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/*
* 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"
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 {
BlockDriverAIOCB common;
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;
} DMAAIOCB;
static void dma_bdrv_cb(void *opaque, int ret);
static void reschedule_dma(void *opaque)
{
DMAAIOCB *dbs = (DMAAIOCB *)opaque;
qemu_bh_delete(dbs->bh);
dbs->bh = NULL;
dma_bdrv_cb(opaque, 0);
}
static void continue_after_map_failure(void *opaque)
{
DMAAIOCB *dbs = (DMAAIOCB *)opaque;
dbs->bh = qemu_bh_new(reschedule_dma, dbs);
qemu_bh_schedule(dbs->bh);
}
static void dma_bdrv_unmap(DMAAIOCB *dbs)
{
int i;
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);
}
}
static void dma_bdrv_cb(void *opaque, int ret)
{
DMAAIOCB *dbs = (DMAAIOCB *)opaque;
target_phys_addr_t cur_addr, cur_len;
void *mem;
dbs->acb = NULL;
dbs->sector_num += dbs->iov.size / 512;
dma_bdrv_unmap(dbs);
qemu_iovec_reset(&dbs->iov);
if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) {
dbs->common.cb(dbs->common.opaque, ret);
qemu_iovec_destroy(&dbs->iov);
qemu_aio_release(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) {
dbs->acb = bdrv_aio_writev(dbs->bs, dbs->sector_num, &dbs->iov,
dbs->iov.size / 512, dma_bdrv_cb, dbs);
} else {
dbs->acb = bdrv_aio_readv(dbs->bs, dbs->sector_num, &dbs->iov,
dbs->iov.size / 512, dma_bdrv_cb, dbs);
}
if (!dbs->acb) {
dma_bdrv_unmap(dbs);
qemu_iovec_destroy(&dbs->iov);
return;
}
}
static void dma_aio_cancel(BlockDriverAIOCB *acb)
{
DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
if (dbs->acb) {
bdrv_aio_cancel(dbs->acb);
}
}
static AIOPool dma_aio_pool = {
.aiocb_size = sizeof(DMAAIOCB),
.cancel = dma_aio_cancel,
};
static BlockDriverAIOCB *dma_bdrv_io(
BlockDriverState *bs, QEMUSGList *sg, uint64_t sector_num,
BlockDriverCompletionFunc *cb, void *opaque,
int is_write)
{
DMAAIOCB *dbs = qemu_aio_get(&dma_aio_pool, bs, cb, opaque);
dbs->acb = NULL;
dbs->bs = bs;
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 flushing is handled in dma_bdrv_cb() calling dma_bdrv_unmap()
* so we don't need to do that here.
*/
dma_bdrv_cb(dbs, 0);
if (!dbs->acb) {
qemu_aio_release(dbs);
return NULL;
}
return &dbs->common;
}
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);
}
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