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ide: move buffered DMA cancel to core 

Buffered DMA cancellation was added to ATAPI devices and implemented
for the BMDMA HBA. Move the code over to common IDE code and allow
it to be used for any HBA.

Signed-off-by: John Snow <jsnow@redhat.com>
Reported-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1453225191-11871-4-git-send-email-jsnow@redhat.com
This commit is contained in:
John Snow 2016-02-10 13:29:39 -05:00
parent 4590355bb7
commit 86698a12f7
3 changed files with 47 additions and 35 deletions
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45
hw/ide/core.c
View File

@ -609,6 +609,51 @@ BlockAIOCB *ide_buffered_readv(IDEState *s, int64_t sector_num,
return aioreq;
}
/**
* Cancel all pending DMA requests.
* Any buffered DMA requests are instantly canceled,
* but any pending unbuffered DMA requests must be waited on.
*/
void ide_cancel_dma_sync(IDEState *s)
{
IDEBufferedRequest *req;
/* First invoke the callbacks of all buffered requests
* and flag those requests as orphaned. Ideally there
* are no unbuffered (Scatter Gather DMA Requests or
* write requests) pending and we can avoid to drain. */
QLIST_FOREACH(req, &s->buffered_requests, list) {
if (!req->orphaned) {
#ifdef DEBUG_IDE
printf("%s: invoking cb %p of buffered request %p with"
" -ECANCELED\n", __func__, req->original_cb, req);
#endif
req->original_cb(req->original_opaque, -ECANCELED);
}
req->orphaned = true;
}
/*
* We can't cancel Scatter Gather DMA in the middle of the
* operation or a partial (not full) DMA transfer would reach
* the storage so we wait for completion instead (we beahve
* like if the DMA was completed by the time the guest trying
* to cancel dma with bmdma_cmd_writeb with BM_CMD_START not
* set).
*
* In the future we'll be able to safely cancel the I/O if the
* whole DMA operation will be submitted to disk with a single
* aio operation with preadv/pwritev.
*/
if (s->bus->dma->aiocb) {
#ifdef DEBUG_IDE
printf("%s: draining all remaining requests", __func__);
#endif
blk_drain_all();
assert(s->bus->dma->aiocb == NULL);
}
}
static void ide_sector_read(IDEState *s);
static void ide_sector_read_cb(void *opaque, int ret)

1
hw/ide/internal.h
View File

@ -586,6 +586,7 @@ BlockAIOCB *ide_issue_trim(BlockBackend *blk,
BlockAIOCB *ide_buffered_readv(IDEState *s, int64_t sector_num,
QEMUIOVector *iov, int nb_sectors,
BlockCompletionFunc *cb, void *opaque);
void ide_cancel_dma_sync(IDEState *s);
/* hw/ide/atapi.c */
void ide_atapi_cmd(IDEState *s);

36
hw/ide/pci.c
View File

@ -234,41 +234,7 @@ void bmdma_cmd_writeb(BMDMAState *bm, uint32_t val)
/* Ignore writes to SSBM if it keeps the old value */
if ((val & BM_CMD_START) != (bm->cmd & BM_CMD_START)) {
if (!(val & BM_CMD_START)) {
/* First invoke the callbacks of all buffered requests
* and flag those requests as orphaned. Ideally there
* are no unbuffered (Scatter Gather DMA Requests or
* write requests) pending and we can avoid to drain. */
IDEBufferedRequest *req;
IDEState *s = idebus_active_if(bm->bus);
QLIST_FOREACH(req, &s->buffered_requests, list) {
if (!req->orphaned) {
#ifdef DEBUG_IDE
printf("%s: invoking cb %p of buffered request %p with"
" -ECANCELED\n", __func__, req->original_cb, req);
#endif
req->original_cb(req->original_opaque, -ECANCELED);
}
req->orphaned = true;
}
/*
* We can't cancel Scatter Gather DMA in the middle of the
* operation or a partial (not full) DMA transfer would reach
* the storage so we wait for completion instead (we beahve
* like if the DMA was completed by the time the guest trying
* to cancel dma with bmdma_cmd_writeb with BM_CMD_START not
* set).
*
* In the future we'll be able to safely cancel the I/O if the
* whole DMA operation will be submitted to disk with a single
* aio operation with preadv/pwritev.
*/
if (bm->bus->dma->aiocb) {
#ifdef DEBUG_IDE
printf("%s: draining all remaining requests", __func__);
#endif
blk_drain_all();
assert(bm->bus->dma->aiocb == NULL);
}
ide_cancel_dma_sync(idebus_active_if(bm->bus));
bm->status &= ~BM_STATUS_DMAING;
} else {
bm->cur_addr = bm->addr;