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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/block-backend.h" | |
11 | #include "sysemu/dma.h" | |
12 | #include "trace.h" | |
13 | #include "qemu/thread.h" | |
14 | #include "qemu/main-loop.h" | |
15 | ||
16 | /* #define DEBUG_IOMMU */ | |
17 | ||
18 | int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len) | |
19 | { | |
20 | dma_barrier(as, DMA_DIRECTION_FROM_DEVICE); | |
21 | ||
22 | #define FILLBUF_SIZE 512 | |
23 | uint8_t fillbuf[FILLBUF_SIZE]; | |
24 | int l; | |
25 | bool error = false; | |
26 | ||
27 | memset(fillbuf, c, FILLBUF_SIZE); | |
28 | while (len > 0) { | |
29 | l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE; | |
30 | error |= address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED, | |
31 | fillbuf, l, true); | |
32 | len -= l; | |
33 | addr += l; | |
34 | } | |
35 | ||
36 | return error; | |
37 | } | |
38 | ||
39 | void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint, | |
40 | AddressSpace *as) | |
41 | { | |
42 | qsg->sg = g_malloc(alloc_hint * sizeof(ScatterGatherEntry)); | |
43 | qsg->nsg = 0; | |
44 | qsg->nalloc = alloc_hint; | |
45 | qsg->size = 0; | |
46 | qsg->as = as; | |
47 | qsg->dev = dev; | |
48 | object_ref(OBJECT(dev)); | |
49 | } | |
50 | ||
51 | void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len) | |
52 | { | |
53 | if (qsg->nsg == qsg->nalloc) { | |
54 | qsg->nalloc = 2 * qsg->nalloc + 1; | |
55 | qsg->sg = g_realloc(qsg->sg, qsg->nalloc * sizeof(ScatterGatherEntry)); | |
56 | } | |
57 | qsg->sg[qsg->nsg].base = base; | |
58 | qsg->sg[qsg->nsg].len = len; | |
59 | qsg->size += len; | |
60 | ++qsg->nsg; | |
61 | } | |
62 | ||
63 | void qemu_sglist_destroy(QEMUSGList *qsg) | |
64 | { | |
65 | object_unref(OBJECT(qsg->dev)); | |
66 | g_free(qsg->sg); | |
67 | memset(qsg, 0, sizeof(*qsg)); | |
68 | } | |
69 | ||
70 | typedef struct { | |
71 | BlockAIOCB common; | |
72 | BlockBackend *blk; | |
73 | BlockAIOCB *acb; | |
74 | QEMUSGList *sg; | |
75 | uint64_t sector_num; | |
76 | DMADirection dir; | |
77 | int sg_cur_index; | |
78 | dma_addr_t sg_cur_byte; | |
79 | QEMUIOVector iov; | |
80 | QEMUBH *bh; | |
81 | DMAIOFunc *io_func; | |
82 | } DMAAIOCB; | |
83 | ||
84 | static void dma_blk_cb(void *opaque, int ret); | |
85 | ||
86 | static void reschedule_dma(void *opaque) | |
87 | { | |
88 | DMAAIOCB *dbs = (DMAAIOCB *)opaque; | |
89 | ||
90 | qemu_bh_delete(dbs->bh); | |
91 | dbs->bh = NULL; | |
92 | dma_blk_cb(dbs, 0); | |
93 | } | |
94 | ||
95 | static void dma_blk_unmap(DMAAIOCB *dbs) | |
96 | { | |
97 | int i; | |
98 | ||
99 | for (i = 0; i < dbs->iov.niov; ++i) { | |
100 | dma_memory_unmap(dbs->sg->as, dbs->iov.iov[i].iov_base, | |
101 | dbs->iov.iov[i].iov_len, dbs->dir, | |
102 | dbs->iov.iov[i].iov_len); | |
103 | } | |
104 | qemu_iovec_reset(&dbs->iov); | |
105 | } | |
106 | ||
107 | static void dma_complete(DMAAIOCB *dbs, int ret) | |
108 | { | |
109 | trace_dma_complete(dbs, ret, dbs->common.cb); | |
110 | ||
111 | dma_blk_unmap(dbs); | |
112 | if (dbs->common.cb) { | |
113 | dbs->common.cb(dbs->common.opaque, ret); | |
114 | } | |
115 | qemu_iovec_destroy(&dbs->iov); | |
116 | if (dbs->bh) { | |
117 | qemu_bh_delete(dbs->bh); | |
118 | dbs->bh = NULL; | |
119 | } | |
120 | qemu_aio_unref(dbs); | |
121 | } | |
122 | ||
123 | static void dma_blk_cb(void *opaque, int ret) | |
124 | { | |
125 | DMAAIOCB *dbs = (DMAAIOCB *)opaque; | |
126 | dma_addr_t cur_addr, cur_len; | |
127 | void *mem; | |
128 | ||
129 | trace_dma_blk_cb(dbs, ret); | |
130 | ||
131 | dbs->acb = NULL; | |
132 | dbs->sector_num += dbs->iov.size / 512; | |
133 | ||
134 | if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) { | |
135 | dma_complete(dbs, ret); | |
136 | return; | |
137 | } | |
138 | dma_blk_unmap(dbs); | |
139 | ||
140 | while (dbs->sg_cur_index < dbs->sg->nsg) { | |
141 | cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte; | |
142 | cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte; | |
143 | mem = dma_memory_map(dbs->sg->as, cur_addr, &cur_len, dbs->dir); | |
144 | if (!mem) | |
145 | break; | |
146 | qemu_iovec_add(&dbs->iov, mem, cur_len); | |
147 | dbs->sg_cur_byte += cur_len; | |
148 | if (dbs->sg_cur_byte == dbs->sg->sg[dbs->sg_cur_index].len) { | |
149 | dbs->sg_cur_byte = 0; | |
150 | ++dbs->sg_cur_index; | |
151 | } | |
152 | } | |
153 | ||
154 | if (dbs->iov.size == 0) { | |
155 | trace_dma_map_wait(dbs); | |
156 | dbs->bh = aio_bh_new(blk_get_aio_context(dbs->blk), | |
157 | reschedule_dma, dbs); | |
158 | cpu_register_map_client(dbs->bh); | |
159 | return; | |
160 | } | |
161 | ||
162 | if (dbs->iov.size & ~BDRV_SECTOR_MASK) { | |
163 | qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK); | |
164 | } | |
165 | ||
166 | dbs->acb = dbs->io_func(dbs->blk, dbs->sector_num, &dbs->iov, | |
167 | dbs->iov.size / 512, dma_blk_cb, dbs); | |
168 | assert(dbs->acb); | |
169 | } | |
170 | ||
171 | static void dma_aio_cancel(BlockAIOCB *acb) | |
172 | { | |
173 | DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common); | |
174 | ||
175 | trace_dma_aio_cancel(dbs); | |
176 | ||
177 | if (dbs->acb) { | |
178 | blk_aio_cancel_async(dbs->acb); | |
179 | } | |
180 | if (dbs->bh) { | |
181 | cpu_unregister_map_client(dbs->bh); | |
182 | qemu_bh_delete(dbs->bh); | |
183 | dbs->bh = NULL; | |
184 | } | |
185 | } | |
186 | ||
187 | ||
188 | static const AIOCBInfo dma_aiocb_info = { | |
189 | .aiocb_size = sizeof(DMAAIOCB), | |
190 | .cancel_async = dma_aio_cancel, | |
191 | }; | |
192 | ||
193 | BlockAIOCB *dma_blk_io( | |
194 | BlockBackend *blk, QEMUSGList *sg, uint64_t sector_num, | |
195 | DMAIOFunc *io_func, BlockCompletionFunc *cb, | |
196 | void *opaque, DMADirection dir) | |
197 | { | |
198 | DMAAIOCB *dbs = blk_aio_get(&dma_aiocb_info, blk, cb, opaque); | |
199 | ||
200 | trace_dma_blk_io(dbs, blk, sector_num, (dir == DMA_DIRECTION_TO_DEVICE)); | |
201 | ||
202 | dbs->acb = NULL; | |
203 | dbs->blk = blk; | |
204 | dbs->sg = sg; | |
205 | dbs->sector_num = sector_num; | |
206 | dbs->sg_cur_index = 0; | |
207 | dbs->sg_cur_byte = 0; | |
208 | dbs->dir = dir; | |
209 | dbs->io_func = io_func; | |
210 | dbs->bh = NULL; | |
211 | qemu_iovec_init(&dbs->iov, sg->nsg); | |
212 | dma_blk_cb(dbs, 0); | |
213 | return &dbs->common; | |
214 | } | |
215 | ||
216 | ||
217 | BlockAIOCB *dma_blk_read(BlockBackend *blk, | |
218 | QEMUSGList *sg, uint64_t sector, | |
219 | void (*cb)(void *opaque, int ret), void *opaque) | |
220 | { | |
221 | return dma_blk_io(blk, sg, sector, blk_aio_readv, cb, opaque, | |
222 | DMA_DIRECTION_FROM_DEVICE); | |
223 | } | |
224 | ||
225 | BlockAIOCB *dma_blk_write(BlockBackend *blk, | |
226 | QEMUSGList *sg, uint64_t sector, | |
227 | void (*cb)(void *opaque, int ret), void *opaque) | |
228 | { | |
229 | return dma_blk_io(blk, sg, sector, blk_aio_writev, cb, opaque, | |
230 | DMA_DIRECTION_TO_DEVICE); | |
231 | } | |
232 | ||
233 | ||
234 | static uint64_t dma_buf_rw(uint8_t *ptr, int32_t len, QEMUSGList *sg, | |
235 | DMADirection dir) | |
236 | { | |
237 | uint64_t resid; | |
238 | int sg_cur_index; | |
239 | ||
240 | resid = sg->size; | |
241 | sg_cur_index = 0; | |
242 | len = MIN(len, resid); | |
243 | while (len > 0) { | |
244 | ScatterGatherEntry entry = sg->sg[sg_cur_index++]; | |
245 | int32_t xfer = MIN(len, entry.len); | |
246 | dma_memory_rw(sg->as, entry.base, ptr, xfer, dir); | |
247 | ptr += xfer; | |
248 | len -= xfer; | |
249 | resid -= xfer; | |
250 | } | |
251 | ||
252 | return resid; | |
253 | } | |
254 | ||
255 | uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg) | |
256 | { | |
257 | return dma_buf_rw(ptr, len, sg, DMA_DIRECTION_FROM_DEVICE); | |
258 | } | |
259 | ||
260 | uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg) | |
261 | { | |
262 | return dma_buf_rw(ptr, len, sg, DMA_DIRECTION_TO_DEVICE); | |
263 | } | |
264 | ||
265 | void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie, | |
266 | QEMUSGList *sg, enum BlockAcctType type) | |
267 | { | |
268 | block_acct_start(blk_get_stats(blk), cookie, sg->size, type); | |
269 | } |