[IA64] SN specific version of dma_get_required_mask()

Create a platform specific version of dma_get_required_mask()
for ia64 SN Altix. All SN Altix platforms support 64 bit DMA
addressing regardless of the size of system memory.
Create an ia64 machvec for dma_get_required_mask, with the
SN version unconditionally returning DMA_64BIT_MASK.

Signed-off-by: John Keller <jpk@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/include/asm/dma-mapping.h b/arch/ia64/include/asm/dma-mapping.h
index bbab7e2..1f912d9 100644
--- a/arch/ia64/include/asm/dma-mapping.h
+++ b/arch/ia64/include/asm/dma-mapping.h
@@ -9,6 +9,8 @@
 #include <linux/scatterlist.h>
 #include <asm/swiotlb.h>
 
+#define ARCH_HAS_DMA_GET_REQUIRED_MASK
+
 struct dma_mapping_ops {
 	int             (*mapping_error)(struct device *dev,
 					 dma_addr_t dma_addr);
diff --git a/arch/ia64/include/asm/machvec.h b/arch/ia64/include/asm/machvec.h
index 59c17e4..fe87b21 100644
--- a/arch/ia64/include/asm/machvec.h
+++ b/arch/ia64/include/asm/machvec.h
@@ -62,6 +62,7 @@
 typedef void ia64_mv_dma_unmap_single_attrs (struct device *, dma_addr_t, size_t, int, struct dma_attrs *);
 typedef int ia64_mv_dma_map_sg_attrs (struct device *, struct scatterlist *, int, int, struct dma_attrs *);
 typedef void ia64_mv_dma_unmap_sg_attrs (struct device *, struct scatterlist *, int, int, struct dma_attrs *);
+typedef u64 ia64_mv_dma_get_required_mask (struct device *);
 
 /*
  * WARNING: The legacy I/O space is _architected_.  Platforms are
@@ -159,6 +160,7 @@
 #  define platform_dma_sync_sg_for_device ia64_mv.dma_sync_sg_for_device
 #  define platform_dma_mapping_error		ia64_mv.dma_mapping_error
 #  define platform_dma_supported	ia64_mv.dma_supported
+#  define platform_dma_get_required_mask ia64_mv.dma_get_required_mask
 #  define platform_irq_to_vector	ia64_mv.irq_to_vector
 #  define platform_local_vector_to_irq	ia64_mv.local_vector_to_irq
 #  define platform_pci_get_legacy_mem	ia64_mv.pci_get_legacy_mem
@@ -213,6 +215,7 @@
 	ia64_mv_dma_sync_sg_for_device *dma_sync_sg_for_device;
 	ia64_mv_dma_mapping_error *dma_mapping_error;
 	ia64_mv_dma_supported *dma_supported;
+	ia64_mv_dma_get_required_mask *dma_get_required_mask;
 	ia64_mv_irq_to_vector *irq_to_vector;
 	ia64_mv_local_vector_to_irq *local_vector_to_irq;
 	ia64_mv_pci_get_legacy_mem_t *pci_get_legacy_mem;
@@ -263,6 +266,7 @@
 	platform_dma_sync_sg_for_device,	\
 	platform_dma_mapping_error,			\
 	platform_dma_supported,			\
+	platform_dma_get_required_mask,		\
 	platform_irq_to_vector,			\
 	platform_local_vector_to_irq,		\
 	platform_pci_get_legacy_mem,		\
@@ -366,6 +370,9 @@
 #ifndef platform_dma_supported
 # define  platform_dma_supported	swiotlb_dma_supported
 #endif
+#ifndef platform_dma_get_required_mask
+# define  platform_dma_get_required_mask	ia64_dma_get_required_mask
+#endif
 #ifndef platform_irq_to_vector
 # define platform_irq_to_vector		__ia64_irq_to_vector
 #endif
diff --git a/arch/ia64/include/asm/machvec_init.h b/arch/ia64/include/asm/machvec_init.h
index ef964b2..37a4698 100644
--- a/arch/ia64/include/asm/machvec_init.h
+++ b/arch/ia64/include/asm/machvec_init.h
@@ -3,6 +3,7 @@
 
 extern ia64_mv_send_ipi_t ia64_send_ipi;
 extern ia64_mv_global_tlb_purge_t ia64_global_tlb_purge;
+extern ia64_mv_dma_get_required_mask ia64_dma_get_required_mask;
 extern ia64_mv_irq_to_vector __ia64_irq_to_vector;
 extern ia64_mv_local_vector_to_irq __ia64_local_vector_to_irq;
 extern ia64_mv_pci_get_legacy_mem_t ia64_pci_get_legacy_mem;
diff --git a/arch/ia64/include/asm/machvec_sn2.h b/arch/ia64/include/asm/machvec_sn2.h
index 781308e..f1a6e0d 100644
--- a/arch/ia64/include/asm/machvec_sn2.h
+++ b/arch/ia64/include/asm/machvec_sn2.h
@@ -67,6 +67,7 @@
 extern ia64_mv_dma_sync_sg_for_device	sn_dma_sync_sg_for_device;
 extern ia64_mv_dma_mapping_error	sn_dma_mapping_error;
 extern ia64_mv_dma_supported		sn_dma_supported;
+extern ia64_mv_dma_get_required_mask	sn_dma_get_required_mask;
 extern ia64_mv_migrate_t		sn_migrate;
 extern ia64_mv_kernel_launch_event_t	sn_kernel_launch_event;
 extern ia64_mv_setup_msi_irq_t		sn_setup_msi_irq;
@@ -123,6 +124,7 @@
 #define platform_dma_sync_sg_for_device	sn_dma_sync_sg_for_device
 #define platform_dma_mapping_error		sn_dma_mapping_error
 #define platform_dma_supported		sn_dma_supported
+#define platform_dma_get_required_mask	sn_dma_get_required_mask
 #define platform_migrate		sn_migrate
 #define platform_kernel_launch_event    sn_kernel_launch_event
 #ifdef CONFIG_PCI_MSI
diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index 211fcfd..61f1af5 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -19,6 +19,7 @@
 #include <linux/ioport.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <linux/bootmem.h>
 
 #include <asm/machvec.h>
 #include <asm/page.h>
@@ -748,6 +749,32 @@
 	pci_cache_line_size = (1 << cci.pcci_line_size) / 4;
 }
 
+u64 ia64_dma_get_required_mask(struct device *dev)
+{
+	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
+	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
+	u64 mask;
+
+	if (!high_totalram) {
+		/* convert to mask just covering totalram */
+		low_totalram = (1 << (fls(low_totalram) - 1));
+		low_totalram += low_totalram - 1;
+		mask = low_totalram;
+	} else {
+		high_totalram = (1 << (fls(high_totalram) - 1));
+		high_totalram += high_totalram - 1;
+		mask = (((u64)high_totalram) << 32) + 0xffffffff;
+	}
+	return mask;
+}
+EXPORT_SYMBOL_GPL(ia64_dma_get_required_mask);
+
+u64 dma_get_required_mask(struct device *dev)
+{
+	return platform_dma_get_required_mask(dev);
+}
+EXPORT_SYMBOL_GPL(dma_get_required_mask);
+
 static int __init pcibios_init(void)
 {
 	set_pci_cacheline_size();
diff --git a/arch/ia64/sn/pci/pci_dma.c b/arch/ia64/sn/pci/pci_dma.c
index 53ebb64..863f501 100644
--- a/arch/ia64/sn/pci/pci_dma.c
+++ b/arch/ia64/sn/pci/pci_dma.c
@@ -356,6 +356,12 @@
 }
 EXPORT_SYMBOL(sn_dma_mapping_error);
 
+u64 sn_dma_get_required_mask(struct device *dev)
+{
+	return DMA_64BIT_MASK;
+}
+EXPORT_SYMBOL_GPL(sn_dma_get_required_mask);
+
 char *sn_pci_get_legacy_mem(struct pci_bus *bus)
 {
 	if (!SN_PCIBUS_BUSSOFT(bus))