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 jumbo_frm(void *p, struct sk_buff *skb, int csum) 28 { 29 struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)p; 30 unsigned int nopaged_len = skb_headlen(skb); 31 struct stmmac_priv *priv = tx_q->priv_data; 32 unsigned int entry = tx_q->cur_tx; 33 unsigned int bmax, len, des2; 34 struct dma_desc *desc; 35 36 if (priv->extend_desc) 37 desc = (struct dma_desc *)(tx_q->dma_etx + entry); 38 else 39 desc = tx_q->dma_tx + entry; 40 41 if (priv->plat->enh_desc) 42 bmax = BUF_SIZE_8KiB; 43 else 44 bmax = BUF_SIZE_2KiB; 45 46 len = nopaged_len - bmax; 47 48 if (nopaged_len > BUF_SIZE_8KiB) { 49 50 des2 = dma_map_single(priv->device, skb->data, bmax, 51 DMA_TO_DEVICE); 52 desc->des2 = cpu_to_le32(des2); 53 if (dma_mapping_error(priv->device, des2)) 54 return -1; 55 56 tx_q->tx_skbuff_dma[entry].buf = des2; 57 tx_q->tx_skbuff_dma[entry].len = bmax; 58 tx_q->tx_skbuff_dma[entry].is_jumbo = true; 59 60 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 61 stmmac_prepare_tx_desc(priv, desc, 1, bmax, csum, 62 STMMAC_RING_MODE, 0, false, skb->len); 63 tx_q->tx_skbuff[entry] = NULL; 64 entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE); 65 66 if (priv->extend_desc) 67 desc = (struct dma_desc *)(tx_q->dma_etx + entry); 68 else 69 desc = tx_q->dma_tx + entry; 70 71 des2 = dma_map_single(priv->device, skb->data + bmax, len, 72 DMA_TO_DEVICE); 73 desc->des2 = cpu_to_le32(des2); 74 if (dma_mapping_error(priv->device, des2)) 75 return -1; 76 tx_q->tx_skbuff_dma[entry].buf = des2; 77 tx_q->tx_skbuff_dma[entry].len = len; 78 tx_q->tx_skbuff_dma[entry].is_jumbo = true; 79 80 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 81 stmmac_prepare_tx_desc(priv, desc, 0, len, csum, 82 STMMAC_RING_MODE, 1, !skb_is_nonlinear(skb), 83 skb->len); 84 } else { 85 des2 = dma_map_single(priv->device, skb->data, 86 nopaged_len, DMA_TO_DEVICE); 87 desc->des2 = cpu_to_le32(des2); 88 if (dma_mapping_error(priv->device, des2)) 89 return -1; 90 tx_q->tx_skbuff_dma[entry].buf = des2; 91 tx_q->tx_skbuff_dma[entry].len = nopaged_len; 92 tx_q->tx_skbuff_dma[entry].is_jumbo = true; 93 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB); 94 stmmac_prepare_tx_desc(priv, desc, 1, nopaged_len, csum, 95 STMMAC_RING_MODE, 0, !skb_is_nonlinear(skb), 96 skb->len); 97 } 98 99 tx_q->cur_tx = entry; 100 101 return entry; 102 } 103 104 static unsigned int is_jumbo_frm(int len, int enh_desc) 105 { 106 unsigned int ret = 0; 107 108 if (len >= BUF_SIZE_4KiB) 109 ret = 1; 110 111 return ret; 112 } 113 114 static void refill_desc3(void *priv_ptr, struct dma_desc *p) 115 { 116 struct stmmac_rx_queue *rx_q = priv_ptr; 117 struct stmmac_priv *priv = rx_q->priv_data; 118 119 /* Fill DES3 in case of RING mode */ 120 if (priv->dma_buf_sz == BUF_SIZE_16KiB) 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 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 clean_desc3(void *priv_ptr, struct dma_desc *p) 131 { 132 struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)priv_ptr; 133 struct stmmac_priv *priv = tx_q->priv_data; 134 unsigned int entry = tx_q->dirty_tx; 135 136 /* des3 is only used for jumbo frames tx or time stamping */ 137 if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo || 138 (tx_q->tx_skbuff_dma[entry].last_segment && 139 !priv->extend_desc && priv->hwts_tx_en))) 140 p->des3 = 0; 141 } 142 143 static int set_16kib_bfsize(int mtu) 144 { 145 int ret = 0; 146 if (unlikely(mtu > BUF_SIZE_8KiB)) 147 ret = BUF_SIZE_16KiB; 148 return ret; 149 } 150 151 const struct stmmac_mode_ops ring_mode_ops = { 152 .is_jumbo_frm = is_jumbo_frm, 153 .jumbo_frm = jumbo_frm, 154 .refill_desc3 = refill_desc3, 155 .init_desc3 = init_desc3, 156 .clean_desc3 = clean_desc3, 157 .set_16kib_bfsize = set_16kib_bfsize, 158 }; 159