[PATCH] x86_64: Add memcpy32_toio to write to PCI MMIO

[Subhransu S. Prusty]

This is needed because the hardware does not support 64-bit moveq
insructions while writing to PCI MMIO.

Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@xxxxxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
---
 arch/x86/include/asm/io.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index b8237d8..fa095fb 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -218,6 +218,28 @@ memcpy_toio(volatile void __iomem *dst, const void *src, size_t count)
 	memcpy((void __force *)dst, src, count);
 }
 
+#ifndef CONFIG_X86_64
+#define MEMCPY_TOIO memcpy_toio
+#else
+#define MEMCPY_TOIO memcpy32_toio
+#endif
+
+/**
+ * memcpy32_toio: Copy using writel commands
+ *
+ * This is needed because the hardware does not support
+ * 64-bit moveq insructions while writing to PCI MMIO
+ */
+static inline void memcpy32_toio(void *dst, const void *src, int count)
+{
+	int i;
+	const u32 *src_32 = src;
+	u32 *dst_32 = dst;
+
+	for (i = 0; i < count/sizeof(u32); i++)
+		writel(*src_32++, dst_32++);
+}
+
 /*
  * ISA space is 'always mapped' on a typical x86 system, no need to
  * explicitly ioremap() it. The fact that the ISA IO space is mapped
-- 
1.9.0

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