leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

io: define stronger ordering for the default writeX() implementation

Browse Source 
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>
This commit is contained in:
Sinan Kaya 2018-04-05 09:09:11 -04:00 committed by Arnd Bergmann
parent 032d59e1cd
commit 755bd04aaf
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
include/asm-generic/io.h
View File

@ -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 */