solos-pci: ensure all TX packets are aligned to 4 bytes

The FPGA can't handled unaligned DMA (yet). So copy into an aligned buffer, if skb->data isn't suitably aligned. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>

solos-pci: ensure all TX packets are aligned to 4 bytes
The FPGA can't handled unaligned DMA (yet). So copy into an aligned buffer, if skb->data isn't suitably aligned. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
David Woodhouse · David S. Miller
1 parent 13af816469
Showing 1 changed file with 23 additions and 4 deletions Side-by-side Diff
drivers/atm/solos-pci.c
@@ -128,9 +128,11 @@
 	struct sk_buff_head cli_queue[4];
 	struct sk_buff *tx_skb[4];
 	struct sk_buff *rx_skb[4];
+	unsigned char *dma_bounce;
 	wait_queue_head_t param_wq;
 	wait_queue_head_t fw_wq;
 	int using_dma;
+	int dma_alignment;
 	int fpga_version;
 	int buffer_size;
 	int atmel_flash;
@@ -1083,7 +1085,12 @@
 				tx_started |= 1 << port;
 				oldskb = skb; /* We're done with this skb already */
 			} else if (skb && card->using_dma) {
-				SKB_CB(skb)->dma_addr = pci_map_single(card->dev, skb->data,
+				unsigned char *data = skb->data;
+				if ((unsigned long)data & card->dma_alignment) {
+					data = card->dma_bounce + (BUF_SIZE * port);
+					memcpy(data, skb->data, skb->len);
+				}
+				SKB_CB(skb)->dma_addr = pci_map_single(card->dev, data,
 								       skb->len, PCI_DMA_TODEVICE);
 				card->tx_skb[port] = skb;
 				iowrite32(SKB_CB(skb)->dma_addr,
  
  
@@ -1261,18 +1268,27 @@
 	else
 		card->atmel_flash = 0;
  
+	data32 = ioread32(card->config_regs + PORTS);
+	card->nr_ports = (data32 & 0x000000FF);
+
 	if (card->fpga_version >= DMA_SUPPORTED) {
 		pci_set_master(dev);
 		card->using_dma = 1;
+		if (1) { /* All known FPGA versions so far */
+			card->dma_alignment = 3;
+			card->dma_bounce = kmalloc(card->nr_ports * BUF_SIZE, GFP_KERNEL);
+			if (!card->dma_bounce) {
+				dev_warn(&card->dev->dev, "Failed to allocate DMA bounce buffers\n");
+				/* Fallback to MMIO doesn't work */
+				goto out_unmap_both;
+			}
+		}
 	} else {
 		card->using_dma = 0;
 		/* Set RX empty flag for all ports */
 		iowrite32(0xF0, card->config_regs + FLAGS_ADDR);
 	}
  
-	data32 = ioread32(card->config_regs + PORTS);
-	card->nr_ports = (data32 & 0x000000FF);
-
 	pci_set_drvdata(dev, card);
  
 	tasklet_init(&card->tlet, solos_bh, (unsigned long)card);
@@ -1319,6 +1335,7 @@
 	tasklet_kill(&card->tlet);
  
  out_unmap_both:
+	kfree(card->dma_bounce);
 	pci_set_drvdata(dev, NULL);
 	pci_iounmap(dev, card->buffers);
  out_unmap_config:
@@ -1428,6 +1445,8 @@
  
 	free_irq(dev->irq, card);
 	tasklet_kill(&card->tlet);
+
+	kfree(card->dma_bounce);
  
 	/* Release device from reset */
 	iowrite32(0, card->config_regs + FPGA_MODE);
...	...	@@ -128,9 +128,11 @@
128	128	struct sk_buff_head cli_queue[4];
129	129	struct sk_buff *tx_skb[4];
130	130	struct sk_buff *rx_skb[4];
	131	+ unsigned char *dma_bounce;
131	132	wait_queue_head_t param_wq;
132	133	wait_queue_head_t fw_wq;
133	134	int using_dma;
	135	+ int dma_alignment;
134	136	int fpga_version;
135	137	int buffer_size;
136	138	int atmel_flash;
...	...	@@ -1083,7 +1085,12 @@
1083	1085	tx_started \|= 1 << port;
1084	1086	oldskb = skb; /* We're done with this skb already */
1085	1087	} else if (skb && card->using_dma) {
1086		- SKB_CB(skb)->dma_addr = pci_map_single(card->dev, skb->data,
	1088	+ unsigned char *data = skb->data;
	1089	+ if ((unsigned long)data & card->dma_alignment) {
	1090	+ data = card->dma_bounce + (BUF_SIZE * port);
	1091	+ memcpy(data, skb->data, skb->len);
	1092	+ }
	1093	+ SKB_CB(skb)->dma_addr = pci_map_single(card->dev, data,
1087	1094	skb->len, PCI_DMA_TODEVICE);
1088	1095	card->tx_skb[port] = skb;
1089	1096	iowrite32(SKB_CB(skb)->dma_addr,
1090	1097
1091	1098
...	...	@@ -1261,18 +1268,27 @@
1261	1268	else
1262	1269	card->atmel_flash = 0;
1263	1270
	1271	+ data32 = ioread32(card->config_regs + PORTS);
	1272	+ card->nr_ports = (data32 & 0x000000FF);
	1273	+
1264	1274	if (card->fpga_version >= DMA_SUPPORTED) {
1265	1275	pci_set_master(dev);
1266	1276	card->using_dma = 1;
	1277	+ if (1) { /* All known FPGA versions so far */
	1278	+ card->dma_alignment = 3;
	1279	+ card->dma_bounce = kmalloc(card->nr_ports * BUF_SIZE, GFP_KERNEL);
	1280	+ if (!card->dma_bounce) {
	1281	+ dev_warn(&card->dev->dev, "Failed to allocate DMA bounce buffers\n");
	1282	+ /* Fallback to MMIO doesn't work */
	1283	+ goto out_unmap_both;
	1284	+ }
	1285	+ }
1267	1286	} else {
1268	1287	card->using_dma = 0;
1269	1288	/* Set RX empty flag for all ports */
1270	1289	iowrite32(0xF0, card->config_regs + FLAGS_ADDR);
1271	1290	}
1272	1291
1273		- data32 = ioread32(card->config_regs + PORTS);
1274		- card->nr_ports = (data32 & 0x000000FF);
1275		-
1276	1292	pci_set_drvdata(dev, card);
1277	1293
1278	1294	tasklet_init(&card->tlet, solos_bh, (unsigned long)card);
...	...	@@ -1319,6 +1335,7 @@
1319	1335	tasklet_kill(&card->tlet);
1320	1336
1321	1337	out_unmap_both:
	1338	+ kfree(card->dma_bounce);
1322	1339	pci_set_drvdata(dev, NULL);
1323	1340	pci_iounmap(dev, card->buffers);
1324	1341	out_unmap_config:
...	...	@@ -1428,6 +1445,8 @@
1428	1445
1429	1446	free_irq(dev->irq, card);
1430	1447	tasklet_kill(&card->tlet);
	1448	+
	1449	+ kfree(card->dma_bounce);
1431	1450
1432	1451	/* Release device from reset */
1433	1452	iowrite32(0, card->config_regs + FPGA_MODE);