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, des2; 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 des2 = dma_map_single(priv->device, skb->data, 48 bmax, DMA_TO_DEVICE); 49 desc->des2 = cpu_to_le32(des2); 50 if (dma_mapping_error(priv->device, des2)) 51 return -1; 52 priv->tx_skbuff_dma[entry].buf = des2; 53 priv->tx_skbuff_dma[entry].len = bmax; 54 /* do not close the descriptor and do not set own bit */ 55 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, STMMAC_CHAIN_MODE, 56 0, false); 57 58 while (len != 0) { 59 priv->tx_skbuff[entry] = NULL; 60 entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE); 61 desc = priv->dma_tx + entry; 62 63 if (len > bmax) { 64 des2 = dma_map_single(priv->device, 65 (skb->data + bmax * i), 66 bmax, DMA_TO_DEVICE); 67 desc->des2 = cpu_to_le32(des2); 68 if (dma_mapping_error(priv->device, des2)) 69 return -1; 70 priv->tx_skbuff_dma[entry].buf = des2; 71 priv->tx_skbuff_dma[entry].len = bmax; 72 priv->hw->desc->prepare_tx_desc(desc, 0, bmax, csum, 73 STMMAC_CHAIN_MODE, 1, 74 false); 75 len -= bmax; 76 i++; 77 } else { 78 des2 = dma_map_single(priv->device, 79 (skb->data + bmax * i), len, 80 DMA_TO_DEVICE); 81 desc->des2 = cpu_to_le32(des2); 82 if (dma_mapping_error(priv->device, des2)) 83 return -1; 84 priv->tx_skbuff_dma[entry].buf = des2; 85 priv->tx_skbuff_dma[entry].len = len; 86 /* last descriptor can be set now */ 87 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum, 88 STMMAC_CHAIN_MODE, 1, 89 true); 90 len = 0; 91 } 92 } 93 94 priv->cur_tx = entry; 95 96 return entry; 97 } 98 99 static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc) 100 { 101 unsigned int ret = 0; 102 103 if ((enh_desc && (len > BUF_SIZE_8KiB)) || 104 (!enh_desc && (len > BUF_SIZE_2KiB))) { 105 ret = 1; 106 } 107 108 return ret; 109 } 110 111 static void stmmac_init_dma_chain(void *des, dma_addr_t phy_addr, 112 unsigned int size, unsigned int extend_desc) 113 { 114 /* 115 * In chained mode the des3 points to the next element in the ring. 116 * The latest element has to point to the head. 117 */ 118 int i; 119 dma_addr_t dma_phy = phy_addr; 120 121 if (extend_desc) { 122 struct dma_extended_desc *p = (struct dma_extended_desc *)des; 123 for (i = 0; i < (size - 1); i++) { 124 dma_phy += sizeof(struct dma_extended_desc); 125 p->basic.des3 = cpu_to_le32((unsigned int)dma_phy); 126 p++; 127 } 128 p->basic.des3 = cpu_to_le32((unsigned int)phy_addr); 129 130 } else { 131 struct dma_desc *p = (struct dma_desc *)des; 132 for (i = 0; i < (size - 1); i++) { 133 dma_phy += sizeof(struct dma_desc); 134 p->des3 = cpu_to_le32((unsigned int)dma_phy); 135 p++; 136 } 137 p->des3 = cpu_to_le32((unsigned int)phy_addr); 138 } 139 } 140 141 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p) 142 { 143 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 144 145 if (priv->hwts_rx_en && !priv->extend_desc) 146 /* NOTE: Device will overwrite des3 with timestamp value if 147 * 1588-2002 time stamping is enabled, hence reinitialize it 148 * to keep explicit chaining in the descriptor. 149 */ 150 p->des3 = cpu_to_le32((unsigned int)(priv->dma_rx_phy + 151 (((priv->dirty_rx) + 1) % 152 DMA_RX_SIZE) * 153 sizeof(struct dma_desc))); 154 } 155 156 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p) 157 { 158 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 159 unsigned int entry = priv->dirty_tx; 160 161 if (priv->tx_skbuff_dma[entry].last_segment && !priv->extend_desc && 162 priv->hwts_tx_en) 163 /* NOTE: Device will overwrite des3 with timestamp value if 164 * 1588-2002 time stamping is enabled, hence reinitialize it 165 * to keep explicit chaining in the descriptor. 166 */ 167 p->des3 = cpu_to_le32((unsigned int)((priv->dma_tx_phy + 168 ((priv->dirty_tx + 1) % DMA_TX_SIZE)) 169 * sizeof(struct dma_desc))); 170 } 171 172 const struct stmmac_mode_ops chain_mode_ops = { 173 .init = stmmac_init_dma_chain, 174 .is_jumbo_frm = stmmac_is_jumbo_frm, 175 .jumbo_frm = stmmac_jumbo_frm, 176 .refill_desc3 = stmmac_refill_desc3, 177 .clean_desc3 = stmmac_clean_desc3, 178 }; 179