1 /******************************************************************************* 2 Specialised functions for managing Ring mode 3 4 Copyright(C) 2011 STMicroelectronics Ltd 5 6 It defines all the functions used to handle the normal/enhanced 7 descriptors in case of the DMA is configured to work in chained or 8 in ring mode. 9 10 This program is free software; you can redistribute it and/or modify it 11 under the terms and conditions of the GNU General Public License, 12 version 2, as published by the Free Software Foundation. 13 14 This program is distributed in the hope it will be useful, but WITHOUT 15 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 17 more details. 18 19 The full GNU General Public License is included in this distribution in 20 the file called "COPYING". 21 22 Author: Giuseppe Cavallaro <peppe.cavallaro@st.com> 23 *******************************************************************************/ 24 25 #include "stmmac.h" 26 27 static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum) 28 { 29 struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)p; 30 unsigned int nopaged_len = skb_headlen(skb); 31 struct stmmac_priv *priv = tx_q->priv_data; 32 unsigned int entry = tx_q->cur_tx; 33 unsigned int bmax, len, des2; 34 struct dma_desc *desc; 35 36 if (priv->extend_desc) 37 desc = (struct dma_desc *)(tx_q->dma_etx + entry); 38 else 39 desc = tx_q->dma_tx + entry; 40 41 if (priv->plat->enh_desc) 42 bmax = BUF_SIZE_8KiB; 43 else 44 bmax = BUF_SIZE_2KiB; 45 46 len = nopaged_len - bmax; 47 48 if (nopaged_len > BUF_SIZE_8KiB) { 49 50 des2 = dma_map_single(priv->device, skb->data, bmax, 51 DMA_TO_DEVICE); 52 desc->des2 = cpu_to_le32(des2); 53 if (dma_mapping_error(priv->device, des2)) 54 return -1; 55 56 tx_q->tx_skbuff_dma[entry].buf = des2; 57 tx_q->tx_skbuff_dma[entry].len = bmax; 58 tx_q->tx_skbuff_dma[entry].is_jumbo = true; 59 60 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 61 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, 62 STMMAC_RING_MODE, 0, 63 false, skb->len); 64 tx_q->tx_skbuff[entry] = NULL; 65 entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE); 66 67 if (priv->extend_desc) 68 desc = (struct dma_desc *)(tx_q->dma_etx + entry); 69 else 70 desc = tx_q->dma_tx + entry; 71 72 des2 = dma_map_single(priv->device, skb->data + bmax, len, 73 DMA_TO_DEVICE); 74 desc->des2 = cpu_to_le32(des2); 75 if (dma_mapping_error(priv->device, des2)) 76 return -1; 77 tx_q->tx_skbuff_dma[entry].buf = des2; 78 tx_q->tx_skbuff_dma[entry].len = len; 79 tx_q->tx_skbuff_dma[entry].is_jumbo = true; 80 81 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 82 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum, 83 STMMAC_RING_MODE, 1, 84 true, skb->len); 85 } else { 86 des2 = dma_map_single(priv->device, skb->data, 87 nopaged_len, DMA_TO_DEVICE); 88 desc->des2 = cpu_to_le32(des2); 89 if (dma_mapping_error(priv->device, des2)) 90 return -1; 91 tx_q->tx_skbuff_dma[entry].buf = des2; 92 tx_q->tx_skbuff_dma[entry].len = nopaged_len; 93 tx_q->tx_skbuff_dma[entry].is_jumbo = true; 94 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 95 priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum, 96 STMMAC_RING_MODE, 0, 97 true, skb->len); 98 } 99 100 tx_q->cur_tx = entry; 101 102 return entry; 103 } 104 105 static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc) 106 { 107 unsigned int ret = 0; 108 109 if (len >= BUF_SIZE_4KiB) 110 ret = 1; 111 112 return ret; 113 } 114 115 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p) 116 { 117 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 118 119 /* Fill DES3 in case of RING mode */ 120 if (priv->dma_buf_sz >= BUF_SIZE_8KiB) 121 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB); 122 } 123 124 /* In ring mode we need to fill the desc3 because it is used as buffer */ 125 static void stmmac_init_desc3(struct dma_desc *p) 126 { 127 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB); 128 } 129 130 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p) 131 { 132 struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)priv_ptr; 133 struct stmmac_priv *priv = tx_q->priv_data; 134 unsigned int entry = tx_q->dirty_tx; 135 136 /* des3 is only used for jumbo frames tx or time stamping */ 137 if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo || 138 (tx_q->tx_skbuff_dma[entry].last_segment && 139 !priv->extend_desc && priv->hwts_tx_en))) 140 p->des3 = 0; 141 } 142 143 static int stmmac_set_16kib_bfsize(int mtu) 144 { 145 int ret = 0; 146 if (unlikely(mtu >= BUF_SIZE_8KiB)) 147 ret = BUF_SIZE_16KiB; 148 return ret; 149 } 150 151 const struct stmmac_mode_ops ring_mode_ops = { 152 .is_jumbo_frm = stmmac_is_jumbo_frm, 153 .jumbo_frm = stmmac_jumbo_frm, 154 .refill_desc3 = stmmac_refill_desc3, 155 .init_desc3 = stmmac_init_desc3, 156 .clean_desc3 = stmmac_clean_desc3, 157 .set_16kib_bfsize = stmmac_set_16kib_bfsize, 158 }; 159