x86: provide a bad_dma_address symbol for i386

It's initially 0, since we don't expect any DMA there.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index 453b4bda2714..55ab3c874d8f 100644
--- a/arch/x86/kernel/pci-dma_32.c
+++ b/arch/x86/kernel/pci-dma_32.c
@@ -14,6 +14,10 @@
 #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);
+
 struct dma_coherent_mem {
         void            *virt_base;
         u32             device_base;