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authorBjorn Helgaas <bhelgaas@google.com>2014-05-20 16:54:23 -0600
committerBjorn Helgaas <bhelgaas@google.com>2014-05-20 16:55:39 -0600
commitace4b3fd67e771951d495aa1f1b1000984083362 (patch)
tree6af143970c659a6755795c1f4a499b4d014c030a
parent88a984ba0795f14a3847edbd7fabe652289ea89b (diff)
sh/PCI: Pass GAPSPCI_DMA_BASE CPU & bus address to dma_declare_coherent_memory()
dma_declare_coherent_memory() needs both the CPU physical address and the bus address of the device memory. They are the same on this platform, but in general we should use pcibios_resource_to_bus() to account for any address translation done by the PCI host bridge. This makes no difference on Dreamcast, but is safer if the usage is copied to future drivers. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Arnd Bergmann <arnd@arndb.de> CC: Magnus Damm <damm@opensource.se> CC: linux-sh@vger.kernel.org
-rw-r--r--arch/sh/drivers/pci/fixups-dreamcast.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/arch/sh/drivers/pci/fixups-dreamcast.c b/arch/sh/drivers/pci/fixups-dreamcast.c
index d6cde700e316..1d1c5a227e50 100644
--- a/arch/sh/drivers/pci/fixups-dreamcast.c
+++ b/arch/sh/drivers/pci/fixups-dreamcast.c
@@ -31,6 +31,8 @@
static void gapspci_fixup_resources(struct pci_dev *dev)
{
struct pci_channel *p = dev->sysdata;
+ struct resource res;
+ struct pci_bus_region region;
printk(KERN_NOTICE "PCI: Fixing up device %s\n", pci_name(dev));
@@ -50,11 +52,21 @@ static void gapspci_fixup_resources(struct pci_dev *dev)
/*
* Redirect dma memory allocations to special memory window.
+ *
+ * If this GAPSPCI region were mapped by a BAR, the CPU
+ * phys_addr_t would be pci_resource_start(), and the bus
+ * address would be pci_bus_address(pci_resource_start()).
+ * But apparently there's no BAR mapping it, so we just
+ * "know" its CPU address is GAPSPCI_DMA_BASE.
*/
+ res.start = GAPSPCI_DMA_BASE;
+ res.end = GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1;
+ res.flags = IORESOURCE_MEM;
+ pcibios_resource_to_bus(dev->bus, &region, &res);
BUG_ON(!dma_declare_coherent_memory(&dev->dev,
- GAPSPCI_DMA_BASE,
- GAPSPCI_DMA_BASE,
- GAPSPCI_DMA_SIZE,
+ res.start,
+ region.start,
+ resource_size(&res),
DMA_MEMORY_MAP |
DMA_MEMORY_EXCLUSIVE));
break;