ARM: io: ensure inb/outb() et.al. are properly ordered on ARMv6+

Ensure that the ISA/PCI IO space accessors are properly ordered on
ARMv6+ architectures.  These should always be ordered with respect to
all other accesses.

This also fixes __iormb() and __iowmb() not being visible to ioread/
iowrite if a platform defines its own MMIO accessors.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 17 insertions, 16 deletions

diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 20e0f7c9e03e..d66605dea55a 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -95,6 +95,15 @@ static inline void __iomem *__typesafe_io(unsigned long addr)
         return (void __iomem *)addr;
 }
 
+/* IO barriers */
+#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
+#define __iormb()               rmb()
+#define __iowmb()               wmb()
+#else
+#define __iormb()               do { } while (0)
+#define __iowmb()               do { } while (0)
+#endif
+
 /*
  * Now, pick up the machine-defined IO definitions
  */
@@ -125,17 +134,17 @@ static inline void __iomem *__typesafe_io(unsigned long addr)
  * The {in,out}[bwl] macros are for emulating x86-style PCI/ISA IO space.
  */
 #ifdef __io
-#define outb(v,p)               __raw_writeb(v,__io(p))
-#define outw(v,p)               __raw_writew((__force __u16) \
-                                        cpu_to_le16(v),__io(p))
-#define outl(v,p)               __raw_writel((__force __u32) \
-                                        cpu_to_le32(v),__io(p))
+#define outb(v,p)       ({ __iowmb(); __raw_writeb(v,__io(p)); })
+#define outw(v,p)       ({ __iowmb(); __raw_writew((__force __u16) \
+                                        cpu_to_le16(v),__io(p)); })
+#define outl(v,p)       ({ __iowmb(); __raw_writel((__force __u32) \
+                                        cpu_to_le32(v),__io(p)); })
 
-#define inb(p)  ({ __u8 __v = __raw_readb(__io(p)); __v; })
+#define inb(p)  ({ __u8 __v = __raw_readb(__io(p)); __iormb(); __v; })
 #define inw(p)  ({ __u16 __v = le16_to_cpu((__force __le16) \
-                        __raw_readw(__io(p))); __v; })
+                        __raw_readw(__io(p))); __iormb(); __v; })
 #define inl(p)  ({ __u32 __v = le32_to_cpu((__force __le32) \
-                        __raw_readl(__io(p))); __v; })
+                        __raw_readl(__io(p))); __iormb(); __v; })
 
 #define outsb(p,d,l)            __raw_writesb(__io(p),d,l)
 #define outsw(p,d,l)            __raw_writesw(__io(p),d,l)
@@ -192,14 +201,6 @@ extern void _memset_io(volatile void __iomem *, int, size_t);
 #define writel_relaxed(v,c)     ((void)__raw_writel((__force u32) \
                                         cpu_to_le32(v),__mem_pci(c)))
 
-#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
-#define __iormb()               rmb()
-#define __iowmb()               wmb()
-#else
-#define __iormb()               do { } while (0)
-#define __iowmb()               do { } while (0)
-#endif
-
 #define readb(c)                ({ u8  __v = readb_relaxed(c); __iormb(); __v; })
 #define readw(c)                ({ u16 __v = readw_relaxed(c); __iormb(); __v; })
 #define readl(c)                ({ u32 __v = readl_relaxed(c); __iormb(); __v; })