[PATCH 02/14] net: ethernet: mtk_eth_soc: increase tx ring side for QDMA devices

Felix Fietkau
2022-11-07T18:56:38Z

In order to use the hardware traffic shaper feature, a larger tx ring is
needed, especially for the scratch ring, which the hardware shaper uses to
reorder packets.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 38 ++++++++++++---------
drivers/net/ethernet/mediatek/mtk_eth_soc.h | 1 +
2 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 789268b15106..02a57729db28 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -938,7 +938,7 @@ 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_DMA_SIZE;
+ int cnt = MTK_QDMA_RING_SIZE;
dma_addr_t dma_addr;
int i;

@@ -2202,19 +2202,25 @@ static int mtk_tx_alloc(struct mtk_eth *eth)
struct mtk_tx_ring *ring = &eth->tx_ring;
int i, sz = soc->txrx.txd_size;
struct mtk_tx_dma_v2 *txd;
+ int ring_size;

- ring->buf = kcalloc(MTK_DMA_SIZE, sizeof(*ring->buf),
+ if (MTK_HAS_CAPS(soc->caps, MTK_QDMA))
+ ring_size = MTK_QDMA_RING_SIZE;
+ else
+ ring_size = MTK_DMA_SIZE;
+
+ ring->buf = kcalloc(ring_size, sizeof(*ring->buf),
GFP_KERNEL);
if (!ring->buf)
goto no_tx_mem;

- ring->dma = dma_alloc_coherent(eth->dma_dev, MTK_DMA_SIZE * sz,
+ ring->dma = dma_alloc_coherent(eth->dma_dev, ring_size * sz,
&ring->phys, GFP_KERNEL);
if (!ring->dma)
goto no_tx_mem;

- for (i = 0; i < MTK_DMA_SIZE; i++) {
- int next = (i + 1) % MTK_DMA_SIZE;
+ for (i = 0; i < ring_size; i++) {
+ int next = (i + 1) % ring_size;
u32 next_ptr = ring->phys + next * sz;

txd = ring->dma + i * sz;
@@ -2234,22 +2240,22 @@ static int mtk_tx_alloc(struct mtk_eth *eth)
* descriptors in ring->dma_pdma.
*/
if (!MTK_HAS_CAPS(soc->caps, MTK_QDMA)) {
- ring->dma_pdma = dma_alloc_coherent(eth->dma_dev, MTK_DMA_SIZE * sz,
+ ring->dma_pdma = dma_alloc_coherent(eth->dma_dev, ring_size * sz,
&ring->phys_pdma, GFP_KERNEL);
if (!ring->dma_pdma)
goto no_tx_mem;

- for (i = 0; i < MTK_DMA_SIZE; i++) {
+ for (i = 0; i < ring_size; i++) {
ring->dma_pdma[i].txd2 = TX_DMA_DESP2_DEF;
ring->dma_pdma[i].txd4 = 0;
}
}

- ring->dma_size = MTK_DMA_SIZE;
- atomic_set(&ring->free_count, MTK_DMA_SIZE - 2);
+ ring->dma_size = ring_size;
+ atomic_set(&ring->free_count, ring_size - 2);
ring->next_free = ring->dma;
ring->last_free = (void *)txd;
- ring->last_free_ptr = (u32)(ring->phys + ((MTK_DMA_SIZE - 1) * sz));
+ ring->last_free_ptr = (u32)(ring->phys + ((ring_size - 1) * sz));
ring->thresh = MAX_SKB_FRAGS;

/* make sure that all changes to the dma ring are flushed before we
@@ -2261,14 +2267,14 @@ static int mtk_tx_alloc(struct mtk_eth *eth)
mtk_w32(eth, ring->phys, soc->reg_map->qdma.ctx_ptr);
mtk_w32(eth, ring->phys, soc->reg_map->qdma.dtx_ptr);
mtk_w32(eth,
- ring->phys + ((MTK_DMA_SIZE - 1) * sz),
+ ring->phys + ((ring_size - 1) * sz),
soc->reg_map->qdma.crx_ptr);
mtk_w32(eth, ring->last_free_ptr, soc->reg_map->qdma.drx_ptr);
mtk_w32(eth, (QDMA_RES_THRES << 8) | QDMA_RES_THRES,
soc->reg_map->qdma.qtx_cfg);
} else {
mtk_w32(eth, ring->phys_pdma, MT7628_TX_BASE_PTR0);
- mtk_w32(eth, MTK_DMA_SIZE, MT7628_TX_MAX_CNT0);
+ mtk_w32(eth, ring_size, MT7628_TX_MAX_CNT0);
mtk_w32(eth, 0, MT7628_TX_CTX_IDX0);
mtk_w32(eth, MT7628_PST_DTX_IDX0, soc->reg_map->pdma.rst_idx);
}
@@ -2286,7 +2292,7 @@ static void mtk_tx_clean(struct mtk_eth *eth)
int i;

if (ring->buf) {
- for (i = 0; i < MTK_DMA_SIZE; i++)
+ for (i = 0; i < ring->dma_size; i++)
mtk_tx_unmap(eth, &ring->buf[i], NULL, false);
kfree(ring->buf);
ring->buf = NULL;
@@ -2294,14 +2300,14 @@ static void mtk_tx_clean(struct mtk_eth *eth)

if (ring->dma) {
dma_free_coherent(eth->dma_dev,
- MTK_DMA_SIZE * soc->txrx.txd_size,
+ ring->dma_size * soc->txrx.txd_size,
ring->dma, ring->phys);
ring->dma = NULL;
}

if (ring->dma_pdma) {
dma_free_coherent(eth->dma_dev,
- MTK_DMA_SIZE * soc->txrx.txd_size,
+ ring->dma_size * soc->txrx.txd_size,
ring->dma_pdma, ring->phys_pdma);
ring->dma_pdma = NULL;
}
@@ -2821,7 +2827,7 @@ static void mtk_dma_free(struct mtk_eth *eth)
netdev_reset_queue(eth->netdev[i]);
if (eth->scratch_ring) {
dma_free_coherent(eth->dma_dev,
- MTK_DMA_SIZE * soc->txrx.txd_size,
+ MTK_QDMA_RING_SIZE * soc->txrx.txd_size,
eth->scratch_ring, eth->phy_scratch_ring);
eth->scratch_ring = NULL;
eth->phy_scratch_ring = 0;
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index dcf2a0d5da33..7c0b6c0c05d8 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -27,6 +27,7 @@
#define MTK_MAX_RX_LENGTH_2K 2048
#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_MAC_COUNT 2
#define MTK_RX_ETH_HLEN (VLAN_ETH_HLEN + ETH_HLEN + ETH_FCS_LEN)
--
2.38.1