1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/*
* DMA helper functions
*
* Copyright (c) 2009 Red Hat
*
* This work is licensed under the terms of the GNU General Public License
* (GNU GPL), version 2 or later.
*/
#include "dma.h"
#include "block_int.h"
static AIOPool dma_aio_pool;
void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint)
{
qsg->sg = qemu_malloc(alloc_hint * sizeof(ScatterGatherEntry));
qsg->nsg = 0;
qsg->nalloc = alloc_hint;
qsg->size = 0;
}
void qemu_sglist_add(QEMUSGList *qsg, target_phys_addr_t base,
target_phys_addr_t len)
{
if (qsg->nsg == qsg->nalloc) {
qsg->nalloc = 2 * qsg->nalloc + 1;
qsg->sg = qemu_realloc(qsg->sg, qsg->nalloc * sizeof(ScatterGatherEntry));
}
qsg->sg[qsg->nsg].base = base;
qsg->sg[qsg->nsg].len = len;
qsg->size += len;
++qsg->nsg;
}
void qemu_sglist_destroy(QEMUSGList *qsg)
{
qemu_free(qsg->sg);
}
typedef struct {
BlockDriverState *bs;
BlockDriverAIOCB *acb;
QEMUSGList *sg;
uint64_t sector_num;
int is_write;
int sg_cur_index;
target_phys_addr_t sg_cur_byte;
QEMUIOVector iov;
QEMUBH *bh;
} DMABlockState;
static void dma_bdrv_cb(void *opaque, int ret);
static void reschedule_dma(void *opaque)
{
DMABlockState *dbs = (DMABlockState *)opaque;
qemu_bh_delete(dbs->bh);
dbs->bh = NULL;
dma_bdrv_cb(opaque, 0);
}
static void continue_after_map_failure(void *opaque)
{
DMABlockState *dbs = (DMABlockState *)opaque;
dbs->bh = qemu_bh_new(reschedule_dma, dbs);
qemu_bh_schedule(dbs->bh);
}
static void dma_bdrv_cb(void *opaque, int ret)
{
DMABlockState *dbs = (DMABlockState *)opaque;
target_phys_addr_t cur_addr, cur_len;
void *mem;
int i;
dbs->sector_num += dbs->iov.size / 512;
for (i = 0; i < dbs->iov.niov; ++i) {
cpu_physical_memory_unmap(dbs->iov.iov[i].iov_base,
dbs->iov.iov[i].iov_len, !dbs->is_write,
dbs->iov.iov[i].iov_len);
}
qemu_iovec_reset(&dbs->iov);
if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) {
dbs->acb->cb(dbs->acb->opaque, ret);
qemu_iovec_destroy(&dbs->iov);
qemu_aio_release(dbs->acb);
qemu_free(dbs);
return;
}
while (dbs->sg_cur_index < dbs->sg->nsg) {
cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte;
cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte;
mem = cpu_physical_memory_map(cur_addr, &cur_len, !dbs->is_write);
if (!mem)
break;
qemu_iovec_add(&dbs->iov, mem, cur_len);
dbs->sg_cur_byte += cur_len;
if (dbs->sg_cur_byte == dbs->sg->sg[dbs->sg_cur_index].len) {
dbs->sg_cur_byte = 0;
++dbs->sg_cur_index;
}
}
if (dbs->iov.size == 0) {
cpu_register_map_client(dbs, continue_after_map_failure);
return;
}
if (dbs->is_write) {
bdrv_aio_writev(dbs->bs, dbs->sector_num, &dbs->iov,
dbs->iov.size / 512, dma_bdrv_cb, dbs);
} else {
bdrv_aio_readv(dbs->bs, dbs->sector_num, &dbs->iov,
dbs->iov.size / 512, dma_bdrv_cb, dbs);
}
}
static BlockDriverAIOCB *dma_bdrv_io(
BlockDriverState *bs, QEMUSGList *sg, uint64_t sector_num,
BlockDriverCompletionFunc *cb, void *opaque,
int is_write)
{
DMABlockState *dbs = qemu_malloc(sizeof(*dbs));
dbs->bs = bs;
dbs->acb = qemu_aio_get_pool(&dma_aio_pool, bs, cb, opaque);
dbs->sg = sg;
dbs->sector_num = sector_num;
dbs->sg_cur_index = 0;
dbs->sg_cur_byte = 0;
dbs->is_write = is_write;
dbs->bh = NULL;
qemu_iovec_init(&dbs->iov, sg->nsg);
dma_bdrv_cb(dbs, 0);
return dbs->acb;
}
BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs,
QEMUSGList *sg, uint64_t sector,
void (*cb)(void *opaque, int ret), void *opaque)
{
return dma_bdrv_io(bs, sg, sector, cb, opaque, 0);
}
BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs,
QEMUSGList *sg, uint64_t sector,
void (*cb)(void *opaque, int ret), void *opaque)
{
return dma_bdrv_io(bs, sg, sector, cb, opaque, 1);
}
static void dma_aio_cancel(BlockDriverAIOCB *acb)
{
DMABlockState *dbs = (DMABlockState *)acb->opaque;
bdrv_aio_cancel(dbs->acb);
}
void dma_helper_init(void)
{
aio_pool_init(&dma_aio_pool, sizeof(BlockDriverAIOCB), dma_aio_cancel);
}
|
