diff options
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/copypage-v6.c | 9 | ||||
| -rw-r--r-- | arch/arm/mm/dma-mapping.c | 5 | ||||
| -rw-r--r-- | arch/arm/mm/flush.c | 25 | ||||
| -rw-r--r-- | arch/arm/mm/highmem.c | 87 | ||||
| -rw-r--r-- | arch/arm/mm/mmu.c | 10 |
5 files changed, 113 insertions, 23 deletions
diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c index 8bca4dea6dfa..f55fa1044f72 100644 --- a/arch/arm/mm/copypage-v6.c +++ b/arch/arm/mm/copypage-v6.c @@ -41,14 +41,7 @@ static void v6_copy_user_highpage_nonaliasing(struct page *to, kfrom = kmap_atomic(from, KM_USER0); kto = kmap_atomic(to, KM_USER1); copy_page(kto, kfrom); -#ifdef CONFIG_HIGHMEM - /* - * kmap_atomic() doesn't set the page virtual address, and - * kunmap_atomic() takes care of cache flushing already. - */ - if (page_address(to) != NULL) -#endif - __cpuc_flush_dcache_area(kto, PAGE_SIZE); + __cpuc_flush_dcache_area(kto, PAGE_SIZE); kunmap_atomic(kto, KM_USER1); kunmap_atomic(kfrom, KM_USER0); } diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 1351edc0b26f..13fa536d82e6 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -464,6 +464,11 @@ static void dma_cache_maint_page(struct page *page, unsigned long offset, vaddr += offset; op(vaddr, len, dir); kunmap_high(page); + } else if (cache_is_vipt()) { + pte_t saved_pte; + vaddr = kmap_high_l1_vipt(page, &saved_pte); + op(vaddr + offset, len, dir); + kunmap_high_l1_vipt(page, saved_pte); } } else { vaddr = page_address(page) + offset; diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index e34f095e2090..c6844cb9b508 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -13,6 +13,7 @@ #include <asm/cacheflush.h> #include <asm/cachetype.h> +#include <asm/highmem.h> #include <asm/smp_plat.h> #include <asm/system.h> #include <asm/tlbflush.h> @@ -152,21 +153,25 @@ void copy_to_user_page(struct vm_area_struct *vma, struct page *page, void __flush_dcache_page(struct address_space *mapping, struct page *page) { - void *addr = page_address(page); - /* * Writeback any data associated with the kernel mapping of this * page. This ensures that data in the physical page is mutually * coherent with the kernels mapping. */ -#ifdef CONFIG_HIGHMEM - /* - * kmap_atomic() doesn't set the page virtual address, and - * kunmap_atomic() takes care of cache flushing already. - */ - if (addr) -#endif - __cpuc_flush_dcache_area(addr, PAGE_SIZE); + if (!PageHighMem(page)) { + __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE); + } else { + void *addr = kmap_high_get(page); + if (addr) { + __cpuc_flush_dcache_area(addr, PAGE_SIZE); + kunmap_high(page); + } else if (cache_is_vipt()) { + pte_t saved_pte; + addr = kmap_high_l1_vipt(page, &saved_pte); + __cpuc_flush_dcache_area(addr, PAGE_SIZE); + kunmap_high_l1_vipt(page, saved_pte); + } + } /* * If this is a page cache page, and we have an aliasing VIPT cache, diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c index 2be1ec7c1b41..77b030f5ec09 100644 --- a/arch/arm/mm/highmem.c +++ b/arch/arm/mm/highmem.c @@ -79,7 +79,8 @@ void kunmap_atomic(void *kvaddr, enum km_type type) unsigned int idx = type + KM_TYPE_NR * smp_processor_id(); if (kvaddr >= (void *)FIXADDR_START) { - __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); + if (cache_is_vivt()) + __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); #ifdef CONFIG_DEBUG_HIGHMEM BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); set_pte_ext(TOP_PTE(vaddr), __pte(0), 0); @@ -124,3 +125,87 @@ struct page *kmap_atomic_to_page(const void *ptr) pte = TOP_PTE(vaddr); return pte_page(*pte); } + +#ifdef CONFIG_CPU_CACHE_VIPT + +#include <linux/percpu.h> + +/* + * The VIVT cache of a highmem page is always flushed before the page + * is unmapped. Hence unmapped highmem pages need no cache maintenance + * in that case. + * + * However unmapped pages may still be cached with a VIPT cache, and + * it is not possible to perform cache maintenance on them using physical + * addresses unfortunately. So we have no choice but to set up a temporary + * virtual mapping for that purpose. + * + * Yet this VIPT cache maintenance may be triggered from DMA support + * functions which are possibly called from interrupt context. As we don't + * want to keep interrupt disabled all the time when such maintenance is + * taking place, we therefore allow for some reentrancy by preserving and + * restoring the previous fixmap entry before the interrupted context is + * resumed. If the reentrancy depth is 0 then there is no need to restore + * the previous fixmap, and leaving the current one in place allow it to + * be reused the next time without a TLB flush (common with DMA). + */ + +static DEFINE_PER_CPU(int, kmap_high_l1_vipt_depth); + +void *kmap_high_l1_vipt(struct page *page, pte_t *saved_pte) +{ + unsigned int idx, cpu = smp_processor_id(); + int *depth = &per_cpu(kmap_high_l1_vipt_depth, cpu); + unsigned long vaddr, flags; + pte_t pte, *ptep; + + idx = KM_L1_CACHE + KM_TYPE_NR * cpu; + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + ptep = TOP_PTE(vaddr); + pte = mk_pte(page, kmap_prot); + + if (!in_interrupt()) + preempt_disable(); + + raw_local_irq_save(flags); + (*depth)++; + if (pte_val(*ptep) == pte_val(pte)) { + *saved_pte = pte; + } else { + *saved_pte = *ptep; + set_pte_ext(ptep, pte, 0); + local_flush_tlb_kernel_page(vaddr); + } + raw_local_irq_restore(flags); + + return (void *)vaddr; +} + +void kunmap_high_l1_vipt(struct page *page, pte_t saved_pte) +{ + unsigned int idx, cpu = smp_processor_id(); + int *depth = &per_cpu(kmap_high_l1_vipt_depth, cpu); + unsigned long vaddr, flags; + pte_t pte, *ptep; + + idx = KM_L1_CACHE + KM_TYPE_NR * cpu; + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + ptep = TOP_PTE(vaddr); + pte = mk_pte(page, kmap_prot); + + BUG_ON(pte_val(*ptep) != pte_val(pte)); + BUG_ON(*depth <= 0); + + raw_local_irq_save(flags); + (*depth)--; + if (*depth != 0 && pte_val(pte) != pte_val(saved_pte)) { + set_pte_ext(ptep, saved_pte, 0); + local_flush_tlb_kernel_page(vaddr); + } + raw_local_irq_restore(flags); + + if (!in_interrupt()) + preempt_enable(); +} + +#endif /* CONFIG_CPU_CACHE_VIPT */ diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 4223d086aa17..241c24a1c18f 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1054,10 +1054,12 @@ void setup_mm_for_reboot(char mode) pgd_t *pgd; int i; - if (current->mm && current->mm->pgd) - pgd = current->mm->pgd; - else - pgd = init_mm.pgd; + /* + * We need to access to user-mode page tables here. For kernel threads + * we don't have any user-mode mappings so we use the context that we + * "borrowed". + */ + pgd = current->active_mm->pgd; base_pmdval = PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | PMD_TYPE_SECT; if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) |