dma/idxd: add configure and info

Add functions for device configuration. The info_get function is included
here since it can be useful for checking successful configuration.

Documentation is also updated to add device configuration usage info.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Reviewed-by: Conor Walsh <conor.walsh@intel.com>
Reviewed-by: Chengwen Feng <fengchengwen@huawei.com>

doc/guides/dmadevs/idxd.rst

@@ -120,3 +120,18 @@ use a subset of configured queues.
 Once probed successfully, irrespective of kernel driver, the device will appear as a ``dmadev``,
 that is a "DMA device type" inside DPDK, and can be accessed using APIs from the
 ``rte_dmadev`` library.
+
+Using IDXD DMAdev Devices
+--------------------------
+
+To use the devices from an application, the dmadev API can be used.
+
+Device Configuration
+~~~~~~~~~~~~~~~~~~~~~
+
+IDXD configuration requirements:
+
+* ``ring_size`` must be a power of two, between 64 and 4096.
+* Only one ``vchan`` is supported per device (work queue).
+* IDXD devices do not support silent mode.
+* The transfer direction must be set to ``RTE_DMA_DIR_MEM_TO_MEM`` to copy from memory to memory.

drivers/dma/idxd/idxd_bus.c

@@ -97,6 +97,9 @@ idxd_dev_close(struct rte_dma_dev *dev)
 static const struct rte_dma_dev_ops idxd_bus_ops = {
 		.dev_close = idxd_dev_close,
 		.dev_dump = idxd_dump,
+		.dev_configure = idxd_configure,
+		.vchan_setup = idxd_vchan_setup,
+		.dev_info_get = idxd_info_get,
 };
 
 static void *

drivers/dma/idxd/idxd_common.c

@@ -39,6 +39,77 @@ idxd_dump(const struct rte_dma_dev *dev, FILE *f)
 	return 0;
 }
 
+int
+idxd_info_get(const struct rte_dma_dev *dev, struct rte_dma_info *info, uint32_t size)
+{
+	struct idxd_dmadev *idxd = dev->fp_obj->dev_private;
+
+	if (size < sizeof(*info))
+		return -EINVAL;
+
+	*info = (struct rte_dma_info) {
+			.dev_capa = RTE_DMA_CAPA_MEM_TO_MEM | RTE_DMA_CAPA_HANDLES_ERRORS |
+				RTE_DMA_CAPA_OPS_COPY | RTE_DMA_CAPA_OPS_FILL,
+			.max_vchans = 1,
+			.max_desc = 4096,
+			.min_desc = 64,
+	};
+	if (idxd->sva_support)
+		info->dev_capa |= RTE_DMA_CAPA_SVA;
+	return 0;
+}
+
+int
+idxd_configure(struct rte_dma_dev *dev __rte_unused, const struct rte_dma_conf *dev_conf,
+		uint32_t conf_sz)
+{
+	if (sizeof(struct rte_dma_conf) != conf_sz)
+		return -EINVAL;
+
+	if (dev_conf->nb_vchans != 1)
+		return -EINVAL;
+	return 0;
+}
+
+int
+idxd_vchan_setup(struct rte_dma_dev *dev, uint16_t vchan __rte_unused,
+		const struct rte_dma_vchan_conf *qconf, uint32_t qconf_sz)
+{
+	struct idxd_dmadev *idxd = dev->fp_obj->dev_private;
+	uint16_t max_desc = qconf->nb_desc;
+
+	if (sizeof(struct rte_dma_vchan_conf) != qconf_sz)
+		return -EINVAL;
+
+	idxd->qcfg = *qconf;
+
+	if (!rte_is_power_of_2(max_desc))
+		max_desc = rte_align32pow2(max_desc);
+	IDXD_PMD_DEBUG("DMA dev %u using %u descriptors", dev->data->dev_id, max_desc);
+	idxd->desc_ring_mask = max_desc - 1;
+	idxd->qcfg.nb_desc = max_desc;
+
+	/* in case we are reconfiguring a device, free any existing memory */
+	rte_free(idxd->desc_ring);
+
+	/* allocate the descriptor ring at 2x size as batches can't wrap */
+	idxd->desc_ring = rte_zmalloc(NULL, sizeof(*idxd->desc_ring) * max_desc * 2, 0);
+	if (idxd->desc_ring == NULL)
+		return -ENOMEM;
+	idxd->desc_iova = rte_mem_virt2iova(idxd->desc_ring);
+
+	idxd->batch_idx_read = 0;
+	idxd->batch_idx_write = 0;
+	idxd->batch_start = 0;
+	idxd->batch_size = 0;
+	idxd->ids_returned = 0;
+	idxd->ids_avail = 0;
+
+	memset(idxd->batch_comp_ring, 0, sizeof(*idxd->batch_comp_ring) *
+			(idxd->max_batches + 1));
+	return 0;
+}
+
 int
 idxd_dmadev_create(const char *name, struct rte_device *dev,
 		   const struct idxd_dmadev *base_idxd,

drivers/dma/idxd/idxd_internal.h

@@ -81,5 +81,11 @@ struct idxd_dmadev {
 int idxd_dmadev_create(const char *name, struct rte_device *dev,
 		const struct idxd_dmadev *base_idxd, const struct rte_dma_dev_ops *ops);
 int idxd_dump(const struct rte_dma_dev *dev, FILE *f);
+int idxd_configure(struct rte_dma_dev *dev, const struct rte_dma_conf *dev_conf,
+		uint32_t conf_sz);
+int idxd_vchan_setup(struct rte_dma_dev *dev, uint16_t vchan,
+		const struct rte_dma_vchan_conf *qconf, uint32_t qconf_sz);
+int idxd_info_get(const struct rte_dma_dev *dev, struct rte_dma_info *dev_info,
+		uint32_t size);
 
 #endif /* _IDXD_INTERNAL_H_ */

drivers/dma/idxd/idxd_pci.c

@@ -85,6 +85,9 @@ idxd_pci_dev_close(struct rte_dma_dev *dev)
 static const struct rte_dma_dev_ops idxd_pci_ops = {
 	.dev_close = idxd_pci_dev_close,
 	.dev_dump = idxd_dump,
+	.dev_configure = idxd_configure,
+	.vchan_setup = idxd_vchan_setup,
+	.dev_info_get = idxd_info_get,
 };
 
 /* each portal uses 4 x 4k pages */