diff options
Diffstat (limited to 'target/linux/generic/pending-5.4/770-08-net-ethernet-mtk_eth_soc-cache-hardware-pointer-of-l.patch')
-rw-r--r-- | target/linux/generic/pending-5.4/770-08-net-ethernet-mtk_eth_soc-cache-hardware-pointer-of-l.patch | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/target/linux/generic/pending-5.4/770-08-net-ethernet-mtk_eth_soc-cache-hardware-pointer-of-l.patch b/target/linux/generic/pending-5.4/770-08-net-ethernet-mtk_eth_soc-cache-hardware-pointer-of-l.patch new file mode 100644 index 0000000000..ddbd751ead --- /dev/null +++ b/target/linux/generic/pending-5.4/770-08-net-ethernet-mtk_eth_soc-cache-hardware-pointer-of-l.patch @@ -0,0 +1,67 @@ +From: Felix Fietkau <nbd@nbd.name> +Date: Thu, 27 Aug 2020 06:32:03 +0200 +Subject: [PATCH] net: ethernet: mtk_eth_soc: cache hardware pointer of last + freed tx descriptor + +The value is only updated by the CPU, so it is cheaper to access from the ring +data structure than from a hardware register + +Signed-off-by: Felix Fietkau <nbd@nbd.name> +--- + +--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c ++++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c +@@ -1358,7 +1358,7 @@ static int mtk_poll_tx_qdma(struct mtk_e + struct mtk_tx_buf *tx_buf; + u32 cpu, dma; + +- cpu = mtk_r32(eth, MTK_QTX_CRX_PTR); ++ cpu = ring->last_free_ptr; + dma = mtk_r32(eth, MTK_QTX_DRX_PTR); + + desc = mtk_qdma_phys_to_virt(ring, cpu); +@@ -1389,6 +1389,7 @@ static int mtk_poll_tx_qdma(struct mtk_e + cpu = next_cpu; + } + ++ ring->last_free_ptr = cpu; + mtk_w32(eth, cpu, MTK_QTX_CRX_PTR); + + return budget; +@@ -1589,6 +1590,7 @@ static int mtk_tx_alloc(struct mtk_eth * + atomic_set(&ring->free_count, MTK_DMA_SIZE - 2); + ring->next_free = &ring->dma[0]; + ring->last_free = &ring->dma[MTK_DMA_SIZE - 1]; ++ ring->last_free_ptr = (u32)(ring->phys + ((MTK_DMA_SIZE - 1) * sz)); + ring->thresh = MAX_SKB_FRAGS; + + /* make sure that all changes to the dma ring are flushed before we +@@ -1602,9 +1604,7 @@ static int mtk_tx_alloc(struct mtk_eth * + mtk_w32(eth, + ring->phys + ((MTK_DMA_SIZE - 1) * sz), + MTK_QTX_CRX_PTR); +- mtk_w32(eth, +- ring->phys + ((MTK_DMA_SIZE - 1) * sz), +- MTK_QTX_DRX_PTR); ++ mtk_w32(eth, ring->last_free_ptr, MTK_QTX_DRX_PTR); + mtk_w32(eth, (QDMA_RES_THRES << 8) | QDMA_RES_THRES, + MTK_QTX_CFG(0)); + } else { +--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h ++++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h +@@ -622,6 +622,7 @@ struct mtk_tx_buf { + * @phys: The physical addr of tx_buf + * @next_free: Pointer to the next free descriptor + * @last_free: Pointer to the last free descriptor ++ * @last_free_ptr: Hardware pointer value of the last free descriptor + * @thresh: The threshold of minimum amount of free descriptors + * @free_count: QDMA uses a linked list. Track how many free descriptors + * are present +@@ -632,6 +633,7 @@ struct mtk_tx_ring { + dma_addr_t phys; + struct mtk_tx_dma *next_free; + struct mtk_tx_dma *last_free; ++ u32 last_free_ptr; + u16 thresh; + atomic_t free_count; + int dma_size; |