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authorGlauber Costa <gcosta@redhat.com>2008-04-08 12:20:52 -0400
committerIngo Molnar <mingo@elte.hu>2008-04-19 13:19:57 -0400
commitf9c258de3494a5249a61fe110ece2082e5927468 (patch)
tree53b6b8a031a1e99a76a579ab42d471356685fb86 /arch/x86/kernel/pci-nommu.c
parent85c246ee16fe00bf7bf9e7ff09a5d17d9a83cf71 (diff)
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.c100
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 00000000000..aec43d56f49
--- /dev/null
+++ b/arch/x86/kernel/pci-nommu.c
@@ -0,0 +1,100 @@
1/* Fallback functions when the main IOMMU code is not compiled in. This
2 code is roughly equivalent to i386. */
3#include <linux/mm.h>
4#include <linux/init.h>
5#include <linux/pci.h>
6#include <linux/string.h>
7#include <linux/dma-mapping.h>
8#include <linux/scatterlist.h>
9
10#include <asm/gart.h>
11#include <asm/processor.h>
12#include <asm/dma.h>
13
14static int
15check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size)
16{
17 if (hwdev && bus + size > *hwdev->dma_mask) {
18 if (*hwdev->dma_mask >= DMA_32BIT_MASK)
19 printk(KERN_ERR
20 "nommu_%s: overflow %Lx+%zu of device mask %Lx\n",
21 name, (long long)bus, size,
22 (long long)*hwdev->dma_mask);
23 return 0;
24 }
25 return 1;
26}
27
28static dma_addr_t
29nommu_map_single(struct device *hwdev, phys_addr_t paddr, size_t size,
30 int direction)
31{
32 dma_addr_t bus = paddr;
33 WARN_ON(size == 0);
34 if (!check_addr("map_single", hwdev, bus, size))
35 return bad_dma_address;
36 flush_write_buffers();
37 return bus;
38}
39
40
41/* Map a set of buffers described by scatterlist in streaming
42 * mode for DMA. This is the scatter-gather version of the
43 * above pci_map_single interface. Here the scatter gather list
44 * elements are each tagged with the appropriate dma address
45 * and length. They are obtained via sg_dma_{address,length}(SG).
46 *
47 * NOTE: An implementation may be able to use a smaller number of
48 * DMA address/length pairs than there are SG table elements.
49 * (for example via virtual mapping capabilities)
50 * The routine returns the number of addr/length pairs actually
51 * used, at most nents.
52 *
53 * Device ownership issues as mentioned above for pci_map_single are
54 * the same here.
55 */
56static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
57 int nents, int direction)
58{
59 struct scatterlist *s;
60 int i;
61
62 WARN_ON(nents == 0 || sg[0].length == 0);
63
64 for_each_sg(sg, s, nents, i) {
65 BUG_ON(!sg_page(s));
66 s->dma_address = sg_phys(s);
67 if (!check_addr("map_sg", hwdev, s->dma_address, s->length))
68 return 0;
69 s->dma_length = s->length;
70 }
71 flush_write_buffers();
72 return nents;
73}
74
75/* Make sure we keep the same behaviour */
76static int nommu_mapping_error(dma_addr_t dma_addr)
77{
78#ifdef CONFIG_X86_32
79 return 0;
80#else
81 return (dma_addr == bad_dma_address);
82#endif
83}
84
85
86const struct dma_mapping_ops nommu_dma_ops = {
87 .map_single = nommu_map_single,
88 .map_sg = nommu_map_sg,
89 .mapping_error = nommu_mapping_error,
90 .is_phys = 1,
91};
92
93void __init no_iommu_init(void)
94{
95 if (dma_ops)
96 return;
97
98 force_iommu = 0; /* no HW IOMMU */
99 dma_ops = &nommu_dma_ops;
100}