dmaengine: ti: k3-udma: Fix smatch warnings

Smatch reports below warnings [1] wrt dereferencing rm_res when it can
potentially be ERR_PTR(). This is possible when entire range is
allocated to Linux
Fix this case by making sure, there is no deference of rm_res when its
ERR_PTR().

[1]:
 drivers/dma/ti/k3-udma.c:4524 udma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
 drivers/dma/ti/k3-udma.c:4537 udma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
 drivers/dma/ti/k3-udma.c:4681 bcdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
 drivers/dma/ti/k3-udma.c:4696 bcdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
 drivers/dma/ti/k3-udma.c:4711 bcdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
 drivers/dma/ti/k3-udma.c:4848 pktdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()
 drivers/dma/ti/k3-udma.c:4861 pktdma_setup_resources() error: 'rm_res' dereferencing possible ERR_PTR()

Reported-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20211209180957.29036-1-vigneshr@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 107 insertions, 50 deletions

diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
index 041d8e32d630..6e56d1cef5ee 100644
--- a/drivers/dma/ti/k3-udma.c
+++ b/drivers/dma/ti/k3-udma.c
@@ -4534,45 +4534,60 @@ static int udma_setup_resources(struct udma_dev *ud)
 	rm_res = tisci_rm->rm_ranges[RM_RANGE_TCHAN];
 	if (IS_ERR(rm_res)) {
 		bitmap_zero(ud->tchan_map, ud->tchan_cnt);
+		irq_res.sets = 1;
 	} else {
 		bitmap_fill(ud->tchan_map, ud->tchan_cnt);
 		for (i = 0; i < rm_res->sets; i++)
 			udma_mark_resource_ranges(ud, ud->tchan_map,
 						  &rm_res->desc[i], "tchan");
+		irq_res.sets = rm_res->sets;
 	}
-	irq_res.sets = rm_res->sets;
 
 	/* rchan and matching default flow ranges */
 	rm_res = tisci_rm->rm_ranges[RM_RANGE_RCHAN];
 	if (IS_ERR(rm_res)) {
 		bitmap_zero(ud->rchan_map, ud->rchan_cnt);
+		irq_res.sets++;
 	} else {
 		bitmap_fill(ud->rchan_map, ud->rchan_cnt);
 		for (i = 0; i < rm_res->sets; i++)
 			udma_mark_resource_ranges(ud, ud->rchan_map,
 						  &rm_res->desc[i], "rchan");
+		irq_res.sets += rm_res->sets;
 	}
 
-	irq_res.sets += rm_res->sets;
 	irq_res.desc = kcalloc(irq_res.sets, sizeof(*irq_res.desc), GFP_KERNEL);
+	if (!irq_res.desc)
+		return -ENOMEM;
 	rm_res = tisci_rm->rm_ranges[RM_RANGE_TCHAN];
-	for (i = 0; i < rm_res->sets; i++) {
-		irq_res.desc[i].start = rm_res->desc[i].start;
-		irq_res.desc[i].num = rm_res->desc[i].num;
-		irq_res.desc[i].start_sec = rm_res->desc[i].start_sec;
-		irq_res.desc[i].num_sec = rm_res->desc[i].num_sec;
+	if (IS_ERR(rm_res)) {
+		irq_res.desc[0].start = 0;
+		irq_res.desc[0].num = ud->tchan_cnt;
+		i = 1;
+	} else {
+		for (i = 0; i < rm_res->sets; i++) {
+			irq_res.desc[i].start = rm_res->desc[i].start;
+			irq_res.desc[i].num = rm_res->desc[i].num;
+			irq_res.desc[i].start_sec = rm_res->desc[i].start_sec;
+			irq_res.desc[i].num_sec = rm_res->desc[i].num_sec;
+		}
 	}
 	rm_res = tisci_rm->rm_ranges[RM_RANGE_RCHAN];
-	for (j = 0; j < rm_res->sets; j++, i++) {
-		if (rm_res->desc[j].num) {
-			irq_res.desc[i].start = rm_res->desc[j].start +
-					ud->soc_data->oes.udma_rchan;
-			irq_res.desc[i].num = rm_res->desc[j].num;
-		}
-		if (rm_res->desc[j].num_sec) {
-			irq_res.desc[i].start_sec = rm_res->desc[j].start_sec +
-					ud->soc_data->oes.udma_rchan;
-			irq_res.desc[i].num_sec = rm_res->desc[j].num_sec;
+	if (IS_ERR(rm_res)) {
+		irq_res.desc[i].start = 0;
+		irq_res.desc[i].num = ud->rchan_cnt;
+	} else {
+		for (j = 0; j < rm_res->sets; j++, i++) {
+			if (rm_res->desc[j].num) {
+				irq_res.desc[i].start = rm_res->desc[j].start +
+						ud->soc_data->oes.udma_rchan;
+				irq_res.desc[i].num = rm_res->desc[j].num;
+			}
+			if (rm_res->desc[j].num_sec) {
+				irq_res.desc[i].start_sec = rm_res->desc[j].start_sec +
+						ud->soc_data->oes.udma_rchan;
+				irq_res.desc[i].num_sec = rm_res->desc[j].num_sec;
+			}
 		}
 	}
 	ret = ti_sci_inta_msi_domain_alloc_irqs(ud->dev, &irq_res);
@@ -4690,14 +4705,15 @@ static int bcdma_setup_resources(struct udma_dev *ud)
 		rm_res = tisci_rm->rm_ranges[RM_RANGE_BCHAN];
 		if (IS_ERR(rm_res)) {
 			bitmap_zero(ud->bchan_map, ud->bchan_cnt);
+			irq_res.sets++;
 		} else {
 			bitmap_fill(ud->bchan_map, ud->bchan_cnt);
 			for (i = 0; i < rm_res->sets; i++)
 				udma_mark_resource_ranges(ud, ud->bchan_map,
 							  &rm_res->desc[i],
 							  "bchan");
+			irq_res.sets += rm_res->sets;
 		}
-		irq_res.sets += rm_res->sets;
 	}
 
 	/* tchan ranges */
@@ -4705,14 +4721,15 @@ static int bcdma_setup_resources(struct udma_dev *ud)
 		rm_res = tisci_rm->rm_ranges[RM_RANGE_TCHAN];
 		if (IS_ERR(rm_res)) {
 			bitmap_zero(ud->tchan_map, ud->tchan_cnt);
+			irq_res.sets += 2;
 		} else {
 			bitmap_fill(ud->tchan_map, ud->tchan_cnt);
 			for (i = 0; i < rm_res->sets; i++)
 				udma_mark_resource_ranges(ud, ud->tchan_map,
 							  &rm_res->desc[i],
 							  "tchan");
+			irq_res.sets += rm_res->sets * 2;
 		}
-		irq_res.sets += rm_res->sets * 2;
 	}
 
 	/* rchan ranges */
@@ -4720,47 +4737,72 @@ static int bcdma_setup_resources(struct udma_dev *ud)
 		rm_res = tisci_rm->rm_ranges[RM_RANGE_RCHAN];
 		if (IS_ERR(rm_res)) {
 			bitmap_zero(ud->rchan_map, ud->rchan_cnt);
+			irq_res.sets += 2;
 		} else {
 			bitmap_fill(ud->rchan_map, ud->rchan_cnt);
 			for (i = 0; i < rm_res->sets; i++)
 				udma_mark_resource_ranges(ud, ud->rchan_map,
 							  &rm_res->desc[i],
 							  "rchan");
+			irq_res.sets += rm_res->sets * 2;
 		}
-		irq_res.sets += rm_res->sets * 2;
 	}
 
 	irq_res.desc = kcalloc(irq_res.sets, sizeof(*irq_res.desc), GFP_KERNEL);
+	if (!irq_res.desc)
+		return -ENOMEM;
 	if (ud->bchan_cnt) {
 		rm_res = tisci_rm->rm_ranges[RM_RANGE_BCHAN];
-		for (i = 0; i < rm_res->sets; i++) {
-			irq_res.desc[i].start = rm_res->desc[i].start +
-						oes->bcdma_bchan_ring;
-			irq_res.desc[i].num = rm_res->desc[i].num;
+		if (IS_ERR(rm_res)) {
+			irq_res.desc[0].start = oes->bcdma_bchan_ring;
+			irq_res.desc[0].num = ud->bchan_cnt;
+			i = 1;
+		} else {
+			for (i = 0; i < rm_res->sets; i++) {
+				irq_res.desc[i].start = rm_res->desc[i].start +
+							oes->bcdma_bchan_ring;
+				irq_res.desc[i].num = rm_res->desc[i].num;
+			}
 		}
 	}
 	if (ud->tchan_cnt) {
 		rm_res = tisci_rm->rm_ranges[RM_RANGE_TCHAN];
-		for (j = 0; j < rm_res->sets; j++, i += 2) {
-			irq_res.desc[i].start = rm_res->desc[j].start +
-						oes->bcdma_tchan_data;
-			irq_res.desc[i].num = rm_res->desc[j].num;
-
-			irq_res.desc[i + 1].start = rm_res->desc[j].start +
-						oes->bcdma_tchan_ring;
-			irq_res.desc[i + 1].num = rm_res->desc[j].num;
+		if (IS_ERR(rm_res)) {
+			irq_res.desc[i].start = oes->bcdma_tchan_data;
+			irq_res.desc[i].num = ud->tchan_cnt;
+			irq_res.desc[i + 1].start = oes->bcdma_tchan_ring;
+			irq_res.desc[i + 1].num = ud->tchan_cnt;
+			i += 2;
+		} else {
+			for (j = 0; j < rm_res->sets; j++, i += 2) {
+				irq_res.desc[i].start = rm_res->desc[j].start +
+							oes->bcdma_tchan_data;
+				irq_res.desc[i].num = rm_res->desc[j].num;
+
+				irq_res.desc[i + 1].start = rm_res->desc[j].start +
+							oes->bcdma_tchan_ring;
+				irq_res.desc[i + 1].num = rm_res->desc[j].num;
+			}
 		}
 	}
 	if (ud->rchan_cnt) {
 		rm_res = tisci_rm->rm_ranges[RM_RANGE_RCHAN];
-		for (j = 0; j < rm_res->sets; j++, i += 2) {
-			irq_res.desc[i].start = rm_res->desc[j].start +
-						oes->bcdma_rchan_data;
-			irq_res.desc[i].num = rm_res->desc[j].num;
-
-			irq_res.desc[i + 1].start = rm_res->desc[j].start +
-						oes->bcdma_rchan_ring;
-			irq_res.desc[i + 1].num = rm_res->desc[j].num;
+		if (IS_ERR(rm_res)) {
+			irq_res.desc[i].start = oes->bcdma_rchan_data;
+			irq_res.desc[i].num = ud->rchan_cnt;
+			irq_res.desc[i + 1].start = oes->bcdma_rchan_ring;
+			irq_res.desc[i + 1].num = ud->rchan_cnt;
+			i += 2;
+		} else {
+			for (j = 0; j < rm_res->sets; j++, i += 2) {
+				irq_res.desc[i].start = rm_res->desc[j].start +
+							oes->bcdma_rchan_data;
+				irq_res.desc[i].num = rm_res->desc[j].num;
+
+				irq_res.desc[i + 1].start = rm_res->desc[j].start +
+							oes->bcdma_rchan_ring;
+				irq_res.desc[i + 1].num = rm_res->desc[j].num;
+			}
 		}
 	}
 
@@ -4858,39 +4900,54 @@ static int pktdma_setup_resources(struct udma_dev *ud)
 	if (IS_ERR(rm_res)) {
 		/* all rflows are assigned exclusively to Linux */
 		bitmap_zero(ud->rflow_in_use, ud->rflow_cnt);
+		irq_res.sets = 1;
 	} else {
 		bitmap_fill(ud->rflow_in_use, ud->rflow_cnt);
 		for (i = 0; i < rm_res->sets; i++)
 			udma_mark_resource_ranges(ud, ud->rflow_in_use,
 						  &rm_res->desc[i], "rflow");
+		irq_res.sets = rm_res->sets;
 	}
-	irq_res.sets = rm_res->sets;
 
 	/* tflow ranges */
 	rm_res = tisci_rm->rm_ranges[RM_RANGE_TFLOW];
 	if (IS_ERR(rm_res)) {
 		/* all tflows are assigned exclusively to Linux */
 		bitmap_zero(ud->tflow_map, ud->tflow_cnt);
+		irq_res.sets++;
 	} else {
 		bitmap_fill(ud->tflow_map, ud->tflow_cnt);
 		for (i = 0; i < rm_res->sets; i++)
 			udma_mark_resource_ranges(ud, ud->tflow_map,
 						  &rm_res->desc[i], "tflow");
+		irq_res.sets += rm_res->sets;
 	}
-	irq_res.sets += rm_res->sets;
 
 	irq_res.desc = kcalloc(irq_res.sets, sizeof(*irq_res.desc), GFP_KERNEL);
+	if (!irq_res.desc)
+		return -ENOMEM;
 	rm_res = tisci_rm->rm_ranges[RM_RANGE_TFLOW];
-	for (i = 0; i < rm_res->sets; i++) {
-		irq_res.desc[i].start = rm_res->desc[i].start +
-					oes->pktdma_tchan_flow;
-		irq_res.desc[i].num = rm_res->desc[i].num;
+	if (IS_ERR(rm_res)) {
+		irq_res.desc[0].start = oes->pktdma_tchan_flow;
+		irq_res.desc[0].num = ud->tflow_cnt;
+		i = 1;
+	} else {
+		for (i = 0; i < rm_res->sets; i++) {
+			irq_res.desc[i].start = rm_res->desc[i].start +
+						oes->pktdma_tchan_flow;
+			irq_res.desc[i].num = rm_res->desc[i].num;
+		}
 	}
 	rm_res = tisci_rm->rm_ranges[RM_RANGE_RFLOW];
-	for (j = 0; j < rm_res->sets; j++, i++) {
-		irq_res.desc[i].start = rm_res->desc[j].start +
-					oes->pktdma_rchan_flow;
-		irq_res.desc[i].num = rm_res->desc[j].num;
+	if (IS_ERR(rm_res)) {
+		irq_res.desc[i].start = oes->pktdma_rchan_flow;
+		irq_res.desc[i].num = ud->rflow_cnt;
+	} else {
+		for (j = 0; j < rm_res->sets; j++, i++) {
+			irq_res.desc[i].start = rm_res->desc[j].start +
+						oes->pktdma_rchan_flow;
+			irq_res.desc[i].num = rm_res->desc[j].num;
+		}
 	}
 	ret = ti_sci_inta_msi_domain_alloc_irqs(ud->dev, &irq_res);
 	kfree(irq_res.desc);