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authorSinan Kaya <okaya@codeaurora.org>2018-04-16 18:16:56 -0400
committerMatt Turner <mattst88@gmail.com>2018-05-22 18:10:36 -0700
commit92d7223a74235054f2aa7227d207d9c57f84dca0 (patch)
tree5334ad1c8c2a41f1133ae7d3905a5163043184ee /arch/alpha/kernel
parentf5e82fa26063e6fad10624ff600457d878fa6e41 (diff)
alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering #2
memory-barriers.txt has been updated with the following requirement. "When using writel(), a prior wmb() is not needed to guarantee that the cache coherent memory writes have completed before writing to the MMIO region." Current writeX() and iowriteX() implementations on alpha are not satisfying this requirement as the barrier is after the register write. Move mb() in writeX() and iowriteX() functions to guarantee that HW observes memory changes before performing register operations. Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Matt Turner <mattst88@gmail.com>
Diffstat (limited to 'arch/alpha/kernel')
-rw-r--r--arch/alpha/kernel/io.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/alpha/kernel/io.c b/arch/alpha/kernel/io.c
index 3e3d49c254c5..c025a3e5e357 100644
--- a/arch/alpha/kernel/io.c
+++ b/arch/alpha/kernel/io.c
@@ -37,20 +37,20 @@ unsigned int ioread32(void __iomem *addr)
void iowrite8(u8 b, void __iomem *addr)
{
- IO_CONCAT(__IO_PREFIX,iowrite8)(b, addr);
mb();
+ IO_CONCAT(__IO_PREFIX,iowrite8)(b, addr);
}
void iowrite16(u16 b, void __iomem *addr)
{
- IO_CONCAT(__IO_PREFIX,iowrite16)(b, addr);
mb();
+ IO_CONCAT(__IO_PREFIX,iowrite16)(b, addr);
}
void iowrite32(u32 b, void __iomem *addr)
{
- IO_CONCAT(__IO_PREFIX,iowrite32)(b, addr);
mb();
+ IO_CONCAT(__IO_PREFIX,iowrite32)(b, addr);
}
EXPORT_SYMBOL(ioread8);
@@ -176,26 +176,26 @@ u64 readq(const volatile void __iomem *addr)
void writeb(u8 b, volatile void __iomem *addr)
{
- __raw_writeb(b, addr);
mb();
+ __raw_writeb(b, addr);
}
void writew(u16 b, volatile void __iomem *addr)
{
- __raw_writew(b, addr);
mb();
+ __raw_writew(b, addr);
}
void writel(u32 b, volatile void __iomem *addr)
{
- __raw_writel(b, addr);
mb();
+ __raw_writel(b, addr);
}
void writeq(u64 b, volatile void __iomem *addr)
{
- __raw_writeq(b, addr);
mb();
+ __raw_writeq(b, addr);
}
EXPORT_SYMBOL(readb);