x86: implement dma_map_single through dma_ops

That's already the name of the game for x86_64. For i386,
we add a pci-base_32.c, that will hold the default operations.
The function call itself goes through dma-mapping.h , the common
header

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 21 insertions, 0 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 7a2a2e93e84b..edd5c54ffde9 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -26,6 +26,7 @@ obj-y			+= pci-dma_$(BITS).o  bootflag.o e820_$(BITS).o
 obj-y			+= quirks.o i8237.o topology.o kdebugfs.o
 obj-y			+= alternative.o i8253.o
 obj-$(CONFIG_X86_64)	+= pci-nommu_64.o bugs_64.o
+obj-$(CONFIG_X86_32)	+= pci-base_32.o
 obj-y			+= tsc_$(BITS).o io_delay.o rtc.o
 
 obj-$(CONFIG_X86_TRAMPOLINE)	+= trampoline.o
diff --git a/arch/x86/kernel/pci-base_32.c b/arch/x86/kernel/pci-base_32.c
new file mode 100644
index 000000000000..b613d735f76c
--- /dev/null
+++ b/arch/x86/kernel/pci-base_32.c
@@ -0,0 +1,20 @@
+#include <linux/mm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/dma-mapping.h>
+#include <asm/dma-mapping.h>
+
+static dma_addr_t pci32_map_single(struct device *dev, void *ptr,
+				   size_t size, int direction)
+{
+	WARN_ON(size == 0);
+	flush_write_buffers();
+	return virt_to_phys(ptr);
+}
+
+static const struct dma_mapping_ops pci32_dma_ops = {
+	.map_single = pci32_map_single,
+};
+
+const struct dma_mapping_ops *dma_ops = &pci32_dma_ops;
+EXPORT_SYMBOL(dma_ops);