--- /dev/null
+/*
+ * 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);
+}
Code Review / kvmfornfv.git / blobdiff