[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>

1 files changed, 27 insertions, 0 deletions

diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index 211fcfd115f..61f1af5c23c 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 @@ static void __init set_pci_cacheline_size(void)
 	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();