Initial import

1 files changed, 249 insertions, 0 deletions

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
new file mode 100644
index 000000000..9286a46b7
--- /dev/null
+++ b/include/linux/highmem.h
@@ -0,0 +1,249 @@
+#ifndef _LINUX_HIGHMEM_H
+#define _LINUX_HIGHMEM_H
+
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/bug.h>
+#include <linux/mm.h>
+#include <linux/uaccess.h>
+#include <linux/hardirq.h>
+
+#include <asm/cacheflush.h>
+
+#ifndef ARCH_HAS_FLUSH_ANON_PAGE
+static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
+{
+}
+#endif
+
+#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
+static inline void flush_kernel_dcache_page(struct page *page)
+{
+}
+static inline void flush_kernel_vmap_range(void *vaddr, int size)
+{
+}
+static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
+{
+}
+#endif
+
+#include <asm/kmap_types.h>
+
+#ifdef CONFIG_HIGHMEM
+#include <asm/highmem.h>
+
+/* declarations for linux/mm/highmem.c */
+unsigned int nr_free_highpages(void);
+extern unsigned long totalhigh_pages;
+
+void kmap_flush_unused(void);
+
+struct page *kmap_to_page(void *addr);
+
+#else /* CONFIG_HIGHMEM */
+
+static inline unsigned int nr_free_highpages(void) { return 0; }
+
+static inline struct page *kmap_to_page(void *addr)
+{
+	return virt_to_page(addr);
+}
+
+#define totalhigh_pages 0UL
+
+#ifndef ARCH_HAS_KMAP
+static inline void *kmap(struct page *page)
+{
+	might_sleep();
+	return page_address(page);
+}
+
+static inline void kunmap(struct page *page)
+{
+}
+
+static inline void *kmap_atomic(struct page *page)
+{
+	pagefault_disable();
+	return page_address(page);
+}
+#define kmap_atomic_prot(page, prot)	kmap_atomic(page)
+
+static inline void __kunmap_atomic(void *addr)
+{
+	pagefault_enable();
+}
+
+#define kmap_atomic_pfn(pfn)	kmap_atomic(pfn_to_page(pfn))
+#define kmap_atomic_to_page(ptr)	virt_to_page(ptr)
+
+#define kmap_flush_unused()	do {} while(0)
+#endif
+
+#endif /* CONFIG_HIGHMEM */
+
+#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32)
+
+DECLARE_PER_CPU(int, __kmap_atomic_idx);
+
+static inline int kmap_atomic_idx_push(void)
+{
+	int idx = __this_cpu_inc_return(__kmap_atomic_idx) - 1;
+
+#ifdef CONFIG_DEBUG_HIGHMEM
+	WARN_ON_ONCE(in_irq() && !irqs_disabled());
+	BUG_ON(idx >= KM_TYPE_NR);
+#endif
+	return idx;
+}
+
+static inline int kmap_atomic_idx(void)
+{
+	return __this_cpu_read(__kmap_atomic_idx) - 1;
+}
+
+static inline void kmap_atomic_idx_pop(void)
+{
+#ifdef CONFIG_DEBUG_HIGHMEM
+	int idx = __this_cpu_dec_return(__kmap_atomic_idx);
+
+	BUG_ON(idx < 0);
+#else
+	__this_cpu_dec(__kmap_atomic_idx);
+#endif
+}
+
+#endif
+
+/*
+ * Prevent people trying to call kunmap_atomic() as if it were kunmap()
+ * kunmap_atomic() should get the return value of kmap_atomic, not the page.
+ */
+#define kunmap_atomic(addr)                                     \
+do {                                                            \
+	BUILD_BUG_ON(__same_type((addr), struct page *));       \
+	__kunmap_atomic(addr);                                  \
+} while (0)
+
+
+/* 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);
+	clear_user_page(addr, vaddr, page);
+	kunmap_atomic(addr);
+}
+#endif
+
+#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
+/**
+ * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
+ * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
+ * @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 but the caller is expected
+ * to specify via movableflags whether the page will be movable in the
+ * future or not
+ *
+ * An architecture may override this function by defining
+ * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
+ * implementation.
+ */
+static inline struct page *
+__alloc_zeroed_user_highpage(gfp_t movableflags,
+			struct vm_area_struct *vma,
+			unsigned long vaddr)
+{
+	struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
+			vma, vaddr);
+
+	if (page)
+		clear_user_highpage(page, vaddr);
+
+	return page;
+}
+#endif
+
+/**
+ * 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
+ *
+ * This function will allocate a page for a VMA that the caller knows will
+ * be able to migrate in the future using move_pages() or reclaimed
+ */
+static inline struct page *
+alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
+					unsigned long vaddr)
+{
+	return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
+}
+
+static inline void clear_highpage(struct page *page)
+{
+	void *kaddr = kmap_atomic(page);
+	clear_page(kaddr);
+	kunmap_atomic(kaddr);
+}
+
+static inline void zero_user_segments(struct page *page,
+	unsigned start1, unsigned end1,
+	unsigned start2, unsigned end2)
+{
+	void *kaddr = kmap_atomic(page);
+
+	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);
+	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);
+}
+
+#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
+
+static inline void copy_user_highpage(struct page *to, struct page *from,
+	unsigned long vaddr, struct vm_area_struct *vma)
+{
+	char *vfrom, *vto;
+
+	vfrom = kmap_atomic(from);
+	vto = kmap_atomic(to);
+	copy_user_page(vto, vfrom, vaddr, to);
+	kunmap_atomic(vto);
+	kunmap_atomic(vfrom);
+}
+
+#endif
+
+static inline void copy_highpage(struct page *to, struct page *from)
+{
+	char *vfrom, *vto;
+
+	vfrom = kmap_atomic(from);
+	vto = kmap_atomic(to);
+	copy_page(vto, vfrom);
+	kunmap_atomic(vto);
+	kunmap_atomic(vfrom);
+}
+
+#endif /* _LINUX_HIGHMEM_H */