[RFC v2 1/8] MIPS: add virt_to_phys() and phys_to_virt()

[Antony Pavlov]

Signed-off-by: Antony Pavlov <antonynpavlov at gmail.com>
Signed-off-by: Peter Mamonov <pmamonov at gmail.com>
---
 arch/mips/include/asm/io.h | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 4bee591..993b30e 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -12,11 +12,46 @@
 
 #include <linux/compiler.h>
 #include <asm/types.h>
+#include <asm/addrspace.h>
 #include <asm/byteorder.h>
 
 void dma_flush_range(unsigned long, unsigned long);
 void dma_inv_range(unsigned long, unsigned long);
 
+/*
+ *     virt_to_phys    -       map virtual addresses to physical
+ *     @address: address to remap
+ *
+ *     The returned physical address is the physical (CPU) mapping for
+ *     the memory address given. It is only valid to use this function on
+ *     addresses directly mapped or allocated via kmalloc.
+ *
+ *     This function does not give bus mappings for DMA transfers. In
+ *     almost all conceivable cases a device driver should not be using
+ *     this function
+ */
+static inline unsigned long virt_to_phys(const void *address)
+{
+	return (unsigned long)address & 0x1fffffff;
+}
+
+/*
+ *     phys_to_virt    -       map physical address to virtual
+ *     @address: address to remap
+ *
+ *     The returned virtual address is a current CPU mapping for
+ *     the memory address given. It is only valid to use this function on
+ *     addresses that have a kernel mapping
+ *
+ *     This function does not handle bus mappings for DMA transfers. In
+ *     almost all conceivable cases a device driver should not be using
+ *     this function
+ */
+static inline void *phys_to_virt(unsigned long address)
+{
+	return (void *)(KSEG0 | (address & 0x1fffffff));
+}
+
 #define	IO_SPACE_LIMIT	0
 
 /*****************************************************************************/
-- 
2.10.2