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
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
|
/*
* Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
*
* Provide default implementations of the DMA mapping callbacks for
* directly mapped busses.
*/
#include <linux/device.h>
#include <linux/dma-direct.h>
#include <linux/dma-debug.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <asm/vio.h>
#include <asm/bug.h>
#include <asm/machdep.h>
#include <asm/swiotlb.h>
#include <asm/iommu.h>
/*
* Generic direct DMA implementation
*
* This implementation supports a per-device offset that can be applied if
* the address at which memory is visible to devices is not 0. Platform code
* can set archdata.dma_data to an unsigned long holding the offset. By
* default the offset is PCI_DRAM_OFFSET.
*/
static u64 __maybe_unused get_pfn_limit(struct device *dev)
{
u64 pfn = (dev->coherent_dma_mask >> PAGE_SHIFT) + 1;
#ifdef CONFIG_SWIOTLB
if (dev->bus_dma_mask && dev->dma_ops == &powerpc_swiotlb_dma_ops)
pfn = min_t(u64, pfn, dev->bus_dma_mask >> PAGE_SHIFT);
#endif
return pfn;
}
int dma_nommu_dma_supported(struct device *dev, u64 mask)
{
#ifdef CONFIG_PPC64
u64 limit = phys_to_dma(dev, (memblock_end_of_DRAM() - 1));
/* Limit fits in the mask, we are good */
if (mask >= limit)
return 1;
#ifdef CONFIG_FSL_SOC
/*
* Freescale gets another chance via ZONE_DMA, however
* that will have to be refined if/when they support iommus
*/
return 1;
#endif
/* Sorry ... */
return 0;
#else
return 1;
#endif
}
#ifndef CONFIG_NOT_COHERENT_CACHE
void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
unsigned long attrs)
{
void *ret;
struct page *page;
int node = dev_to_node(dev);
#ifdef CONFIG_FSL_SOC
u64 pfn = get_pfn_limit(dev);
int zone;
/*
* This code should be OK on other platforms, but we have drivers that
* don't set coherent_dma_mask. As a workaround we just ifdef it. This
* whole routine needs some serious cleanup.
*/
zone = dma_pfn_limit_to_zone(pfn);
if (zone < 0) {
dev_err(dev, "%s: No suitable zone for pfn %#llx\n",
__func__, pfn);
return NULL;
}
switch (zone) {
#ifdef CONFIG_ZONE_DMA
case ZONE_DMA:
flag |= GFP_DMA;
break;
#endif
};
#endif /* CONFIG_FSL_SOC */
page = alloc_pages_node(node, flag, get_order(size));
if (page == NULL)
return NULL;
ret = page_address(page);
memset(ret, 0, size);
*dma_handle = phys_to_dma(dev,__pa(ret));
return ret;
}
void __dma_nommu_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
unsigned long attrs)
{
free_pages((unsigned long)vaddr, get_order(size));
}
#endif /* !CONFIG_NOT_COHERENT_CACHE */
int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
unsigned long attrs)
{
struct scatterlist *sg;
int i;
for_each_sg(sgl, sg, nents, i) {
sg->dma_address = phys_to_dma(dev, sg_phys(sg));
sg->dma_length = sg->length;
if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
continue;
__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
return nents;
}
static void dma_nommu_unmap_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
unsigned long attrs)
{
struct scatterlist *sg;
int i;
for_each_sg(sgl, sg, nents, i)
__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
u64 dma_nommu_get_required_mask(struct device *dev)
{
u64 end, mask;
end = memblock_end_of_DRAM() + get_dma_offset(dev);
mask = 1ULL << (fls64(end) - 1);
mask += mask - 1;
return mask;
}
dma_addr_t dma_nommu_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir, unsigned long attrs)
{
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync_page(page, offset, size, dir);
return phys_to_dma(dev, page_to_phys(page)) + offset;
}
static inline void dma_nommu_unmap_page(struct device *dev,
dma_addr_t dma_address,
size_t size,
enum dma_data_direction direction,
unsigned long attrs)
{
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync(bus_to_virt(dma_address), size, direction);
}
#ifdef CONFIG_NOT_COHERENT_CACHE
static inline void dma_nommu_sync_sg(struct device *dev,
struct scatterlist *sgl, int nents,
enum dma_data_direction direction)
{
struct scatterlist *sg;
int i;
for_each_sg(sgl, sg, nents, i)
__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
static inline void dma_nommu_sync_single(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
__dma_sync(bus_to_virt(dma_handle), size, direction);
}
#endif
const struct dma_map_ops dma_nommu_ops = {
.alloc = __dma_nommu_alloc_coherent,
.free = __dma_nommu_free_coherent,
.map_sg = dma_nommu_map_sg,
.unmap_sg = dma_nommu_unmap_sg,
.dma_supported = dma_nommu_dma_supported,
.map_page = dma_nommu_map_page,
.unmap_page = dma_nommu_unmap_page,
.get_required_mask = dma_nommu_get_required_mask,
#ifdef CONFIG_NOT_COHERENT_CACHE
.sync_single_for_cpu = dma_nommu_sync_single,
.sync_single_for_device = dma_nommu_sync_single,
.sync_sg_for_cpu = dma_nommu_sync_sg,
.sync_sg_for_device = dma_nommu_sync_sg,
#endif
};
EXPORT_SYMBOL(dma_nommu_ops);
static int __init dma_init(void)
{
#ifdef CONFIG_IBMVIO
dma_debug_add_bus(&vio_bus_type);
#endif
return 0;
}
fs_initcall(dma_init);
|