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-rw-r--r--include/asm-generic/early_ioremap.h6
-rw-r--r--mm/early_ioremap.c22
2 files changed, 28 insertions, 0 deletions
diff --git a/include/asm-generic/early_ioremap.h b/include/asm-generic/early_ioremap.h
index a5de55c04fb2..e539f27ec51b 100644
--- a/include/asm-generic/early_ioremap.h
+++ b/include/asm-generic/early_ioremap.h
@@ -33,6 +33,12 @@ extern void early_ioremap_setup(void);
*/
extern void early_ioremap_reset(void);
+/*
+ * Early copy from unmapped memory to kernel mapped memory.
+ */
+extern void copy_from_early_mem(void *dest, phys_addr_t src,
+ unsigned long size);
+
#else
static inline void early_ioremap_init(void) { }
static inline void early_ioremap_setup(void) { }
diff --git a/mm/early_ioremap.c b/mm/early_ioremap.c
index e10ccd299d66..a0baeb4be934 100644
--- a/mm/early_ioremap.c
+++ b/mm/early_ioremap.c
@@ -217,6 +217,28 @@ early_memremap(resource_size_t phys_addr, unsigned long size)
return (__force void *)__early_ioremap(phys_addr, size,
FIXMAP_PAGE_NORMAL);
}
+
+#define MAX_MAP_CHUNK (NR_FIX_BTMAPS << PAGE_SHIFT)
+
+void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
+{
+ unsigned long slop, clen;
+ char *p;
+
+ while (size) {
+ slop = src & ~PAGE_MASK;
+ clen = size;
+ if (clen > MAX_MAP_CHUNK - slop)
+ clen = MAX_MAP_CHUNK - slop;
+ p = early_memremap(src & PAGE_MASK, clen + slop);
+ memcpy(dest, p + slop, clen);
+ early_memunmap(p, clen + slop);
+ dest += clen;
+ src += clen;
+ size -= clen;
+ }
+}
+
#else /* CONFIG_MMU */
void __init __iomem *