diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 33513b9a67f3e69dad897cc01a33b1b78849ae0a..05cfed4485fae802dc9be64f0a0feb9cf3214150 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -80,8 +80,6 @@ static inline void writeq(__u64 val, volatile void __iomem *addr)
 #define readq			readq
 #define writeq			writeq
 
-extern int iommu_bio_merge;
-
 #ifdef CONFIG_X86_32
 # include "io_32.h"
 #else
diff --git a/arch/x86/include/asm/io_64.h b/arch/x86/include/asm/io_64.h
index fea325a1122f4abf66d340113a9a82787a75832f..563c16270ba6d3fee1bda648f873109b7c1d2b3f 100644
--- a/arch/x86/include/asm/io_64.h
+++ b/arch/x86/include/asm/io_64.h
@@ -232,8 +232,6 @@ void memset_io(volatile void __iomem *a, int b, size_t c);
 
 #define flush_write_buffers()
 
-#define BIO_VMERGE_BOUNDARY iommu_bio_merge
-
 /*
  * Convert a virtual cached pointer to an uncached pointer
  */
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 12eeb4bfcdeb39727cf4b1e70c1c08590249682d..da93c65f8f0bc67a12a1d25579dda1372b70863d 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -31,11 +31,6 @@ int no_iommu __read_mostly;
 /* Set this to 1 if there is a HW IOMMU in the system */
 int iommu_detected __read_mostly = 0;
 
-/* This tells the BIO block layer to assume merging. Default to off
-   because we cannot guarantee merging later. */
-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);
 
@@ -189,7 +184,6 @@ static __init int iommu_setup(char *p)
 		}
 
 		if (!strncmp(p, "biomerge", 8)) {
-			iommu_bio_merge = 4096;
 			iommu_merge = 1;
 			force_iommu = 1;
 		}