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 txsize = priv->dma_tx_size; 35 unsigned int entry = priv->cur_tx % txsize; 36 struct dma_desc *desc; 37 unsigned int nopaged_len = skb_headlen(skb); 38 unsigned int bmax, len; 39 40 if (priv->extend_desc) 41 desc = (struct dma_desc *)(priv->dma_etx + entry); 42 else 43 desc = priv->dma_tx + entry; 44 45 if (priv->plat->enh_desc) 46 bmax = BUF_SIZE_8KiB; 47 else 48 bmax = BUF_SIZE_2KiB; 49 50 len = nopaged_len - bmax; 51 52 if (nopaged_len > BUF_SIZE_8KiB) { 53 54 desc->des2 = dma_map_single(priv->device, skb->data, 55 bmax, DMA_TO_DEVICE); 56 if (dma_mapping_error(priv->device, desc->des2)) 57 return -1; 58 59 priv->tx_skbuff_dma[entry].buf = desc->des2; 60 desc->des3 = desc->des2 + BUF_SIZE_4KiB; 61 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, 62 STMMAC_RING_MODE); 63 wmb(); 64 priv->tx_skbuff[entry] = NULL; 65 entry = (++priv->cur_tx) % txsize; 66 67 if (priv->extend_desc) 68 desc = (struct dma_desc *)(priv->dma_etx + entry); 69 else 70 desc = priv->dma_tx + entry; 71 72 desc->des2 = dma_map_single(priv->device, skb->data + bmax, 73 len, DMA_TO_DEVICE); 74 if (dma_mapping_error(priv->device, desc->des2)) 75 return -1; 76 priv->tx_skbuff_dma[entry].buf = desc->des2; 77 desc->des3 = desc->des2 + BUF_SIZE_4KiB; 78 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum, 79 STMMAC_RING_MODE); 80 wmb(); 81 priv->hw->desc->set_tx_owner(desc); 82 } else { 83 desc->des2 = dma_map_single(priv->device, skb->data, 84 nopaged_len, DMA_TO_DEVICE); 85 if (dma_mapping_error(priv->device, desc->des2)) 86 return -1; 87 priv->tx_skbuff_dma[entry].buf = desc->des2; 88 desc->des3 = desc->des2 + BUF_SIZE_4KiB; 89 priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum, 90 STMMAC_RING_MODE); 91 } 92 93 return entry; 94 } 95 96 static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc) 97 { 98 unsigned int ret = 0; 99 100 if (len >= BUF_SIZE_4KiB) 101 ret = 1; 102 103 return ret; 104 } 105 106 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p) 107 { 108 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 109 110 /* Fill DES3 in case of RING mode */ 111 if (priv->dma_buf_sz >= BUF_SIZE_8KiB) 112 p->des3 = p->des2 + BUF_SIZE_8KiB; 113 } 114 115 /* In ring mode we need to fill the desc3 because it is used as buffer */ 116 static void stmmac_init_desc3(struct dma_desc *p) 117 { 118 p->des3 = p->des2 + BUF_SIZE_8KiB; 119 } 120 121 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p) 122 { 123 if (unlikely(p->des3)) 124 p->des3 = 0; 125 } 126 127 static int stmmac_set_16kib_bfsize(int mtu) 128 { 129 int ret = 0; 130 if (unlikely(mtu >= BUF_SIZE_8KiB)) 131 ret = BUF_SIZE_16KiB; 132 return ret; 133 } 134 135 const struct stmmac_mode_ops ring_mode_ops = { 136 .is_jumbo_frm = stmmac_is_jumbo_frm, 137 .jumbo_frm = stmmac_jumbo_frm, 138 .refill_desc3 = stmmac_refill_desc3, 139 .init_desc3 = stmmac_init_desc3, 140 .clean_desc3 = stmmac_clean_desc3, 141 .set_16kib_bfsize = stmmac_set_16kib_bfsize, 142 }; 143