From 429388682dc266e7a693f9c27e3aabd341d55343 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 22 Jun 2018 09:31:15 +0100 Subject: arm64: Avoid flush_icache_range() in alternatives patching code The implementation of flush_icache_range() includes instruction sequences which are themselves patched at runtime, so it is not safe to call from the patching framework. This patch reworks the alternatives cache-flushing code so that it rolls its own internal D-cache maintenance using DC CIVAC before invalidating the entire I-cache after all alternatives have been applied at boot. Modules don't cause any issues, since flush_icache_range() is safe to call by the time they are loaded. Acked-by: Mark Rutland Reported-by: Rohit Khanna Cc: Alexander Van Brunt Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/alternative.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'arch/arm64/include/asm') diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h index a91933b1e2e6..4b650ec1d7dd 100644 --- a/arch/arm64/include/asm/alternative.h +++ b/arch/arm64/include/asm/alternative.h @@ -28,7 +28,12 @@ typedef void (*alternative_cb_t)(struct alt_instr *alt, __le32 *origptr, __le32 *updptr, int nr_inst); void __init apply_alternatives_all(void); -void apply_alternatives(void *start, size_t length); + +#ifdef CONFIG_MODULES +void apply_alternatives_module(void *start, size_t length); +#else +static inline void apply_alternatives_module(void *start, size_t length) { } +#endif #define ALTINSTR_ENTRY(feature,cb) \ " .word 661b - .\n" /* label */ \ -- cgit v1.2.3 From 24fe1b0efad4fcdd32ce46cffeab297f22581707 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 22 Jun 2018 09:31:16 +0100 Subject: arm64: Remove unnecessary ISBs from set_{pte,pmd,pud} Commit 7f0b1bf04511 ("arm64: Fix barriers used for page table modifications") fixed a reported issue with fixmap page-table entries not being visible to the walker due to a missing DSB instruction. At the same time, it added ISB instructions to the arm64 set_{pte,pmd,pud} functions, which are not required by the architecture and make little sense in isolation. Remove the redundant ISBs. Acked-by: Catalin Marinas Acked-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'arch/arm64/include/asm') diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 9f82d6b53851..1bdeca8918a6 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -224,10 +224,8 @@ static inline void set_pte(pte_t *ptep, pte_t pte) * Only if the new pte is valid and kernel, otherwise TLB maintenance * or update_mmu_cache() have the necessary barriers. */ - if (pte_valid_not_user(pte)) { + if (pte_valid_not_user(pte)) dsb(ishst); - isb(); - } } extern void __sync_icache_dcache(pte_t pteval); @@ -434,7 +432,6 @@ static inline void set_pmd(pmd_t *pmdp, pmd_t pmd) { WRITE_ONCE(*pmdp, pmd); dsb(ishst); - isb(); } static inline void pmd_clear(pmd_t *pmdp) @@ -485,7 +482,6 @@ static inline void set_pud(pud_t *pudp, pud_t pud) { WRITE_ONCE(*pudp, pud); dsb(ishst); - isb(); } static inline void pud_clear(pud_t *pudp) -- cgit v1.2.3