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 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_priv *priv = (struct stmmac_priv *)p; 30 unsigned int entry = priv->cur_tx; 31 struct dma_desc *desc = priv->dma_tx + entry; 32 unsigned int nopaged_len = skb_headlen(skb); 33 unsigned int bmax, des2; 34 unsigned int i = 1, len; 35 36 if (priv->plat->enh_desc) 37 bmax = BUF_SIZE_8KiB; 38 else 39 bmax = BUF_SIZE_2KiB; 40 41 len = nopaged_len - bmax; 42 43 des2 = dma_map_single(priv->device, skb->data, 44 bmax, DMA_TO_DEVICE); 45 desc->des2 = cpu_to_le32(des2); 46 if (dma_mapping_error(priv->device, des2)) 47 return -1; 48 priv->tx_skbuff_dma[entry].buf = des2; 49 priv->tx_skbuff_dma[entry].len = bmax; 50 /* do not close the descriptor and do not set own bit */ 51 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, STMMAC_CHAIN_MODE, 52 0, false); 53 54 while (len != 0) { 55 priv->tx_skbuff[entry] = NULL; 56 entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE); 57 desc = priv->dma_tx + entry; 58 59 if (len > bmax) { 60 des2 = dma_map_single(priv->device, 61 (skb->data + bmax * i), 62 bmax, DMA_TO_DEVICE); 63 desc->des2 = cpu_to_le32(des2); 64 if (dma_mapping_error(priv->device, des2)) 65 return -1; 66 priv->tx_skbuff_dma[entry].buf = des2; 67 priv->tx_skbuff_dma[entry].len = bmax; 68 priv->hw->desc->prepare_tx_desc(desc, 0, bmax, csum, 69 STMMAC_CHAIN_MODE, 1, 70 false); 71 len -= bmax; 72 i++; 73 } else { 74 des2 = dma_map_single(priv->device, 75 (skb->data + bmax * i), len, 76 DMA_TO_DEVICE); 77 desc->des2 = cpu_to_le32(des2); 78 if (dma_mapping_error(priv->device, des2)) 79 return -1; 80 priv->tx_skbuff_dma[entry].buf = des2; 81 priv->tx_skbuff_dma[entry].len = len; 82 /* last descriptor can be set now */ 83 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum, 84 STMMAC_CHAIN_MODE, 1, 85 true); 86 len = 0; 87 } 88 } 89 90 priv->cur_tx = entry; 91 92 return entry; 93 } 94 95 static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc) 96 { 97 unsigned int ret = 0; 98 99 if ((enh_desc && (len > BUF_SIZE_8KiB)) || 100 (!enh_desc && (len > BUF_SIZE_2KiB))) { 101 ret = 1; 102 } 103 104 return ret; 105 } 106 107 static void stmmac_init_dma_chain(void *des, dma_addr_t phy_addr, 108 unsigned int size, unsigned int extend_desc) 109 { 110 /* 111 * In chained mode the des3 points to the next element in the ring. 112 * The latest element has to point to the head. 113 */ 114 int i; 115 dma_addr_t dma_phy = phy_addr; 116 117 if (extend_desc) { 118 struct dma_extended_desc *p = (struct dma_extended_desc *)des; 119 for (i = 0; i < (size - 1); i++) { 120 dma_phy += sizeof(struct dma_extended_desc); 121 p->basic.des3 = cpu_to_le32((unsigned int)dma_phy); 122 p++; 123 } 124 p->basic.des3 = cpu_to_le32((unsigned int)phy_addr); 125 126 } else { 127 struct dma_desc *p = (struct dma_desc *)des; 128 for (i = 0; i < (size - 1); i++) { 129 dma_phy += sizeof(struct dma_desc); 130 p->des3 = cpu_to_le32((unsigned int)dma_phy); 131 p++; 132 } 133 p->des3 = cpu_to_le32((unsigned int)phy_addr); 134 } 135 } 136 137 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p) 138 { 139 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 140 141 if (priv->hwts_rx_en && !priv->extend_desc) 142 /* NOTE: Device will overwrite des3 with timestamp value if 143 * 1588-2002 time stamping is enabled, hence reinitialize it 144 * to keep explicit chaining in the descriptor. 145 */ 146 p->des3 = cpu_to_le32((unsigned int)(priv->dma_rx_phy + 147 (((priv->dirty_rx) + 1) % 148 DMA_RX_SIZE) * 149 sizeof(struct dma_desc))); 150 } 151 152 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p) 153 { 154 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 155 unsigned int entry = priv->dirty_tx; 156 157 if (priv->tx_skbuff_dma[entry].last_segment && !priv->extend_desc && 158 priv->hwts_tx_en) 159 /* NOTE: Device will overwrite des3 with timestamp value if 160 * 1588-2002 time stamping is enabled, hence reinitialize it 161 * to keep explicit chaining in the descriptor. 162 */ 163 p->des3 = cpu_to_le32((unsigned int)((priv->dma_tx_phy + 164 ((priv->dirty_tx + 1) % DMA_TX_SIZE)) 165 * sizeof(struct dma_desc))); 166 } 167 168 const struct stmmac_mode_ops chain_mode_ops = { 169 .init = stmmac_init_dma_chain, 170 .is_jumbo_frm = stmmac_is_jumbo_frm, 171 .jumbo_frm = stmmac_jumbo_frm, 172 .refill_desc3 = stmmac_refill_desc3, 173 .clean_desc3 = stmmac_clean_desc3, 174 }; 175