2 files changed, 31 insertions, 5 deletions

diff --git a/arch/x86/include/asm/iomap.h b/arch/x86/include/asm/iomap.h
index 0e9fe1d..f35eb45 100644
--- a/arch/x86/include/asm/iomap.h
+++ b/arch/x86/include/asm/iomap.h
@@ -26,13 +26,16 @@
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 
-int
-is_io_mapping_possible(resource_size_t base, unsigned long size);
-
 void *
 iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot);
 
 void
 iounmap_atomic(void *kvaddr, enum km_type type);
 
+int
+iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot);
+
+void
+iomap_free(resource_size_t base, unsigned long size);
+
 #endif /* _ASM_X86_IOMAP_H */
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index fe6f84c..84e236c 100644
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -21,7 +21,7 @@
 #include <linux/module.h>
 #include <linux/highmem.h>
 
-int is_io_mapping_possible(resource_size_t base, unsigned long size)
+static int is_io_mapping_possible(resource_size_t base, unsigned long size)
 {
 #if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT)
 	/* There is no way to map greater than 1 << 32 address without PAE */
@@ -30,7 +30,30 @@ int is_io_mapping_possible(resource_size_t base, unsigned long size)
 #endif
 	return 1;
 }
-EXPORT_SYMBOL_GPL(is_io_mapping_possible);
+
+int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot)
+{
+	unsigned long flag = _PAGE_CACHE_WC;
+	int ret;
+
+	if (!is_io_mapping_possible(base, size))
+		return -EINVAL;
+
+	ret = io_reserve_memtype(base, base + size, &flag);
+	if (ret)
+		return ret;
+
+	*prot = __pgprot(__PAGE_KERNEL | flag);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(iomap_create_wc);
+
+void
+iomap_free(resource_size_t base, unsigned long size)
+{
+	io_free_memtype(base, base + size);
+}
+EXPORT_SYMBOL_GPL(iomap_free);
 
 void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot)
 {