[PATCH v7 16/16] dma/dpaa: add SG data validation and ERR050757 fix

[Hemant Agrawal]

From: Gagandeep Singh <g.singh at nxp.com>

Add scatter-gather (SG) support to the QDMA driver, enabled by default
via the s_sg_enable flag. Add optional data validation mode controlled
by the s_data_validation flag for debugging transfer correctness.

Add a workaround for hardware errata ERR050757: when
RTE_DMA_DPAA_ERRATA_ERR050757 is defined, configure the source frame
descriptor with stride settings (sss/ssd = FSL_QDMA_CMD_SS_ERR050757_LEN)
to force PCI read transactions to stay within the errata-safe length
limit, preventing data corruption on affected silicon.

Signed-off-by: Gagandeep Singh <g.singh at nxp.com>
---
 drivers/dma/dpaa/dpaa_qdma.c | 73 ++++++++++++++++++++++++------------
 1 file changed, 49 insertions(+), 24 deletions(-)

diff --git a/drivers/dma/dpaa/dpaa_qdma.c b/drivers/dma/dpaa/dpaa_qdma.c
index 6a4022c652..14ab102a90 100644
--- a/drivers/dma/dpaa/dpaa_qdma.c
+++ b/drivers/dma/dpaa/dpaa_qdma.c
@@ -17,7 +17,6 @@ static uint32_t s_sg_max_entry_sz = 2000;
 #ifdef RTE_DMA_DPAA_ERRATA_ERR050757
 static int s_pci_read = 1;
 #endif
-
 #define DPAA_DMA_ERROR_CHECK "dpaa_dma_err_check"
 
 static inline void
@@ -118,7 +117,8 @@ dma_pool_alloc(char *nm, int size, int aligned, dma_addr_t *phy_addr)
 	if (!virt_addr)
 		return NULL;
 
-	*phy_addr = rte_mem_virt2iova(virt_addr);
+	if (phy_addr)
+		*phy_addr = rte_mem_virt2iova(virt_addr);
 
 	return virt_addr;
 }
@@ -398,6 +398,8 @@ fsl_qdma_data_validation(struct fsl_qdma_desc *desc[],
 	char err_msg[512];
 	int offset;
 
+	if (likely(!s_data_validation))
+		return;
 
 	offset = sprintf(err_msg, "Fatal TC%d/queue%d: ",
 		fsl_queue->block_id,
@@ -722,19 +724,21 @@ fsl_qdma_enqueue_desc_single(struct fsl_qdma_queue *fsl_queue,
 	ft = fsl_queue->ft[fsl_queue->ci];
 
 #ifdef RTE_DMA_DPAA_ERRATA_ERR050757
-	sdf = &ft->df.sdf;
-	sdf->srttype = FSL_QDMA_CMD_RWTTYPE;
+	if (s_pci_read) {
+		sdf = &ft->df.sdf;
+		sdf->srttype = FSL_QDMA_CMD_RWTTYPE;
 #ifdef RTE_DMA_DPAA_ERRATA_ERR050265
-	sdf->prefetch = 1;
+		sdf->prefetch = 1;
 #endif
-	if (len > FSL_QDMA_CMD_SS_ERR050757_LEN) {
-		sdf->ssen = 1;
-		sdf->sss = FSL_QDMA_CMD_SS_ERR050757_LEN;
-		sdf->ssd = FSL_QDMA_CMD_SS_ERR050757_LEN;
-	} else {
-		sdf->ssen = 0;
-		sdf->sss = 0;
-		sdf->ssd = 0;
+		if (len > FSL_QDMA_CMD_SS_ERR050757_LEN) {
+			sdf->ssen = 1;
+			sdf->sss = FSL_QDMA_CMD_SS_ERR050757_LEN;
+			sdf->ssd = FSL_QDMA_CMD_SS_ERR050757_LEN;
+		} else {
+			sdf->ssen = 0;
+			sdf->sss = 0;
+			sdf->ssd = 0;
+		}
 	}
 #endif
 	csgf_src = &ft->desc_sbuf;
@@ -838,19 +842,21 @@ fsl_qdma_enqueue_desc_sg(struct fsl_qdma_queue *fsl_queue)
 	csgf_src->length = total_len;
 	csgf_dest->length = total_len;
 #ifdef RTE_DMA_DPAA_ERRATA_ERR050757
-	sdf = &ft->df.sdf;
-	sdf->srttype = FSL_QDMA_CMD_RWTTYPE;
+	if (s_pci_read) {
+		sdf = &ft->df.sdf;
+		sdf->srttype = FSL_QDMA_CMD_RWTTYPE;
 #ifdef RTE_DMA_DPAA_ERRATA_ERR050265
-	sdf->prefetch = 1;
+		sdf->prefetch = 1;
 #endif
-	if (total_len > FSL_QDMA_CMD_SS_ERR050757_LEN) {
-		sdf->ssen = 1;
-		sdf->sss = FSL_QDMA_CMD_SS_ERR050757_LEN;
-		sdf->ssd = FSL_QDMA_CMD_SS_ERR050757_LEN;
-	} else {
-		sdf->ssen = 0;
-		sdf->sss = 0;
-		sdf->ssd = 0;
+		if (total_len > FSL_QDMA_CMD_SS_ERR050757_LEN) {
+			sdf->ssen = 1;
+			sdf->sss = FSL_QDMA_CMD_SS_ERR050757_LEN;
+			sdf->ssd = FSL_QDMA_CMD_SS_ERR050757_LEN;
+		} else {
+			sdf->ssen = 0;
+			sdf->sss = 0;
+			sdf->ssd = 0;
+		}
 	}
 #endif
 	ret = fsl_qdma_enqueue_desc_to_ring(fsl_queue, num);
@@ -889,6 +895,25 @@ fsl_qdma_enqueue_desc(struct fsl_qdma_queue *fsl_queue)
 			fsl_queue->pending_num = 0;
 		}
 		return ret;
+	} else if (!s_sg_enable) {
+		while (fsl_queue->pending_num > 0) {
+			ret = fsl_qdma_enqueue_desc_single(fsl_queue,
+				fsl_queue->pending_desc[start].dst,
+				fsl_queue->pending_desc[start].src,
+				fsl_queue->pending_desc[start].len);
+			if (!ret) {
+				start = (start + 1) &
+					(fsl_queue->pending_max - 1);
+				fsl_queue->pending_start = start;
+				fsl_queue->pending_num--;
+			} else {
+				DPAA_QDMA_ERR("Eq pending desc failed(%d)",
+					ret);
+				return -EIO;
+			}
+		}
+
+		return 0;
 	}
 
 	return fsl_qdma_enqueue_desc_sg(fsl_queue);
-- 
2.25.1