diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index 7f36d00600b43da38ba4fda7fa59aa61da7d60ab..feb988a7ec37dcf2336d7a908e5561b0cc3ee7d5 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -11,7 +11,11 @@
#define kmap_prot PAGE_KERNEL
-#define flush_cache_kmaps() flush_cache_all()
+#define flush_cache_kmaps() \
+ do { \
+ if (cache_is_vivt()) \
+ flush_cache_all(); \
+ } while (0)
extern pte_t *pkmap_page_table;
@@ -21,11 +25,20 @@ extern void *kmap_high(struct page *page);
extern void *kmap_high_get(struct page *page);
extern void kunmap_high(struct page *page);
+extern void *kmap_high_l1_vipt(struct page *page, pte_t *saved_pte);
+extern void kunmap_high_l1_vipt(struct page *page, pte_t saved_pte);
+
+/*
+ * The following functions are already defined by <linux/highmem.h>
+ * when CONFIG_HIGHMEM is not set.
+ */
+#ifdef CONFIG_HIGHMEM
extern void *kmap(struct page *page);
extern void kunmap(struct page *page);
extern void *kmap_atomic(struct page *page, enum km_type type);
extern void kunmap_atomic(void *kvaddr, enum km_type type);
extern void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
extern struct page *kmap_atomic_to_page(const void *ptr);
+#endif
#endif
diff --git a/arch/arm/include/asm/kmap_types.h b/arch/arm/include/asm/kmap_types.h
index c019949a5189dc725a937006eb8445c18d0ad2ef..c4b2ea3fbe4249c886fad25593553502e63f5796 100644
--- a/arch/arm/include/asm/kmap_types.h
+++ b/arch/arm/include/asm/kmap_types.h
@@ -18,6 +18,7 @@ enum km_type {
KM_IRQ1,
KM_SOFTIRQ0,
KM_SOFTIRQ1,
+ KM_L1_CACHE,
KM_L2_CACHE,
KM_TYPE_NR
};
diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
index 8bca4dea6dfa234bbcf0c343a70f87f751de3b66..f55fa1044f72b829d0c307683f9ab12d768a4893 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 1351edc0b26feba5330e3bf045b74702ffe88683..13fa536d82e695ff69b6e74f8e95853cf7199ede 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 e34f095e2090517b8f968f4af6703e60dd371c8b..c6844cb9b508dde69c49af40bb0d2956b126b8d3 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 2be1ec7c1b41acea66987a3ef532e96020b71c5b..77b030f5ec09fa2dfbbcc562f345eb0ec04e3092 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 */