[MIPS] page.h: remove __pa() usages.

__pa() was used by virt_to_page() and virt_addr_valid(). These
latter are used when kernel is initialised so __pa() is not
appropriate, we use virt_to_phys() instead.

Futhermore __pa() is going to take care of CKSEG0/XKPHYS
address mix for 64 bit kernels. This makes __pa() more complex
than virt_to_phys() and this extra work is not needed by
virt_to_page() and virt_addr_valid().

Eventually it consolidates virt_to_phys() prototype by making
its argument 'const'. this avoids some warnings that was due
to some virt_to_page() usages which pass const pointer.

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 2de4d3c..3049912 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -90,9 +90,9 @@
 	if (!empty_zero_page)
 		panic("Oh boy, that early out of memory?");
 
-	page = virt_to_page(empty_zero_page);
+	page = virt_to_page((void *)empty_zero_page);
 	split_page(page, order);
-	while (page < virt_to_page(empty_zero_page + (PAGE_SIZE << order))) {
+	while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
 		SetPageReserved(page);
 		page++;
 	}
@@ -448,8 +448,8 @@
 	unsigned long addr;
 
 	for (addr = begin; addr < end; addr += PAGE_SIZE) {
-		ClearPageReserved(virt_to_page(addr));
-		init_page_count(virt_to_page(addr));
+		ClearPageReserved(virt_to_page((void *)addr));
+		init_page_count(virt_to_page((void *)addr));
 		memset((void *)addr, 0xcc, PAGE_SIZE);
 		free_page(addr);
 		totalram_pages++;
diff --git a/include/asm-mips/io.h b/include/asm-mips/io.h
index bc5f3c5..d77b657 100644
--- a/include/asm-mips/io.h
+++ b/include/asm-mips/io.h
@@ -113,7 +113,7 @@
  *     almost all conceivable cases a device driver should not be using
  *     this function
  */
-static inline unsigned long virt_to_phys(volatile void * address)
+static inline unsigned long virt_to_phys(volatile const void *address)
 {
 	return (unsigned long)address - PAGE_OFFSET;
 }
diff --git a/include/asm-mips/page.h b/include/asm-mips/page.h
index 85b258e..edb33a1 100644
--- a/include/asm-mips/page.h
+++ b/include/asm-mips/page.h
@@ -34,7 +34,9 @@
 
 #ifndef __ASSEMBLY__
 
+#include <linux/pfn.h>
 #include <asm/cpu-features.h>
+#include <asm/io.h>
 
 extern void clear_page(void * page);
 extern void copy_page(void * to, void * from);
@@ -160,8 +162,8 @@
 
 #endif
 
-#define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
-#define virt_addr_valid(kaddr)	pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
+#define virt_to_page(kaddr)	pfn_to_page(PFN_DOWN(virt_to_phys(kaddr)))
+#define virt_addr_valid(kaddr)	pfn_valid(PFN_DOWN(virt_to_phys(kaddr)))
 
 #define VM_DATA_DEFAULT_FLAGS	(VM_READ | VM_WRITE | VM_EXEC | \
 				 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
diff --git a/include/asm-mips/pgtable.h b/include/asm-mips/pgtable.h
index 1ca4d1e..f2e1325 100644
--- a/include/asm-mips/pgtable.h
+++ b/include/asm-mips/pgtable.h
@@ -67,7 +67,7 @@
 extern unsigned long zero_page_mask;
 
 #define ZERO_PAGE(vaddr) \
-	(virt_to_page(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask)))
+	(virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask))))
 
 #define __HAVE_ARCH_MOVE_PTE
 #define move_pte(pte, prot, old_addr, new_addr)				\