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authorRobin Murphy <robin.murphy@arm.com>2016-04-26 13:38:20 +0300
committerWill Deacon <will.deacon@arm.com>2016-05-03 20:23:02 +0300
commite511267bc25e18926826e7cccdf7872bcbb4776a (patch)
treeae8d3be2bee8b89cfaa309a88ebd229f76b5f95c /include/linux/io-64-nonatomic-hi-lo.h
parentf0cfffc48cac516e37711786227f6808491913a5 (diff)
downloadlinux-e511267bc25e18926826e7cccdf7872bcbb4776a.tar.xz
io-64-nonatomic: Add relaxed accessor variants
Whilst commit 9439eb3ab9d1 ("asm-generic: io: implement relaxed accessor macros as conditional wrappers") makes the *_relaxed forms of I/O accessors universally available to drivers, in cases where writeq() is implemented via the io-64-nonatomic helpers, writeq_relaxed() will end up falling back to writel() regardless of whether writel_relaxed() is available (identically for s/write/read/). Add corresponding relaxed forms of the nonatomic helpers to delegate to the equivalent 32-bit accessors as appropriate. We also need to fix io.h to avoid defining default relaxed variants if the basic accessors themselves don't exist. CC: Christoph Hellwig <hch@lst.de> CC: Darren Hart <dvhart@linux.intel.com> CC: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'include/linux/io-64-nonatomic-hi-lo.h')
-rw-r--r--include/linux/io-64-nonatomic-hi-lo.h25
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/io-64-nonatomic-hi-lo.h b/include/linux/io-64-nonatomic-hi-lo.h
index 11d7e840d913..defcc4644ce3 100644
--- a/include/linux/io-64-nonatomic-hi-lo.h
+++ b/include/linux/io-64-nonatomic-hi-lo.h
@@ -21,6 +21,23 @@ static inline void hi_lo_writeq(__u64 val, volatile void __iomem *addr)
writel(val, addr);
}
+static inline __u64 hi_lo_readq_relaxed(const volatile void __iomem *addr)
+{
+ const volatile u32 __iomem *p = addr;
+ u32 low, high;
+
+ high = readl_relaxed(p + 1);
+ low = readl_relaxed(p);
+
+ return low + ((u64)high << 32);
+}
+
+static inline void hi_lo_writeq_relaxed(__u64 val, volatile void __iomem *addr)
+{
+ writel_relaxed(val >> 32, addr + 4);
+ writel_relaxed(val, addr);
+}
+
#ifndef readq
#define readq hi_lo_readq
#endif
@@ -29,4 +46,12 @@ static inline void hi_lo_writeq(__u64 val, volatile void __iomem *addr)
#define writeq hi_lo_writeq
#endif
+#ifndef readq_relaxed
+#define readq_relaxed hi_lo_readq_relaxed
+#endif
+
+#ifndef writeq_relaxed
+#define writeq_relaxed hi_lo_writeq_relaxed
+#endif
+
#endif /* _LINUX_IO_64_NONATOMIC_HI_LO_H_ */