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authorPaolo Bonzini <pbonzini@redhat.com>2020-10-06 09:01:22 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2020-10-12 11:50:21 -0400
commit800d4deda04be016a95fbbf397c830a2d14ff9f6 (patch)
tree3079145f9804bb8c96deb3640fa51c5680ccae2a /softmmu/dma-helpers.c
parent8d0bceba24cc0917d9c6c5252d78db3d9fd5c58d (diff)
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softmmu: move more files to softmmu/
Keep most softmmu_ss files into the system-emulation-specific directory. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'softmmu/dma-helpers.c')
-rw-r--r--softmmu/dma-helpers.c331
1 files changed, 331 insertions, 0 deletions
diff --git a/softmmu/dma-helpers.c b/softmmu/dma-helpers.c
new file mode 100644
index 0000000..03c92e0
--- /dev/null
+++ b/softmmu/dma-helpers.c
@@ -0,0 +1,331 @@
+/*
+ * 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 "qemu/osdep.h"
+#include "sysemu/block-backend.h"
+#include "sysemu/dma.h"
+#include "trace/trace-root.h"
+#include "qemu/thread.h"
+#include "qemu/main-loop.h"
+#include "sysemu/cpu-timers.h"
+#include "qemu/range.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_write(as, addr, MEMTXATTRS_UNSPECIFIED,
+ fillbuf, l);
+ 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;
+ AioContext *ctx;
+ BlockAIOCB *acb;
+ QEMUSGList *sg;
+ uint32_t align;
+ uint64_t offset;
+ DMADirection dir;
+ int sg_cur_index;
+ dma_addr_t sg_cur_byte;
+ QEMUIOVector iov;
+ QEMUBH *bh;
+ DMAIOFunc *io_func;
+ void *io_func_opaque;
+} DMAAIOCB;
+
+static void dma_blk_cb(void *opaque, int ret);
+
+static void reschedule_dma(void *opaque)
+{
+ DMAAIOCB *dbs = (DMAAIOCB *)opaque;
+
+ assert(!dbs->acb && dbs->bh);
+ 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);
+
+ assert(!dbs->acb && !dbs->bh);
+ dma_blk_unmap(dbs);
+ if (dbs->common.cb) {
+ dbs->common.cb(dbs->common.opaque, ret);
+ }
+ qemu_iovec_destroy(&dbs->iov);
+ 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->offset += dbs->iov.size;
+
+ 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);
+ /*
+ * Make reads deterministic in icount mode. Windows sometimes issues
+ * disk read requests with overlapping SGs. It leads
+ * to non-determinism, because resulting buffer contents may be mixed
+ * from several sectors. This code splits all SGs into several
+ * groups. SGs in every group do not overlap.
+ */
+ if (mem && icount_enabled() && dbs->dir == DMA_DIRECTION_FROM_DEVICE) {
+ int i;
+ for (i = 0 ; i < dbs->iov.niov ; ++i) {
+ if (ranges_overlap((intptr_t)dbs->iov.iov[i].iov_base,
+ dbs->iov.iov[i].iov_len, (intptr_t)mem,
+ cur_len)) {
+ dma_memory_unmap(dbs->sg->as, mem, cur_len,
+ dbs->dir, cur_len);
+ mem = NULL;
+ break;
+ }
+ }
+ }
+ 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(dbs->ctx, reschedule_dma, dbs);
+ cpu_register_map_client(dbs->bh);
+ return;
+ }
+
+ if (!QEMU_IS_ALIGNED(dbs->iov.size, dbs->align)) {
+ qemu_iovec_discard_back(&dbs->iov,
+ QEMU_ALIGN_DOWN(dbs->iov.size, dbs->align));
+ }
+
+ aio_context_acquire(dbs->ctx);
+ dbs->acb = dbs->io_func(dbs->offset, &dbs->iov,
+ dma_blk_cb, dbs, dbs->io_func_opaque);
+ aio_context_release(dbs->ctx);
+ assert(dbs->acb);
+}
+
+static void dma_aio_cancel(BlockAIOCB *acb)
+{
+ DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
+
+ trace_dma_aio_cancel(dbs);
+
+ assert(!(dbs->acb && dbs->bh));
+ if (dbs->acb) {
+ /* This will invoke dma_blk_cb. */
+ blk_aio_cancel_async(dbs->acb);
+ return;
+ }
+
+ if (dbs->bh) {
+ cpu_unregister_map_client(dbs->bh);
+ qemu_bh_delete(dbs->bh);
+ dbs->bh = NULL;
+ }
+ if (dbs->common.cb) {
+ dbs->common.cb(dbs->common.opaque, -ECANCELED);
+ }
+}
+
+static AioContext *dma_get_aio_context(BlockAIOCB *acb)
+{
+ DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
+
+ return dbs->ctx;
+}
+
+static const AIOCBInfo dma_aiocb_info = {
+ .aiocb_size = sizeof(DMAAIOCB),
+ .cancel_async = dma_aio_cancel,
+ .get_aio_context = dma_get_aio_context,
+};
+
+BlockAIOCB *dma_blk_io(AioContext *ctx,
+ QEMUSGList *sg, uint64_t offset, uint32_t align,
+ DMAIOFunc *io_func, void *io_func_opaque,
+ BlockCompletionFunc *cb,
+ void *opaque, DMADirection dir)
+{
+ DMAAIOCB *dbs = qemu_aio_get(&dma_aiocb_info, NULL, cb, opaque);
+
+ trace_dma_blk_io(dbs, io_func_opaque, offset, (dir == DMA_DIRECTION_TO_DEVICE));
+
+ dbs->acb = NULL;
+ dbs->sg = sg;
+ dbs->ctx = ctx;
+ dbs->offset = offset;
+ dbs->align = align;
+ dbs->sg_cur_index = 0;
+ dbs->sg_cur_byte = 0;
+ dbs->dir = dir;
+ dbs->io_func = io_func;
+ dbs->io_func_opaque = io_func_opaque;
+ dbs->bh = NULL;
+ qemu_iovec_init(&dbs->iov, sg->nsg);
+ dma_blk_cb(dbs, 0);
+ return &dbs->common;
+}
+
+
+static
+BlockAIOCB *dma_blk_read_io_func(int64_t offset, QEMUIOVector *iov,
+ BlockCompletionFunc *cb, void *cb_opaque,
+ void *opaque)
+{
+ BlockBackend *blk = opaque;
+ return blk_aio_preadv(blk, offset, iov, 0, cb, cb_opaque);
+}
+
+BlockAIOCB *dma_blk_read(BlockBackend *blk,
+ QEMUSGList *sg, uint64_t offset, uint32_t align,
+ void (*cb)(void *opaque, int ret), void *opaque)
+{
+ return dma_blk_io(blk_get_aio_context(blk), sg, offset, align,
+ dma_blk_read_io_func, blk, cb, opaque,
+ DMA_DIRECTION_FROM_DEVICE);
+}
+
+static
+BlockAIOCB *dma_blk_write_io_func(int64_t offset, QEMUIOVector *iov,
+ BlockCompletionFunc *cb, void *cb_opaque,
+ void *opaque)
+{
+ BlockBackend *blk = opaque;
+ return blk_aio_pwritev(blk, offset, iov, 0, cb, cb_opaque);
+}
+
+BlockAIOCB *dma_blk_write(BlockBackend *blk,
+ QEMUSGList *sg, uint64_t offset, uint32_t align,
+ void (*cb)(void *opaque, int ret), void *opaque)
+{
+ return dma_blk_io(blk_get_aio_context(blk), sg, offset, align,
+ dma_blk_write_io_func, blk, 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);
+}