[dpdk-dev] [PATCH v3 1/8] bus/vdev: add DMA mapping ops

[Maxime Coquelin <maxime.coquelin@redhat.com>]

Add DMA map/unmap operation callbacks to the vdev bus, which
could be used by DMA capable vdev drivers.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 drivers/bus/vdev/rte_bus_vdev.h | 46 +++++++++++++++++++++++++++--
 drivers/bus/vdev/vdev.c         | 52 +++++++++++++++++++++++++++++++++
 2 files changed, 95 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/vdev/rte_bus_vdev.h b/drivers/bus/vdev/rte_bus_vdev.h
index 78a032cea8..d14eeb41b0 100644
--- a/drivers/bus/vdev/rte_bus_vdev.h
+++ b/drivers/bus/vdev/rte_bus_vdev.h
@@ -63,14 +63,54 @@ typedef int (rte_vdev_probe_t)(struct rte_vdev_device *dev);
  */
 typedef int (rte_vdev_remove_t)(struct rte_vdev_device *dev);
 
+/**
+ * Driver-specific DMA mapping. After a successful call the device
+ * will be able to read/write from/to this segment.
+ *
+ * @param dev
+ *   Pointer to the Virtual device.
+ * @param addr
+ *   Starting virtual address of memory to be mapped.
+ * @param iova
+ *   Starting IOVA address of memory to be mapped.
+ * @param len
+ *   Length of memory segment being mapped.
+ * @return
+ *   - 0 On success.
+ *   - Negative value and rte_errno is set otherwise.
+ */
+typedef int (rte_vdev_dma_map_t)(struct rte_vdev_device *dev, void *addr,
+			    uint64_t iova, size_t len);
+
+/**
+ * Driver-specific DMA un-mapping. After a successful call the device
+ * will not be able to read/write from/to this segment.
+ *
+ * @param dev
+ *   Pointer to the Virtual device.
+ * @param addr
+ *   Starting virtual address of memory to be unmapped.
+ * @param iova
+ *   Starting IOVA address of memory to be unmapped.
+ * @param len
+ *   Length of memory segment being unmapped.
+ * @return
+ *   - 0 On success.
+ *   - Negative value and rte_errno is set otherwise.
+ */
+typedef int (rte_vdev_dma_unmap_t)(struct rte_vdev_device *dev, void *addr,
+			      uint64_t iova, size_t len);
+
 /**
  * A virtual device driver abstraction.
  */
 struct rte_vdev_driver {
 	TAILQ_ENTRY(rte_vdev_driver) next; /**< Next in list. */
-	struct rte_driver driver;      /**< Inherited general driver. */
-	rte_vdev_probe_t *probe;       /**< Virtual device probe function. */
-	rte_vdev_remove_t *remove;     /**< Virtual device remove function. */
+	struct rte_driver driver;        /**< Inherited general driver. */
+	rte_vdev_probe_t *probe;         /**< Virtual device probe function. */
+	rte_vdev_remove_t *remove;       /**< Virtual device remove function. */
+	rte_vdev_dma_map_t *dma_map;     /**< Virtual device DMA map function. */
+	rte_vdev_dma_unmap_t *dma_unmap; /**< Virtual device DMA unmap function. */
 };
 
 /**
diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index d746149a2e..0e94ea9d26 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -134,6 +134,56 @@ vdev_parse(const char *name, void *addr)
 	return driver == NULL;
 }
 
+static int
+vdev_dma_map(struct rte_device *dev, void *addr, uint64_t iova, size_t len)
+{
+	struct rte_vdev_device *vdev = RTE_DEV_TO_VDEV(dev);
+	const struct rte_vdev_driver *driver;
+
+	if (!vdev) {
+		rte_errno = EINVAL;
+		return -1;
+	}
+
+	if (!vdev->device.driver) {
+		VDEV_LOG(DEBUG, "no driver attach to device %s", dev->name);
+		return 1;
+	}
+
+	driver = container_of(vdev->device.driver, const struct rte_vdev_driver,
+			driver);
+
+	if (driver->dma_map)
+		return driver->dma_map(vdev, addr, iova, len);
+
+	return 0;
+}
+
+static int
+vdev_dma_unmap(struct rte_device *dev, void *addr, uint64_t iova, size_t len)
+{
+	struct rte_vdev_device *vdev = RTE_DEV_TO_VDEV(dev);
+	const struct rte_vdev_driver *driver;
+
+	if (!vdev) {
+		rte_errno = EINVAL;
+		return -1;
+	}
+
+	if (!vdev->device.driver) {
+		VDEV_LOG(DEBUG, "no driver attach to device %s", dev->name);
+		return 1;
+	}
+
+	driver = container_of(vdev->device.driver, const struct rte_vdev_driver,
+			driver);
+
+	if (driver->dma_unmap)
+		return driver->dma_unmap(vdev, addr, iova, len);
+
+	return 0;
+}
+
 static int
 vdev_probe_all_drivers(struct rte_vdev_device *dev)
 {
@@ -551,6 +601,8 @@ static struct rte_bus rte_vdev_bus = {
 	.plug = vdev_plug,
 	.unplug = vdev_unplug,
 	.parse = vdev_parse,
+	.dma_map = vdev_dma_map,
+	.dma_unmap = vdev_dma_unmap,
 	.dev_iterate = rte_vdev_dev_iterate,
 };
 
-- 
2.26.2