[PATCH RFC 2/8] xen/arm: implement read[bl] and write[bl]

[Ian Campbell <ian.campbell@citrix.com>]

These are used in common driver code (specifically ns16550)

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
 xen/include/asm-arm/io.h |   48 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/xen/include/asm-arm/io.h b/xen/include/asm-arm/io.h
index aea5233..170263f 100644
--- a/xen/include/asm-arm/io.h
+++ b/xen/include/asm-arm/io.h
@@ -1,6 +1,54 @@
 #ifndef _ASM_IO_H
 #define _ASM_IO_H
 
+static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
+{
+        asm volatile("strb %1, %0"
+                     : "+Qo" (*(volatile u8 __force *)addr)
+                     : "r" (val));
+}
+
+static inline void __raw_writel(u32 val, volatile void __iomem *addr)
+{
+        asm volatile("str %1, %0"
+                     : "+Qo" (*(volatile u32 __force *)addr)
+                     : "r" (val));
+}
+
+static inline u8 __raw_readb(const volatile void __iomem *addr)
+{
+        u8 val;
+        asm volatile("ldrb %1, %0"
+                     : "+Qo" (*(volatile u8 __force *)addr),
+                       "=r" (val));
+        return val;
+}
+
+static inline u32 __raw_readl(const volatile void __iomem *addr)
+{
+        u32 val;
+        asm volatile("ldr %1, %0"
+                     : "+Qo" (*(volatile u32 __force *)addr),
+                       "=r" (val));
+        return val;
+}
+
+#define __iormb()               rmb()
+#define __iowmb()               wmb()
+
+#define readb_relaxed(c) ({ u8  __r = __raw_readb(c); __r; })
+#define readl_relaxed(c) ({ u32 __r = le32_to_cpu((__force __le32) \
+                                        __raw_readl(c)); __r; })
+
+#define writeb_relaxed(v,c)     __raw_writeb(v,c)
+#define writel_relaxed(v,c)     __raw_writel((__force u32) cpu_to_le32(v),c)
+
+#define readb(c)                ({ u8  __v = readb_relaxed(c); __iormb(); __v; })
+#define readl(c)                ({ u32 __v = readl_relaxed(c); __iormb(); __v; })
+
+#define writeb(v,c)             ({ __iowmb(); writeb_relaxed(v,c); })
+#define writel(v,c)             ({ __iowmb(); writel_relaxed(v,c); })
+
 #endif
 /*
  * Local variables:
-- 
1.7.10.4