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
stmmac_jumbo_frm(void * p,struct sk_buff * skb,int csum)27 static int stmmac_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 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum,
62 STMMAC_RING_MODE, 0,
63 false, skb->len);
64 tx_q->tx_skbuff[entry] = NULL;
65 entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE);
66
67 if (priv->extend_desc)
68 desc = (struct dma_desc *)(tx_q->dma_etx + entry);
69 else
70 desc = tx_q->dma_tx + entry;
71
72 des2 = dma_map_single(priv->device, skb->data + bmax, len,
73 DMA_TO_DEVICE);
74 desc->des2 = cpu_to_le32(des2);
75 if (dma_mapping_error(priv->device, des2))
76 return -1;
77 tx_q->tx_skbuff_dma[entry].buf = des2;
78 tx_q->tx_skbuff_dma[entry].len = len;
79 tx_q->tx_skbuff_dma[entry].is_jumbo = true;
80
81 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
82 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum,
83 STMMAC_RING_MODE, 1,
84 true, skb->len);
85 } else {
86 des2 = dma_map_single(priv->device, skb->data,
87 nopaged_len, DMA_TO_DEVICE);
88 desc->des2 = cpu_to_le32(des2);
89 if (dma_mapping_error(priv->device, des2))
90 return -1;
91 tx_q->tx_skbuff_dma[entry].buf = des2;
92 tx_q->tx_skbuff_dma[entry].len = nopaged_len;
93 tx_q->tx_skbuff_dma[entry].is_jumbo = true;
94 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
95 priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum,
96 STMMAC_RING_MODE, 0,
97 true, skb->len);
98 }
99
100 tx_q->cur_tx = entry;
101
102 return entry;
103 }
104
stmmac_is_jumbo_frm(int len,int enh_desc)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
stmmac_refill_desc3(void * priv_ptr,struct dma_desc * p)115 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p)
116 {
117 struct stmmac_rx_queue *rx_q = priv_ptr;
118 struct stmmac_priv *priv = rx_q->priv_data;
119
120 /* Fill DES3 in case of RING mode */
121 if (priv->dma_buf_sz == BUF_SIZE_16KiB)
122 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
123 }
124
125 /* In ring mode we need to fill the desc3 because it is used as buffer */
stmmac_init_desc3(struct dma_desc * p)126 static void stmmac_init_desc3(struct dma_desc *p)
127 {
128 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
129 }
130
stmmac_clean_desc3(void * priv_ptr,struct dma_desc * p)131 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
132 {
133 struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)priv_ptr;
134 struct stmmac_priv *priv = tx_q->priv_data;
135 unsigned int entry = tx_q->dirty_tx;
136
137 /* des3 is only used for jumbo frames tx or time stamping */
138 if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo ||
139 (tx_q->tx_skbuff_dma[entry].last_segment &&
140 !priv->extend_desc && priv->hwts_tx_en)))
141 p->des3 = 0;
142 }
143
stmmac_set_16kib_bfsize(int mtu)144 static int stmmac_set_16kib_bfsize(int mtu)
145 {
146 int ret = 0;
147 if (unlikely(mtu > BUF_SIZE_8KiB))
148 ret = BUF_SIZE_16KiB;
149 return ret;
150 }
151
152 const struct stmmac_mode_ops ring_mode_ops = {
153 .is_jumbo_frm = stmmac_is_jumbo_frm,
154 .jumbo_frm = stmmac_jumbo_frm,
155 .refill_desc3 = stmmac_refill_desc3,
156 .init_desc3 = stmmac_init_desc3,
157 .clean_desc3 = stmmac_clean_desc3,
158 .set_16kib_bfsize = stmmac_set_16kib_bfsize,
159 };
160