root / dma-helpers.c @ 8ab9b418
History | View | Annotate | Download (7 kB)
1 |
/*
|
---|---|
2 |
* DMA helper functions
|
3 |
*
|
4 |
* Copyright (c) 2009 Red Hat
|
5 |
*
|
6 |
* This work is licensed under the terms of the GNU General Public License
|
7 |
* (GNU GPL), version 2 or later.
|
8 |
*/
|
9 |
|
10 |
#include "sysemu/dma.h" |
11 |
#include "trace.h" |
12 |
#include "qemu/range.h" |
13 |
#include "qemu/thread.h" |
14 |
|
15 |
/* #define DEBUG_IOMMU */
|
16 |
|
17 |
int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len)
|
18 |
{ |
19 |
dma_barrier(as, DMA_DIRECTION_FROM_DEVICE); |
20 |
|
21 |
#define FILLBUF_SIZE 512 |
22 |
uint8_t fillbuf[FILLBUF_SIZE]; |
23 |
int l;
|
24 |
bool error = false; |
25 |
|
26 |
memset(fillbuf, c, FILLBUF_SIZE); |
27 |
while (len > 0) { |
28 |
l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE; |
29 |
error |= address_space_rw(as, addr, fillbuf, l, true);
|
30 |
len -= l; |
31 |
addr += l; |
32 |
} |
33 |
|
34 |
return error;
|
35 |
} |
36 |
|
37 |
void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint, |
38 |
AddressSpace *as) |
39 |
{ |
40 |
qsg->sg = g_malloc(alloc_hint * sizeof(ScatterGatherEntry));
|
41 |
qsg->nsg = 0;
|
42 |
qsg->nalloc = alloc_hint; |
43 |
qsg->size = 0;
|
44 |
qsg->as = as; |
45 |
qsg->dev = dev; |
46 |
object_ref(OBJECT(dev)); |
47 |
} |
48 |
|
49 |
void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len)
|
50 |
{ |
51 |
if (qsg->nsg == qsg->nalloc) {
|
52 |
qsg->nalloc = 2 * qsg->nalloc + 1; |
53 |
qsg->sg = g_realloc(qsg->sg, qsg->nalloc * sizeof(ScatterGatherEntry));
|
54 |
} |
55 |
qsg->sg[qsg->nsg].base = base; |
56 |
qsg->sg[qsg->nsg].len = len; |
57 |
qsg->size += len; |
58 |
++qsg->nsg; |
59 |
} |
60 |
|
61 |
void qemu_sglist_destroy(QEMUSGList *qsg)
|
62 |
{ |
63 |
object_unref(OBJECT(qsg->dev)); |
64 |
g_free(qsg->sg); |
65 |
memset(qsg, 0, sizeof(*qsg)); |
66 |
} |
67 |
|
68 |
typedef struct { |
69 |
BlockDriverAIOCB common; |
70 |
BlockDriverState *bs; |
71 |
BlockDriverAIOCB *acb; |
72 |
QEMUSGList *sg; |
73 |
uint64_t sector_num; |
74 |
DMADirection dir; |
75 |
bool in_cancel;
|
76 |
int sg_cur_index;
|
77 |
dma_addr_t sg_cur_byte; |
78 |
QEMUIOVector iov; |
79 |
QEMUBH *bh; |
80 |
DMAIOFunc *io_func; |
81 |
} DMAAIOCB; |
82 |
|
83 |
static void dma_bdrv_cb(void *opaque, int ret); |
84 |
|
85 |
static void reschedule_dma(void *opaque) |
86 |
{ |
87 |
DMAAIOCB *dbs = (DMAAIOCB *)opaque; |
88 |
|
89 |
qemu_bh_delete(dbs->bh); |
90 |
dbs->bh = NULL;
|
91 |
dma_bdrv_cb(dbs, 0);
|
92 |
} |
93 |
|
94 |
static void continue_after_map_failure(void *opaque) |
95 |
{ |
96 |
DMAAIOCB *dbs = (DMAAIOCB *)opaque; |
97 |
|
98 |
dbs->bh = qemu_bh_new(reschedule_dma, dbs); |
99 |
qemu_bh_schedule(dbs->bh); |
100 |
} |
101 |
|
102 |
static void dma_bdrv_unmap(DMAAIOCB *dbs) |
103 |
{ |
104 |
int i;
|
105 |
|
106 |
for (i = 0; i < dbs->iov.niov; ++i) { |
107 |
dma_memory_unmap(dbs->sg->as, dbs->iov.iov[i].iov_base, |
108 |
dbs->iov.iov[i].iov_len, dbs->dir, |
109 |
dbs->iov.iov[i].iov_len); |
110 |
} |
111 |
qemu_iovec_reset(&dbs->iov); |
112 |
} |
113 |
|
114 |
static void dma_complete(DMAAIOCB *dbs, int ret) |
115 |
{ |
116 |
trace_dma_complete(dbs, ret, dbs->common.cb); |
117 |
|
118 |
dma_bdrv_unmap(dbs); |
119 |
if (dbs->common.cb) {
|
120 |
dbs->common.cb(dbs->common.opaque, ret); |
121 |
} |
122 |
qemu_iovec_destroy(&dbs->iov); |
123 |
if (dbs->bh) {
|
124 |
qemu_bh_delete(dbs->bh); |
125 |
dbs->bh = NULL;
|
126 |
} |
127 |
if (!dbs->in_cancel) {
|
128 |
/* Requests may complete while dma_aio_cancel is in progress. In
|
129 |
* this case, the AIOCB should not be released because it is still
|
130 |
* referenced by dma_aio_cancel. */
|
131 |
qemu_aio_release(dbs); |
132 |
} |
133 |
} |
134 |
|
135 |
static void dma_bdrv_cb(void *opaque, int ret) |
136 |
{ |
137 |
DMAAIOCB *dbs = (DMAAIOCB *)opaque; |
138 |
dma_addr_t cur_addr, cur_len; |
139 |
void *mem;
|
140 |
|
141 |
trace_dma_bdrv_cb(dbs, ret); |
142 |
|
143 |
dbs->acb = NULL;
|
144 |
dbs->sector_num += dbs->iov.size / 512;
|
145 |
dma_bdrv_unmap(dbs); |
146 |
|
147 |
if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) { |
148 |
dma_complete(dbs, ret); |
149 |
return;
|
150 |
} |
151 |
|
152 |
while (dbs->sg_cur_index < dbs->sg->nsg) {
|
153 |
cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte; |
154 |
cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte; |
155 |
mem = dma_memory_map(dbs->sg->as, cur_addr, &cur_len, dbs->dir); |
156 |
if (!mem)
|
157 |
break;
|
158 |
qemu_iovec_add(&dbs->iov, mem, cur_len); |
159 |
dbs->sg_cur_byte += cur_len; |
160 |
if (dbs->sg_cur_byte == dbs->sg->sg[dbs->sg_cur_index].len) {
|
161 |
dbs->sg_cur_byte = 0;
|
162 |
++dbs->sg_cur_index; |
163 |
} |
164 |
} |
165 |
|
166 |
if (dbs->iov.size == 0) { |
167 |
trace_dma_map_wait(dbs); |
168 |
cpu_register_map_client(dbs, continue_after_map_failure); |
169 |
return;
|
170 |
} |
171 |
|
172 |
dbs->acb = dbs->io_func(dbs->bs, dbs->sector_num, &dbs->iov, |
173 |
dbs->iov.size / 512, dma_bdrv_cb, dbs);
|
174 |
assert(dbs->acb); |
175 |
} |
176 |
|
177 |
static void dma_aio_cancel(BlockDriverAIOCB *acb) |
178 |
{ |
179 |
DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common); |
180 |
|
181 |
trace_dma_aio_cancel(dbs); |
182 |
|
183 |
if (dbs->acb) {
|
184 |
BlockDriverAIOCB *acb = dbs->acb; |
185 |
dbs->acb = NULL;
|
186 |
dbs->in_cancel = true;
|
187 |
bdrv_aio_cancel(acb); |
188 |
dbs->in_cancel = false;
|
189 |
} |
190 |
dbs->common.cb = NULL;
|
191 |
dma_complete(dbs, 0);
|
192 |
} |
193 |
|
194 |
static const AIOCBInfo dma_aiocb_info = { |
195 |
.aiocb_size = sizeof(DMAAIOCB),
|
196 |
.cancel = dma_aio_cancel, |
197 |
}; |
198 |
|
199 |
BlockDriverAIOCB *dma_bdrv_io( |
200 |
BlockDriverState *bs, QEMUSGList *sg, uint64_t sector_num, |
201 |
DMAIOFunc *io_func, BlockDriverCompletionFunc *cb, |
202 |
void *opaque, DMADirection dir)
|
203 |
{ |
204 |
DMAAIOCB *dbs = qemu_aio_get(&dma_aiocb_info, bs, cb, opaque); |
205 |
|
206 |
trace_dma_bdrv_io(dbs, bs, sector_num, (dir == DMA_DIRECTION_TO_DEVICE)); |
207 |
|
208 |
dbs->acb = NULL;
|
209 |
dbs->bs = bs; |
210 |
dbs->sg = sg; |
211 |
dbs->sector_num = sector_num; |
212 |
dbs->sg_cur_index = 0;
|
213 |
dbs->sg_cur_byte = 0;
|
214 |
dbs->dir = dir; |
215 |
dbs->io_func = io_func; |
216 |
dbs->bh = NULL;
|
217 |
qemu_iovec_init(&dbs->iov, sg->nsg); |
218 |
dma_bdrv_cb(dbs, 0);
|
219 |
return &dbs->common;
|
220 |
} |
221 |
|
222 |
|
223 |
BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs, |
224 |
QEMUSGList *sg, uint64_t sector, |
225 |
void (*cb)(void *opaque, int ret), void *opaque) |
226 |
{ |
227 |
return dma_bdrv_io(bs, sg, sector, bdrv_aio_readv, cb, opaque,
|
228 |
DMA_DIRECTION_FROM_DEVICE); |
229 |
} |
230 |
|
231 |
BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs, |
232 |
QEMUSGList *sg, uint64_t sector, |
233 |
void (*cb)(void *opaque, int ret), void *opaque) |
234 |
{ |
235 |
return dma_bdrv_io(bs, sg, sector, bdrv_aio_writev, cb, opaque,
|
236 |
DMA_DIRECTION_TO_DEVICE); |
237 |
} |
238 |
|
239 |
|
240 |
static uint64_t dma_buf_rw(uint8_t *ptr, int32_t len, QEMUSGList *sg,
|
241 |
DMADirection dir) |
242 |
{ |
243 |
uint64_t resid; |
244 |
int sg_cur_index;
|
245 |
|
246 |
resid = sg->size; |
247 |
sg_cur_index = 0;
|
248 |
len = MIN(len, resid); |
249 |
while (len > 0) { |
250 |
ScatterGatherEntry entry = sg->sg[sg_cur_index++]; |
251 |
int32_t xfer = MIN(len, entry.len); |
252 |
dma_memory_rw(sg->as, entry.base, ptr, xfer, dir); |
253 |
ptr += xfer; |
254 |
len -= xfer; |
255 |
resid -= xfer; |
256 |
} |
257 |
|
258 |
return resid;
|
259 |
} |
260 |
|
261 |
uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg) |
262 |
{ |
263 |
return dma_buf_rw(ptr, len, sg, DMA_DIRECTION_FROM_DEVICE);
|
264 |
} |
265 |
|
266 |
uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg) |
267 |
{ |
268 |
return dma_buf_rw(ptr, len, sg, DMA_DIRECTION_TO_DEVICE);
|
269 |
} |
270 |
|
271 |
void dma_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie,
|
272 |
QEMUSGList *sg, enum BlockAcctType type)
|
273 |
{ |
274 |
bdrv_acct_start(bs, cookie, sg->size, type); |
275 |
} |