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>
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index ac2abc8..2594644 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -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 @@
/* 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;