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authorChris Metcalf <cmetcalf@tilera.com>2013-08-30 10:12:36 -0400
committerChris Metcalf <cmetcalf@tilera.com>2013-09-03 14:53:37 -0400
commitb40f451d56de69477a2244a0b4082f644699673f (patch)
treea1f113a598fd28f61ae9a26e8eb19e528309beff /arch/tile/kernel/pci-dma.c
parent6d715790ef6b5b903779a14d995ce3d9e680bec0 (diff)
downloadlinux-b40f451d56de69477a2244a0b4082f644699673f.tar.bz2
tile PCI RC: make default consistent DMA mask 32-bit
This change sets the PCI devices' initial DMA capabilities conservatively and promotes them at the request of the driver, as opposed to assuming advanced DMA capabilities. The old design runs the risk of breaking drivers that assume default capabilities. 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.c21
1 files changed, 12 insertions, 9 deletions
diff --git a/arch/tile/kernel/pci-dma.c b/arch/tile/kernel/pci-dma.c
index d94f4872e94f..09b58703ac26 100644
--- a/arch/tile/kernel/pci-dma.c
+++ b/arch/tile/kernel/pci-dma.c
@@ -588,15 +588,18 @@ int dma_set_coherent_mask(struct device *dev, u64 mask)
{
struct dma_map_ops *dma_ops = get_dma_ops(dev);
- /* Handle hybrid PCI devices with limited memory addressability. */
- if ((dma_ops == gx_pci_dma_map_ops ||
- dma_ops == gx_hybrid_pci_dma_map_ops ||
- dma_ops == gx_legacy_pci_dma_map_ops) &&
- (mask <= DMA_BIT_MASK(32))) {
- if (dma_ops == gx_pci_dma_map_ops)
- set_dma_ops(dev, gx_hybrid_pci_dma_map_ops);
-
- if (mask > dev->archdata.max_direct_dma_addr)
+ /*
+ * For PCI devices with 64-bit DMA addressing capability, promote
+ * the dma_ops to full capability for both streams and consistent
+ * memory access. For 32-bit capable devices, limit the consistent
+ * memory DMA range to max_direct_dma_addr.
+ */
+ if (dma_ops == gx_pci_dma_map_ops ||
+ dma_ops == gx_hybrid_pci_dma_map_ops ||
+ dma_ops == gx_legacy_pci_dma_map_ops) {
+ if (mask == DMA_BIT_MASK(64))
+ set_dma_ops(dev, gx_pci_dma_map_ops);
+ else if (mask > dev->archdata.max_direct_dma_addr)
mask = dev->archdata.max_direct_dma_addr;
}