diff options
| -rw-r--r-- | arch/s390/Kconfig | 1 | ||||
| -rw-r--r-- | arch/s390/include/asm/pgalloc.h | 3 | ||||
| -rw-r--r-- | arch/s390/include/asm/tlb.h | 22 | ||||
| -rw-r--r-- | arch/s390/mm/pgtable.c | 63 |
4 files changed, 61 insertions, 28 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 2b7c0fbe578..9015060919a 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -90,7 +90,6 @@ config S390 select HAVE_KERNEL_XZ select HAVE_ARCH_MUTEX_CPU_RELAX select HAVE_ARCH_JUMP_LABEL if !MARCH_G5 - select HAVE_RCU_TABLE_FREE if SMP select ARCH_SAVE_PAGE_KEYS if HIBERNATION select HAVE_MEMBLOCK select HAVE_MEMBLOCK_NODE_MAP diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h index 8eef9b5b3cf..78e3041919d 100644 --- a/arch/s390/include/asm/pgalloc.h +++ b/arch/s390/include/asm/pgalloc.h @@ -22,10 +22,7 @@ void crst_table_free(struct mm_struct *, unsigned long *); unsigned long *page_table_alloc(struct mm_struct *, unsigned long); void page_table_free(struct mm_struct *, unsigned long *); -#ifdef CONFIG_HAVE_RCU_TABLE_FREE void page_table_free_rcu(struct mmu_gather *, unsigned long *); -void __tlb_remove_table(void *_table); -#endif static inline void clear_table(unsigned long *s, unsigned long val, size_t n) { diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h index c687a2c8346..775a5eea8f9 100644 --- a/arch/s390/include/asm/tlb.h +++ b/arch/s390/include/asm/tlb.h @@ -30,14 +30,10 @@ struct mmu_gather { struct mm_struct *mm; -#ifdef CONFIG_HAVE_RCU_TABLE_FREE struct mmu_table_batch *batch; -#endif unsigned int fullmm; - unsigned int need_flush; }; -#ifdef CONFIG_HAVE_RCU_TABLE_FREE struct mmu_table_batch { struct rcu_head rcu; unsigned int nr; @@ -49,7 +45,6 @@ struct mmu_table_batch { extern void tlb_table_flush(struct mmu_gather *tlb); extern void tlb_remove_table(struct mmu_gather *tlb, void *table); -#endif static inline void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, @@ -57,29 +52,20 @@ static inline void tlb_gather_mmu(struct mmu_gather *tlb, { tlb->mm = mm; tlb->fullmm = full_mm_flush; - tlb->need_flush = 0; -#ifdef CONFIG_HAVE_RCU_TABLE_FREE tlb->batch = NULL; -#endif if (tlb->fullmm) __tlb_flush_mm(mm); } static inline void tlb_flush_mmu(struct mmu_gather *tlb) { - if (!tlb->need_flush) - return; - tlb->need_flush = 0; - __tlb_flush_mm(tlb->mm); -#ifdef CONFIG_HAVE_RCU_TABLE_FREE tlb_table_flush(tlb); -#endif } static inline void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) { - tlb_flush_mmu(tlb); + tlb_table_flush(tlb); } /* @@ -105,10 +91,8 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long address) { -#ifdef CONFIG_HAVE_RCU_TABLE_FREE if (!tlb->fullmm) return page_table_free_rcu(tlb, (unsigned long *) pte); -#endif page_table_free(tlb->mm, (unsigned long *) pte); } @@ -125,10 +109,8 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd, #ifdef __s390x__ if (tlb->mm->context.asce_limit <= (1UL << 31)) return; -#ifdef CONFIG_HAVE_RCU_TABLE_FREE if (!tlb->fullmm) return tlb_remove_table(tlb, pmd); -#endif crst_table_free(tlb->mm, (unsigned long *) pmd); #endif } @@ -146,10 +128,8 @@ static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, #ifdef __s390x__ if (tlb->mm->context.asce_limit <= (1UL << 42)) return; -#ifdef CONFIG_HAVE_RCU_TABLE_FREE if (!tlb->fullmm) return tlb_remove_table(tlb, pud); -#endif crst_table_free(tlb->mm, (unsigned long *) pud); #endif } diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 373adf69b01..6e765bf0067 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -678,8 +678,6 @@ void page_table_free(struct mm_struct *mm, unsigned long *table) } } -#ifdef CONFIG_HAVE_RCU_TABLE_FREE - static void __page_table_free_rcu(void *table, unsigned bit) { struct page *page; @@ -733,7 +731,66 @@ void __tlb_remove_table(void *_table) free_pages((unsigned long) table, ALLOC_ORDER); } -#endif +static void tlb_remove_table_smp_sync(void *arg) +{ + /* Simply deliver the interrupt */ +} + +static void tlb_remove_table_one(void *table) +{ + /* + * This isn't an RCU grace period and hence the page-tables cannot be + * assumed to be actually RCU-freed. + * + * It is however sufficient for software page-table walkers that rely + * on IRQ disabling. See the comment near struct mmu_table_batch. + */ + smp_call_function(tlb_remove_table_smp_sync, NULL, 1); + __tlb_remove_table(table); +} + +static void tlb_remove_table_rcu(struct rcu_head *head) +{ + struct mmu_table_batch *batch; + int i; + + batch = container_of(head, struct mmu_table_batch, rcu); + + for (i = 0; i < batch->nr; i++) + __tlb_remove_table(batch->tables[i]); + + free_page((unsigned long)batch); +} + +void tlb_table_flush(struct mmu_gather *tlb) +{ + struct mmu_table_batch **batch = &tlb->batch; + + if (*batch) { + __tlb_flush_mm(tlb->mm); + call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu); + *batch = NULL; + } +} + +void tlb_remove_table(struct mmu_gather *tlb, void *table) +{ + struct mmu_table_batch **batch = &tlb->batch; + + if (*batch == NULL) { + *batch = (struct mmu_table_batch *) + __get_free_page(GFP_NOWAIT | __GFP_NOWARN); + if (*batch == NULL) { + __tlb_flush_mm(tlb->mm); + tlb_remove_table_one(table); + return; + } + (*batch)->nr = 0; + } + (*batch)->tables[(*batch)->nr++] = table; + if ((*batch)->nr == MAX_TABLE_BATCH) + tlb_table_flush(tlb); +} /* * switch on pgstes for its userspace process (for kvm) |