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x86: provide readq()/writeq() on 32-bit too 

Impact: add new API for drivers

Add implementation of readq/writeq to x86_32, and add config value to
the x86 architecture to determine existence of readq/writeq.

Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Hitoshi Mitake 2008-11-30 17:16:04 +09:00 committed by Ingo Molnar
parent ed313489ba
commit 2c5643b1c5
2 changed files with 26 additions and 0 deletions
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2
arch/x86/Kconfig
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@ -19,6 +19,8 @@ config X86_64
config X86
def_bool y
select HAVE_AOUT if X86_32
select HAVE_READQ
select HAVE_WRITEQ
select HAVE_UNSTABLE_SCHED_CLOCK
select HAVE_IDE
select HAVE_OPROFILE

24
arch/x86/include/asm/io.h
View File

@ -4,6 +4,7 @@
#define ARCH_HAS_IOREMAP_WC
#include <linux/compiler.h>
#include <asm-generic/int-ll64.h>
#define build_mmio_read(name, size, type, reg, barrier) \
static inline type name(const volatile void __iomem *addr) \
@ -57,6 +58,29 @@ build_mmio_write(__writeq, "q", unsigned long, "r", )
/* Let people know we have them */
#define readq readq
#define writeq writeq
#else /* CONFIG_X86_32 from here */
static inline __u64 readq(const volatile void __iomem *addr)
{
const volatile u32 __iomem *p = addr;
u32 l, h;
l = readl(p);
h = readl(p + 1);
return l + ((u64)h << 32);
}
static inline void writeq(__u64 val, volatile void __iomem *addr)
{
writel(val, addr);
writel(val >> 32, addr+4);
}
#define readq readq
#define writeq writeq
#endif
extern int iommu_bio_merge;