diff options
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/alternative.h | 7 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/simd.h | 19 |
3 files changed, 14 insertions, 18 deletions
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 */ \ 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) diff --git a/arch/arm64/include/asm/simd.h b/arch/arm64/include/asm/simd.h index fa8b3fe932e6..6495cc51246f 100644 --- a/arch/arm64/include/asm/simd.h +++ b/arch/arm64/include/asm/simd.h @@ -29,20 +29,15 @@ DECLARE_PER_CPU(bool, kernel_neon_busy); static __must_check inline bool may_use_simd(void) { /* - * The raw_cpu_read() is racy if called with preemption enabled. - * This is not a bug: kernel_neon_busy is only set when - * preemption is disabled, so we cannot migrate to another CPU - * while it is set, nor can we migrate to a CPU where it is set. - * So, if we find it clear on some CPU then we're guaranteed to - * find it clear on any CPU we could migrate to. - * - * If we are in between kernel_neon_begin()...kernel_neon_end(), - * the flag will be set, but preemption is also disabled, so we - * can't migrate to another CPU and spuriously see it become - * false. + * kernel_neon_busy is only set while preemption is disabled, + * and is clear whenever preemption is enabled. Since + * this_cpu_read() is atomic w.r.t. preemption, kernel_neon_busy + * cannot change under our feet -- if it's set we cannot be + * migrated, and if it's clear we cannot be migrated to a CPU + * where it is set. */ return !in_irq() && !irqs_disabled() && !in_nmi() && - !raw_cpu_read(kernel_neon_busy); + !this_cpu_read(kernel_neon_busy); } #else /* ! CONFIG_KERNEL_MODE_NEON */ |
