x86: move bad_dma_address

It goes to pci-dma.c, and is removed from the arch-specific files.
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/pci-dma.c

@@ -35,6 +35,8 @@ int iommu_detected __read_mostly = 0;
 int iommu_bio_merge __read_mostly = 0;
 EXPORT_SYMBOL(iommu_bio_merge);
 
+dma_addr_t bad_dma_address __read_mostly = 0;
+EXPORT_SYMBOL(bad_dma_address);
 
 int dma_set_mask(struct device *dev, u64 mask)
 {

arch/x86/kernel/pci-dma_32.c

@@ -14,10 +14,6 @@
 #include <linux/module.h>
 #include <asm/io.h>
 
-/* For i386, we make it point to the NULL address */
-dma_addr_t bad_dma_address __read_mostly = 0x0;
-EXPORT_SYMBOL(bad_dma_address);
-
 static int dma_alloc_from_coherent_mem(struct device *dev, ssize_t size,
 				       dma_addr_t *dma_handle, void **ret)
 {

arch/x86/kernel/pci-dma_64.c

@@ -14,8 +14,6 @@
 #include <asm/gart.h>
 #include <asm/calgary.h>
 
-dma_addr_t bad_dma_address __read_mostly;
-EXPORT_SYMBOL(bad_dma_address);
 
 /* Dummy device used for NULL arguments (normally ISA). Better would
    be probably a smaller DMA mask, but this is bug-to-bug compatible