x86: io: implement dummy relaxed accessor macros for writes (cbc908ef) · Commits · 戴 / test

write{b,w,l,q}_relaxed are implemented by some architectures in order to permit memory-mapped I/O accesses with weaker barrier semantics than the non-relaxed variants. This patch adds dummy macros for the write accessors to x86, in the same vein as the dummy definitions for the relaxed read accessors. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by:

Will Deacon <will.deacon@arm.com>

arch/x86/include/asm/io.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -74,6 +74,9 @@ build_mmio_write(__writel, "l", unsigned int, "r", )
		#define __raw_readw __readw
		#define __raw_readl __readl

		#define writeb_relaxed(v, a) __writeb(v, a)
		#define writew_relaxed(v, a) __writew(v, a)
		#define writel_relaxed(v, a) __writel(v, a)
		#define __raw_writeb __writeb
		#define __raw_writew __writew
		#define __raw_writel __writel
		@@ -86,6 +89,7 @@ build_mmio_read(readq, "q", unsigned long, "=r", :"memory")
		build_mmio_write(writeq, "q", unsigned long, "r", :"memory")

		#define readq_relaxed(a) readq(a)
		#define writeq_relaxed(v, a) writeq(v, a)

		#define __raw_readq(a) readq(a)
		#define __raw_writeq(val, addr) writeq(val, addr)

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