[U-Boot] [RFC][PATCH V0 4/7] arm: asm: io.h: define readX_relaxed and writeX_relaxed

Philippe Reynes philippe.reynes at softathome.com
Fri Nov 16 13:57:01 UTC 2018


Signed-off-by: Philippe Reynes <philippe.reynes at softathome.com>
---
 arch/arm/include/asm/io.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
index 5df7472..ab6bc59 100644
--- a/arch/arm/include/asm/io.h
+++ b/arch/arm/include/asm/io.h
@@ -123,6 +123,21 @@ static inline void __raw_readsl(unsigned long addr, void *data, int longlen)
 #define readq(c)	({ u64 __v = __arch_getq(c); __iormb(); __v; })
 
 /*
+ * Relaxed I/O memory access primitives. These follow the Device memory
+ * ordering rules but do not guarantee any ordering relative to Normal memory
+ * accesses.
+ */
+#define readb_relaxed(c)        ({ u8  __r = __raw_readb(c); __r; })
+#define readw_relaxed(c)        ({ u16 __r = le16_to_cpu((__force __le16)__raw_readw(c)); __r; })
+#define readl_relaxed(c)        ({ u32 __r = le32_to_cpu((__force __le32)__raw_readl(c)); __r; })
+#define readq_relaxed(c)        ({ u64 __r = le64_to_cpu((__force __le64)__raw_readq(c)); __r; })
+
+#define writeb_relaxed(v,c)     ((void)__raw_writeb((v),(c)))
+#define writew_relaxed(v,c)     ((void)__raw_writew((__force u16)cpu_to_le16(v),(c)))
+#define writel_relaxed(v,c)     ((void)__raw_writel((__force u32)cpu_to_le32(v),(c)))
+#define writeq_relaxed(v,c)     ((void)__raw_writeq((__force u64)cpu_to_le64(v),(c)))
+
+/*
  * The compiler seems to be incapable of optimising constants
  * properly.  Spell it out to the compiler in some cases.
  * These are only valid for small values of "off" (< 1<<12)
-- 
2.7.4



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