[dpdk-dev] [PATCH 4/8] dma/ioat: add configuration functions

[Conor Walsh <conor.walsh@intel.com>]

Add functions for device configuration. The info_get and close functions
are included here also. info_get can be useful for checking successful
configuration and close is used by the dmadev api when releasing a
configured device.

Signed-off-by: Conor Walsh <conor.walsh@intel.com>
---
 doc/guides/dmadevs/ioat.rst    | 24 ++++++++++
 drivers/dma/ioat/ioat_dmadev.c | 80 ++++++++++++++++++++++++++++++++++
 2 files changed, 104 insertions(+)

diff --git a/doc/guides/dmadevs/ioat.rst b/doc/guides/dmadevs/ioat.rst
index 45a2e65d70..b6d88fe966 100644
--- a/doc/guides/dmadevs/ioat.rst
+++ b/doc/guides/dmadevs/ioat.rst
@@ -62,3 +62,27 @@ For example::
 Once probed successfully, 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.
+
+Device Configuration
+~~~~~~~~~~~~~~~~~~~~~
+
+Configuring an IOAT dmadev device is done using the ``rte_dmadev_configure()``
+and ``rte_dmadev_vchan_setup()`` APIs. ``rte_dmadev_configure()`` uses the structure
+``rte_dmadev_conf`` to configure an IOAT device, within this struct the number
+of virtual DMA channels for the device is set and silent mode can be enabled.
+Each IOAT device can only use 1 virtual DMA channel and silent mode is not
+supported so these will always be set to ``1`` and ``false``.
+``rte_dmadev_vchan_setup()`` uses the structure ``rte_dmadev_vchan_conf`` to setup
+a virtual DMA channel within this struct the transfer direction and ring size
+are set. Generally for an onboard Intel\ |reg| IOAT device the transfer direction
+will be set to ``RTE_DMA_DIR_MEM_TO_MEM`` to copy from memory to memory (more info
+available in the dmadev API guide). The ring size must be a power of two, between
+64 and 4096.
+
+The following code shows how the device is configured in ``test_dmadev.c``:
+
+.. literalinclude:: ../../../app/test/test_dmadev.c
+   :language: c
+   :start-after: Setup of the dmadev device. 8<
+   :end-before: >8 End of setup of the dmadev device.
+   :dedent: 1
diff --git a/drivers/dma/ioat/ioat_dmadev.c b/drivers/dma/ioat/ioat_dmadev.c
index c4d7ad4236..db862b72c0 100644
--- a/drivers/dma/ioat/ioat_dmadev.c
+++ b/drivers/dma/ioat/ioat_dmadev.c
@@ -12,9 +12,85 @@ static struct rte_pci_driver ioat_pmd_drv;
 
 RTE_LOG_REGISTER_DEFAULT(ioat_pmd_logtype, INFO);
 
+#define DESC_SZ sizeof(struct ioat_dma_hw_desc)
+
 #define IOAT_PMD_NAME dmadev_ioat
 #define IOAT_PMD_NAME_STR RTE_STR(IOAT_PMD_NAME)
 
+/* Configure a device. */
+static int
+ioat_dev_configure(struct rte_dmadev *dev __rte_unused, const struct rte_dmadev_conf *dev_conf)
+{
+	if (dev_conf->nb_vchans != 1)
+		return -EINVAL;
+	return 0;
+}
+
+/* Setup a virtual channel for IOAT, only 1 vchan is supported. */
+static int
+ioat_vchan_setup(struct rte_dmadev *dev, uint16_t vchan __rte_unused,
+		const struct rte_dmadev_vchan_conf *qconf)
+{
+	struct ioat_dmadev *ioat = dev->dev_private;
+	uint16_t max_desc = qconf->nb_desc;
+	int i;
+
+	ioat->qcfg = *qconf;
+
+	if (!rte_is_power_of_2(max_desc)) {
+		max_desc = rte_align32pow2(max_desc);
+		IOAT_PMD_DEBUG("DMA dev %u using %u descriptors", dev->data->dev_id, max_desc);
+		ioat->qcfg.nb_desc = max_desc;
+	}
+
+	/* In case we are reconfiguring a device, free any existing memory. */
+	rte_free(ioat->desc_ring);
+
+	ioat->desc_ring = rte_zmalloc(NULL, sizeof(*ioat->desc_ring) * max_desc, 0);
+	if (ioat->desc_ring == NULL)
+		return -ENOMEM;
+
+	ioat->ring_addr = rte_mem_virt2iova(ioat->desc_ring);
+
+	ioat->status_addr = rte_mem_virt2iova(ioat) + offsetof(struct ioat_dmadev, status);
+
+	ioat->offset = 0;
+
+	/* Configure descriptor ring - each one points to next. */
+	for (i = 0; i < ioat->qcfg.nb_desc; i++) {
+		ioat->desc_ring[i].next = ioat->ring_addr +
+				(((i + 1) % ioat->qcfg.nb_desc) * DESC_SZ);
+	}
+
+	return 0;
+}
+
+/* Get device information of a device. */
+static int
+ioat_dev_info_get(const struct rte_dmadev *dev, struct rte_dmadev_info *info, uint32_t size)
+{
+	struct ioat_dmadev *ioat = dev->dev_private;
+
+	if (size < sizeof(*info))
+		return -EINVAL;
+	info->device = dev->device;
+	info->dev_capa = RTE_DMADEV_CAPA_MEM_TO_MEM |
+			RTE_DMADEV_CAPA_OPS_COPY | RTE_DMADEV_CAPA_OPS_FILL,
+	info->max_vchans = 1;
+	info->min_desc = 32;
+	info->max_desc = 4096;
+	info->nb_vchans = (ioat->desc_ring == NULL);
+	return 0;
+}
+
+/* Close a configured device. */
+static int
+ioat_dev_close(struct rte_dmadev *dev)
+{
+	RTE_SET_USED(dev);
+	return 0;
+}
+
 /* Dump DMA device info. */
 static int
 ioat_dev_dump(const struct rte_dmadev *dev, FILE *f)
@@ -77,7 +153,11 @@ static int
 ioat_dmadev_create(const char *name, struct rte_pci_device *dev)
 {
 	static const struct rte_dmadev_ops ioat_dmadev_ops = {
+		.dev_close = ioat_dev_close,
+		.dev_configure = ioat_dev_configure,
 		.dev_dump = ioat_dev_dump,
+		.dev_info_get = ioat_dev_info_get,
+		.vchan_setup = ioat_vchan_setup,
 	};
 
 	struct rte_dmadev *dmadev = NULL;
-- 
2.25.1