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
|
#include <linux/cpu.h>
#include <linux/dma-mapping.h>
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <xen/features.h>
enum dma_cache_op {
DMA_UNMAP,
DMA_MAP,
};
/* functions called by SWIOTLB */
static void dma_cache_maint(dma_addr_t handle, unsigned long offset,
size_t size, enum dma_data_direction dir, enum dma_cache_op op)
{
unsigned long pfn;
size_t left = size;
pfn = (handle >> PAGE_SHIFT) + offset / PAGE_SIZE;
offset %= PAGE_SIZE;
do {
size_t len = left;
/* TODO: cache flush */
offset = 0;
pfn++;
left -= len;
} while (left);
}
static void __xen_dma_page_dev_to_cpu(struct device *hwdev, dma_addr_t handle,
size_t size, enum dma_data_direction dir)
{
dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_UNMAP);
}
static void __xen_dma_page_cpu_to_dev(struct device *hwdev, dma_addr_t handle,
size_t size, enum dma_data_direction dir)
{
dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_MAP);
}
void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
if (!__generic_dma_ops(hwdev)->unmap_page)
return;
if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
return;
__xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
}
void __xen_dma_sync_single_for_cpu(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
if (!__generic_dma_ops(hwdev)->sync_single_for_cpu)
return;
__xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
}
void __xen_dma_sync_single_for_device(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
if (!__generic_dma_ops(hwdev)->sync_single_for_device)
return;
__xen_dma_page_cpu_to_dev(hwdev, handle, size, dir);
}
int __init xen_mm32_init(void)
{
if (!xen_initial_domain())
return 0;
return 0;
}
arch_initcall(xen_mm32_init);
|
