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authorSinan Kaya <okaya@codeaurora.org>2018-04-05 09:09:11 -0400
committerArnd Bergmann <arnd@arndb.de>2018-04-06 12:01:56 +0200
commit755bd04aaf4bf7c49ce8aad2677ea4d14271fc46 (patch)
treea0899a14c45441eada77bc04a6ccf8fbec69db13 /include/asm-generic/io.h
parent032d59e1cde9dd71bb5918e1f6529776623ee86b (diff)
io: define stronger ordering for the default writeX() implementation
The default implementation of mapping writeX() to __raw_writeX() is wrong. writeX() has stronger ordering semantics. Compiler is allowed to reorder memory writes against __raw_writeX(). Use the previously defined __io_aw() and __io_bw() macros to harden code generation according to architecture support. Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'include/asm-generic/io.h')
-rw-r--r--include/asm-generic/io.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index d27e8af9dd5a..964725e4f459 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -208,7 +208,9 @@ static inline u64 readq(const volatile void __iomem *addr)
#define writeb writeb
static inline void writeb(u8 value, volatile void __iomem *addr)
{
+ __io_bw();
__raw_writeb(value, addr);
+ __io_aw();
}
#endif
@@ -216,7 +218,9 @@ static inline void writeb(u8 value, volatile void __iomem *addr)
#define writew writew
static inline void writew(u16 value, volatile void __iomem *addr)
{
+ __io_bw();
__raw_writew(cpu_to_le16(value), addr);
+ __io_aw();
}
#endif
@@ -224,7 +228,9 @@ static inline void writew(u16 value, volatile void __iomem *addr)
#define writel writel
static inline void writel(u32 value, volatile void __iomem *addr)
{
+ __io_bw();
__raw_writel(__cpu_to_le32(value), addr);
+ __io_aw();
}
#endif
@@ -233,7 +239,9 @@ static inline void writel(u32 value, volatile void __iomem *addr)
#define writeq writeq
static inline void writeq(u64 value, volatile void __iomem *addr)
{
+ __io_bw();
__raw_writeq(__cpu_to_le64(value), addr);
+ __io_aw();
}
#endif
#endif /* CONFIG_64BIT */