147 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*******************************************************************************3 Specialised functions for managing Ring mode4 5 Copyright(C) 2011 STMicroelectronics Ltd6 7 It defines all the functions used to handle the normal/enhanced8 descriptors in case of the DMA is configured to work in chained or9 in ring mode.10 11 12 Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>13*******************************************************************************/14 15#include "stmmac.h"16 17static int jumbo_frm(struct stmmac_tx_queue *tx_q, struct sk_buff *skb,18 int csum)19{20 unsigned int nopaged_len = skb_headlen(skb);21 struct stmmac_priv *priv = tx_q->priv_data;22 unsigned int entry = tx_q->cur_tx;23 unsigned int bmax, len, des2;24 struct dma_desc *desc;25 26 if (priv->extend_desc)27 desc = (struct dma_desc *)(tx_q->dma_etx + entry);28 else29 desc = tx_q->dma_tx + entry;30 31 if (priv->plat->enh_desc)32 bmax = BUF_SIZE_8KiB;33 else34 bmax = BUF_SIZE_2KiB;35 36 len = nopaged_len - bmax;37 38 if (nopaged_len > BUF_SIZE_8KiB) {39 40 des2 = dma_map_single(priv->device, skb->data, bmax,41 DMA_TO_DEVICE);42 desc->des2 = cpu_to_le32(des2);43 if (dma_mapping_error(priv->device, des2))44 return -1;45 46 tx_q->tx_skbuff_dma[entry].buf = des2;47 tx_q->tx_skbuff_dma[entry].len = bmax;48 tx_q->tx_skbuff_dma[entry].is_jumbo = true;49 50 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);51 stmmac_prepare_tx_desc(priv, desc, 1, bmax, csum,52 STMMAC_RING_MODE, 0, false, skb->len);53 tx_q->tx_skbuff[entry] = NULL;54 entry = STMMAC_GET_ENTRY(entry, priv->dma_conf.dma_tx_size);55 56 if (priv->extend_desc)57 desc = (struct dma_desc *)(tx_q->dma_etx + entry);58 else59 desc = tx_q->dma_tx + entry;60 61 des2 = dma_map_single(priv->device, skb->data + bmax, len,62 DMA_TO_DEVICE);63 desc->des2 = cpu_to_le32(des2);64 if (dma_mapping_error(priv->device, des2))65 return -1;66 tx_q->tx_skbuff_dma[entry].buf = des2;67 tx_q->tx_skbuff_dma[entry].len = len;68 tx_q->tx_skbuff_dma[entry].is_jumbo = true;69 70 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);71 stmmac_prepare_tx_desc(priv, desc, 0, len, csum,72 STMMAC_RING_MODE, 1, !skb_is_nonlinear(skb),73 skb->len);74 } else {75 des2 = dma_map_single(priv->device, skb->data,76 nopaged_len, DMA_TO_DEVICE);77 desc->des2 = cpu_to_le32(des2);78 if (dma_mapping_error(priv->device, des2))79 return -1;80 tx_q->tx_skbuff_dma[entry].buf = des2;81 tx_q->tx_skbuff_dma[entry].len = nopaged_len;82 tx_q->tx_skbuff_dma[entry].is_jumbo = true;83 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);84 stmmac_prepare_tx_desc(priv, desc, 1, nopaged_len, csum,85 STMMAC_RING_MODE, 0, !skb_is_nonlinear(skb),86 skb->len);87 }88 89 tx_q->cur_tx = entry;90 91 return entry;92}93 94static unsigned int is_jumbo_frm(int len, int enh_desc)95{96 unsigned int ret = 0;97 98 if (len >= BUF_SIZE_4KiB)99 ret = 1;100 101 return ret;102}103 104static void refill_desc3(struct stmmac_rx_queue *rx_q, struct dma_desc *p)105{106 struct stmmac_priv *priv = rx_q->priv_data;107 108 /* Fill DES3 in case of RING mode */109 if (priv->dma_conf.dma_buf_sz == BUF_SIZE_16KiB)110 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);111}112 113/* In ring mode we need to fill the desc3 because it is used as buffer */114static void init_desc3(struct dma_desc *p)115{116 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);117}118 119static void clean_desc3(struct stmmac_tx_queue *tx_q, struct dma_desc *p)120{121 struct stmmac_priv *priv = tx_q->priv_data;122 unsigned int entry = tx_q->dirty_tx;123 124 /* des3 is only used for jumbo frames tx or time stamping */125 if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo ||126 (tx_q->tx_skbuff_dma[entry].last_segment &&127 !priv->extend_desc && priv->hwts_tx_en)))128 p->des3 = 0;129}130 131static int set_16kib_bfsize(int mtu)132{133 int ret = 0;134 if (unlikely(mtu > BUF_SIZE_8KiB))135 ret = BUF_SIZE_16KiB;136 return ret;137}138 139const struct stmmac_mode_ops ring_mode_ops = {140 .is_jumbo_frm = is_jumbo_frm,141 .jumbo_frm = jumbo_frm,142 .refill_desc3 = refill_desc3,143 .init_desc3 = init_desc3,144 .clean_desc3 = clean_desc3,145 .set_16kib_bfsize = set_16kib_bfsize,146};147