Openwrt/target/linux/generic/pending-5.4/770-08-net-ethernet-mtk_eth_soc-cache-hardware-pointer-of-l.patch
John Audia 752cd29904 kernel: bump 5.4 to 5.4.124
Manually rebased:
  generic/hack-5.4/662-remove_pfifo_fast.patch

All other patches automatically rebased.

Build system: x86_64
Build-tested: ipq806x/R7800
Run-tested: ipq806x/R7800

No dmesg regressions, everything functional

Signed-off-by: John Audia <graysky@archlinux.us>
[manual changes to ramips/patches-5.10/835-asoc-add-mt7620-support.patch]
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2021-06-06 00:25:25 +02:00

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
@@ -1379,7 +1379,7 @@ 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);
@@ -1413,6 +1413,7 @@ 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;
@@ -1613,6 +1614,7 @@ 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
@@ -1626,9 +1628,7 @@ 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
@@ -644,6 +644,7 @@ 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
@@ -654,6 +655,7 @@ 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;