openwrtv4/target/linux/generic/patches-3.18/077-03-bgmac-implement-scatter-gather-support.patch
Felix Fietkau 7eeb254cc4 treewide: replace nbd@openwrt.org with nbd@nbd.name
Signed-off-by: Felix Fietkau <nbd@nbd.name>
2016-06-07 08:58:42 +02:00

267 lines
7.5 KiB
Diff

From: Felix Fietkau <nbd@nbd.name>
Date: Mon, 23 Mar 2015 02:42:26 +0100
Subject: [PATCH] bgmac: implement scatter/gather support
Always use software checksumming, since the hardware does not have any
checksum offload support.
This significantly improves local TCP tx performance.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -115,53 +115,91 @@ static void bgmac_dma_tx_enable(struct b
bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_CTL, ctl);
}
+static void
+bgmac_dma_tx_add_buf(struct bgmac *bgmac, struct bgmac_dma_ring *ring,
+ int i, int len, u32 ctl0)
+{
+ struct bgmac_slot_info *slot;
+ struct bgmac_dma_desc *dma_desc;
+ u32 ctl1;
+
+ if (i == ring->num_slots - 1)
+ ctl0 |= BGMAC_DESC_CTL0_EOT;
+
+ ctl1 = len & BGMAC_DESC_CTL1_LEN;
+
+ slot = &ring->slots[i];
+ dma_desc = &ring->cpu_base[i];
+ dma_desc->addr_low = cpu_to_le32(lower_32_bits(slot->dma_addr));
+ dma_desc->addr_high = cpu_to_le32(upper_32_bits(slot->dma_addr));
+ dma_desc->ctl0 = cpu_to_le32(ctl0);
+ dma_desc->ctl1 = cpu_to_le32(ctl1);
+}
+
static netdev_tx_t bgmac_dma_tx_add(struct bgmac *bgmac,
struct bgmac_dma_ring *ring,
struct sk_buff *skb)
{
struct device *dma_dev = bgmac->core->dma_dev;
struct net_device *net_dev = bgmac->net_dev;
- struct bgmac_dma_desc *dma_desc;
- struct bgmac_slot_info *slot;
- u32 ctl0, ctl1;
+ struct bgmac_slot_info *slot = &ring->slots[ring->end];
int free_slots;
+ int nr_frags;
+ u32 flags;
+ int index = ring->end;
+ int i;
if (skb->len > BGMAC_DESC_CTL1_LEN) {
bgmac_err(bgmac, "Too long skb (%d)\n", skb->len);
- goto err_stop_drop;
+ goto err_drop;
}
+ if (skb->ip_summed == CHECKSUM_PARTIAL)
+ skb_checksum_help(skb);
+
+ nr_frags = skb_shinfo(skb)->nr_frags;
+
if (ring->start <= ring->end)
free_slots = ring->start - ring->end + BGMAC_TX_RING_SLOTS;
else
free_slots = ring->start - ring->end;
- if (free_slots == 1) {
+
+ if (free_slots <= nr_frags + 1) {
bgmac_err(bgmac, "TX ring is full, queue should be stopped!\n");
netif_stop_queue(net_dev);
return NETDEV_TX_BUSY;
}
- slot = &ring->slots[ring->end];
- slot->skb = skb;
- slot->dma_addr = dma_map_single(dma_dev, skb->data, skb->len,
+ slot->dma_addr = dma_map_single(dma_dev, skb->data, skb_headlen(skb),
DMA_TO_DEVICE);
- if (dma_mapping_error(dma_dev, slot->dma_addr)) {
- bgmac_err(bgmac, "Mapping error of skb on ring 0x%X\n",
- ring->mmio_base);
- goto err_stop_drop;
- }
+ if (unlikely(dma_mapping_error(dma_dev, slot->dma_addr)))
+ goto err_dma_head;
- ctl0 = BGMAC_DESC_CTL0_IOC | BGMAC_DESC_CTL0_SOF | BGMAC_DESC_CTL0_EOF;
- if (ring->end == ring->num_slots - 1)
- ctl0 |= BGMAC_DESC_CTL0_EOT;
- ctl1 = skb->len & BGMAC_DESC_CTL1_LEN;
+ flags = BGMAC_DESC_CTL0_SOF;
+ if (!nr_frags)
+ flags |= BGMAC_DESC_CTL0_EOF | BGMAC_DESC_CTL0_IOC;
+
+ bgmac_dma_tx_add_buf(bgmac, ring, index, skb_headlen(skb), flags);
+ flags = 0;
+
+ for (i = 0; i < nr_frags; i++) {
+ struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i];
+ int len = skb_frag_size(frag);
+
+ index = (index + 1) % BGMAC_TX_RING_SLOTS;
+ slot = &ring->slots[index];
+ slot->dma_addr = skb_frag_dma_map(dma_dev, frag, 0,
+ len, DMA_TO_DEVICE);
+ if (unlikely(dma_mapping_error(dma_dev, slot->dma_addr)))
+ goto err_dma;
- dma_desc = ring->cpu_base;
- dma_desc += ring->end;
- dma_desc->addr_low = cpu_to_le32(lower_32_bits(slot->dma_addr));
- dma_desc->addr_high = cpu_to_le32(upper_32_bits(slot->dma_addr));
- dma_desc->ctl0 = cpu_to_le32(ctl0);
- dma_desc->ctl1 = cpu_to_le32(ctl1);
+ if (i == nr_frags - 1)
+ flags |= BGMAC_DESC_CTL0_EOF | BGMAC_DESC_CTL0_IOC;
+
+ bgmac_dma_tx_add_buf(bgmac, ring, index, len, flags);
+ }
+
+ slot->skb = skb;
netdev_sent_queue(net_dev, skb->len);
@@ -170,20 +208,35 @@ static netdev_tx_t bgmac_dma_tx_add(stru
/* Increase ring->end to point empty slot. We tell hardware the first
* slot it should *not* read.
*/
- if (++ring->end >= BGMAC_TX_RING_SLOTS)
- ring->end = 0;
+ ring->end = (index + 1) % BGMAC_TX_RING_SLOTS;
bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_TX_INDEX,
ring->index_base +
ring->end * sizeof(struct bgmac_dma_desc));
- /* Always keep one slot free to allow detecting bugged calls. */
- if (--free_slots == 1)
+ free_slots -= nr_frags + 1;
+ if (free_slots < 8)
netif_stop_queue(net_dev);
return NETDEV_TX_OK;
-err_stop_drop:
- netif_stop_queue(net_dev);
+err_dma:
+ dma_unmap_single(dma_dev, slot->dma_addr, skb_headlen(skb),
+ DMA_TO_DEVICE);
+
+ while (i > 0) {
+ int index = (ring->end + i) % BGMAC_TX_RING_SLOTS;
+ struct bgmac_slot_info *slot = &ring->slots[index];
+ u32 ctl1 = le32_to_cpu(ring->cpu_base[index].ctl1);
+ int len = ctl1 & BGMAC_DESC_CTL1_LEN;
+
+ dma_unmap_page(dma_dev, slot->dma_addr, len, DMA_TO_DEVICE);
+ }
+
+err_dma_head:
+ bgmac_err(bgmac, "Mapping error of skb on ring 0x%X\n",
+ ring->mmio_base);
+
+err_drop:
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
@@ -205,32 +258,45 @@ static void bgmac_dma_tx_free(struct bgm
while (ring->start != empty_slot) {
struct bgmac_slot_info *slot = &ring->slots[ring->start];
+ u32 ctl1 = le32_to_cpu(ring->cpu_base[ring->start].ctl1);
+ int len = ctl1 & BGMAC_DESC_CTL1_LEN;
- if (slot->skb) {
+ if (!slot->dma_addr) {
+ bgmac_err(bgmac, "Hardware reported transmission for empty TX ring slot %d! End of ring: %d\n",
+ ring->start, ring->end);
+ goto next;
+ }
+
+ if (ctl1 & BGMAC_DESC_CTL0_SOF)
/* Unmap no longer used buffer */
- dma_unmap_single(dma_dev, slot->dma_addr,
- slot->skb->len, DMA_TO_DEVICE);
- slot->dma_addr = 0;
+ dma_unmap_single(dma_dev, slot->dma_addr, len,
+ DMA_TO_DEVICE);
+ else
+ dma_unmap_page(dma_dev, slot->dma_addr, len,
+ DMA_TO_DEVICE);
+ if (slot->skb) {
bytes_compl += slot->skb->len;
pkts_compl++;
/* Free memory! :) */
dev_kfree_skb(slot->skb);
slot->skb = NULL;
- } else {
- bgmac_err(bgmac, "Hardware reported transmission for empty TX ring slot %d! End of ring: %d\n",
- ring->start, ring->end);
}
+next:
+ slot->dma_addr = 0;
if (++ring->start >= BGMAC_TX_RING_SLOTS)
ring->start = 0;
freed = true;
}
+ if (!pkts_compl)
+ return;
+
netdev_completed_queue(bgmac->net_dev, pkts_compl, bytes_compl);
- if (freed && netif_queue_stopped(bgmac->net_dev))
+ if (netif_queue_stopped(bgmac->net_dev))
netif_wake_queue(bgmac->net_dev);
}
@@ -439,17 +505,25 @@ static void bgmac_dma_tx_ring_free(struc
struct bgmac_dma_ring *ring)
{
struct device *dma_dev = bgmac->core->dma_dev;
+ struct bgmac_dma_desc *dma_desc = ring->cpu_base;
struct bgmac_slot_info *slot;
int i;
for (i = 0; i < ring->num_slots; i++) {
+ int len = dma_desc[i].ctl1 & BGMAC_DESC_CTL1_LEN;
+
slot = &ring->slots[i];
- if (slot->skb) {
- if (slot->dma_addr)
- dma_unmap_single(dma_dev, slot->dma_addr,
- slot->skb->len, DMA_TO_DEVICE);
- dev_kfree_skb(slot->skb);
- }
+ dev_kfree_skb(slot->skb);
+
+ if (!slot->dma_addr)
+ continue;
+
+ if (slot->skb)
+ dma_unmap_single(dma_dev, slot->dma_addr,
+ len, DMA_TO_DEVICE);
+ else
+ dma_unmap_page(dma_dev, slot->dma_addr,
+ len, DMA_TO_DEVICE);
}
}
@@ -1583,6 +1657,10 @@ static int bgmac_probe(struct bcma_devic
goto err_dma_free;
}
+ net_dev->features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
+ net_dev->hw_features = net_dev->features;
+ net_dev->vlan_features = net_dev->features;
+
err = register_netdev(bgmac->net_dev);
if (err) {
bgmac_err(bgmac, "Cannot register net device\n");