From 152a2a8b5e1d4cbe91a7c66f1028db15164a3766 Mon Sep 17 00:00:00 2001
From: David Woodhouse <David.Woodhouse@intel.com>
Date: Wed, 19 Dec 2012 11:01:21 +0000
Subject: [PATCH] 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>
---
drivers/atm/solos-pci.c | 27 +++++++++++++++++++++++----
1 file changed, 23 insertions(+), 4 deletions(-)
diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index aa4f35d52a92..d70abe77f737 100644
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -128,9 +128,11 @@ struct solos_card {
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 @@ static uint32_t fpga_tx(struct solos_card *card)
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 @@ static int fpga_probe(struct pci_dev *dev, const struct pci_device_id *id)
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 @@ static int fpga_probe(struct pci_dev *dev, const struct pci_device_id *id)
tasklet_kill(&card->tlet);
out_unmap_both:
+ kfree(card->dma_bounce);
pci_set_drvdata(dev, NULL);
pci_iounmap(dev, card->buffers);
out_unmap_config:
@@ -1429,6 +1446,8 @@ static void fpga_remove(struct pci_dev *dev)
free_irq(dev->irq, card);
tasklet_kill(&card->tlet);
+ kfree(card->dma_bounce);
+
/* Release device from reset */
iowrite32(0, card->config_regs + FPGA_MODE);
(void)ioread32(card->config_regs + FPGA_MODE);
--
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