Merge remote-tracking branch 'kraxel/usb.84' into staging
[qemu/ar7.git] / dma-helpers.c
blob5afba47478c2bb70086ac31f387e3345e7d64b44
1 /*
2 * DMA helper functions
4 * Copyright (c) 2009 Red Hat
6 * This work is licensed under the terms of the GNU General Public License
7 * (GNU GPL), version 2 or later.
8 */
10 #include "sysemu/dma.h"
11 #include "trace.h"
12 #include "qemu/range.h"
13 #include "qemu/thread.h"
15 /* #define DEBUG_IOMMU */
17 int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len)
19 dma_barrier(as, DMA_DIRECTION_FROM_DEVICE);
21 #define FILLBUF_SIZE 512
22 uint8_t fillbuf[FILLBUF_SIZE];
23 int l;
24 bool error = false;
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;
34 return error;
37 void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint, AddressSpace *as)
39 qsg->sg = g_malloc(alloc_hint * sizeof(ScatterGatherEntry));
40 qsg->nsg = 0;
41 qsg->nalloc = alloc_hint;
42 qsg->size = 0;
43 qsg->as = as;
46 void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len)
48 if (qsg->nsg == qsg->nalloc) {
49 qsg->nalloc = 2 * qsg->nalloc + 1;
50 qsg->sg = g_realloc(qsg->sg, qsg->nalloc * sizeof(ScatterGatherEntry));
52 qsg->sg[qsg->nsg].base = base;
53 qsg->sg[qsg->nsg].len = len;
54 qsg->size += len;
55 ++qsg->nsg;
58 void qemu_sglist_destroy(QEMUSGList *qsg)
60 g_free(qsg->sg);
61 memset(qsg, 0, sizeof(*qsg));
64 typedef struct {
65 BlockDriverAIOCB common;
66 BlockDriverState *bs;
67 BlockDriverAIOCB *acb;
68 QEMUSGList *sg;
69 uint64_t sector_num;
70 DMADirection dir;
71 bool in_cancel;
72 int sg_cur_index;
73 dma_addr_t sg_cur_byte;
74 QEMUIOVector iov;
75 QEMUBH *bh;
76 DMAIOFunc *io_func;
77 } DMAAIOCB;
79 static void dma_bdrv_cb(void *opaque, int ret);
81 static void reschedule_dma(void *opaque)
83 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
85 qemu_bh_delete(dbs->bh);
86 dbs->bh = NULL;
87 dma_bdrv_cb(dbs, 0);
90 static void continue_after_map_failure(void *opaque)
92 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
94 dbs->bh = qemu_bh_new(reschedule_dma, dbs);
95 qemu_bh_schedule(dbs->bh);
98 static void dma_bdrv_unmap(DMAAIOCB *dbs)
100 int i;
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);
107 qemu_iovec_reset(&dbs->iov);
110 static void dma_complete(DMAAIOCB *dbs, int ret)
112 trace_dma_complete(dbs, ret, dbs->common.cb);
114 dma_bdrv_unmap(dbs);
115 if (dbs->common.cb) {
116 dbs->common.cb(dbs->common.opaque, ret);
118 qemu_iovec_destroy(&dbs->iov);
119 if (dbs->bh) {
120 qemu_bh_delete(dbs->bh);
121 dbs->bh = NULL;
123 if (!dbs->in_cancel) {
124 /* Requests may complete while dma_aio_cancel is in progress. In
125 * this case, the AIOCB should not be released because it is still
126 * referenced by dma_aio_cancel. */
127 qemu_aio_release(dbs);
131 static void dma_bdrv_cb(void *opaque, int ret)
133 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
134 dma_addr_t cur_addr, cur_len;
135 void *mem;
137 trace_dma_bdrv_cb(dbs, ret);
139 dbs->acb = NULL;
140 dbs->sector_num += dbs->iov.size / 512;
141 dma_bdrv_unmap(dbs);
143 if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) {
144 dma_complete(dbs, ret);
145 return;
148 while (dbs->sg_cur_index < dbs->sg->nsg) {
149 cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte;
150 cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte;
151 mem = dma_memory_map(dbs->sg->as, cur_addr, &cur_len, dbs->dir);
152 if (!mem)
153 break;
154 qemu_iovec_add(&dbs->iov, mem, cur_len);
155 dbs->sg_cur_byte += cur_len;
156 if (dbs->sg_cur_byte == dbs->sg->sg[dbs->sg_cur_index].len) {
157 dbs->sg_cur_byte = 0;
158 ++dbs->sg_cur_index;
162 if (dbs->iov.size == 0) {
163 trace_dma_map_wait(dbs);
164 cpu_register_map_client(dbs, continue_after_map_failure);
165 return;
168 dbs->acb = dbs->io_func(dbs->bs, dbs->sector_num, &dbs->iov,
169 dbs->iov.size / 512, dma_bdrv_cb, dbs);
170 assert(dbs->acb);
173 static void dma_aio_cancel(BlockDriverAIOCB *acb)
175 DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
177 trace_dma_aio_cancel(dbs);
179 if (dbs->acb) {
180 BlockDriverAIOCB *acb = dbs->acb;
181 dbs->acb = NULL;
182 dbs->in_cancel = true;
183 bdrv_aio_cancel(acb);
184 dbs->in_cancel = false;
186 dbs->common.cb = NULL;
187 dma_complete(dbs, 0);
190 static const AIOCBInfo dma_aiocb_info = {
191 .aiocb_size = sizeof(DMAAIOCB),
192 .cancel = dma_aio_cancel,
195 BlockDriverAIOCB *dma_bdrv_io(
196 BlockDriverState *bs, QEMUSGList *sg, uint64_t sector_num,
197 DMAIOFunc *io_func, BlockDriverCompletionFunc *cb,
198 void *opaque, DMADirection dir)
200 DMAAIOCB *dbs = qemu_aio_get(&dma_aiocb_info, bs, cb, opaque);
202 trace_dma_bdrv_io(dbs, bs, sector_num, (dir == DMA_DIRECTION_TO_DEVICE));
204 dbs->acb = NULL;
205 dbs->bs = bs;
206 dbs->sg = sg;
207 dbs->sector_num = sector_num;
208 dbs->sg_cur_index = 0;
209 dbs->sg_cur_byte = 0;
210 dbs->dir = dir;
211 dbs->io_func = io_func;
212 dbs->bh = NULL;
213 qemu_iovec_init(&dbs->iov, sg->nsg);
214 dma_bdrv_cb(dbs, 0);
215 return &dbs->common;
219 BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs,
220 QEMUSGList *sg, uint64_t sector,
221 void (*cb)(void *opaque, int ret), void *opaque)
223 return dma_bdrv_io(bs, sg, sector, bdrv_aio_readv, cb, opaque,
224 DMA_DIRECTION_FROM_DEVICE);
227 BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs,
228 QEMUSGList *sg, uint64_t sector,
229 void (*cb)(void *opaque, int ret), void *opaque)
231 return dma_bdrv_io(bs, sg, sector, bdrv_aio_writev, cb, opaque,
232 DMA_DIRECTION_TO_DEVICE);
236 static uint64_t dma_buf_rw(uint8_t *ptr, int32_t len, QEMUSGList *sg,
237 DMADirection dir)
239 uint64_t resid;
240 int sg_cur_index;
242 resid = sg->size;
243 sg_cur_index = 0;
244 len = MIN(len, resid);
245 while (len > 0) {
246 ScatterGatherEntry entry = sg->sg[sg_cur_index++];
247 int32_t xfer = MIN(len, entry.len);
248 dma_memory_rw(sg->as, entry.base, ptr, xfer, dir);
249 ptr += xfer;
250 len -= xfer;
251 resid -= xfer;
254 return resid;
257 uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg)
259 return dma_buf_rw(ptr, len, sg, DMA_DIRECTION_FROM_DEVICE);
262 uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg)
264 return dma_buf_rw(ptr, len, sg, DMA_DIRECTION_TO_DEVICE);
267 void dma_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie,
268 QEMUSGList *sg, enum BlockAcctType type)
270 bdrv_acct_start(bs, cookie, sg->size, type);