1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
/* Glue code to lib/swiotlb.c */
#include <linux/pci.h>
#include <linux/cache.h>
#include <linux/module.h>
#include <linux/swiotlb.h>
#include <linux/bootmem.h>
#include <linux/dma-mapping.h>
#include <asm/iommu.h>
#include <asm/swiotlb.h>
#include <asm/dma.h>
int swiotlb __read_mostly;
void * __init swiotlb_alloc_boot(size_t size, unsigned long nslabs)
{
return alloc_bootmem_low_pages(size);
}
void *swiotlb_alloc(unsigned order, unsigned long nslabs)
{
return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
}
dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
{
return paddr;
}
phys_addr_t swiotlb_bus_to_phys(dma_addr_t baddr)
{
return baddr;
}
int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
{
return 0;
}
static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags)
{
void *vaddr;
vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
if (vaddr)
return vaddr;
return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
}
static struct dma_map_ops swiotlb_dma_ops = {
.mapping_error = swiotlb_dma_mapping_error,
.alloc_coherent = x86_swiotlb_alloc_coherent,
.free_coherent = swiotlb_free_coherent,
.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
.sync_single_for_device = swiotlb_sync_single_for_device,
.sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
.sync_single_range_for_device = swiotlb_sync_single_range_for_device,
.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
.sync_sg_for_device = swiotlb_sync_sg_for_device,
.map_sg = swiotlb_map_sg_attrs,
.unmap_sg = swiotlb_unmap_sg_attrs,
.map_page = swiotlb_map_page,
.unmap_page = swiotlb_unmap_page,
.dma_supported = NULL,
};
void __init pci_swiotlb_init(void)
{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
#ifdef CONFIG_X86_64
if ((!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN) ||
iommu_pass_through)
swiotlb = 1;
#endif
if (swiotlb_force)
swiotlb = 1;
if (swiotlb) {
printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
swiotlb_init();
dma_ops = &swiotlb_dma_ops;
}
}
|
