5a981dca87ffb1c6f9abb2bec204d35b7f6903e2
[linux-2.6.git] / arch / x86_64 / kernel / pci-nommu.c
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 <asm/proto.h>
8 #include <asm/processor.h>
9
10 int iommu_merge = 0;
11 EXPORT_SYMBOL(iommu_merge);
12
13 dma_addr_t bad_dma_address;
14 EXPORT_SYMBOL(bad_dma_address);
15
16 int iommu_bio_merge = 0;
17 EXPORT_SYMBOL(iommu_bio_merge);
18
19 int iommu_sac_force = 0;
20 EXPORT_SYMBOL(iommu_sac_force);
21
22 /* 
23  * Dummy IO MMU functions
24  */
25
26 void *dma_alloc_coherent(struct device *hwdev, size_t size,
27                          dma_addr_t *dma_handle, gfp_t gfp)
28 {
29         void *ret;
30         u64 mask;
31         int order = get_order(size);
32
33         if (hwdev)
34                 mask = hwdev->coherent_dma_mask & *hwdev->dma_mask;
35         else
36                 mask = 0xffffffff;
37         for (;;) {
38                 ret = (void *)__get_free_pages(gfp, order);
39                 if (ret == NULL)
40                         return NULL;
41                 *dma_handle = virt_to_bus(ret);
42                 if ((*dma_handle & ~mask) == 0)
43                         break;
44                 free_pages((unsigned long)ret, order);
45                 if (gfp & GFP_DMA)
46                         return NULL;
47                 gfp |= GFP_DMA;
48         }
49
50         memset(ret, 0, size);
51         return ret;
52 }
53 EXPORT_SYMBOL(dma_alloc_coherent);
54
55 void dma_free_coherent(struct device *hwdev, size_t size,
56                          void *vaddr, dma_addr_t dma_handle)
57 {
58         free_pages((unsigned long)vaddr, get_order(size));
59 }
60 EXPORT_SYMBOL(dma_free_coherent);
61
62 int dma_supported(struct device *hwdev, u64 mask)
63 {
64         /*
65          * we fall back to GFP_DMA when the mask isn't all 1s,
66          * so we can't guarantee allocations that must be
67          * within a tighter range than GFP_DMA..
68          * RED-PEN this won't work for pci_map_single. Caller has to
69          * use GFP_DMA in the first place.
70          */
71         if (mask < 0x00ffffff)
72                 return 0;
73
74         return 1;
75
76 EXPORT_SYMBOL(dma_supported);
77
78 int dma_get_cache_alignment(void)
79 {
80         return boot_cpu_data.x86_clflush_size;
81 }
82 EXPORT_SYMBOL(dma_get_cache_alignment);
83
84 static int __init check_ram(void) 
85
86         if (end_pfn >= 0xffffffff>>PAGE_SHIFT) { 
87                 printk(
88                 KERN_ERR "WARNING more than 4GB of memory but IOMMU not compiled in.\n"
89                 KERN_ERR "WARNING 32bit PCI may malfunction.\n");
90         } 
91         return 0;
92
93 __initcall(check_ram);
94