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linux-next/include/linux/io-64-nonatomic-hi-lo.h
Robin Murphy e511267bc2 io-64-nonatomic: Add relaxed accessor variants
Whilst commit 9439eb3ab9 ("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>
2016-05-03 18:23:02 +01:00

58 lines
1.1 KiB
C

#ifndef _LINUX_IO_64_NONATOMIC_HI_LO_H_
#define _LINUX_IO_64_NONATOMIC_HI_LO_H_
#include <linux/io.h>
#include <asm-generic/int-ll64.h>
static inline __u64 hi_lo_readq(const volatile void __iomem *addr)
{
const volatile u32 __iomem *p = addr;
u32 low, high;
high = readl(p + 1);
low = readl(p);
return low + ((u64)high << 32);
}
static inline void hi_lo_writeq(__u64 val, volatile void __iomem *addr)
{
writel(val >> 32, addr + 4);
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
#ifndef writeq
#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_ */