]> err.no Git - linux-2.6/blobdiff - include/asm-mips/io.h
[MIPS] Work around bad code generation for <asm/io.h>.
[linux-2.6] / include / asm-mips / io.h
index 3061870b7f6cae67d4e9e8e2eebe412ca8456539..ba1d7bbc15d2e437553e2df6c818ed77a85ea0d4 100644 (file)
@@ -4,7 +4,7 @@
  * for more details.
  *
  * Copyright (C) 1994, 1995 Waldorf GmbH
- * Copyright (C) 1994 - 2000 Ralf Baechle
+ * Copyright (C) 1994 - 2000, 06 Ralf Baechle
  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  * Copyright (C) 2004, 2005  MIPS Technologies, Inc.  All rights reserved.
  *     Author: Maciej W. Rozycki <macro@mips.com>
@@ -18,7 +18,6 @@
 #include <linux/types.h>
 
 #include <asm/addrspace.h>
-#include <asm/bug.h>
 #include <asm/byteorder.h>
 #include <asm/cpu.h>
 #include <asm/cpu-features.h>
  * 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.
+ * string I/O functions), hence the "__mem_" prefix.
  */
 #if defined(CONFIG_SWAP_IO_SPACE)
 
 # define ioswabb(x)            (x)
-# define mem_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)
+#  define __mem_ioswabw(x)     le16_to_cpu(x)
 # else
 #  define ioswabw(x)           le16_to_cpu(x)
-#  define mem_ioswabw(x)       (x)
+#  define __mem_ioswabw(x)     (x)
 # endif
 # define ioswabl(x)            le32_to_cpu(x)
-# define mem_ioswabl(x)                (x)
+# define __mem_ioswabl(x)      (x)
 # define ioswabq(x)            le64_to_cpu(x)
-# define mem_ioswabq(x)                (x)
+# define __mem_ioswabq(x)      (x)
 
 #else
 
 # define ioswabb(x)            (x)
-# define mem_ioswabb(x)                (x)
+# define __mem_ioswabb(x)      (x)
 # define ioswabw(x)            (x)
-# define mem_ioswabw(x)                cpu_to_le16(x)
+# define __mem_ioswabw(x)      cpu_to_le16(x)
 # define ioswabl(x)            (x)
-# define mem_ioswabl(x)                cpu_to_le32(x)
+# define __mem_ioswabl(x)      cpu_to_le32(x)
 # define ioswabq(x)            (x)
-# define mem_ioswabq(x)                cpu_to_le32(x)
+# define __mem_ioswabq(x)      cpu_to_le32(x)
 
 #endif
 
  */
 extern const unsigned long mips_io_port_base;
 
-#define set_io_port_base(base) \
-       do { * (unsigned long *) &mips_io_port_base = (base); } while (0)
+/*
+ * Gcc will generate code to load the value of mips_io_port_base after each
+ * function call which may be fairly wasteful in some cases.  So we don't
+ * play quite by the book.  We tell gcc mips_io_port_base is a long variable
+ * which solves the code generation issue.  Now we need to violate the
+ * aliasing rules a little to make initialization possible and finally we
+ * will need the barrier() to fight side effects of the aliasing chat.
+ * This trickery will eventually collapse under gcc's optimizer.  Oh well.
+ */
+static inline void set_io_port_base(unsigned long base)
+{
+       * (unsigned long *) &mips_io_port_base = base;
+       barrier();
+}
 
 /*
  * Thanks to James van Artsdalen for a better timing-fix than
@@ -283,6 +294,24 @@ static inline void __iomem * __ioremap_mode(phys_t offset, unsigned long size,
 #define ioremap_nocache(offset, size)                                  \
        __ioremap_mode((offset), (size), _CACHE_UNCACHED)
 
+/*
+ * ioremap_cachable -   map bus memory into CPU space
+ * @offset:         bus address of the memory
+ * @size:           size of the resource to map
+ *
+ * ioremap_nocache performs a platform specific sequence of operations to
+ * make bus memory CPU accessible via the readb/readw/readl/writeb/
+ * writew/writel functions and the other mmio helpers. The returned
+ * address is not guaranteed to be usable directly as a virtual
+ * address.
+ *
+ * This version of ioremap ensures that the memory is marked cachable by
+ * the CPU.  Also enables full write-combining.  Useful for some
+ * memory-like regions on I/O busses.
+ */
+#define ioremap_cachable(offset, size)                                 \
+       __ioremap_mode((offset), (size), PAGE_CACHABLE_DEFAULT)
+
 /*
  * These two are MIPS specific ioremap variant.  ioremap_cacheable_cow
  * requests a cachable mapping, ioremap_uncached_accelerated requests a
@@ -343,7 +372,7 @@ static inline void pfx##write##bwlq(type val,                               \
                BUG();                                                  \
 }                                                                      \
                                                                        \
-static inline type pfx##read##bwlq(volatile void __iomem *mem)         \
+static inline type pfx##read##bwlq(const volatile void __iomem *mem)   \
 {                                                                      \
        volatile type *__mem;                                           \
        type __val;                                                     \
@@ -418,7 +447,7 @@ __BUILD_MEMORY_SINGLE(bus, bwlq, type, 1)
                                                                        \
 __BUILD_MEMORY_PFX(__raw_, bwlq, type)                                 \
 __BUILD_MEMORY_PFX(, bwlq, type)                                       \
-__BUILD_MEMORY_PFX(mem_, bwlq, type)                                   \
+__BUILD_MEMORY_PFX(__mem_, bwlq, type)                                 \
 
 BUILDIO_MEM(b, u8)
 BUILDIO_MEM(w, u16)
@@ -431,7 +460,7 @@ BUILDIO_MEM(q, u64)
 
 #define BUILDIO_IOPORT(bwlq, type)                                     \
        __BUILD_IOPORT_PFX(, bwlq, type)                                \
-       __BUILD_IOPORT_PFX(mem_, bwlq, type)
+       __BUILD_IOPORT_PFX(__mem_, bwlq, type)
 
 BUILDIO_IOPORT(b, u8)
 BUILDIO_IOPORT(w, u16)
@@ -459,13 +488,13 @@ __BUILDIO(q, u64)
 
 #define __BUILD_MEMORY_STRING(bwlq, type)                              \
                                                                        \
-static inline void writes##bwlq(volatile void __iomem *mem, void *addr,        \
-                               unsigned int count)                     \
+static inline void writes##bwlq(volatile void __iomem *mem,            \
+                               const void *addr, unsigned int count)   \
 {                                                                      \
-       volatile type *__addr = addr;                                   \
+       const volatile type *__addr = addr;                             \
                                                                        \
        while (count--) {                                               \
-               mem_write##bwlq(*__addr, mem);                          \
+               __mem_write##bwlq(*__addr, mem);                        \
                __addr++;                                               \
        }                                                               \
 }                                                                      \
@@ -476,7 +505,7 @@ static inline void reads##bwlq(volatile void __iomem *mem, void *addr,      \
        volatile type *__addr = addr;                                   \
                                                                        \
        while (count--) {                                               \
-               *__addr = mem_read##bwlq(mem);                          \
+               *__addr = __mem_read##bwlq(mem);                        \
                __addr++;                                               \
        }                                                               \
 }
@@ -489,7 +518,7 @@ static inline void outs##bwlq(unsigned long port, const void *addr, \
        const volatile type *__addr = addr;                             \
                                                                        \
        while (count--) {                                               \
-               mem_out##bwlq(*__addr, port);                           \
+               __mem_out##bwlq(*__addr, port);                         \
                __addr++;                                               \
        }                                                               \
 }                                                                      \
@@ -500,7 +529,7 @@ static inline void ins##bwlq(unsigned long port, void *addr,                \
        volatile type *__addr = addr;                                   \
                                                                        \
        while (count--) {                                               \
-               *__addr = mem_in##bwlq(port);                           \
+               *__addr = __mem_in##bwlq(port);                         \
                __addr++;                                               \
        }                                                               \
 }