Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm

Pull ARM updates from Russell King:
 "This is the first chunk of ARM updates for this merge window.
  Conflicts are expected in two files - asm/timex.h and
  mach-integrator/integrator_cp.c.  Nothing particularly stands out more
  than anything else.

  Most of the growth is down to the opcodes stuff from Dave Martin,
  which is countered by Rob's patches to use more of the asm-generic
  headers on ARM."

(A few more conflicts grew since then, but it all looked fairly trivial)

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (44 commits)
  ARM: 7548/1: include linux/sched.h in syscall.h
  ARM: 7541/1: Add ARM ERRATA 775420 workaround
  ARM: ensure vm_struct has its phys_addr member filled in
  ARM: 7540/1: kexec: Check segment memory addresses
  ARM: 7539/1: kexec: scan for dtb magic in segments
  ARM: 7538/1: delay: add registration mechanism for delay timer sources
  ARM: 7536/1: smp: Formalize an IPI for wakeup
  ARM: 7525/1: ptrace: use updated syscall number for syscall auditing
  ARM: 7524/1: support syscall tracing
  ARM: 7519/1: integrator: convert platform devices to Device Tree
  ARM: 7518/1: integrator: convert AMBA devices to device tree
  ARM: 7517/1: integrator: initial device tree support
  ARM: 7516/1: plat-versatile: add DT support to FPGA IRQ
  ARM: 7515/1: integrator: check PL010 base address from resource
  ARM: 7514/1: integrator: call common init function from machine
  ARM: 7522/1: arch_timers: register a time/cycle counter
  ARM: 7523/1: arch_timers: enable the use of the virtual timer
  ARM: 7531/1: mark kernelmode mem{cpy,set} non-experimental
  ARM: 7520/1: Build dtb files in all target
  ARM: Fix build warning in arch/arm/mm/alignment.c
  ...

1 files changed, 61 insertions, 6 deletions

diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 8f4db67533e..35c1ed89b93 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -47,13 +47,68 @@ extern void __raw_readsb(const void __iomem *addr, void *data, int bytelen);
 extern void __raw_readsw(const void __iomem *addr, void *data, int wordlen);
 extern void __raw_readsl(const void __iomem *addr, void *data, int longlen);
 
-#define __raw_writeb(v,a)	((void)(__chk_io_ptr(a), *(volatile unsigned char __force  *)(a) = (v)))
-#define __raw_writew(v,a)	((void)(__chk_io_ptr(a), *(volatile unsigned short __force *)(a) = (v)))
-#define __raw_writel(v,a)	((void)(__chk_io_ptr(a), *(volatile unsigned int __force   *)(a) = (v)))
+#if __LINUX_ARM_ARCH__ < 6
+/*
+ * Half-word accesses are problematic with RiscPC due to limitations of
+ * the bus. Rather than special-case the machine, just let the compiler
+ * generate the access for CPUs prior to ARMv6.
+ */
+#define __raw_readw(a)         (__chk_io_ptr(a), *(volatile unsigned short __force *)(a))
+#define __raw_writew(v,a)      ((void)(__chk_io_ptr(a), *(volatile unsigned short __force *)(a) = (v)))
+#else
+/*
+ * When running under a hypervisor, we want to avoid I/O accesses with
+ * writeback addressing modes as these incur a significant performance
+ * overhead (the address generation must be emulated in software).
+ */
+static inline void __raw_writew(u16 val, volatile void __iomem *addr)
+{
+	asm volatile("strh %1, %0"
+		     : "+Qo" (*(volatile u16 __force *)addr)
+		     : "r" (val));
+}
+
+static inline u16 __raw_readw(const volatile void __iomem *addr)
+{
+	u16 val;
+	asm volatile("ldrh %1, %0"
+		     : "+Qo" (*(volatile u16 __force *)addr),
+		       "=r" (val));
+	return val;
+}
+#endif
 
-#define __raw_readb(a)		(__chk_io_ptr(a), *(volatile unsigned char __force  *)(a))
-#define __raw_readw(a)		(__chk_io_ptr(a), *(volatile unsigned short __force *)(a))
-#define __raw_readl(a)		(__chk_io_ptr(a), *(volatile unsigned int __force   *)(a))
+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;
+}
 
 /*
  * Architecture ioremap implementation.