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 txsize = priv->dma_tx_size; 35 unsigned int entry = priv->cur_tx % txsize; 36 struct dma_desc *desc = priv->dma_tx + entry; 37 unsigned int nopaged_len = skb_headlen(skb); 38 unsigned int bmax; 39 unsigned int i = 1, len; 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 desc->des2 = dma_map_single(priv->device, skb->data, 49 bmax, DMA_TO_DEVICE); 50 if (dma_mapping_error(priv->device, desc->des2)) 51 return -1; 52 priv->tx_skbuff_dma[entry].buf = desc->des2; 53 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, STMMAC_CHAIN_MODE); 54 55 while (len != 0) { 56 priv->tx_skbuff[entry] = NULL; 57 entry = (++priv->cur_tx) % txsize; 58 desc = priv->dma_tx + entry; 59 60 if (len > bmax) { 61 desc->des2 = dma_map_single(priv->device, 62 (skb->data + bmax * i), 63 bmax, DMA_TO_DEVICE); 64 if (dma_mapping_error(priv->device, desc->des2)) 65 return -1; 66 priv->tx_skbuff_dma[entry].buf = desc->des2; 67 priv->hw->desc->prepare_tx_desc(desc, 0, bmax, csum, 68 STMMAC_CHAIN_MODE); 69 priv->hw->desc->set_tx_owner(desc); 70 len -= bmax; 71 i++; 72 } else { 73 desc->des2 = dma_map_single(priv->device, 74 (skb->data + bmax * i), len, 75 DMA_TO_DEVICE); 76 if (dma_mapping_error(priv->device, desc->des2)) 77 return -1; 78 priv->tx_skbuff_dma[entry].buf = desc->des2; 79 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum, 80 STMMAC_CHAIN_MODE); 81 priv->hw->desc->set_tx_owner(desc); 82 len = 0; 83 } 84 } 85 return entry; 86 } 87 88 static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc) 89 { 90 unsigned int ret = 0; 91 92 if ((enh_desc && (len > BUF_SIZE_8KiB)) || 93 (!enh_desc && (len > BUF_SIZE_2KiB))) { 94 ret = 1; 95 } 96 97 return ret; 98 } 99 100 static void stmmac_init_dma_chain(void *des, dma_addr_t phy_addr, 101 unsigned int size, unsigned int extend_desc) 102 { 103 /* 104 * In chained mode the des3 points to the next element in the ring. 105 * The latest element has to point to the head. 106 */ 107 int i; 108 dma_addr_t dma_phy = phy_addr; 109 110 if (extend_desc) { 111 struct dma_extended_desc *p = (struct dma_extended_desc *)des; 112 for (i = 0; i < (size - 1); i++) { 113 dma_phy += sizeof(struct dma_extended_desc); 114 p->basic.des3 = (unsigned int)dma_phy; 115 p++; 116 } 117 p->basic.des3 = (unsigned int)phy_addr; 118 119 } else { 120 struct dma_desc *p = (struct dma_desc *)des; 121 for (i = 0; i < (size - 1); i++) { 122 dma_phy += sizeof(struct dma_desc); 123 p->des3 = (unsigned int)dma_phy; 124 p++; 125 } 126 p->des3 = (unsigned int)phy_addr; 127 } 128 } 129 130 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p) 131 { 132 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 133 134 if (priv->hwts_rx_en && !priv->extend_desc) 135 /* NOTE: Device will overwrite des3 with timestamp value if 136 * 1588-2002 time stamping is enabled, hence reinitialize it 137 * to keep explicit chaining in the descriptor. 138 */ 139 p->des3 = (unsigned int)(priv->dma_rx_phy + 140 (((priv->dirty_rx) + 1) % 141 priv->dma_rx_size) * 142 sizeof(struct dma_desc)); 143 } 144 145 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p) 146 { 147 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 148 149 if (priv->hw->desc->get_tx_ls(p) && !priv->extend_desc) 150 /* NOTE: Device will overwrite des3 with timestamp value if 151 * 1588-2002 time stamping is enabled, hence reinitialize it 152 * to keep explicit chaining in the descriptor. 153 */ 154 p->des3 = (unsigned int)(priv->dma_tx_phy + 155 (((priv->dirty_tx + 1) % 156 priv->dma_tx_size) * 157 sizeof(struct dma_desc))); 158 } 159 160 const struct stmmac_mode_ops chain_mode_ops = { 161 .init = stmmac_init_dma_chain, 162 .is_jumbo_frm = stmmac_is_jumbo_frm, 163 .jumbo_frm = stmmac_jumbo_frm, 164 .refill_desc3 = stmmac_refill_desc3, 165 .clean_desc3 = stmmac_clean_desc3, 166 }; 167