXT_H #define __ASM_MMU_CONTEXT_H -#define FALKOR_RESERVED_ASID 1 - #ifndef __ASSEMBLY__ #include diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c index 6f4017046323..78a2dc596fee 100644 --- a/arch/arm64/mm/context.c +++ b/arch/arm64/mm/context.c @@ -79,13 +79,6 @@ void verify_cpu_asid_bits(void) } } -static void set_reserved_asid_bits(void) -{ - if (IS_ENABLED(CONFIG_QCOM_FALKOR_ERRATUM_1003) && - cpus_have_const_cap(ARM64_WORKAROUND_QCOM_FALKOR_E1003)) - __set_bit(FALKOR_RESERVED_ASID, asid_map); -} - static void flush_context(unsigned int cpu) { int i; @@ -94,8 +87,6 @@ static void flush_context(unsigned int cpu) /* Update the list of reserved ASIDs and the ASID bitmap. */ bitmap_clear(asid_map, 0, NUM_USER_ASIDS); - set_reserved_asid_bits(); - for_each_possible_cpu(i) { asid = atomic64_xchg_relaxed(&per_cpu(active_asids, i), 0); /* @@ -254,8 +245,6 @@ static int asids_init(void) panic("Failed to allocate bitmap for %lu ASIDs\n", NUM_USER_ASIDS); - set_reserved_asid_bits(); - pr_info("ASID allocator initialised with %lu entries\n", NUM_USER_ASIDS); return 0; } diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index a8a64898a2aa..f2ff0837577c 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -138,7 +138,6 @@ ENDPROC(cpu_do_resume) * - pgd_phys - physical address of new TTB */ ENTRY(cpu_do_switch_mm) - pre_ttbr0_update_workaround x0, x2, x3 mrs x2, ttbr1_el1 mmid x1, x1 // get mm->context.id bfi x2, x1, #48, #16 // set the ASID -- 2.30.2