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

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.

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)

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();
 }

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;

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);
 		}
 	}
 

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 */