PCI: Use pci_generic_prep_mwi on ia64

The pci_generic_prep_mwi() code does everything that pcibios_prep_mwi()
does on ia64.  All we need to do is be sure that pci_cache_line_size
is set appropriately, and we can delete pcibios_prep_mwi().

Using SMP_CACHE_BYTES as the default was wrong on uniprocessor machines
as it is only 8 bytes.  The default in the generic code of L1_CACHE_BYTES
is at least as good.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/asm-ia64/pci.h b/include/asm-ia64/pci.h
index ef616fd..825eb7d 100644
--- a/include/asm-ia64/pci.h
+++ b/include/asm-ia64/pci.h
@@ -26,16 +26,18 @@
 struct pci_dev;
 
 /*
- * PCI_DMA_BUS_IS_PHYS should be set to 1 if there is _necessarily_ a direct correspondence
- * between device bus addresses and CPU physical addresses.  Platforms with a hardware I/O
- * MMU _must_ turn this off to suppress the bounce buffer handling code in the block and
- * network device layers.  Platforms with separate bus address spaces _must_ turn this off
- * and provide a device DMA mapping implementation that takes care of the necessary
+ * PCI_DMA_BUS_IS_PHYS should be set to 1 if there is _necessarily_ a direct
+ * correspondence between device bus addresses and CPU physical addresses.
+ * Platforms with a hardware I/O MMU _must_ turn this off to suppress the
+ * bounce buffer handling code in the block and network device layers.
+ * Platforms with separate bus address spaces _must_ turn this off and provide
+ * a device DMA mapping implementation that takes care of the necessary
  * address translation.
  *
- * For now, the ia64 platforms which may have separate/multiple bus address spaces all
- * have I/O MMUs which support the merging of physically discontiguous buffers, so we can
- * use that as the sole factor to determine the setting of PCI_DMA_BUS_IS_PHYS.
+ * For now, the ia64 platforms which may have separate/multiple bus address
+ * spaces all have I/O MMUs which support the merging of physically
+ * discontiguous buffers, so we can use that as the sole factor to determine
+ * the setting of PCI_DMA_BUS_IS_PHYS.
  */
 extern unsigned long ia64_max_iommu_merge_mask;
 #define PCI_DMA_BUS_IS_PHYS	(ia64_max_iommu_merge_mask == ~0UL)
@@ -52,9 +54,6 @@
 	/* We don't do dynamic PCI IRQ allocation */
 }
 
-#define HAVE_ARCH_PCI_MWI 1
-extern int pcibios_prep_mwi (struct pci_dev *);
-
 #include <asm-generic/pci-dma-compat.h>
 
 /* pci_unmap_{single,page} is not a nop, thus... */