From ace4b3fd67e771951d495aa1f1b1000984083362 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Tue, 20 May 2014 16:54:23 -0600 Subject: [PATCH] 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 Acked-by: Arnd Bergmann CC: Magnus Damm CC: linux-sh@vger.kernel.org --- arch/sh/drivers/pci/fixups-dreamcast.c | 18 +++++++++++++++--- 1 file 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, ®ion, &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;