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