From 4912ba72d6e27d0f19ec062ffd00a8c0165a2f67 Mon Sep 17 00:00:00 2001
From: "Maciej W. Rozycki" <macro@linux-mips.org>
Date: Tue, 22 Feb 2005 21:49:17 +0000
Subject: [PATCH] Define mem_*() I/O accessory functions that preserve byte
 addresses. Add missing ____raw_*q() functions.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 include/asm-mips/io.h | 46 +++++++++++++++++++++++++------------------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/include/asm-mips/io.h b/include/asm-mips/io.h
index 1f2fe11f4124..644c085e29f3 100644
--- a/include/asm-mips/io.h
+++ b/include/asm-mips/io.h
@@ -34,7 +34,7 @@
 #undef CONF_SLOWDOWN_IO
 
 /*
- * Raw operations are never swapped in software.  Otoh values that raw
+ * Raw operations are never swapped in software.  OTOH values that raw
  * operations are working on may or may not have been swapped by the bus
  * hardware.  An example use would be for flash memory that's used for
  * execute in place.
@@ -43,45 +43,53 @@
 # define __raw_ioswabw(x)	(x)
 # define __raw_ioswabl(x)	(x)
 # define __raw_ioswabq(x)	(x)
+# define ____raw_ioswabq(x)	(x)
 
 /*
  * Sane hardware offers swapping of PCI/ISA I/O space accesses in hardware;
  * less sane hardware forces software to fiddle with this...
+ *
+ * Regardless, if the host bus endianness mismatches that of PCI/ISA, then
+ * you can't have the numerical value of data and byte addresses within
+ * multibyte quantities both preserved at the same time.  Hence two
+ * variations of functions: non-prefixed ones that preserve the value
+ * and prefixed ones that preserve byte addresses.  The latters are
+ * typically used for moving raw data between a peripheral and memory (cf.
+ * string I/O functions), hence the "mem_" prefix.
  */
 #if defined(CONFIG_SWAP_IO_SPACE)
 
 # define ioswabb(x)		(x)
+# define mem_ioswabb(x)		(x)
 # ifdef CONFIG_SGI_IP22
 /*
  * IP22 seems braindead enough to swap 16bits values in hardware, but
  * not 32bits.  Go figure... Can't tell without documentation.
  */
 #  define ioswabw(x)		(x)
+#  define mem_ioswabw(x)	le16_to_cpu(x)
 # else
 #  define ioswabw(x)		le16_to_cpu(x)
+#  define mem_ioswabw(x)	(x)
 # endif
 # define ioswabl(x)		le32_to_cpu(x)
+# define mem_ioswabl(x)		(x)
 # define ioswabq(x)		le64_to_cpu(x)
+# define mem_ioswabq(x)		(x)
 
 #else
 
 # define ioswabb(x)		(x)
+# define mem_ioswabb(x)		(x)
 # define ioswabw(x)		(x)
+# define mem_ioswabw(x)		cpu_to_le16(x)
 # define ioswabl(x)		(x)
+# define mem_ioswabl(x)		cpu_to_le32(x)
 # define ioswabq(x)		(x)
+# define mem_ioswabq(x)		cpu_to_le32(x)
 
 #endif
 
-/*
- * Native bus accesses never swapped.
- */
-#define bus_ioswabb(x)		(x)
-#define bus_ioswabw(x)		(x)
-#define bus_ioswabl(x)		(x)
-#define bus_ioswabq(x)		(x)
-
-#define __bus_ioswabq		bus_ioswabq
-
 #define IO_SPACE_LIMIT 0xffff
 
 /*
@@ -388,15 +396,15 @@ __BUILD_IOPORT_SINGLE(bus, bwlq, type, _p, SLOW_DOWN_IO)
 
 #define BUILDIO(bwlq, type)						\
 									\
-__BUILD_MEMORY_PFX(, bwlq, type)					\
 __BUILD_MEMORY_PFX(__raw_, bwlq, type)					\
-__BUILD_MEMORY_PFX(bus_, bwlq, type)					\
+__BUILD_MEMORY_PFX(, bwlq, type)					\
+__BUILD_MEMORY_PFX(mem_, bwlq, type)					\
 __BUILD_IOPORT_PFX(, bwlq, type)					\
-__BUILD_IOPORT_PFX(__raw_, bwlq, type)
+__BUILD_IOPORT_PFX(mem_, bwlq, type)
 
 #define __BUILDIO(bwlq, type)						\
 									\
-__BUILD_MEMORY_SINGLE(__bus_, bwlq, type, 0)
+__BUILD_MEMORY_SINGLE(____raw_, bwlq, type, 0)
 
 BUILDIO(b, u8)
 BUILDIO(w, u16)
@@ -424,7 +432,7 @@ static inline void writes##bwlq(volatile void __iomem *mem, void *addr,	\
 	volatile type *__addr = addr;					\
 									\
 	while (count--) {						\
-		__raw_write##bwlq(*__addr, mem);			\
+		mem_write##bwlq(*__addr, mem);				\
 		__addr++;						\
 	}								\
 }									\
@@ -435,7 +443,7 @@ static inline void reads##bwlq(volatile void __iomem *mem, void *addr,	\
 	volatile type *__addr = addr;					\
 									\
 	while (count--) {						\
-		*__addr = __raw_read##bwlq(mem);			\
+		*__addr = mem_read##bwlq(mem);				\
 		__addr++;						\
 	}								\
 }
@@ -448,7 +456,7 @@ static inline void outs##bwlq(unsigned long port, void *addr,		\
 	volatile type *__addr = addr;					\
 									\
 	while (count--) {						\
-		__raw_out##bwlq(*__addr, port);				\
+		mem_out##bwlq(*__addr, port);				\
 		__addr++;						\
 	}								\
 }									\
@@ -459,7 +467,7 @@ static inline void ins##bwlq(unsigned long port, void *addr,		\
 	volatile type *__addr = addr;					\
 									\
 	while (count--) {						\
-		*__addr = __raw_in##bwlq(port);				\
+		*__addr = mem_in##bwlq(port);				\
 		__addr++;						\
 	}								\
 }