openwrt/target/linux/generic/pending-5.4/770-08-net-ethernet-mtk_eth_soc-cache-hardware-pointer-of-l.patch
Hauke Mehrtens be0639063a kernel: bump 5.4 to 5.4.203
Merged upstream:
 bcm27xx/patches-5.4/950-1014-Revert-mailbox-avoid-timer-start-from-callback.patch
 generic/backport-5.4/080-wireguard-0021-crypto-blake2s-generic-C-library-implementation-and-.patch

Manually adapted:
 layerscape/patches-5.4/801-audio-0005-Revert-ASoC-fsl_sai-Add-support-for-SAI-new-version.patch
 oxnas/patches-5.4/100-oxnas-clk-plla-pllb.patch

Compile-tested: lantiq/xrx200
Run-tested: lantiq/xrx200

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2022-07-03 19:58:31 +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
@@ -1393,7 +1393,7 @@ 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);
@@ -1427,6 +1427,7 @@ 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;
@@ -1627,6 +1628,7 @@ 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
@@ -1640,9 +1642,7 @@ 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;