Merge branch 'highmem' into devel

1 files changed, 41 insertions, 0 deletions

diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h
new file mode 100644
index 000000000000..bbae919bceb4
--- /dev/null
+++ b/arch/arm/include/asm/fixmap.h
@@ -0,0 +1,41 @@
+#ifndef _ASM_FIXMAP_H
+#define _ASM_FIXMAP_H
+
+/*
+ * Nothing too fancy for now.
+ *
+ * On ARM we already have well known fixed virtual addresses imposed by
+ * the architecture such as the vector page which is located at 0xffff0000,
+ * therefore a second level page table is already allocated covering
+ * 0xfff00000 upwards.
+ *
+ * The cache flushing code in proc-xscale.S uses the virtual area between
+ * 0xfffe0000 and 0xfffeffff.
+ */
+
+#define FIXADDR_START		0xfff00000UL
+#define FIXADDR_TOP		0xfffe0000UL
+#define FIXADDR_SIZE		(FIXADDR_TOP - FIXADDR_START)
+
+#define FIX_KMAP_BEGIN		0
+#define FIX_KMAP_END		(FIXADDR_SIZE >> PAGE_SHIFT)
+
+#define __fix_to_virt(x)	(FIXADDR_START + ((x) << PAGE_SHIFT))
+#define __virt_to_fix(x)	(((x) - FIXADDR_START) >> PAGE_SHIFT)
+
+extern void __this_fixmap_does_not_exist(void);
+
+static inline unsigned long fix_to_virt(const unsigned int idx)
+{
+	if (idx >= FIX_KMAP_END)
+		__this_fixmap_does_not_exist();
+	return __fix_to_virt(idx);
+}
+
+static inline unsigned int virt_to_fix(const unsigned long vaddr)
+{
+	BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
+	return __virt_to_fix(vaddr);
+}
+
+#endif