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