[PATCH] PA-RISC IOMMU-related fixes

 - PCI_DMA_BUS_IS_PHYS is only true if we don't have an IOMMU.  Getting this
   wrong results in system panics when we run out of bounce buffers.
 - parisc_vmerge_boundary and parisc_vmerge_max_size need to be available on
   all machines, not just ones with GSC.
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/parisc/kernel/setup.c

@@ -53,6 +53,15 @@ struct proc_dir_entry * proc_runway_root = NULL;
 struct proc_dir_entry * proc_gsc_root = NULL;
 struct proc_dir_entry * proc_mckinley_root = NULL;
 
+#if !defined(CONFIG_PA20) && (defined(CONFIG_IOMMU_CCIO) || defined(CONFIG_IOMMU_SBA))
+int parisc_bus_is_phys = 1;	/* Assume no IOMMU is present */
+EXPORT_SYMBOL(parisc_bus_is_phys);
+#endif
+
+/* This sets the vmerge boundary and size, it's here because it has to
+ * be available on all platforms (zero means no-virtual merging) */
+unsigned long parisc_vmerge_boundary = 0;
+unsigned long parisc_vmerge_max_size = 0;
 
 void __init setup_cmdline(char **cmdline_p)
 {

include/asm-parisc/pci.h

@@ -106,11 +106,28 @@ static __inline__  int pci_is_lmmio(struct pci_hba_data *hba, unsigned long a)
 struct pci_bus;
 struct pci_dev;
 
-/* The PCI address space does equal the physical memory
- * address space.  The networking and block device layers use
+/*
+ * If the PCI device's view of memory is the same as the CPU's view of memory,
+ * PCI_DMA_BUS_IS_PHYS is true.  The networking and block device layers use
  * this boolean for bounce buffer decisions.
  */
-#define PCI_DMA_BUS_IS_PHYS     (1)
+#ifdef CONFIG_PA20
+/* All PA-2.0 machines have an IOMMU. */
+#define PCI_DMA_BUS_IS_PHYS	0
+#define parisc_has_iommu()	do { } while (0)
+#else
+
+#if defined(CONFIG_IOMMU_CCIO) || defined(CONFIG_IOMMU_SBA)
+extern int parisc_bus_is_phys; 	/* in arch/parisc/kernel/setup.c */
+#define PCI_DMA_BUS_IS_PHYS	parisc_bus_is_phys
+#define parisc_has_iommu()	do { parisc_bus_is_phys = 0; } while (0)
+#else
+#define PCI_DMA_BUS_IS_PHYS	1
+#define parisc_has_iommu()	do { } while (0)
+#endif
+
+#endif	/* !CONFIG_PA20 */
+
 
 /*
 ** Most PCI devices (eg Tulip, NCR720) also export the same registers