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authorChris Metcalf <cmetcalf@tilera.com>2012-05-09 12:26:30 -0400
committerChris Metcalf <cmetcalf@tilera.com>2012-07-18 16:40:11 -0400
commiteef015c8aa74451f848307fe5f65485070533bbb (patch)
tree7fca680be2246812c14920c0fb44fbe717786dc6 /arch/tile/kernel/pci-dma.c
parentbbaa22c3a0d0be4406d26e5a73d1e8e504787986 (diff)
downloadlinux-linaro-stable-eef015c8aa74451f848307fe5f65485070533bbb.tar.gz
arch/tile: enable ZONE_DMA for tilegx
This is required for PCI root complex legacy support and USB OHCI root complex support. With this change tilegx now supports allocating memory whose PA fits in 32 bits. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Diffstat (limited to 'arch/tile/kernel/pci-dma.c')
-rw-r--r--arch/tile/kernel/pci-dma.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/tile/kernel/pci-dma.c b/arch/tile/kernel/pci-dma.c
index 9814d7082f24..edd856a000c5 100644
--- a/arch/tile/kernel/pci-dma.c
+++ b/arch/tile/kernel/pci-dma.c
@@ -45,14 +45,17 @@ void *dma_alloc_coherent(struct device *dev,
gfp |= __GFP_ZERO;
/*
- * By forcing NUMA node 0 for 32-bit masks we ensure that the
- * high 32 bits of the resulting PA will be zero. If the mask
- * size is, e.g., 24, we may still not be able to guarantee a
- * suitable memory address, in which case we will return NULL.
- * But such devices are uncommon.
+ * If the mask specifies that the memory be in the first 4 GB, then
+ * we force the allocation to come from the DMA zone. We also
+ * force the node to 0 since that's the only node where the DMA
+ * zone isn't empty. If the mask size is smaller than 32 bits, we
+ * may still not be able to guarantee a suitable memory address, in
+ * which case we will return NULL. But such devices are uncommon.
*/
- if (dma_mask <= DMA_BIT_MASK(32))
+ if (dma_mask <= DMA_BIT_MASK(32)) {
+ gfp |= GFP_DMA;
node = 0;
+ }
pg = homecache_alloc_pages_node(node, gfp, order, PAGE_HOME_DMA);
if (pg == NULL)