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 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; 32 unsigned int nopaged_len = skb_headlen(skb); 33 unsigned int bmax, len, des2; 34 35 if (priv->extend_desc) 36 desc = (struct dma_desc *)(priv->dma_etx + entry); 37 else 38 desc = priv->dma_tx + entry; 39 40 if (priv->plat->enh_desc) 41 bmax = BUF_SIZE_8KiB; 42 else 43 bmax = BUF_SIZE_2KiB; 44 45 len = nopaged_len - bmax; 46 47 if (nopaged_len > BUF_SIZE_8KiB) { 48 49 des2 = dma_map_single(priv->device, skb->data, bmax, 50 DMA_TO_DEVICE); 51 desc->des2 = cpu_to_le32(des2); 52 if (dma_mapping_error(priv->device, des2)) 53 return -1; 54 55 priv->tx_skbuff_dma[entry].buf = des2; 56 priv->tx_skbuff_dma[entry].len = bmax; 57 priv->tx_skbuff_dma[entry].is_jumbo = true; 58 59 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 60 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum, 61 STMMAC_RING_MODE, 0, false); 62 priv->tx_skbuff[entry] = NULL; 63 entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE); 64 65 if (priv->extend_desc) 66 desc = (struct dma_desc *)(priv->dma_etx + entry); 67 else 68 desc = priv->dma_tx + entry; 69 70 des2 = dma_map_single(priv->device, skb->data + bmax, len, 71 DMA_TO_DEVICE); 72 desc->des2 = cpu_to_le32(des2); 73 if (dma_mapping_error(priv->device, des2)) 74 return -1; 75 priv->tx_skbuff_dma[entry].buf = des2; 76 priv->tx_skbuff_dma[entry].len = len; 77 priv->tx_skbuff_dma[entry].is_jumbo = true; 78 79 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 80 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum, 81 STMMAC_RING_MODE, 1, true); 82 } else { 83 des2 = dma_map_single(priv->device, skb->data, 84 nopaged_len, DMA_TO_DEVICE); 85 desc->des2 = cpu_to_le32(des2); 86 if (dma_mapping_error(priv->device, des2)) 87 return -1; 88 priv->tx_skbuff_dma[entry].buf = des2; 89 priv->tx_skbuff_dma[entry].len = nopaged_len; 90 priv->tx_skbuff_dma[entry].is_jumbo = true; 91 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 92 priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum, 93 STMMAC_RING_MODE, 0, true); 94 } 95 96 priv->cur_tx = entry; 97 98 return entry; 99 } 100 101 static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc) 102 { 103 unsigned int ret = 0; 104 105 if (len >= BUF_SIZE_4KiB) 106 ret = 1; 107 108 return ret; 109 } 110 111 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p) 112 { 113 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 114 115 /* Fill DES3 in case of RING mode */ 116 if (priv->dma_buf_sz >= BUF_SIZE_8KiB) 117 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB); 118 } 119 120 /* In ring mode we need to fill the desc3 because it is used as buffer */ 121 static void stmmac_init_desc3(struct dma_desc *p) 122 { 123 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB); 124 } 125 126 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p) 127 { 128 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr; 129 unsigned int entry = priv->dirty_tx; 130 131 /* des3 is only used for jumbo frames tx or time stamping */ 132 if (unlikely(priv->tx_skbuff_dma[entry].is_jumbo || 133 (priv->tx_skbuff_dma[entry].last_segment && 134 !priv->extend_desc && priv->hwts_tx_en))) 135 p->des3 = 0; 136 } 137 138 static int stmmac_set_16kib_bfsize(int mtu) 139 { 140 int ret = 0; 141 if (unlikely(mtu >= BUF_SIZE_8KiB)) 142 ret = BUF_SIZE_16KiB; 143 return ret; 144 } 145 146 const struct stmmac_mode_ops ring_mode_ops = { 147 .is_jumbo_frm = stmmac_is_jumbo_frm, 148 .jumbo_frm = stmmac_jumbo_frm, 149 .refill_desc3 = stmmac_refill_desc3, 150 .init_desc3 = stmmac_init_desc3, 151 .clean_desc3 = stmmac_clean_desc3, 152 .set_16kib_bfsize = stmmac_set_16kib_bfsize, 153 }; 154