1 /******************************************************************************* 2 Specialised functions for managing Ring 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; 36 unsigned int nopaged_len = skb_headlen(skb); 37 unsigned int bmax, len, des2; 38 39 if (priv->extend_desc) 40 desc = (struct dma_desc *)(priv->dma_etx + entry); 41 else 42 desc = priv->dma_tx + entry; 43 44 if (priv->plat->enh_desc) 45 bmax = BUF_SIZE_8KiB; 46 else 47 bmax = BUF_SIZE_2KiB; 48 49 len = nopaged_len - bmax; 50 51 if (nopaged_len > BUF_SIZE_8KiB) { 52 53 des2 = dma_map_single(priv->device, skb->data, bmax, 54 DMA_TO_DEVICE); 55 desc->des2 = cpu_to_le32(des2); 56 if (dma_mapping_error(priv->device, des2)) 57 return -1; 58 59 priv->tx_skbuff_dma[entry].buf = des2; 60 priv->tx_skbuff_dma[entry].len = bmax; 61 priv->tx_skbuff_dma[entry].is_jumbo = true; 62 63 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 64 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, 65 STMMAC_RING_MODE, 0, false); 66 priv->tx_skbuff[entry] = NULL; 67 entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE); 68 69 if (priv->extend_desc) 70 desc = (struct dma_desc *)(priv->dma_etx + entry); 71 else 72 desc = priv->dma_tx + entry; 73 74 des2 = dma_map_single(priv->device, skb->data + bmax, len, 75 DMA_TO_DEVICE); 76 desc->des2 = cpu_to_le32(des2); 77 if (dma_mapping_error(priv->device, des2)) 78 return -1; 79 priv->tx_skbuff_dma[entry].buf = des2; 80 priv->tx_skbuff_dma[entry].len = len; 81 priv->tx_skbuff_dma[entry].is_jumbo = true; 82 83 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 84 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum, 85 STMMAC_RING_MODE, 1, true); 86 } else { 87 des2 = dma_map_single(priv->device, skb->data, 88 nopaged_len, DMA_TO_DEVICE); 89 desc->des2 = cpu_to_le32(des2); 90 if (dma_mapping_error(priv->device, des2)) 91 return -1; 92 priv->tx_skbuff_dma[entry].buf = des2; 93 priv->tx_skbuff_dma[entry].len = nopaged_len; 94 priv->tx_skbuff_dma[entry].is_jumbo = true; 95 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 96 priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum, 97 STMMAC_RING_MODE, 0, true); 98 } 99 100 priv->cur_tx = entry; 101 102 return entry; 103 } 104 105 static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc) 106 { 107 unsigned int ret = 0; 108 109 if (len >= BUF_SIZE_4KiB) 110 ret = 1; 111 112 return ret; 113 } 114 115 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p) 116 { 117 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 118 119 /* Fill DES3 in case of RING mode */ 120 if (priv->dma_buf_sz >= BUF_SIZE_8KiB) 121 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB); 122 } 123 124 /* In ring mode we need to fill the desc3 because it is used as buffer */ 125 static void stmmac_init_desc3(struct dma_desc *p) 126 { 127 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB); 128 } 129 130 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p) 131 { 132 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 133 unsigned int entry = priv->dirty_tx; 134 135 /* des3 is only used for jumbo frames tx or time stamping */ 136 if (unlikely(priv->tx_skbuff_dma[entry].is_jumbo || 137 (priv->tx_skbuff_dma[entry].last_segment && 138 !priv->extend_desc && priv->hwts_tx_en))) 139 p->des3 = 0; 140 } 141 142 static int stmmac_set_16kib_bfsize(int mtu) 143 { 144 int ret = 0; 145 if (unlikely(mtu >= BUF_SIZE_8KiB)) 146 ret = BUF_SIZE_16KiB; 147 return ret; 148 } 149 150 const struct stmmac_mode_ops ring_mode_ops = { 151 .is_jumbo_frm = stmmac_is_jumbo_frm, 152 .jumbo_frm = stmmac_jumbo_frm, 153 .refill_desc3 = stmmac_refill_desc3, 154 .init_desc3 = stmmac_init_desc3, 155 .clean_desc3 = stmmac_clean_desc3, 156 .set_16kib_bfsize = stmmac_set_16kib_bfsize, 157 }; 158