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author | Glauber Costa <gcosta@redhat.com> | 2008-04-08 18:20:52 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-04-19 19:19:57 +0200 |
commit | f9c258de3494a5249a61fe110ece2082e5927468 (patch) | |
tree | 53b6b8a031a1e99a76a579ab42d471356685fb86 /arch/x86/kernel/pci-nommu.c | |
parent | x86: move definition to pci-dma.c (diff) | |
download | linux-f9c258de3494a5249a61fe110ece2082e5927468.tar.xz linux-f9c258de3494a5249a61fe110ece2082e5927468.zip |
x86: unify pci-nommu
merge pci-base_32.c and pci-nommu_64.c into pci-nommu.c
Their code were made the same, so now they can be merged.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/pci-nommu.c')
-rw-r--r-- | arch/x86/kernel/pci-nommu.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c new file mode 100644 index 000000000000..aec43d56f49c --- /dev/null +++ b/arch/x86/kernel/pci-nommu.c @@ -0,0 +1,100 @@ +/* Fallback functions when the main IOMMU code is not compiled in. This + code is roughly equivalent to i386. */ +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/pci.h> +#include <linux/string.h> +#include <linux/dma-mapping.h> +#include <linux/scatterlist.h> + +#include <asm/gart.h> +#include <asm/processor.h> +#include <asm/dma.h> + +static int +check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size) +{ + if (hwdev && bus + size > *hwdev->dma_mask) { + if (*hwdev->dma_mask >= DMA_32BIT_MASK) + printk(KERN_ERR + "nommu_%s: overflow %Lx+%zu of device mask %Lx\n", + name, (long long)bus, size, + (long long)*hwdev->dma_mask); + return 0; + } + return 1; +} + +static dma_addr_t +nommu_map_single(struct device *hwdev, phys_addr_t paddr, size_t size, + int direction) +{ + dma_addr_t bus = paddr; + WARN_ON(size == 0); + if (!check_addr("map_single", hwdev, bus, size)) + return bad_dma_address; + flush_write_buffers(); + return bus; +} + + +/* Map a set of buffers described by scatterlist in streaming + * mode for DMA. This is the scatter-gather version of the + * above pci_map_single interface. Here the scatter gather list + * elements are each tagged with the appropriate dma address + * and length. They are obtained via sg_dma_{address,length}(SG). + * + * NOTE: An implementation may be able to use a smaller number of + * DMA address/length pairs than there are SG table elements. + * (for example via virtual mapping capabilities) + * The routine returns the number of addr/length pairs actually + * used, at most nents. + * + * Device ownership issues as mentioned above for pci_map_single are + * the same here. + */ +static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg, + int nents, int direction) +{ + struct scatterlist *s; + int i; + + WARN_ON(nents == 0 || sg[0].length == 0); + + for_each_sg(sg, s, nents, i) { + BUG_ON(!sg_page(s)); + s->dma_address = sg_phys(s); + if (!check_addr("map_sg", hwdev, s->dma_address, s->length)) + return 0; + s->dma_length = s->length; + } + flush_write_buffers(); + return nents; +} + +/* Make sure we keep the same behaviour */ +static int nommu_mapping_error(dma_addr_t dma_addr) +{ +#ifdef CONFIG_X86_32 + return 0; +#else + return (dma_addr == bad_dma_address); +#endif +} + + +const struct dma_mapping_ops nommu_dma_ops = { + .map_single = nommu_map_single, + .map_sg = nommu_map_sg, + .mapping_error = nommu_mapping_error, + .is_phys = 1, +}; + +void __init no_iommu_init(void) +{ + if (dma_ops) + return; + + force_iommu = 0; /* no HW IOMMU */ + dma_ops = &nommu_dma_ops; +} |