[RFC PATCH 3/8] mm/ioremap: Define generic_ioremap_prot() and generic_iounmap()

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Define a generic version of ioremap_prot() and iounmap() that
architectures can call after they have performed the necessary
alteration to parameters and/or necessary verifications.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 include/asm-generic/io.h |  4 ++++
 mm/ioremap.c             | 26 ++++++++++++++++++++------
 2 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index a68f8fbf423b..43eb4f62e954 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1073,9 +1073,13 @@ static inline bool iounmap_allowed(void *addr)
 }
 #endif
 
+void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
+                                  pgprot_t prot);
+
 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 			   unsigned long prot);
 void iounmap(volatile void __iomem *addr);
+void generic_iounmap(volatile void __iomem *addr);
 
 static inline void __iomem *ioremap(phys_addr_t addr, size_t size)
 {
diff --git a/mm/ioremap.c b/mm/ioremap.c
index 8652426282cc..9f34a8f90b58 100644
--- a/mm/ioremap.c
+++ b/mm/ioremap.c
@@ -11,8 +11,8 @@
 #include <linux/io.h>
 #include <linux/export.h>
 
-void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
-			   unsigned long prot)
+void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
+				   pgprot_t prot)
 {
 	unsigned long offset, vaddr;
 	phys_addr_t last_addr;
@@ -28,7 +28,7 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 	phys_addr -= offset;
 	size = PAGE_ALIGN(size + offset);
 
-	if (!ioremap_allowed(phys_addr, size, prot))
+	if (!ioremap_allowed(phys_addr, size, pgprot_val(prot)))
 		return NULL;
 
 	area = get_vm_area_caller(size, VM_IOREMAP,
@@ -38,17 +38,24 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
 	vaddr = (unsigned long)area->addr;
 	area->phys_addr = phys_addr;
 
-	if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
-			       __pgprot(prot))) {
+	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
 		free_vm_area(area);
 		return NULL;
 	}
 
 	return (void __iomem *)(vaddr + offset);
 }
+
+#ifndef ioremap_prot
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
+{
+	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
+}
 EXPORT_SYMBOL(ioremap_prot);
+#endif
 
-void iounmap(volatile void __iomem *addr)
+void generic_iounmap(volatile void __iomem *addr)
 {
 	void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
 
@@ -58,4 +65,11 @@ void iounmap(volatile void __iomem *addr)
 	if (is_vmalloc_addr(vaddr))
 		vunmap(vaddr);
 }
+
+#ifndef iounmap
+void iounmap(volatile void __iomem *addr)
+{
+	generic_iounmap(addr);
+}
 EXPORT_SYMBOL(iounmap);
+#endif
-- 
2.37.1