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net: ethernet: mtk_eth_soc: handle dma buffer size soc specific
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The mainline MTK ethernet driver suffers long time from rarly but
annoying tx queue timeouts. We think that this is caused by fixed
dma sizes hardcoded for all SoCs.

We suspect this problem arises from a low level of free TX DMADs,
the TX Ring alomost full.

The transmit timeout is caused by the Tx queue not waking up. The
Tx queue stops when the free counter is less than ring->thres, and
it will wake up once the free counter is greater than ring->thres.
If the CPU is too late to wake up the Tx queues, it may cause a
transmit timeout.
Therefore, we increased the TX and RX DMADs to improve this error
situation.

Use the dma-size implementation from SDK in a per SoC manner. In
difference to SDK we have no RSS feature yet, so all RX/TX sizes
should be raised from 512 to 2048 byte except fqdma on mt7988 to
avoid the tx timeout issue.

Fixes: 656e705 ("net-next: mediatek: add support for MT7623 ethernet")
Suggested-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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@frank-w @davem330
frank-w authored and davem330 committed Jun 5, 2024
1 parent 5b4b62a commit c57e558
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Showing 2 changed files with 77 additions and 36 deletions.
104 changes: 70 additions & 34 deletions drivers/net/ethernet/mediatek/mtk_eth_soc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1131,9 +1131,9 @@ static int mtk_init_fq_dma(struct mtk_eth *eth)
{
const struct mtk_soc_data *soc = eth->soc;
dma_addr_t phy_ring_tail;
int cnt = MTK_QDMA_RING_SIZE;
int cnt = soc->tx.fq_dma_size;
dma_addr_t dma_addr;
int i;
int i, j, len;

if (MTK_HAS_CAPS(eth->soc->caps, MTK_SRAM))
eth->scratch_ring = eth->sram_base;
Expand All @@ -1142,40 +1142,46 @@ static int mtk_init_fq_dma(struct mtk_eth *eth)
cnt * soc->tx.desc_size,
&eth->phy_scratch_ring,
GFP_KERNEL);

if (unlikely(!eth->scratch_ring))
return -ENOMEM;

eth->scratch_head = kcalloc(cnt, MTK_QDMA_PAGE_SIZE, GFP_KERNEL);
if (unlikely(!eth->scratch_head))
return -ENOMEM;
phy_ring_tail = eth->phy_scratch_ring + soc->tx.desc_size * (cnt - 1);

dma_addr = dma_map_single(eth->dma_dev,
eth->scratch_head, cnt * MTK_QDMA_PAGE_SIZE,
DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(eth->dma_dev, dma_addr)))
return -ENOMEM;
for (j = 0; j < DIV_ROUND_UP(soc->tx.fq_dma_size, MTK_FQ_DMA_LENGTH); j++) {
len = min_t(int, cnt - j * MTK_FQ_DMA_LENGTH, MTK_FQ_DMA_LENGTH);
eth->scratch_head[j] = kcalloc(len, MTK_QDMA_PAGE_SIZE, GFP_KERNEL);

phy_ring_tail = eth->phy_scratch_ring + soc->tx.desc_size * (cnt - 1);
if (unlikely(!eth->scratch_head[j]))
return -ENOMEM;

for (i = 0; i < cnt; i++) {
dma_addr_t addr = dma_addr + i * MTK_QDMA_PAGE_SIZE;
struct mtk_tx_dma_v2 *txd;
dma_addr = dma_map_single(eth->dma_dev,
eth->scratch_head[j], len * MTK_QDMA_PAGE_SIZE,
DMA_FROM_DEVICE);

txd = eth->scratch_ring + i * soc->tx.desc_size;
txd->txd1 = addr;
if (i < cnt - 1)
txd->txd2 = eth->phy_scratch_ring +
(i + 1) * soc->tx.desc_size;
if (unlikely(dma_mapping_error(eth->dma_dev, dma_addr)))
return -ENOMEM;

txd->txd3 = TX_DMA_PLEN0(MTK_QDMA_PAGE_SIZE);
if (MTK_HAS_CAPS(soc->caps, MTK_36BIT_DMA))
txd->txd3 |= TX_DMA_PREP_ADDR64(addr);
txd->txd4 = 0;
if (mtk_is_netsys_v2_or_greater(eth)) {
txd->txd5 = 0;
txd->txd6 = 0;
txd->txd7 = 0;
txd->txd8 = 0;
for (i = 0; i < cnt; i++) {
struct mtk_tx_dma_v2 *txd;

txd = eth->scratch_ring + (j * MTK_FQ_DMA_LENGTH + i) * soc->tx.desc_size;
txd->txd1 = dma_addr + i * MTK_QDMA_PAGE_SIZE;
if (j * MTK_FQ_DMA_LENGTH + i < cnt)
txd->txd2 = eth->phy_scratch_ring +
(j * MTK_FQ_DMA_LENGTH + i + 1) * soc->tx.desc_size;

txd->txd3 = TX_DMA_PLEN0(MTK_QDMA_PAGE_SIZE);
if (MTK_HAS_CAPS(soc->caps, MTK_36BIT_DMA))
txd->txd3 |= TX_DMA_PREP_ADDR64(dma_addr + i * MTK_QDMA_PAGE_SIZE);

txd->txd4 = 0;
if (mtk_is_netsys_v2_or_greater(eth)) {
txd->txd5 = 0;
txd->txd6 = 0;
txd->txd7 = 0;
txd->txd8 = 0;
}
}
}

Expand Down Expand Up @@ -2457,16 +2463,16 @@ static int mtk_tx_alloc(struct mtk_eth *eth)
if (MTK_HAS_CAPS(soc->caps, MTK_QDMA))
ring_size = MTK_QDMA_RING_SIZE;
else
ring_size = MTK_DMA_SIZE;
ring_size = soc->tx.dma_size;

ring->buf = kcalloc(ring_size, sizeof(*ring->buf),
GFP_KERNEL);
if (!ring->buf)
goto no_tx_mem;

if (MTK_HAS_CAPS(soc->caps, MTK_SRAM)) {
ring->dma = eth->sram_base + ring_size * sz;
ring->phys = eth->phy_scratch_ring + ring_size * (dma_addr_t)sz;
ring->dma = eth->sram_base + soc->tx.fq_dma_size * sz;
ring->phys = eth->phy_scratch_ring + soc->tx.fq_dma_size * (dma_addr_t)sz;
} else {
ring->dma = dma_alloc_coherent(eth->dma_dev, ring_size * sz,
&ring->phys, GFP_KERNEL);
Expand Down Expand Up @@ -2588,14 +2594,15 @@ static void mtk_tx_clean(struct mtk_eth *eth)
static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
{
const struct mtk_reg_map *reg_map = eth->soc->reg_map;
const struct mtk_soc_data *soc = eth->soc;
struct mtk_rx_ring *ring;
int rx_data_len, rx_dma_size, tx_ring_size;
int i;

if (MTK_HAS_CAPS(eth->soc->caps, MTK_QDMA))
tx_ring_size = MTK_QDMA_RING_SIZE;
else
tx_ring_size = MTK_DMA_SIZE;
tx_ring_size = soc->tx.dma_size;

if (rx_flag == MTK_RX_FLAGS_QDMA) {
if (ring_no)
Expand All @@ -2610,7 +2617,7 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
rx_dma_size = MTK_HW_LRO_DMA_SIZE;
} else {
rx_data_len = ETH_DATA_LEN;
rx_dma_size = MTK_DMA_SIZE;
rx_dma_size = soc->rx.dma_size;
}

ring->frag_size = mtk_max_frag_size(rx_data_len);
Expand Down Expand Up @@ -3139,7 +3146,10 @@ static void mtk_dma_free(struct mtk_eth *eth)
mtk_rx_clean(eth, &eth->rx_ring[i], false);
}

kfree(eth->scratch_head);
for (i = 0; i < DIV_ROUND_UP(soc->tx.fq_dma_size, MTK_FQ_DMA_LENGTH); i++) {
kfree(eth->scratch_head[i]);
eth->scratch_head[i] = NULL;
}
}

static bool mtk_hw_reset_check(struct mtk_eth *eth)
Expand Down Expand Up @@ -5052,11 +5062,14 @@ static const struct mtk_soc_data mt2701_data = {
.desc_size = sizeof(struct mtk_tx_dma),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
.dma_size = MTK_DMA_SIZE(2K),
.fq_dma_size = MTK_DMA_SIZE(2K),
},
.rx = {
.desc_size = sizeof(struct mtk_rx_dma),
.irq_done_mask = MTK_RX_DONE_INT,
.dma_l4_valid = RX_DMA_L4_VALID,
.dma_size = MTK_DMA_SIZE(2K),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
},
Expand All @@ -5076,11 +5089,14 @@ static const struct mtk_soc_data mt7621_data = {
.desc_size = sizeof(struct mtk_tx_dma),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
.dma_size = MTK_DMA_SIZE(2K),
.fq_dma_size = MTK_DMA_SIZE(2K),
},
.rx = {
.desc_size = sizeof(struct mtk_rx_dma),
.irq_done_mask = MTK_RX_DONE_INT,
.dma_l4_valid = RX_DMA_L4_VALID,
.dma_size = MTK_DMA_SIZE(2K),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
},
Expand All @@ -5102,11 +5118,14 @@ static const struct mtk_soc_data mt7622_data = {
.desc_size = sizeof(struct mtk_tx_dma),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
.dma_size = MTK_DMA_SIZE(2K),
.fq_dma_size = MTK_DMA_SIZE(2K),
},
.rx = {
.desc_size = sizeof(struct mtk_rx_dma),
.irq_done_mask = MTK_RX_DONE_INT,
.dma_l4_valid = RX_DMA_L4_VALID,
.dma_size = MTK_DMA_SIZE(2K),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
},
Expand All @@ -5127,11 +5146,14 @@ static const struct mtk_soc_data mt7623_data = {
.desc_size = sizeof(struct mtk_tx_dma),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
.dma_size = MTK_DMA_SIZE(2K),
.fq_dma_size = MTK_DMA_SIZE(2K),
},
.rx = {
.desc_size = sizeof(struct mtk_rx_dma),
.irq_done_mask = MTK_RX_DONE_INT,
.dma_l4_valid = RX_DMA_L4_VALID,
.dma_size = MTK_DMA_SIZE(2K),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
},
Expand All @@ -5150,11 +5172,14 @@ static const struct mtk_soc_data mt7629_data = {
.desc_size = sizeof(struct mtk_tx_dma),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
.dma_size = MTK_DMA_SIZE(2K),
.fq_dma_size = MTK_DMA_SIZE(2K),
},
.rx = {
.desc_size = sizeof(struct mtk_rx_dma),
.irq_done_mask = MTK_RX_DONE_INT,
.dma_l4_valid = RX_DMA_L4_VALID,
.dma_size = MTK_DMA_SIZE(2K),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
},
Expand All @@ -5176,13 +5201,16 @@ static const struct mtk_soc_data mt7981_data = {
.desc_size = sizeof(struct mtk_tx_dma_v2),
.dma_max_len = MTK_TX_DMA_BUF_LEN_V2,
.dma_len_offset = 8,
.dma_size = MTK_DMA_SIZE(2K),
.fq_dma_size = MTK_DMA_SIZE(2K),
},
.rx = {
.desc_size = sizeof(struct mtk_rx_dma),
.irq_done_mask = MTK_RX_DONE_INT,
.dma_l4_valid = RX_DMA_L4_VALID_V2,
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
.dma_size = MTK_DMA_SIZE(2K),
},
};

Expand All @@ -5202,13 +5230,16 @@ static const struct mtk_soc_data mt7986_data = {
.desc_size = sizeof(struct mtk_tx_dma_v2),
.dma_max_len = MTK_TX_DMA_BUF_LEN_V2,
.dma_len_offset = 8,
.dma_size = MTK_DMA_SIZE(2K),
.fq_dma_size = MTK_DMA_SIZE(2K),
},
.rx = {
.desc_size = sizeof(struct mtk_rx_dma),
.irq_done_mask = MTK_RX_DONE_INT,
.dma_l4_valid = RX_DMA_L4_VALID_V2,
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
.dma_size = MTK_DMA_SIZE(2K),
},
};

Expand All @@ -5228,13 +5259,16 @@ static const struct mtk_soc_data mt7988_data = {
.desc_size = sizeof(struct mtk_tx_dma_v2),
.dma_max_len = MTK_TX_DMA_BUF_LEN_V2,
.dma_len_offset = 8,
.dma_size = MTK_DMA_SIZE(2K),
.fq_dma_size = MTK_DMA_SIZE(4K),
},
.rx = {
.desc_size = sizeof(struct mtk_rx_dma_v2),
.irq_done_mask = MTK_RX_DONE_INT_V2,
.dma_l4_valid = RX_DMA_L4_VALID_V2,
.dma_max_len = MTK_TX_DMA_BUF_LEN_V2,
.dma_len_offset = 8,
.dma_size = MTK_DMA_SIZE(2K),
},
};

Expand All @@ -5249,13 +5283,15 @@ static const struct mtk_soc_data rt5350_data = {
.desc_size = sizeof(struct mtk_tx_dma),
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
.dma_size = MTK_DMA_SIZE(2K),
},
.rx = {
.desc_size = sizeof(struct mtk_rx_dma),
.irq_done_mask = MTK_RX_DONE_INT,
.dma_l4_valid = RX_DMA_L4_VALID_PDMA,
.dma_max_len = MTK_TX_DMA_BUF_LEN,
.dma_len_offset = 16,
.dma_size = MTK_DMA_SIZE(2K),
},
};

Expand Down
9 changes: 7 additions & 2 deletions drivers/net/ethernet/mediatek/mtk_eth_soc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,7 +32,9 @@
#define MTK_TX_DMA_BUF_LEN 0x3fff
#define MTK_TX_DMA_BUF_LEN_V2 0xffff
#define MTK_QDMA_RING_SIZE 2048
#define MTK_DMA_SIZE 512
#define MTK_DMA_SIZE(x) (SZ_##x)
#define MTK_FQ_DMA_HEAD 32
#define MTK_FQ_DMA_LENGTH 2048
#define MTK_RX_ETH_HLEN (ETH_HLEN + ETH_FCS_LEN)
#define MTK_RX_HLEN (NET_SKB_PAD + MTK_RX_ETH_HLEN + NET_IP_ALIGN)
#define MTK_DMA_DUMMY_DESC 0xffffffff
Expand Down Expand Up @@ -1176,13 +1178,16 @@ struct mtk_soc_data {
u32 desc_size;
u32 dma_max_len;
u32 dma_len_offset;
u32 dma_size;
u32 fq_dma_size;
} tx;
struct {
u32 desc_size;
u32 irq_done_mask;
u32 dma_l4_valid;
u32 dma_max_len;
u32 dma_len_offset;
u32 dma_size;
} rx;
};

Expand Down Expand Up @@ -1264,7 +1269,7 @@ struct mtk_eth {
struct napi_struct rx_napi;
void *scratch_ring;
dma_addr_t phy_scratch_ring;
void *scratch_head;
void *scratch_head[MTK_FQ_DMA_HEAD];
struct clk *clks[MTK_CLK_MAX];

struct mii_bus *mii_bus;
Expand Down

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