summaryrefslogtreecommitdiff
path: root/arch/arm/xen/mm32.c
blob: c86919bbea8347a502191ae4f9c1aed43f78642e (plain)
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
86
87
88
89
90
91
92
93
94
#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_map_page(struct device *hwdev, struct page *page,
	     dma_addr_t dev_addr, unsigned long offset, size_t size,
	     enum dma_data_direction dir, struct dma_attrs *attrs)
{
	if (is_device_dma_coherent(hwdev))
		return;
	if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
		return;

	__xen_dma_page_cpu_to_dev(hwdev, dev_addr, size, dir);
}

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 (is_device_dma_coherent(hwdev))
		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 (is_device_dma_coherent(hwdev))
		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 (is_device_dma_coherent(hwdev))
		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);