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.
11 #include "block_int.h"
13 static AIOPool dma_aio_pool;
15 void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint)
17 qsg->sg = qemu_malloc(alloc_hint * sizeof(ScatterGatherEntry));
19 qsg->nalloc = alloc_hint;
23 void qemu_sglist_add(QEMUSGList *qsg, target_phys_addr_t base,
24 target_phys_addr_t len)
26 if (qsg->nsg == qsg->nalloc) {
27 qsg->nalloc = 2 * qsg->nalloc + 1;
28 qsg->sg = qemu_realloc(qsg->sg, qsg->nalloc * sizeof(ScatterGatherEntry));
30 qsg->sg[qsg->nsg].base = base;
31 qsg->sg[qsg->nsg].len = len;
36 void qemu_sglist_destroy(QEMUSGList *qsg)
42 BlockDriverAIOCB common;
44 BlockDriverAIOCB *acb;
49 target_phys_addr_t sg_cur_byte;
54 static void dma_bdrv_cb(void *opaque, int ret);
56 static void reschedule_dma(void *opaque)
58 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
60 qemu_bh_delete(dbs->bh);
62 dma_bdrv_cb(opaque, 0);
65 static void continue_after_map_failure(void *opaque)
67 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
69 dbs->bh = qemu_bh_new(reschedule_dma, dbs);
70 qemu_bh_schedule(dbs->bh);
73 static void dma_bdrv_unmap(DMAAIOCB *dbs)
77 for (i = 0; i < dbs->iov.niov; ++i) {
78 cpu_physical_memory_unmap(dbs->iov.iov[i].iov_base,
79 dbs->iov.iov[i].iov_len, !dbs->is_write,
80 dbs->iov.iov[i].iov_len);
84 static void dma_bdrv_cb(void *opaque, int ret)
86 DMAAIOCB *dbs = (DMAAIOCB *)opaque;
87 target_phys_addr_t cur_addr, cur_len;
91 dbs->sector_num += dbs->iov.size / 512;
93 qemu_iovec_reset(&dbs->iov);
95 if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) {
96 dbs->common.cb(dbs->common.opaque, ret);
97 qemu_iovec_destroy(&dbs->iov);
98 qemu_aio_release(dbs);
102 while (dbs->sg_cur_index < dbs->sg->nsg) {
103 cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte;
104 cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte;
105 mem = cpu_physical_memory_map(cur_addr, &cur_len, !dbs->is_write);
108 qemu_iovec_add(&dbs->iov, mem, cur_len);
109 dbs->sg_cur_byte += cur_len;
110 if (dbs->sg_cur_byte == dbs->sg->sg[dbs->sg_cur_index].len) {
111 dbs->sg_cur_byte = 0;
116 if (dbs->iov.size == 0) {
117 cpu_register_map_client(dbs, continue_after_map_failure);
122 dbs->acb = bdrv_aio_writev(dbs->bs, dbs->sector_num, &dbs->iov,
123 dbs->iov.size / 512, dma_bdrv_cb, dbs);
125 dbs->acb = bdrv_aio_readv(dbs->bs, dbs->sector_num, &dbs->iov,
126 dbs->iov.size / 512, dma_bdrv_cb, dbs);
130 qemu_iovec_destroy(&dbs->iov);
135 static BlockDriverAIOCB *dma_bdrv_io(
136 BlockDriverState *bs, QEMUSGList *sg, uint64_t sector_num,
137 BlockDriverCompletionFunc *cb, void *opaque,
140 DMAAIOCB *dbs = qemu_aio_get_pool(&dma_aio_pool, bs, cb, opaque);
145 dbs->sector_num = sector_num;
146 dbs->sg_cur_index = 0;
147 dbs->sg_cur_byte = 0;
148 dbs->is_write = is_write;
150 qemu_iovec_init(&dbs->iov, sg->nsg);
153 qemu_aio_release(dbs);
160 BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs,
161 QEMUSGList *sg, uint64_t sector,
162 void (*cb)(void *opaque, int ret), void *opaque)
164 return dma_bdrv_io(bs, sg, sector, cb, opaque, 0);
167 BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs,
168 QEMUSGList *sg, uint64_t sector,
169 void (*cb)(void *opaque, int ret), void *opaque)
171 return dma_bdrv_io(bs, sg, sector, cb, opaque, 1);
174 static void dma_aio_cancel(BlockDriverAIOCB *acb)
176 DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
179 bdrv_aio_cancel(dbs->acb);
183 void dma_helper_init(void)
185 aio_pool_init(&dma_aio_pool, sizeof(DMAAIOCB), dma_aio_cancel);