Merge branch 'kmap_atomic_fixes' of git://git.linaro.org/people/nico/linux

6 files changed, 48 insertions, 150 deletions

diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index 1fc684e70ab6..7080e2c8fa62 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -25,9 +25,6 @@ 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.
diff --git a/arch/arm/mm/cache-feroceon-l2.c b/arch/arm/mm/cache-feroceon-l2.c
index 6e77c042d8e9..e0b0e7a4ec68 100644
--- a/arch/arm/mm/cache-feroceon-l2.c
+++ b/arch/arm/mm/cache-feroceon-l2.c
@@ -13,13 +13,9 @@
  */
 
 #include <linux/init.h>
+#include <linux/highmem.h>
 #include <asm/cacheflush.h>
-#include <asm/kmap_types.h>
-#include <asm/fixmap.h>
-#include <asm/pgtable.h>
-#include <asm/tlbflush.h>
 #include <plat/cache-feroceon-l2.h>
-#include "mm.h"
 
 /*
  * Low-level cache maintenance operations.
@@ -39,27 +35,30 @@
  * between which we don't want to be preempted.
  */
 
-static inline unsigned long l2_start_va(unsigned long paddr)
+static inline unsigned long l2_get_va(unsigned long paddr)
 {
 #ifdef CONFIG_HIGHMEM
         /*
-         * Let's do our own fixmap stuff in a minimal way here.
          * Because range ops can't be done on physical addresses,
          * we simply install a virtual mapping for it only for the
          * TLB lookup to occur, hence no need to flush the untouched
-         * memory mapping.  This is protected with the disabling of
-         * interrupts by the caller.
+         * memory mapping afterwards (note: a cache flush may happen
+         * in some circumstances depending on the path taken in kunmap_atomic).
          */
-        unsigned long idx = KM_L2_CACHE + KM_TYPE_NR * smp_processor_id();
-        unsigned long vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-        set_pte_ext(TOP_PTE(vaddr), pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL), 0);
-        local_flush_tlb_kernel_page(vaddr);
-        return vaddr + (paddr & ~PAGE_MASK);
+        void *vaddr = kmap_atomic_pfn(paddr >> PAGE_SHIFT);
+        return (unsigned long)vaddr + (paddr & ~PAGE_MASK);
 #else
         return __phys_to_virt(paddr);
 #endif
 }
 
+static inline void l2_put_va(unsigned long vaddr)
+{
+#ifdef CONFIG_HIGHMEM
+        kunmap_atomic((void *)vaddr);
+#endif
+}
+
 static inline void l2_clean_pa(unsigned long addr)
 {
         __asm__("mcr p15, 1, %0, c15, c9, 3" : : "r" (addr));
@@ -76,13 +75,14 @@ static inline void l2_clean_pa_range(unsigned long start, unsigned long end)
          */
         BUG_ON((start ^ end) >> PAGE_SHIFT);
 
-        raw_local_irq_save(flags);
-        va_start = l2_start_va(start);
+        va_start = l2_get_va(start);
         va_end = va_start + (end - start);
+        raw_local_irq_save(flags);
         __asm__("mcr p15, 1, %0, c15, c9, 4\n\t"
                 "mcr p15, 1, %1, c15, c9, 5"
                 : : "r" (va_start), "r" (va_end));
         raw_local_irq_restore(flags);
+        l2_put_va(va_start);
 }
 
 static inline void l2_clean_inv_pa(unsigned long addr)
@@ -106,13 +106,14 @@ static inline void l2_inv_pa_range(unsigned long start, unsigned long end)
          */
         BUG_ON((start ^ end) >> PAGE_SHIFT);
 
-        raw_local_irq_save(flags);
-        va_start = l2_start_va(start);
+        va_start = l2_get_va(start);
         va_end = va_start + (end - start);
+        raw_local_irq_save(flags);
         __asm__("mcr p15, 1, %0, c15, c11, 4\n\t"
                 "mcr p15, 1, %1, c15, c11, 5"
                 : : "r" (va_start), "r" (va_end));
         raw_local_irq_restore(flags);
+        l2_put_va(va_start);
 }
 
 static inline void l2_inv_all(void)
diff --git a/arch/arm/mm/cache-xsc3l2.c b/arch/arm/mm/cache-xsc3l2.c
index c3154928bccd..5a32020471e3 100644
--- a/arch/arm/mm/cache-xsc3l2.c
+++ b/arch/arm/mm/cache-xsc3l2.c
@@ -17,14 +17,10 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 #include <linux/init.h>
+#include <linux/highmem.h>
 #include <asm/system.h>
 #include <asm/cputype.h>
 #include <asm/cacheflush.h>
-#include <asm/kmap_types.h>
-#include <asm/fixmap.h>
-#include <asm/pgtable.h>
-#include <asm/tlbflush.h>
-#include "mm.h"
 
 #define CR_L2   (1 << 26)
 
@@ -71,16 +67,15 @@ static inline void xsc3_l2_inv_all(void)
         dsb();
 }
 
+static inline void l2_unmap_va(unsigned long va)
+{
 #ifdef CONFIG_HIGHMEM
-#define l2_map_save_flags(x)            raw_local_save_flags(x)
-#define l2_map_restore_flags(x)         raw_local_irq_restore(x)
-#else
-#define l2_map_save_flags(x)            ((x) = 0)
-#define l2_map_restore_flags(x)         ((void)(x))
+        if (va != -1)
+                kunmap_atomic((void *)va);
 #endif
+}
 
-static inline unsigned long l2_map_va(unsigned long pa, unsigned long prev_va,
-                                      unsigned long flags)
+static inline unsigned long l2_map_va(unsigned long pa, unsigned long prev_va)
 {
 #ifdef CONFIG_HIGHMEM
         unsigned long va = prev_va & PAGE_MASK;
@@ -89,17 +84,10 @@ static inline unsigned long l2_map_va(unsigned long pa, unsigned long prev_va,
                 /*
                  * Switching to a new page.  Because cache ops are
                  * using virtual addresses only, we must put a mapping
-                 * in place for it.  We also enable interrupts for a
-                 * short while and disable them again to protect this
-                 * mapping.
+                 * in place for it.
                  */
-                unsigned long idx;
-                raw_local_irq_restore(flags);
-                idx = KM_L2_CACHE + KM_TYPE_NR * smp_processor_id();
-                va = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-                raw_local_irq_restore(flags | PSR_I_BIT);
-                set_pte_ext(TOP_PTE(va), pfn_pte(pa >> PAGE_SHIFT, PAGE_KERNEL), 0);
-                local_flush_tlb_kernel_page(va);
+                l2_unmap_va(prev_va);
+                va = (unsigned long)kmap_atomic_pfn(pa >> PAGE_SHIFT);
         }
         return va + (pa_offset >> (32 - PAGE_SHIFT));
 #else
@@ -109,7 +97,7 @@ static inline unsigned long l2_map_va(unsigned long pa, unsigned long prev_va,
 
 static void xsc3_l2_inv_range(unsigned long start, unsigned long end)
 {
-        unsigned long vaddr, flags;
+        unsigned long vaddr;
 
         if (start == 0 && end == -1ul) {
                 xsc3_l2_inv_all();
@@ -117,13 +105,12 @@ static void xsc3_l2_inv_range(unsigned long start, unsigned long end)
         }
 
         vaddr = -1;  /* to force the first mapping */
-        l2_map_save_flags(flags);
 
         /*
          * Clean and invalidate partial first cache line.
          */
         if (start & (CACHE_LINE_SIZE - 1)) {
-                vaddr = l2_map_va(start & ~(CACHE_LINE_SIZE - 1), vaddr, flags);
+                vaddr = l2_map_va(start & ~(CACHE_LINE_SIZE - 1), vaddr);
                 xsc3_l2_clean_mva(vaddr);
                 xsc3_l2_inv_mva(vaddr);
                 start = (start | (CACHE_LINE_SIZE - 1)) + 1;
@@ -133,7 +120,7 @@ static void xsc3_l2_inv_range(unsigned long start, unsigned long end)
          * Invalidate all full cache lines between 'start' and 'end'.
          */
         while (start < (end & ~(CACHE_LINE_SIZE - 1))) {
-                vaddr = l2_map_va(start, vaddr, flags);
+                vaddr = l2_map_va(start, vaddr);
                 xsc3_l2_inv_mva(vaddr);
                 start += CACHE_LINE_SIZE;
         }
@@ -142,31 +129,30 @@ static void xsc3_l2_inv_range(unsigned long start, unsigned long end)
          * Clean and invalidate partial last cache line.
          */
         if (start < end) {
-                vaddr = l2_map_va(start, vaddr, flags);
+                vaddr = l2_map_va(start, vaddr);
                 xsc3_l2_clean_mva(vaddr);
                 xsc3_l2_inv_mva(vaddr);
         }
 
-        l2_map_restore_flags(flags);
+        l2_unmap_va(vaddr);
 
         dsb();
 }
 
 static void xsc3_l2_clean_range(unsigned long start, unsigned long end)
 {
-        unsigned long vaddr, flags;
+        unsigned long vaddr;
 
         vaddr = -1;  /* to force the first mapping */
-        l2_map_save_flags(flags);
 
         start &= ~(CACHE_LINE_SIZE - 1);
         while (start < end) {
-                vaddr = l2_map_va(start, vaddr, flags);
+                vaddr = l2_map_va(start, vaddr);
                 xsc3_l2_clean_mva(vaddr);
                 start += CACHE_LINE_SIZE;
         }
 
-        l2_map_restore_flags(flags);
+        l2_unmap_va(vaddr);
 
         dsb();
 }
@@ -193,7 +179,7 @@ static inline void xsc3_l2_flush_all(void)
 
 static void xsc3_l2_flush_range(unsigned long start, unsigned long end)
 {
-        unsigned long vaddr, flags;
+        unsigned long vaddr;
 
         if (start == 0 && end == -1ul) {
                 xsc3_l2_flush_all();
@@ -201,17 +187,16 @@ static void xsc3_l2_flush_range(unsigned long start, unsigned long end)
         }
 
         vaddr = -1;  /* to force the first mapping */
-        l2_map_save_flags(flags);
 
         start &= ~(CACHE_LINE_SIZE - 1);
         while (start < end) {
-                vaddr = l2_map_va(start, vaddr, flags);
+                vaddr = l2_map_va(start, vaddr);
                 xsc3_l2_clean_mva(vaddr);
                 xsc3_l2_inv_mva(vaddr);
                 start += CACHE_LINE_SIZE;
         }
 
-        l2_map_restore_flags(flags);
+        l2_unmap_va(vaddr);
 
         dsb();
 }
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ac6a36142fcd..809f1bf9fa29 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -17,6 +17,7 @@
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
+#include <linux/highmem.h>
 
 #include <asm/memory.h>
 #include <asm/highmem.h>
@@ -480,10 +481,10 @@ static void dma_cache_maint_page(struct page *page, unsigned long 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);
+                                /* unmapped pages might still be cached */
+                                vaddr = kmap_atomic(page);
                                 op(vaddr + offset, len, dir);
-                                kunmap_high_l1_vipt(page, saved_pte);
+                                kunmap_atomic(vaddr);
                         }
                 } else {
                         vaddr = page_address(page) + offset;
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 391ffae75098..c29f2839f1d2 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/highmem.h>
 
 #include <asm/cacheflush.h>
 #include <asm/cachetype.h>
@@ -180,10 +181,10 @@ void __flush_dcache_page(struct address_space *mapping, struct page *page)
                         __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);
+                        /* unmapped pages might still be cached */
+                        addr = kmap_atomic(page);
                         __cpuc_flush_dcache_area(addr, PAGE_SIZE);
-                        kunmap_high_l1_vipt(page, saved_pte);
+                        kunmap_atomic(addr);
                 }
         }
 
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index c435fd9e1da9..807c0573abbe 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -140,90 +140,3 @@ 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;
-        int *depth;
-        unsigned long vaddr, flags;
-        pte_t pte, *ptep;
-
-        if (!in_interrupt())
-                preempt_disable();
-
-        cpu = smp_processor_id();
-        depth = &per_cpu(kmap_high_l1_vipt_depth, cpu);
-
-        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);
-
-        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 */