sparc: io: implement dummy relaxed accessor macros for writes

write{b,w,l,q}_relaxed are implemented by some architectures in order to
permit memory-mapped I/O accesses with weaker barrier semantics than the
non-relaxed variants.

This patch adds dummy macros for the write accessors to sparc, in the
same vein as the dummy definitions for the relaxed read accessors. The
existing relaxed read{b,w,l} accessors are moved into asm/io.h, since
they are identical between 32-bit and 64-bit machines.
Acked-by: N"David S. Miller" <davem@davemloft.net>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

arch/sparc/include/asm/io.h

@@ -10,6 +10,15 @@
  * Defines used for both SPARC32 and SPARC64
  */
 
+/* Relaxed accessors for MMIO */
+#define readb_relaxed(__addr)		readb(__addr)
+#define readw_relaxed(__addr)		readw(__addr)
+#define readl_relaxed(__addr)		readl(__addr)
+
+#define writeb_relaxed(__b, __addr)	writeb(__b, __addr)
+#define writew_relaxed(__w, __addr)	writew(__w, __addr)
+#define writel_relaxed(__l, __addr)	writel(__l, __addr)
+
 /* Big endian versions of memory read/write routines */
 #define readb_be(__addr)	__raw_readb(__addr)
 #define readw_be(__addr)	__raw_readw(__addr)

arch/sparc/include/asm/io_32.h

@@ -4,10 +4,6 @@
 #include <linux/kernel.h>
 #include <linux/ioport.h>  /* struct resource */
 
-#define readb_relaxed(__addr)	readb(__addr)
-#define readw_relaxed(__addr)	readw(__addr)
-#define readl_relaxed(__addr)	readl(__addr)
-
 #define IO_SPACE_LIMIT 0xffffffff
 
 #define memset_io(d,c,sz)     _memset_io(d,c,sz)

arch/sparc/include/asm/io_64.h

@@ -136,6 +136,7 @@ static inline u32 readl(const volatile void __iomem *addr)
 }
 
 #define readq readq
+#define readq_relaxed readq
 static inline u64 readq(const volatile void __iomem *addr)
 {	u64 ret;
 
@@ -175,6 +176,7 @@ static inline void writel(u32 l, volatile void __iomem *addr)
 }
 
 #define writeq writeq
+#define writeq_relaxed writeq
 static inline void writeq(u64 q, volatile void __iomem *addr)
 {
 	__asm__ __volatile__("stxa\t%r0, [%1] %2\t/* pci_writeq */"
@@ -183,7 +185,6 @@ static inline void writeq(u64 q, volatile void __iomem *addr)
 			     : "memory");
 }
 
-
 #define inb inb
 static inline u8 inb(unsigned long addr)
 {
@@ -264,11 +265,6 @@ static inline void iowrite32_rep(void __iomem *port, const void *buf, unsigned l
 	outsl((unsigned long __force)port, buf, count);
 }
 
-#define readb_relaxed(__addr)	readb(__addr)
-#define readw_relaxed(__addr)	readw(__addr)
-#define readl_relaxed(__addr)	readl(__addr)
-#define readq_relaxed(__addr)	readq(__addr)
-
 /* Valid I/O Space regions are anywhere, because each PCI bus supported
  * can live in an arbitrary area of the physical address range.
  */