68 lines
2.3 KiB
Diff
68 lines
2.3 KiB
Diff
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
|
|
@@ -1362,7 +1362,7 @@ 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);
|
|
@@ -1396,6 +1396,7 @@ 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;
|
|
@@ -1596,6 +1597,7 @@ 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
|
|
@@ -1609,9 +1611,7 @@ 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
|
|
@@ -624,6 +624,7 @@ 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
|
|
@@ -634,6 +635,7 @@ 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;
|