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authorMark Salter <msalter@redhat.com>2014-04-07 15:39:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-07 16:36:15 -0700
commit9e5c33d7aeeef62e5fa7e74f94432685bd03026b (patch)
treeff62a742103d422f2c74c192af434a0023324c0e /include/asm-generic/early_ioremap.h
parent6b550f6f2004017f1b4633d2c9e39b610bfe84f0 (diff)
mm: create generic early_ioremap() support
This patch creates a generic implementation of early_ioremap() support based on the existing x86 implementation. early_ioremp() is useful for early boot code which needs to temporarily map I/O or memory regions before normal mapping functions such as ioremap() are available. Some architectures have optional MMU. In the no-MMU case, the remap functions simply return the passed in physical address and the unmap functions do nothing. Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-generic/early_ioremap.h')
-rw-r--r--include/asm-generic/early_ioremap.h42
1 files changed, 42 insertions, 0 deletions
diff --git a/include/asm-generic/early_ioremap.h b/include/asm-generic/early_ioremap.h
new file mode 100644
index 000000000000..a5de55c04fb2
--- /dev/null
+++ b/include/asm-generic/early_ioremap.h
@@ -0,0 +1,42 @@
+#ifndef _ASM_EARLY_IOREMAP_H_
+#define _ASM_EARLY_IOREMAP_H_
+
+#include <linux/types.h>
+
+/*
+ * early_ioremap() and early_iounmap() are for temporary early boot-time
+ * mappings, before the real ioremap() is functional.
+ */
+extern void __iomem *early_ioremap(resource_size_t phys_addr,
+ unsigned long size);
+extern void *early_memremap(resource_size_t phys_addr,
+ unsigned long size);
+extern void early_iounmap(void __iomem *addr, unsigned long size);
+extern void early_memunmap(void *addr, unsigned long size);
+
+/*
+ * Weak function called by early_ioremap_reset(). It does nothing, but
+ * architectures may provide their own version to do any needed cleanups.
+ */
+extern void early_ioremap_shutdown(void);
+
+#if defined(CONFIG_GENERIC_EARLY_IOREMAP) && defined(CONFIG_MMU)
+/* Arch-specific initialization */
+extern void early_ioremap_init(void);
+
+/* Generic initialization called by architecture code */
+extern void early_ioremap_setup(void);
+
+/*
+ * Called as last step in paging_init() so library can act
+ * accordingly for subsequent map/unmap requests.
+ */
+extern void early_ioremap_reset(void);
+
+#else
+static inline void early_ioremap_init(void) { }
+static inline void early_ioremap_setup(void) { }
+static inline void early_ioremap_reset(void) { }
+#endif
+
+#endif /* _ASM_EARLY_IOREMAP_H_ */

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