Re: [PATCH v5 12/17] net: sgi: ioc3-eth: use dma-direct for dma allocations

From: Jakub Kicinski
Date: Mon Aug 19 2019 - 20:07:48 EST


On Mon, 19 Aug 2019 18:31:35 +0200, Thomas Bogendoerfer wrote:
> @@ -1386,18 +1427,24 @@ static netdev_tx_t ioc3_start_xmit(struct sk_buff *skb, struct net_device *dev)
> unsigned long b2 = (data | 0x3fffUL) + 1UL;
> unsigned long s1 = b2 - data;
> unsigned long s2 = data + len - b2;
> + dma_addr_t d;
>
> desc->cmd = cpu_to_be32(len | ETXD_INTWHENDONE |
> ETXD_B1V | ETXD_B2V | w0);
> desc->bufcnt = cpu_to_be32((s1 << ETXD_B1CNT_SHIFT) |
> (s2 << ETXD_B2CNT_SHIFT));
> - desc->p1 = cpu_to_be64(ioc3_map(skb->data, 1));
> - desc->p2 = cpu_to_be64(ioc3_map((void *)b2, 1));
> + d = dma_map_single(ip->dma_dev, skb->data, s1, DMA_TO_DEVICE);

You'll need to check the DMA address with dma_mapping_error(dev, addr),
otherwise static checkers will get upset.

> + desc->p1 = cpu_to_be64(ioc3_map(d, PCI64_ATTR_PREF));
> + d = dma_map_single(ip->dma_dev, (void *)b2, s1, DMA_TO_DEVICE);
> + desc->p2 = cpu_to_be64(ioc3_map(d, PCI64_ATTR_PREF));