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10#include "dma.h"
11#include "block_int.h"
12
13void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint)
14{
15 qsg->sg = qemu_malloc(alloc_hint * sizeof(ScatterGatherEntry));
16 qsg->nsg = 0;
17 qsg->nalloc = alloc_hint;
18 qsg->size = 0;
19}
20
21void qemu_sglist_add(QEMUSGList *qsg, target_phys_addr_t base,
22 target_phys_addr_t len)
23{
24 if (qsg->nsg == qsg->nalloc) {
25 qsg->nalloc = 2 * qsg->nalloc + 1;
26 qsg->sg = qemu_realloc(qsg->sg, qsg->nalloc * sizeof(ScatterGatherEntry));
27 }
28 qsg->sg[qsg->nsg].base = base;
29 qsg->sg[qsg->nsg].len = len;
30 qsg->size += len;
31 ++qsg->nsg;
32}
33
34void qemu_sglist_destroy(QEMUSGList *qsg)
35{
36 qemu_free(qsg->sg);
37}
38
39typedef struct {
40 BlockDriverAIOCB common;
41 BlockDriverState *bs;
42 BlockDriverAIOCB *acb;
43 QEMUSGList *sg;
44 uint64_t sector_num;
45 int is_write;
46 int sg_cur_index;
47 target_phys_addr_t sg_cur_byte;
48 QEMUIOVector iov;
49 QEMUBH *bh;
50 DMAIOFunc *io_func;
51} DMAAIOCB;
52
53static void dma_bdrv_cb(void *opaque, int ret);
54
55static void reschedule_dma(void *opaque)
56{
57 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
58
59 qemu_bh_delete(dbs->bh);
60 dbs->bh = NULL;
61 dma_bdrv_cb(opaque, 0);
62}
63
64static void continue_after_map_failure(void *opaque)
65{
66 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
67
68 dbs->bh = qemu_bh_new(reschedule_dma, dbs);
69 qemu_bh_schedule(dbs->bh);
70}
71
72static void dma_bdrv_unmap(DMAAIOCB *dbs)
73{
74 int i;
75
76 for (i = 0; i < dbs->iov.niov; ++i) {
77 cpu_physical_memory_unmap(dbs->iov.iov[i].iov_base,
78 dbs->iov.iov[i].iov_len, !dbs->is_write,
79 dbs->iov.iov[i].iov_len);
80 }
81}
82
83static void dma_bdrv_cb(void *opaque, int ret)
84{
85 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
86 target_phys_addr_t cur_addr, cur_len;
87 void *mem;
88
89 dbs->acb = NULL;
90 dbs->sector_num += dbs->iov.size / 512;
91 dma_bdrv_unmap(dbs);
92 qemu_iovec_reset(&dbs->iov);
93
94 if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) {
95 dbs->common.cb(dbs->common.opaque, ret);
96 qemu_iovec_destroy(&dbs->iov);
97 qemu_aio_release(dbs);
98 return;
99 }
100
101 while (dbs->sg_cur_index < dbs->sg->nsg) {
102 cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte;
103 cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte;
104 mem = cpu_physical_memory_map(cur_addr, &cur_len, !dbs->is_write);
105 if (!mem)
106 break;
107 qemu_iovec_add(&dbs->iov, mem, cur_len);
108 dbs->sg_cur_byte += cur_len;
109 if (dbs->sg_cur_byte == dbs->sg->sg[dbs->sg_cur_index].len) {
110 dbs->sg_cur_byte = 0;
111 ++dbs->sg_cur_index;
112 }
113 }
114
115 if (dbs->iov.size == 0) {
116 cpu_register_map_client(dbs, continue_after_map_failure);
117 return;
118 }
119
120 dbs->acb = dbs->io_func(dbs->bs, dbs->sector_num, &dbs->iov,
121 dbs->iov.size / 512, dma_bdrv_cb, dbs);
122 if (!dbs->acb) {
123 dma_bdrv_unmap(dbs);
124 qemu_iovec_destroy(&dbs->iov);
125 return;
126 }
127}
128
129static void dma_aio_cancel(BlockDriverAIOCB *acb)
130{
131 DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
132
133 if (dbs->acb) {
134 bdrv_aio_cancel(dbs->acb);
135 }
136}
137
138static AIOPool dma_aio_pool = {
139 .aiocb_size = sizeof(DMAAIOCB),
140 .cancel = dma_aio_cancel,
141};
142
143BlockDriverAIOCB *dma_bdrv_io(
144 BlockDriverState *bs, QEMUSGList *sg, uint64_t sector_num,
145 DMAIOFunc *io_func, BlockDriverCompletionFunc *cb,
146 void *opaque, int is_write)
147{
148 DMAAIOCB *dbs = qemu_aio_get(&dma_aio_pool, bs, cb, opaque);
149
150 dbs->acb = NULL;
151 dbs->bs = bs;
152 dbs->sg = sg;
153 dbs->sector_num = sector_num;
154 dbs->sg_cur_index = 0;
155 dbs->sg_cur_byte = 0;
156 dbs->is_write = is_write;
157 dbs->io_func = io_func;
158 dbs->bh = NULL;
159 qemu_iovec_init(&dbs->iov, sg->nsg);
160 dma_bdrv_cb(dbs, 0);
161 if (!dbs->acb) {
162 qemu_aio_release(dbs);
163 return NULL;
164 }
165 return &dbs->common;
166}
167
168
169BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs,
170 QEMUSGList *sg, uint64_t sector,
171 void (*cb)(void *opaque, int ret), void *opaque)
172{
173 return dma_bdrv_io(bs, sg, sector, bdrv_aio_readv, cb, opaque, 0);
174}
175
176BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs,
177 QEMUSGList *sg, uint64_t sector,
178 void (*cb)(void *opaque, int ret), void *opaque)
179{
180 return dma_bdrv_io(bs, sg, sector, bdrv_aio_writev, cb, opaque, 1);
181}
182
