net: ethernet: mtk_eth_soc: handle dma buffer size soc specific

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: 656e705243fd ("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>

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index cae46290a7aee28a2d4feb4ab65ec5340dc91bf8..c84ce54a84a00e88fd463723fd66dbdd6a86c44a 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -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;
@@ -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;
+                       }
                }
        }
 
@@ -2457,7 +2463,7 @@ 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);
@@ -2465,8 +2471,8 @@ static int mtk_tx_alloc(struct mtk_eth *eth)
                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);
@@ -2588,6 +2594,7 @@ 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;
@@ -2595,7 +2602,7 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
        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)
@@ -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);
@@ -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)
@@ -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,
        },
@@ -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,
        },
@@ -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,
        },
@@ -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,
        },
@@ -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,
        },
@@ -5176,6 +5201,8 @@ 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),
@@ -5183,6 +5210,7 @@ static const struct mtk_soc_data mt7981_data = {
                .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),
        },
 };
 
@@ -5202,6 +5230,8 @@ 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),
@@ -5209,6 +5239,7 @@ static const struct mtk_soc_data mt7986_data = {
                .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),
        },
 };
 
@@ -5228,6 +5259,8 @@ 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),
@@ -5235,6 +5268,7 @@ static const struct mtk_soc_data mt7988_data = {
                .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),
        },
 };
 
@@ -5249,6 +5283,7 @@ 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),
@@ -5256,6 +5291,7 @@ static const struct mtk_soc_data rt5350_data = {
                .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),
        },
 };
 

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 4eab30b44070633a2357f8517a6ad1e5c8340149..f5174f6cb1bbec5bfc525f31e6b7359b8e900634 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -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
@@ -1176,6 +1178,8 @@ 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;
@@ -1183,6 +1187,7 @@ struct mtk_soc_data {
                u32     dma_l4_valid;
                u32     dma_max_len;
                u32     dma_len_offset;
+               u32     dma_size;
        } rx;
 };
 
@@ -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;