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10#include "qemu/osdep.h"
11#include "sysemu/block-backend.h"
12#include "sysemu/dma.h"
13#include "trace-root.h"
14#include "qemu/thread.h"
15#include "qemu/main-loop.h"
16
17
18
19int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len)
20{
21 dma_barrier(as, DMA_DIRECTION_FROM_DEVICE);
22
23#define FILLBUF_SIZE 512
24 uint8_t fillbuf[FILLBUF_SIZE];
25 int l;
26 bool error = false;
27
28 memset(fillbuf, c, FILLBUF_SIZE);
29 while (len > 0) {
30 l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE;
31 error |= address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED,
32 fillbuf, l, true);
33 len -= l;
34 addr += l;
35 }
36
37 return error;
38}
39
40void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
41 AddressSpace *as)
42{
43 qsg->sg = g_malloc(alloc_hint * sizeof(ScatterGatherEntry));
44 qsg->nsg = 0;
45 qsg->nalloc = alloc_hint;
46 qsg->size = 0;
47 qsg->as = as;
48 qsg->dev = dev;
49 object_ref(OBJECT(dev));
50}
51
52void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len)
53{
54 if (qsg->nsg == qsg->nalloc) {
55 qsg->nalloc = 2 * qsg->nalloc + 1;
56 qsg->sg = g_realloc(qsg->sg, qsg->nalloc * sizeof(ScatterGatherEntry));
57 }
58 qsg->sg[qsg->nsg].base = base;
59 qsg->sg[qsg->nsg].len = len;
60 qsg->size += len;
61 ++qsg->nsg;
62}
63
64void qemu_sglist_destroy(QEMUSGList *qsg)
65{
66 object_unref(OBJECT(qsg->dev));
67 g_free(qsg->sg);
68 memset(qsg, 0, sizeof(*qsg));
69}
70
71typedef struct {
72 BlockAIOCB common;
73 AioContext *ctx;
74 BlockAIOCB *acb;
75 QEMUSGList *sg;
76 uint32_t align;
77 uint64_t offset;
78 DMADirection dir;
79 int sg_cur_index;
80 dma_addr_t sg_cur_byte;
81 QEMUIOVector iov;
82 QEMUBH *bh;
83 DMAIOFunc *io_func;
84 void *io_func_opaque;
85} DMAAIOCB;
86
87static void dma_blk_cb(void *opaque, int ret);
88
89static void reschedule_dma(void *opaque)
90{
91 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
92
93 qemu_bh_delete(dbs->bh);
94 dbs->bh = NULL;
95 dma_blk_cb(dbs, 0);
96}
97
98static void dma_blk_unmap(DMAAIOCB *dbs)
99{
100 int i;
101
102 for (i = 0; i < dbs->iov.niov; ++i) {
103 dma_memory_unmap(dbs->sg->as, dbs->iov.iov[i].iov_base,
104 dbs->iov.iov[i].iov_len, dbs->dir,
105 dbs->iov.iov[i].iov_len);
106 }
107 qemu_iovec_reset(&dbs->iov);
108}
109
110static void dma_complete(DMAAIOCB *dbs, int ret)
111{
112 trace_dma_complete(dbs, ret, dbs->common.cb);
113
114 dma_blk_unmap(dbs);
115 if (dbs->common.cb) {
116 dbs->common.cb(dbs->common.opaque, ret);
117 }
118 qemu_iovec_destroy(&dbs->iov);
119 if (dbs->bh) {
120 qemu_bh_delete(dbs->bh);
121 dbs->bh = NULL;
122 }
123 qemu_aio_unref(dbs);
124}
125
126static void dma_blk_cb(void *opaque, int ret)
127{
128 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
129 dma_addr_t cur_addr, cur_len;
130 void *mem;
131
132 trace_dma_blk_cb(dbs, ret);
133
134 dbs->acb = NULL;
135 dbs->offset += dbs->iov.size;
136
137 if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) {
138 dma_complete(dbs, ret);
139 return;
140 }
141 dma_blk_unmap(dbs);
142
143 while (dbs->sg_cur_index < dbs->sg->nsg) {
144 cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte;
145 cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte;
146 mem = dma_memory_map(dbs->sg->as, cur_addr, &cur_len, dbs->dir);
147 if (!mem)
148 break;
149 qemu_iovec_add(&dbs->iov, mem, cur_len);
150 dbs->sg_cur_byte += cur_len;
151 if (dbs->sg_cur_byte == dbs->sg->sg[dbs->sg_cur_index].len) {
152 dbs->sg_cur_byte = 0;
153 ++dbs->sg_cur_index;
154 }
155 }
156
157 if (dbs->iov.size == 0) {
158 trace_dma_map_wait(dbs);
159 dbs->bh = aio_bh_new(dbs->ctx, reschedule_dma, dbs);
160 cpu_register_map_client(dbs->bh);
161 return;
162 }
163
164 if (!QEMU_IS_ALIGNED(dbs->iov.size, dbs->align)) {
165 qemu_iovec_discard_back(&dbs->iov,
166 QEMU_ALIGN_DOWN(dbs->iov.size, dbs->align));
167 }
168
169 aio_context_acquire(dbs->ctx);
170 dbs->acb = dbs->io_func(dbs->offset, &dbs->iov,
171 dma_blk_cb, dbs, dbs->io_func_opaque);
172 aio_context_release(dbs->ctx);
173 assert(dbs->acb);
174}
175
176static void dma_aio_cancel(BlockAIOCB *acb)
177{
178 DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
179
180 trace_dma_aio_cancel(dbs);
181
182 if (dbs->acb) {
183 blk_aio_cancel_async(dbs->acb);
184 }
185 if (dbs->bh) {
186 cpu_unregister_map_client(dbs->bh);
187 qemu_bh_delete(dbs->bh);
188 dbs->bh = NULL;
189 }
190}
191
192static AioContext *dma_get_aio_context(BlockAIOCB *acb)
193{
194 DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
195
196 return dbs->ctx;
197}
198
199static const AIOCBInfo dma_aiocb_info = {
200 .aiocb_size = sizeof(DMAAIOCB),
201 .cancel_async = dma_aio_cancel,
202 .get_aio_context = dma_get_aio_context,
203};
204
205BlockAIOCB *dma_blk_io(AioContext *ctx,
206 QEMUSGList *sg, uint64_t offset, uint32_t align,
207 DMAIOFunc *io_func, void *io_func_opaque,
208 BlockCompletionFunc *cb,
209 void *opaque, DMADirection dir)
210{
211 DMAAIOCB *dbs = qemu_aio_get(&dma_aiocb_info, NULL, cb, opaque);
212
213 trace_dma_blk_io(dbs, io_func_opaque, offset, (dir == DMA_DIRECTION_TO_DEVICE));
214
215 dbs->acb = NULL;
216 dbs->sg = sg;
217 dbs->ctx = ctx;
218 dbs->offset = offset;
219 dbs->align = align;
220 dbs->sg_cur_index = 0;
221 dbs->sg_cur_byte = 0;
222 dbs->dir = dir;
223 dbs->io_func = io_func;
224 dbs->io_func_opaque = io_func_opaque;
225 dbs->bh = NULL;
226 qemu_iovec_init(&dbs->iov, sg->nsg);
227 dma_blk_cb(dbs, 0);
228 return &dbs->common;
229}
230
231
232static
233BlockAIOCB *dma_blk_read_io_func(int64_t offset, QEMUIOVector *iov,
234 BlockCompletionFunc *cb, void *cb_opaque,
235 void *opaque)
236{
237 BlockBackend *blk = opaque;
238 return blk_aio_preadv(blk, offset, iov, 0, cb, cb_opaque);
239}
240
241BlockAIOCB *dma_blk_read(BlockBackend *blk,
242 QEMUSGList *sg, uint64_t offset, uint32_t align,
243 void (*cb)(void *opaque, int ret), void *opaque)
244{
245 return dma_blk_io(blk_get_aio_context(blk), sg, offset, align,
246 dma_blk_read_io_func, blk, cb, opaque,
247 DMA_DIRECTION_FROM_DEVICE);
248}
249
250static
251BlockAIOCB *dma_blk_write_io_func(int64_t offset, QEMUIOVector *iov,
252 BlockCompletionFunc *cb, void *cb_opaque,
253 void *opaque)
254{
255 BlockBackend *blk = opaque;
256 return blk_aio_pwritev(blk, offset, iov, 0, cb, cb_opaque);
257}
258
259BlockAIOCB *dma_blk_write(BlockBackend *blk,
260 QEMUSGList *sg, uint64_t offset, uint32_t align,
261 void (*cb)(void *opaque, int ret), void *opaque)
262{
263 return dma_blk_io(blk_get_aio_context(blk), sg, offset, align,
264 dma_blk_write_io_func, blk, cb, opaque,
265 DMA_DIRECTION_TO_DEVICE);
266}
267
268
269static uint64_t dma_buf_rw(uint8_t *ptr, int32_t len, QEMUSGList *sg,
270 DMADirection dir)
271{
272 uint64_t resid;
273 int sg_cur_index;
274
275 resid = sg->size;
276 sg_cur_index = 0;
277 len = MIN(len, resid);
278 while (len > 0) {
279 ScatterGatherEntry entry = sg->sg[sg_cur_index++];
280 int32_t xfer = MIN(len, entry.len);
281 dma_memory_rw(sg->as, entry.base, ptr, xfer, dir);
282 ptr += xfer;
283 len -= xfer;
284 resid -= xfer;
285 }
286
287 return resid;
288}
289
290uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg)
291{
292 return dma_buf_rw(ptr, len, sg, DMA_DIRECTION_FROM_DEVICE);
293}
294
295uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg)
296{
297 return dma_buf_rw(ptr, len, sg, DMA_DIRECTION_TO_DEVICE);
298}
299
300void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie,
301 QEMUSGList *sg, enum BlockAcctType type)
302{
303 block_acct_start(blk_get_stats(blk), cookie, sg->size, type);
304}
305
