diff options
| -rw-r--r-- | dma-helpers.c | 31 | ||||
| -rw-r--r-- | dma.h | 3 |
2 files changed, 34 insertions, 0 deletions
diff --git a/dma-helpers.c b/dma-helpers.c index f08cdb5454..df0a42172f 100644 --- a/dma-helpers.c +++ b/dma-helpers.c @@ -204,3 +204,34 @@ BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs, { return dma_bdrv_io(bs, sg, sector, bdrv_aio_writev, cb, opaque, true); } + + +static uint64_t dma_buf_rw(uint8_t *ptr, int32_t len, QEMUSGList *sg, bool to_dev) +{ + uint64_t resid; + int sg_cur_index; + + resid = sg->size; + sg_cur_index = 0; + len = MIN(len, resid); + while (len > 0) { + ScatterGatherEntry entry = sg->sg[sg_cur_index++]; + int32_t xfer = MIN(len, entry.len); + cpu_physical_memory_rw(entry.base, ptr, xfer, !to_dev); + ptr += xfer; + len -= xfer; + resid -= xfer; + } + + return resid; +} + +uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg) +{ + return dma_buf_rw(ptr, len, sg, 0); +} + +uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg) +{ + return dma_buf_rw(ptr, len, sg, 1); +} @@ -58,4 +58,7 @@ BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs, BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs, QEMUSGList *sg, uint64_t sector, BlockDriverCompletionFunc *cb, void *opaque); +uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg); +uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg); + #endif |