kernel: add bgmac fixes for various issues

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 45388
This commit is contained in:
Felix Fietkau 2015-04-12 10:35:21 +00:00
parent 503ccc502d
commit 8904cd1dcc
4 changed files with 330 additions and 0 deletions

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@ -0,0 +1,123 @@
From: Felix Fietkau <nbd@openwrt.org>
Date: Sun, 12 Apr 2015 09:58:56 +0200
Subject: [PATCH] bgmac: simplify tx ring index handling
Keep incrementing ring->start and ring->end instead of pointing it to
the actual ring slot entry. This simplifies the calculation of the
number of free slots.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -142,11 +142,10 @@ static netdev_tx_t bgmac_dma_tx_add(stru
{
struct device *dma_dev = bgmac->core->dma_dev;
struct net_device *net_dev = bgmac->net_dev;
- struct bgmac_slot_info *slot = &ring->slots[ring->end];
- int free_slots;
+ int index = ring->end % BGMAC_TX_RING_SLOTS;
+ struct bgmac_slot_info *slot = &ring->slots[index];
int nr_frags;
u32 flags;
- int index = ring->end;
int i;
if (skb->len > BGMAC_DESC_CTL1_LEN) {
@@ -158,13 +157,7 @@ static netdev_tx_t bgmac_dma_tx_add(stru
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 <= nr_frags + 1) {
+ if (ring->end - ring->start + nr_frags + 1 >= BGMAC_TX_RING_SLOTS) {
bgmac_err(bgmac, "TX ring is full, queue should be stopped!\n");
netif_stop_queue(net_dev);
return NETDEV_TX_BUSY;
@@ -200,7 +193,7 @@ static netdev_tx_t bgmac_dma_tx_add(stru
}
slot->skb = skb;
-
+ ring->end += nr_frags + 1;
netdev_sent_queue(net_dev, skb->len);
wmb();
@@ -208,13 +201,12 @@ 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.
*/
- 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));
+ (ring->end % BGMAC_TX_RING_SLOTS) *
+ sizeof(struct bgmac_dma_desc));
- free_slots -= nr_frags + 1;
- if (free_slots < 8)
+ if (ring->end - ring->start >= BGMAC_TX_RING_SLOTS - 8)
netif_stop_queue(net_dev);
return NETDEV_TX_OK;
@@ -256,17 +248,17 @@ static void bgmac_dma_tx_free(struct bgm
empty_slot &= BGMAC_DMA_TX_STATDPTR;
empty_slot /= sizeof(struct bgmac_dma_desc);
- 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;
+ while (ring->start != ring->end) {
+ int slot_idx = ring->start % BGMAC_TX_RING_SLOTS;
+ struct bgmac_slot_info *slot = &ring->slots[slot_idx];
+ u32 ctl1;
+ int len;
- 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 (slot_idx == empty_slot)
+ break;
+ ctl1 = le32_to_cpu(ring->cpu_base[slot_idx].ctl1);
+ len = ctl1 & BGMAC_DESC_CTL1_LEN;
if (ctl1 & BGMAC_DESC_CTL0_SOF)
/* Unmap no longer used buffer */
dma_unmap_single(dma_dev, slot->dma_addr, len,
@@ -284,10 +276,8 @@ static void bgmac_dma_tx_free(struct bgm
slot->skb = NULL;
}
-next:
slot->dma_addr = 0;
- if (++ring->start >= BGMAC_TX_RING_SLOTS)
- ring->start = 0;
+ ring->start++;
freed = true;
}
--- a/drivers/net/ethernet/broadcom/bgmac.h
+++ b/drivers/net/ethernet/broadcom/bgmac.h
@@ -414,10 +414,10 @@ enum bgmac_dma_ring_type {
* empty.
*/
struct bgmac_dma_ring {
- u16 num_slots;
- u16 start;
- u16 end;
+ u32 start;
+ u32 end;
+ u16 num_slots;
u16 mmio_base;
struct bgmac_dma_desc *cpu_base;
dma_addr_t dma_base;

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@ -0,0 +1,87 @@
From: Felix Fietkau <nbd@openwrt.org>
Date: Sun, 12 Apr 2015 10:08:04 +0200
Subject: [PATCH] bgmac: leave interrupts disabled as long as there is work
to do
Always poll rx and tx during NAPI poll instead of relying on the status
of the first interrupt. This prevents bgmac_poll from leaving unfinished
work around until the next IRQ.
In my tests this makes bridging/routing throughput under heavy load more
stable and ensures that no new IRQs arrive as long as bgmac_poll uses up
the entire budget.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -1105,8 +1105,6 @@ static void bgmac_chip_reset(struct bgma
bgmac_phy_init(bgmac);
netdev_reset_queue(bgmac->net_dev);
-
- bgmac->int_status = 0;
}
static void bgmac_chip_intrs_on(struct bgmac *bgmac)
@@ -1221,14 +1219,13 @@ static irqreturn_t bgmac_interrupt(int i
if (!int_status)
return IRQ_NONE;
- /* Ack */
- bgmac_write(bgmac, BGMAC_INT_STATUS, int_status);
+ int_status &= ~(BGMAC_IS_TX0 | BGMAC_IS_RX);
+ if (int_status)
+ bgmac_err(bgmac, "Unknown IRQs: 0x%08X\n", int_status);
/* Disable new interrupts until handling existing ones */
bgmac_chip_intrs_off(bgmac);
- bgmac->int_status = int_status;
-
napi_schedule(&bgmac->napi);
return IRQ_HANDLED;
@@ -1237,25 +1234,17 @@ static irqreturn_t bgmac_interrupt(int i
static int bgmac_poll(struct napi_struct *napi, int weight)
{
struct bgmac *bgmac = container_of(napi, struct bgmac, napi);
- struct bgmac_dma_ring *ring;
int handled = 0;
- if (bgmac->int_status & BGMAC_IS_TX0) {
- ring = &bgmac->tx_ring[0];
- bgmac_dma_tx_free(bgmac, ring);
- bgmac->int_status &= ~BGMAC_IS_TX0;
- }
+ /* Ack */
+ bgmac_write(bgmac, BGMAC_INT_STATUS, ~0);
- if (bgmac->int_status & BGMAC_IS_RX) {
- ring = &bgmac->rx_ring[0];
- handled += bgmac_dma_rx_read(bgmac, ring, weight);
- bgmac->int_status &= ~BGMAC_IS_RX;
- }
+ bgmac_dma_tx_free(bgmac, &bgmac->tx_ring[0]);
+ handled += bgmac_dma_rx_read(bgmac, &bgmac->rx_ring[0], weight);
- if (bgmac->int_status) {
- bgmac_err(bgmac, "Unknown IRQs: 0x%08X\n", bgmac->int_status);
- bgmac->int_status = 0;
- }
+ /* poll again if more events arrived in the mean time */
+ if (bgmac_read(bgmac, BGMAC_INT_STATUS) & (BGMAC_IS_TX0 | BGMAC_IS_RX))
+ return handled;
if (handled < weight) {
napi_complete(napi);
--- a/drivers/net/ethernet/broadcom/bgmac.h
+++ b/drivers/net/ethernet/broadcom/bgmac.h
@@ -452,7 +452,6 @@ struct bgmac {
/* Int */
u32 int_mask;
- u32 int_status;
/* Current MAC state */
int mac_speed;

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@ -0,0 +1,66 @@
From: Felix Fietkau <nbd@openwrt.org>
Date: Sun, 12 Apr 2015 10:13:28 +0200
Subject: [PATCH] bgmac: set received skb headroom to NET_SKB_PAD
A packet buffer offset of 30 bytes is inefficient, because the first 2
bytes end up in a different cacheline.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -342,13 +342,13 @@ static int bgmac_dma_rx_skb_for_slot(str
return -ENOMEM;
/* Poison - if everything goes fine, hardware will overwrite it */
- rx = buf;
+ rx = buf + BGMAC_RX_BUF_OFFSET;
rx->len = cpu_to_le16(0xdead);
rx->flags = cpu_to_le16(0xbeef);
/* Map skb for the DMA */
- dma_addr = dma_map_single(dma_dev, buf, BGMAC_RX_BUF_SIZE,
- DMA_FROM_DEVICE);
+ dma_addr = dma_map_single(dma_dev, buf + BGMAC_RX_BUF_OFFSET,
+ BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
if (dma_mapping_error(dma_dev, dma_addr)) {
bgmac_err(bgmac, "DMA mapping error\n");
put_page(virt_to_head_page(buf));
@@ -399,7 +399,7 @@ static int bgmac_dma_rx_read(struct bgma
while (ring->start != ring->end) {
struct device *dma_dev = bgmac->core->dma_dev;
struct bgmac_slot_info *slot = &ring->slots[ring->start];
- struct bgmac_rx_header *rx = slot->buf;
+ struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET;
struct sk_buff *skb;
void *buf = slot->buf;
u16 len, flags;
@@ -450,8 +450,10 @@ static int bgmac_dma_rx_read(struct bgma
BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE);
- skb_put(skb, BGMAC_RX_FRAME_OFFSET + len);
- skb_pull(skb, BGMAC_RX_FRAME_OFFSET);
+ skb_put(skb, BGMAC_RX_FRAME_OFFSET +
+ BGMAC_RX_BUF_OFFSET + len);
+ skb_pull(skb, BGMAC_RX_FRAME_OFFSET +
+ BGMAC_RX_BUF_OFFSET);
skb_checksum_none_assert(skb);
skb->protocol = eth_type_trans(skb, bgmac->net_dev);
--- a/drivers/net/ethernet/broadcom/bgmac.h
+++ b/drivers/net/ethernet/broadcom/bgmac.h
@@ -360,9 +360,11 @@
#define BGMAC_RX_HEADER_LEN 28 /* Last 24 bytes are unused. Well... */
#define BGMAC_RX_FRAME_OFFSET 30 /* There are 2 unused bytes between header and real data */
+#define BGMAC_RX_BUF_OFFSET (NET_SKB_PAD + NET_IP_ALIGN - \
+ BGMAC_RX_FRAME_OFFSET)
#define BGMAC_RX_MAX_FRAME_SIZE 1536 /* Copied from b44/tg3 */
#define BGMAC_RX_BUF_SIZE (BGMAC_RX_FRAME_OFFSET + BGMAC_RX_MAX_FRAME_SIZE)
-#define BGMAC_RX_ALLOC_SIZE (SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE) + \
+#define BGMAC_RX_ALLOC_SIZE (SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE + BGMAC_RX_BUF_OFFSET) + \
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
#define BGMAC_BFL_ENETROBO 0x0010 /* has ephy roboswitch spi */

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@ -0,0 +1,54 @@
From: Felix Fietkau <nbd@openwrt.org>
Date: Sun, 12 Apr 2015 11:59:47 +0200
Subject: [PATCH] bgmac: fix DMA rx corruption
The driver needs to inform the hardware about the first invalid (not yet
filled) rx slot, by writing its DMA descriptor pointer offset to the
BGMAC_DMA_RX_INDEX register.
This register was set to a value exceeding the rx ring size, effectively
allowing the hardware constant access to the full ring, regardless of
which slots are initialized.
Fix this by updating the register in bgmac_dma_rx_setup_desc.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -380,6 +380,12 @@ static void bgmac_dma_rx_setup_desc(stru
dma_desc->addr_high = cpu_to_le32(upper_32_bits(ring->slots[desc_idx].dma_addr));
dma_desc->ctl0 = cpu_to_le32(ctl0);
dma_desc->ctl1 = cpu_to_le32(ctl1);
+
+ desc_idx = (desc_idx + 1) % BGMAC_RX_RING_SLOTS;
+
+ bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
+ ring->index_base +
+ desc_idx * sizeof(struct bgmac_dma_desc));
}
static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring,
@@ -394,9 +400,7 @@ static int bgmac_dma_rx_read(struct bgma
end_slot &= BGMAC_DMA_RX_STATDPTR;
end_slot /= sizeof(struct bgmac_dma_desc);
- ring->end = end_slot;
-
- while (ring->start != ring->end) {
+ while (ring->start != end_slot) {
struct device *dma_dev = bgmac->core->dma_dev;
struct bgmac_slot_info *slot = &ring->slots[ring->start];
struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET;
@@ -693,10 +697,6 @@ static void bgmac_dma_init(struct bgmac
for (j = 0; j < ring->num_slots; j++)
bgmac_dma_rx_setup_desc(bgmac, ring, j);
- bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
- ring->index_base +
- ring->num_slots * sizeof(struct bgmac_dma_desc));
-
ring->start = 0;
ring->end = 0;
}