1 /******************************************************************************* 2 Specialised functions for managing Chained 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 You should have received a copy of the GNU General Public License along with 20 this program; if not, write to the Free Software Foundation, Inc., 21 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. 22 23 The full GNU General Public License is included in this distribution in 24 the file called "COPYING". 25 26 Author: Giuseppe Cavallaro <peppe.cavallaro@st.com> 27 *******************************************************************************/ 28 29 #include "stmmac.h" 30 31 static int stmmac_jumbo_frm(void *p, struct sk_buff *skb, int csum) 32 { 33 struct stmmac_priv *priv = (struct stmmac_priv *)p; 34 unsigned int entry = priv->cur_tx; 35 struct dma_desc *desc = priv->dma_tx + entry; 36 unsigned int nopaged_len = skb_headlen(skb); 37 unsigned int bmax; 38 unsigned int i = 1, len; 39 40 if (priv->plat->enh_desc) 41 bmax = BUF_SIZE_8KiB; 42 else 43 bmax = BUF_SIZE_2KiB; 44 45 len = nopaged_len - bmax; 46 47 desc->des2 = dma_map_single(priv->device, skb->data, 48 bmax, DMA_TO_DEVICE); 49 if (dma_mapping_error(priv->device, desc->des2)) 50 return -1; 51 priv->tx_skbuff_dma[entry].buf = desc->des2; 52 priv->tx_skbuff_dma[entry].len = bmax; 53 /* do not close the descriptor and do not set own bit */ 54 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, STMMAC_CHAIN_MODE, 55 0, false); 56 57 while (len != 0) { 58 priv->tx_skbuff[entry] = NULL; 59 entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE); 60 desc = priv->dma_tx + entry; 61 62 if (len > bmax) { 63 desc->des2 = dma_map_single(priv->device, 64 (skb->data + bmax * i), 65 bmax, DMA_TO_DEVICE); 66 if (dma_mapping_error(priv->device, desc->des2)) 67 return -1; 68 priv->tx_skbuff_dma[entry].buf = desc->des2; 69 priv->tx_skbuff_dma[entry].len = bmax; 70 priv->hw->desc->prepare_tx_desc(desc, 0, bmax, csum, 71 STMMAC_CHAIN_MODE, 1, 72 false); 73 len -= bmax; 74 i++; 75 } else { 76 desc->des2 = dma_map_single(priv->device, 77 (skb->data + bmax * i), len, 78 DMA_TO_DEVICE); 79 if (dma_mapping_error(priv->device, desc->des2)) 80 return -1; 81 priv->tx_skbuff_dma[entry].buf = desc->des2; 82 priv->tx_skbuff_dma[entry].len = len; 83 /* last descriptor can be set now */ 84 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum, 85 STMMAC_CHAIN_MODE, 1, 86 true); 87 len = 0; 88 } 89 } 90 91 priv->cur_tx = entry; 92 93 return entry; 94 } 95 96 static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc) 97 { 98 unsigned int ret = 0; 99 100 if ((enh_desc && (len > BUF_SIZE_8KiB)) || 101 (!enh_desc && (len > BUF_SIZE_2KiB))) { 102 ret = 1; 103 } 104 105 return ret; 106 } 107 108 static void stmmac_init_dma_chain(void *des, dma_addr_t phy_addr, 109 unsigned int size, unsigned int extend_desc) 110 { 111 /* 112 * In chained mode the des3 points to the next element in the ring. 113 * The latest element has to point to the head. 114 */ 115 int i; 116 dma_addr_t dma_phy = phy_addr; 117 118 if (extend_desc) { 119 struct dma_extended_desc *p = (struct dma_extended_desc *)des; 120 for (i = 0; i < (size - 1); i++) { 121 dma_phy += sizeof(struct dma_extended_desc); 122 p->basic.des3 = (unsigned int)dma_phy; 123 p++; 124 } 125 p->basic.des3 = (unsigned int)phy_addr; 126 127 } else { 128 struct dma_desc *p = (struct dma_desc *)des; 129 for (i = 0; i < (size - 1); i++) { 130 dma_phy += sizeof(struct dma_desc); 131 p->des3 = (unsigned int)dma_phy; 132 p++; 133 } 134 p->des3 = (unsigned int)phy_addr; 135 } 136 } 137 138 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p) 139 { 140 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 141 142 if (priv->hwts_rx_en && !priv->extend_desc) 143 /* NOTE: Device will overwrite des3 with timestamp value if 144 * 1588-2002 time stamping is enabled, hence reinitialize it 145 * to keep explicit chaining in the descriptor. 146 */ 147 p->des3 = (unsigned int)(priv->dma_rx_phy + 148 (((priv->dirty_rx) + 1) % 149 DMA_RX_SIZE) * 150 sizeof(struct dma_desc)); 151 } 152 153 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p) 154 { 155 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 156 unsigned int entry = priv->dirty_tx; 157 158 if (priv->tx_skbuff_dma[entry].last_segment && !priv->extend_desc && 159 priv->hwts_tx_en) 160 /* NOTE: Device will overwrite des3 with timestamp value if 161 * 1588-2002 time stamping is enabled, hence reinitialize it 162 * to keep explicit chaining in the descriptor. 163 */ 164 p->des3 = (unsigned int)((priv->dma_tx_phy + 165 ((priv->dirty_tx + 1) % DMA_TX_SIZE)) 166 * sizeof(struct dma_desc)); 167 } 168 169 const struct stmmac_mode_ops chain_mode_ops = { 170 .init = stmmac_init_dma_chain, 171 .is_jumbo_frm = stmmac_is_jumbo_frm, 172 .jumbo_frm = stmmac_jumbo_frm, 173 .refill_desc3 = stmmac_refill_desc3, 174 .clean_desc3 = stmmac_clean_desc3, 175 }; 176