diff options
Diffstat (limited to 'arch/powerpc/kernel/pci_direct_iommu.c')
-rw-r--r-- | arch/powerpc/kernel/pci_direct_iommu.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/pci_direct_iommu.c b/arch/powerpc/kernel/pci_direct_iommu.c new file mode 100644 index 00000000000..e1a32f802c0 --- /dev/null +++ b/arch/powerpc/kernel/pci_direct_iommu.c @@ -0,0 +1,94 @@ +/* + * Support for DMA from PCI devices to main memory on + * machines without an iommu or with directly addressable + * RAM (typically a pmac with 2Gb of RAM or less) + * + * Copyright (C) 2003 Benjamin Herrenschmidt (benh@kernel.crashing.org) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/pci.h> +#include <linux/delay.h> +#include <linux/string.h> +#include <linux/init.h> +#include <linux/bootmem.h> +#include <linux/mm.h> +#include <linux/dma-mapping.h> + +#include <asm/sections.h> +#include <asm/io.h> +#include <asm/prom.h> +#include <asm/pci-bridge.h> +#include <asm/machdep.h> +#include <asm/pmac_feature.h> +#include <asm/abs_addr.h> +#include <asm/ppc-pci.h> + +static void *pci_direct_alloc_coherent(struct device *hwdev, size_t size, + dma_addr_t *dma_handle, gfp_t flag) +{ + void *ret; + + ret = (void *)__get_free_pages(flag, get_order(size)); + if (ret != NULL) { + memset(ret, 0, size); + *dma_handle = virt_to_abs(ret); + } + return ret; +} + +static void pci_direct_free_coherent(struct device *hwdev, size_t size, + void *vaddr, dma_addr_t dma_handle) +{ + free_pages((unsigned long)vaddr, get_order(size)); +} + +static dma_addr_t pci_direct_map_single(struct device *hwdev, void *ptr, + size_t size, enum dma_data_direction direction) +{ + return virt_to_abs(ptr); +} + +static void pci_direct_unmap_single(struct device *hwdev, dma_addr_t dma_addr, + size_t size, enum dma_data_direction direction) +{ +} + +static int pci_direct_map_sg(struct device *hwdev, struct scatterlist *sg, + int nents, enum dma_data_direction direction) +{ + int i; + + for (i = 0; i < nents; i++, sg++) { + sg->dma_address = page_to_phys(sg->page) + sg->offset; + sg->dma_length = sg->length; + } + + return nents; +} + +static void pci_direct_unmap_sg(struct device *hwdev, struct scatterlist *sg, + int nents, enum dma_data_direction direction) +{ +} + +static int pci_direct_dma_supported(struct device *dev, u64 mask) +{ + return mask < 0x100000000ull; +} + +void __init pci_direct_iommu_init(void) +{ + pci_dma_ops.alloc_coherent = pci_direct_alloc_coherent; + pci_dma_ops.free_coherent = pci_direct_free_coherent; + pci_dma_ops.map_single = pci_direct_map_single; + pci_dma_ops.unmap_single = pci_direct_unmap_single; + pci_dma_ops.map_sg = pci_direct_map_sg; + pci_dma_ops.unmap_sg = pci_direct_unmap_sg; + pci_dma_ops.dma_supported = pci_direct_dma_supported; +} |