dma/ioat: add start and stop

Add start, stop and recover functions for IOAT devices.

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

diff --git a/doc/guides/dmadevs/ioat.rst b/doc/guides/dmadevs/ioat.rst
index af69556..df159f9 100644 (file)
--- a/doc/guides/dmadevs/ioat.rst
+++ b/doc/guides/dmadevs/ioat.rst
@@ -82,3 +82,6 @@ IOAT configuration requirements:
 * Only one ``vchan`` is supported per device.
 * Silent mode is not supported.
 * The transfer direction must be set to ``RTE_DMA_DIR_MEM_TO_MEM`` to copy from memory to memory.
+
+Once configured, the device can then be made ready for use by calling the
+``rte_dma_start()`` API.

diff --git a/drivers/dma/ioat/ioat_dmadev.c b/drivers/dma/ioat/ioat_dmadev.c
index ada57c5..cf28f4a 100644 (file)
--- a/drivers/dma/ioat/ioat_dmadev.c
+++ b/drivers/dma/ioat/ioat_dmadev.c
@@ -78,6 +78,96 @@ ioat_vchan_setup(struct rte_dma_dev *dev, uint16_t vchan __rte_unused,
        return 0;
 }
 
+/* Recover IOAT device. */
+static inline int
+__ioat_recover(struct ioat_dmadev *ioat)
+{
+       uint32_t chanerr, retry = 0;
+       uint16_t mask = ioat->qcfg.nb_desc - 1;
+
+       /* Clear any channel errors. Reading and writing to chanerr does this. */
+       chanerr = ioat->regs->chanerr;
+       ioat->regs->chanerr = chanerr;
+
+       /* Reset Channel. */
+       ioat->regs->chancmd = IOAT_CHANCMD_RESET;
+
+       /* Write new chain address to trigger state change. */
+       ioat->regs->chainaddr = ioat->desc_ring[(ioat->next_read - 1) & mask].next;
+       /* Ensure channel control and status addr are correct. */
+       ioat->regs->chanctrl = IOAT_CHANCTRL_ANY_ERR_ABORT_EN |
+                       IOAT_CHANCTRL_ERR_COMPLETION_EN;
+       ioat->regs->chancmp = ioat->status_addr;
+
+       /* Allow HW time to move to the ARMED state. */
+       do {
+               rte_pause();
+               retry++;
+       } while (ioat->regs->chansts != IOAT_CHANSTS_ARMED && retry < 200);
+
+       /* Exit as failure if device is still HALTED. */
+       if (ioat->regs->chansts != IOAT_CHANSTS_ARMED)
+               return -1;
+
+       /* Store next write as offset as recover will move HW and SW ring out of sync. */
+       ioat->offset = ioat->next_read;
+
+       /* Prime status register with previous address. */
+       ioat->status = ioat->desc_ring[(ioat->next_read - 2) & mask].next;
+
+       return 0;
+}
+
+/* Start a configured device. */
+static int
+ioat_dev_start(struct rte_dma_dev *dev)
+{
+       struct ioat_dmadev *ioat = dev->fp_obj->dev_private;
+
+       if (ioat->qcfg.nb_desc == 0 || ioat->desc_ring == NULL)
+               return -EBUSY;
+
+       /* Inform hardware of where the descriptor ring is. */
+       ioat->regs->chainaddr = ioat->ring_addr;
+       /* Inform hardware of where to write the status/completions. */
+       ioat->regs->chancmp = ioat->status_addr;
+
+       /* Prime the status register to be set to the last element. */
+       ioat->status = ioat->ring_addr + ((ioat->qcfg.nb_desc - 1) * DESC_SZ);
+
+       printf("IOAT.status: %s [0x%"PRIx64"]\n",
+                       chansts_readable[ioat->status & IOAT_CHANSTS_STATUS],
+                       ioat->status);
+
+       if ((ioat->regs->chansts & IOAT_CHANSTS_STATUS) == IOAT_CHANSTS_HALTED) {
+               IOAT_PMD_WARN("Device HALTED on start, attempting to recover\n");
+               if (__ioat_recover(ioat) != 0) {
+                       IOAT_PMD_ERR("Device couldn't be recovered");
+                       return -1;
+               }
+       }
+
+       return 0;
+}
+
+/* Stop a configured device. */
+static int
+ioat_dev_stop(struct rte_dma_dev *dev)
+{
+       struct ioat_dmadev *ioat = dev->fp_obj->dev_private;
+       uint32_t retry = 0;
+
+       ioat->regs->chancmd = IOAT_CHANCMD_SUSPEND;
+
+       do {
+               rte_pause();
+               retry++;
+       } while ((ioat->regs->chansts & IOAT_CHANSTS_STATUS) != IOAT_CHANSTS_SUSPENDED
+                       && retry < 200);
+
+       return ((ioat->regs->chansts & IOAT_CHANSTS_STATUS) == IOAT_CHANSTS_SUSPENDED) ? 0 : -1;
+}
+
 /* Get device information of a device. */
 static int
 ioat_dev_info_get(const struct rte_dma_dev *dev, struct rte_dma_info *info, uint32_t size)
@@ -193,6 +283,8 @@ ioat_dmadev_create(const char *name, struct rte_pci_device *dev)
                .dev_configure = ioat_dev_configure,
                .dev_dump = ioat_dev_dump,
                .dev_info_get = ioat_dev_info_get,
+               .dev_start = ioat_dev_start,
+               .dev_stop = ioat_dev_stop,
                .vchan_setup = ioat_vchan_setup,
        };