From: Kevin Laatz <kevin.laatz@intel.com>
Date: Wed, 20 Oct 2021 16:30:10 +0000 (+0000)
Subject: dma/idxd: add burst capacity
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=9459de4edc992b149c91f4d1b21b802b254747fa;p=dpdk.git

dma/idxd: add burst capacity

Add support for the burst capacity API. This API will provide the calling
application with the remaining capacity of the current burst (limited by
max HW batch size).

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

diff --git a/drivers/dma/idxd/idxd_common.c b/drivers/dma/idxd/idxd_common.c
index 5ba0b69e12..fc11b11337 100644
--- a/drivers/dma/idxd/idxd_common.c
+++ b/drivers/dma/idxd/idxd_common.c
@@ -468,6 +468,26 @@ idxd_info_get(const struct rte_dma_dev *dev, struct rte_dma_info *info, uint32_t
 	return 0;
 }
 
+uint16_t
+idxd_burst_capacity(const void *dev_private, uint16_t vchan __rte_unused)
+{
+	const struct idxd_dmadev *idxd = dev_private;
+	uint16_t write_idx = idxd->batch_start + idxd->batch_size;
+	uint16_t used_space;
+
+	/* Check for space in the batch ring */
+	if ((idxd->batch_idx_read == 0 && idxd->batch_idx_write == idxd->max_batches) ||
+			idxd->batch_idx_write + 1 == idxd->batch_idx_read)
+		return 0;
+
+	/* For descriptors, check for wrap-around on write but not read */
+	if (idxd->ids_returned > write_idx)
+		write_idx += idxd->desc_ring_mask + 1;
+	used_space = write_idx - idxd->ids_returned;
+
+	return RTE_MIN((idxd->desc_ring_mask - used_space), idxd->max_batch_size);
+}
+
 int
 idxd_configure(struct rte_dma_dev *dev __rte_unused, const struct rte_dma_conf *dev_conf,
 		uint32_t conf_sz)
@@ -553,6 +573,7 @@ idxd_dmadev_create(const char *name, struct rte_device *dev,
 	dmadev->fp_obj->submit = idxd_submit;
 	dmadev->fp_obj->completed = idxd_completed;
 	dmadev->fp_obj->completed_status = idxd_completed_status;
+	dmadev->fp_obj->burst_capacity = idxd_burst_capacity;
 
 	idxd = dmadev->data->dev_private;
 	*idxd = *base_idxd; /* copy over the main fields already passed in */
diff --git a/drivers/dma/idxd/idxd_internal.h b/drivers/dma/idxd/idxd_internal.h
index 50acb82d3d..3375600217 100644
--- a/drivers/dma/idxd/idxd_internal.h
+++ b/drivers/dma/idxd/idxd_internal.h
@@ -104,5 +104,6 @@ int idxd_stats_get(const struct rte_dma_dev *dev, uint16_t vchan,
 int idxd_stats_reset(struct rte_dma_dev *dev, uint16_t vchan);
 int idxd_vchan_status(const struct rte_dma_dev *dev, uint16_t vchan,
 		enum rte_dma_vchan_status *status);
+uint16_t idxd_burst_capacity(const void *dev_private, uint16_t vchan);
 
 #endif /* _IDXD_INTERNAL_H_ */
diff --git a/drivers/dma/idxd/idxd_pci.c b/drivers/dma/idxd/idxd_pci.c
index 81952cfc40..1aabacee41 100644
--- a/drivers/dma/idxd/idxd_pci.c
+++ b/drivers/dma/idxd/idxd_pci.c
@@ -258,6 +258,7 @@ init_pci_device(struct rte_pci_device *dev, struct idxd_dmadev *idxd,
 
 	idxd->u.pci = pci;
 	idxd->max_batches = wq_size;
+	idxd->max_batch_size = 1 << lg2_max_batch;
 
 	/* enable the device itself */
 	err_code = idxd_pci_dev_command(idxd, idxd_enable_dev);