[v2,04/10] dma/ioat: add configuration functions
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Commit Message
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 | 88 ++++++++++++++++++++++++++++++++++
2 files changed, 112 insertions(+)
Comments
On 03/09/2021 12:17, Conor Walsh wrote:
> 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 | 88 ++++++++++++++++++++++++++++++++++
> 2 files changed, 112 insertions(+)
>
Reviewed-by: Kevin Laatz <kevin.laatz@intel.com>
@@ -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
@@ -12,9 +12,93 @@ 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);
+
+ /* Ensure all counters are reset, if reconfiguring/restarting device. */
+ ioat->next_read = 0;
+ ioat->next_write = 0;
+ ioat->last_write = 0;
+ ioat->offset = 0;
+ ioat->failure = 0;
+
+ /* Reset Stats. */
+ memset(&ioat->stats, 0, sizeof(ioat->stats));
+
+ /* 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 +161,11 @@ 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;