diff options
Diffstat (limited to 'src/dma-helpers.c')
| -rw-r--r-- | src/dma-helpers.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/src/dma-helpers.c b/src/dma-helpers.c new file mode 100644 index 0000000..4faec5d --- /dev/null +++ b/src/dma-helpers.c @@ -0,0 +1,269 @@ +/* + * 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 "sysemu/block-backend.h" +#include "sysemu/dma.h" +#include "trace.h" +#include "qemu/thread.h" +#include "qemu/main-loop.h" + +/* #define DEBUG_IOMMU */ + +int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len) +{ + dma_barrier(as, DMA_DIRECTION_FROM_DEVICE); + +#define FILLBUF_SIZE 512 + uint8_t fillbuf[FILLBUF_SIZE]; + int l; + bool error = false; + + memset(fillbuf, c, FILLBUF_SIZE); + while (len > 0) { + l = len < FILLBUF_SIZE ? len : FILLBUF_SIZE; + error |= address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED, + fillbuf, l, true); + len -= l; + addr += l; + } + + return error; +} + +void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint, + AddressSpace *as) +{ + qsg->sg = g_malloc(alloc_hint * sizeof(ScatterGatherEntry)); + qsg->nsg = 0; + qsg->nalloc = alloc_hint; + qsg->size = 0; + qsg->as = as; + qsg->dev = dev; + object_ref(OBJECT(dev)); +} + +void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len) +{ + if (qsg->nsg == qsg->nalloc) { + qsg->nalloc = 2 * qsg->nalloc + 1; + qsg->sg = g_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) +{ + object_unref(OBJECT(qsg->dev)); + g_free(qsg->sg); + memset(qsg, 0, sizeof(*qsg)); +} + +typedef struct { + BlockAIOCB common; + BlockBackend *blk; + BlockAIOCB *acb; + QEMUSGList *sg; + uint64_t sector_num; + DMADirection dir; + int sg_cur_index; + dma_addr_t sg_cur_byte; + QEMUIOVector iov; + QEMUBH *bh; + DMAIOFunc *io_func; +} DMAAIOCB; + +static void dma_blk_cb(void *opaque, int ret); + +static void reschedule_dma(void *opaque) +{ + DMAAIOCB *dbs = (DMAAIOCB *)opaque; + + qemu_bh_delete(dbs->bh); + dbs->bh = NULL; + dma_blk_cb(dbs, 0); +} + +static void dma_blk_unmap(DMAAIOCB *dbs) +{ + int i; + + for (i = 0; i < dbs->iov.niov; ++i) { + dma_memory_unmap(dbs->sg->as, dbs->iov.iov[i].iov_base, + dbs->iov.iov[i].iov_len, dbs->dir, + dbs->iov.iov[i].iov_len); + } + qemu_iovec_reset(&dbs->iov); +} + +static void dma_complete(DMAAIOCB *dbs, int ret) +{ + trace_dma_complete(dbs, ret, dbs->common.cb); + + dma_blk_unmap(dbs); + if (dbs->common.cb) { + dbs->common.cb(dbs->common.opaque, ret); + } + qemu_iovec_destroy(&dbs->iov); + if (dbs->bh) { + qemu_bh_delete(dbs->bh); + dbs->bh = NULL; + } + qemu_aio_unref(dbs); +} + +static void dma_blk_cb(void *opaque, int ret) +{ + DMAAIOCB *dbs = (DMAAIOCB *)opaque; + dma_addr_t cur_addr, cur_len; + void *mem; + + trace_dma_blk_cb(dbs, ret); + + dbs->acb = NULL; + dbs->sector_num += dbs->iov.size / 512; + + if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) { + dma_complete(dbs, ret); + return; + } + dma_blk_unmap(dbs); + + 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 = dma_memory_map(dbs->sg->as, cur_addr, &cur_len, dbs->dir); + 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) { + trace_dma_map_wait(dbs); + dbs->bh = aio_bh_new(blk_get_aio_context(dbs->blk), + reschedule_dma, dbs); + cpu_register_map_client(dbs->bh); + return; + } + + if (dbs->iov.size & ~BDRV_SECTOR_MASK) { + qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK); + } + + dbs->acb = dbs->io_func(dbs->blk, dbs->sector_num, &dbs->iov, + dbs->iov.size / 512, dma_blk_cb, dbs); + assert(dbs->acb); +} + +static void dma_aio_cancel(BlockAIOCB *acb) +{ + DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common); + + trace_dma_aio_cancel(dbs); + + if (dbs->acb) { + blk_aio_cancel_async(dbs->acb); + } + if (dbs->bh) { + cpu_unregister_map_client(dbs->bh); + qemu_bh_delete(dbs->bh); + dbs->bh = NULL; + } +} + + +static const AIOCBInfo dma_aiocb_info = { + .aiocb_size = sizeof(DMAAIOCB), + .cancel_async = dma_aio_cancel, +}; + +BlockAIOCB *dma_blk_io( + BlockBackend *blk, QEMUSGList *sg, uint64_t sector_num, + DMAIOFunc *io_func, BlockCompletionFunc *cb, + void *opaque, DMADirection dir) +{ + DMAAIOCB *dbs = blk_aio_get(&dma_aiocb_info, blk, cb, opaque); + + trace_dma_blk_io(dbs, blk, sector_num, (dir == DMA_DIRECTION_TO_DEVICE)); + + dbs->acb = NULL; + dbs->blk = blk; + dbs->sg = sg; + dbs->sector_num = sector_num; + dbs->sg_cur_index = 0; + dbs->sg_cur_byte = 0; + dbs->dir = dir; + dbs->io_func = io_func; + dbs->bh = NULL; + qemu_iovec_init(&dbs->iov, sg->nsg); + dma_blk_cb(dbs, 0); + return &dbs->common; +} + + +BlockAIOCB *dma_blk_read(BlockBackend *blk, + QEMUSGList *sg, uint64_t sector, + void (*cb)(void *opaque, int ret), void *opaque) +{ + return dma_blk_io(blk, sg, sector, blk_aio_readv, cb, opaque, + DMA_DIRECTION_FROM_DEVICE); +} + +BlockAIOCB *dma_blk_write(BlockBackend *blk, + QEMUSGList *sg, uint64_t sector, + void (*cb)(void *opaque, int ret), void *opaque) +{ + return dma_blk_io(blk, sg, sector, blk_aio_writev, cb, opaque, + DMA_DIRECTION_TO_DEVICE); +} + + +static uint64_t dma_buf_rw(uint8_t *ptr, int32_t len, QEMUSGList *sg, + DMADirection dir) +{ + 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); + dma_memory_rw(sg->as, entry.base, ptr, xfer, dir); + 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, DMA_DIRECTION_FROM_DEVICE); +} + +uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg) +{ + return dma_buf_rw(ptr, len, sg, DMA_DIRECTION_TO_DEVICE); +} + +void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie, + QEMUSGList *sg, enum BlockAcctType type) +{ + block_acct_start(blk_get_stats(blk), cookie, sg->size, type); +} |
