ext4: Use slab allocator for sub-page sized allocations

[safe/jmp/linux-2.6] / include / linux / highmem.h

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 12c5e4e..ab2cc20 100644 (file)
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -19,8 +19,21 @@ static inline void flush_kernel_dcache_page(struct page *page)
 }
 #endif
 
-#ifdef CONFIG_HIGHMEM
+#include <asm/kmap_types.h>
+
+#if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT)
 
+void debug_kmap_atomic(enum km_type type);
+
+#else
+
+static inline void debug_kmap_atomic(enum km_type type)
+{
+}
+
+#endif
+
+#ifdef CONFIG_HIGHMEM
 #include <asm/highmem.h>
 
 /* declarations for linux/mm/highmem.c */
@@ -33,7 +46,7 @@ void kmap_flush_unused(void);
 
 static inline unsigned int nr_free_highpages(void) { return 0; }
 
-#define totalhigh_pages 0
+#define totalhigh_pages 0UL
 
 #ifndef ARCH_HAS_KMAP
 static inline void *kmap(struct page *page)
@@ -42,9 +55,9 @@ static inline void *kmap(struct page *page)
        return page_address(page);
 }
 
-#define kunmap(page) do { (void) (page); } while (0)
-
-#include <asm/kmap_types.h>
+static inline void kunmap(struct page *page)
+{
+}
 
 static inline void *kmap_atomic(struct page *page, enum km_type idx)
 {
@@ -63,14 +76,14 @@ static inline void *kmap_atomic(struct page *page, enum km_type idx)
 #endif /* CONFIG_HIGHMEM */
 
 /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */
+#ifndef clear_user_highpage
 static inline void clear_user_highpage(struct page *page, unsigned long vaddr)
 {
        void *addr = kmap_atomic(page, KM_USER0);
        clear_user_page(addr, vaddr, page);
        kunmap_atomic(addr, KM_USER0);
-       /* Make sure this page is cleared on other CPU's too before using it */
-       smp_wmb();
 }
+#endif
 
 #ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
 /**
@@ -103,21 +116,6 @@ __alloc_zeroed_user_highpage(gfp_t movableflags,
 #endif
 
 /**
- * alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA
- * @vma: The VMA the page is to be allocated for
- * @vaddr: The virtual address the page will be inserted into
- *
- * This function will allocate a page for a VMA that the caller knows will
- * not be able to move in the future using move_pages() or reclaim. If it
- * is known that the page can move, use alloc_zeroed_user_highpage_movable
- */
-static inline struct page *
-alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr)
-{
-       return __alloc_zeroed_user_highpage(0, vma, vaddr);
-}
-
-/**
  * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
  * @vma: The VMA the page is to be allocated for
  * @vaddr: The virtual address the page will be inserted into
@@ -139,28 +137,40 @@ static inline void clear_highpage(struct page *page)
        kunmap_atomic(kaddr, KM_USER0);
 }
 
-/*
- * Same but also flushes aliased cache contents to RAM.
- *
- * This must be a macro because KM_USER0 and friends aren't defined if
- * !CONFIG_HIGHMEM
- */
-#define zero_user_page(page, offset, size, km_type)            \
-       do {                                                    \
-               void *kaddr;                                    \
-                                                               \
-               BUG_ON((offset) + (size) > PAGE_SIZE);          \
-                                                               \
-               kaddr = kmap_atomic(page, km_type);             \
-               memset((char *)kaddr + (offset), 0, (size));    \
-               flush_dcache_page(page);                        \
-               kunmap_atomic(kaddr, (km_type));                \
-       } while (0)
+static inline void zero_user_segments(struct page *page,
+       unsigned start1, unsigned end1,
+       unsigned start2, unsigned end2)
+{
+       void *kaddr = kmap_atomic(page, KM_USER0);
+
+       BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
+
+       if (end1 > start1)
+               memset(kaddr + start1, 0, end1 - start1);
+
+       if (end2 > start2)
+               memset(kaddr + start2, 0, end2 - start2);
+
+       kunmap_atomic(kaddr, KM_USER0);
+       flush_dcache_page(page);
+}
+
+static inline void zero_user_segment(struct page *page,
+       unsigned start, unsigned end)
+{
+       zero_user_segments(page, start, end, 0, 0);
+}
+
+static inline void zero_user(struct page *page,
+       unsigned start, unsigned size)
+{
+       zero_user_segments(page, start, start + size, 0, 0);
+}
 
 static inline void __deprecated memclear_highpage_flush(struct page *page,
                        unsigned int offset, unsigned int size)
 {
-       zero_user_page(page, offset, size, KM_USER0);
+       zero_user(page, offset, size);
 }
 
 #ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
@@ -175,8 +185,6 @@ static inline void copy_user_highpage(struct page *to, struct page *from,
        copy_user_page(vto, vfrom, vaddr, to);
        kunmap_atomic(vfrom, KM_USER0);
        kunmap_atomic(vto, KM_USER1);
-       /* Make sure this page is cleared on other CPU's too before using it */
-       smp_wmb();
 }
 
 #endif