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
stmmac_jumbo_frm(void * p,struct sk_buff * skb,int csum)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 entry = priv->cur_tx;
35 struct dma_desc *desc;
36 unsigned int nopaged_len = skb_headlen(skb);
37 unsigned int bmax, len;
38
39 if (priv->extend_desc)
40 desc = (struct dma_desc *)(priv->dma_etx + entry);
41 else
42 desc = priv->dma_tx + entry;
43
44 if (priv->plat->enh_desc)
45 bmax = BUF_SIZE_8KiB;
46 else
47 bmax = BUF_SIZE_2KiB;
48
49 len = nopaged_len - bmax;
50
51 if (nopaged_len > BUF_SIZE_8KiB) {
52
53 desc->des2 = dma_map_single(priv->device, skb->data,
54 bmax, DMA_TO_DEVICE);
55 if (dma_mapping_error(priv->device, desc->des2))
56 return -1;
57
58 priv->tx_skbuff_dma[entry].buf = desc->des2;
59 priv->tx_skbuff_dma[entry].len = bmax;
60 priv->tx_skbuff_dma[entry].is_jumbo = true;
61
62 desc->des3 = desc->des2 + BUF_SIZE_4KiB;
63 priv->hw->desc->prepare_tx_desc(desc, 1, bmax, csum,
64 STMMAC_RING_MODE, 0, false);
65 priv->tx_skbuff[entry] = NULL;
66 entry = STMMAC_GET_ENTRY(entry, DMA_TX_SIZE);
67
68 if (priv->extend_desc)
69 desc = (struct dma_desc *)(priv->dma_etx + entry);
70 else
71 desc = priv->dma_tx + entry;
72
73 desc->des2 = dma_map_single(priv->device, skb->data + bmax,
74 len, DMA_TO_DEVICE);
75 if (dma_mapping_error(priv->device, desc->des2))
76 return -1;
77 priv->tx_skbuff_dma[entry].buf = desc->des2;
78 priv->tx_skbuff_dma[entry].len = len;
79 priv->tx_skbuff_dma[entry].is_jumbo = true;
80
81 desc->des3 = desc->des2 + BUF_SIZE_4KiB;
82 priv->hw->desc->prepare_tx_desc(desc, 0, len, csum,
83 STMMAC_RING_MODE, 1, true);
84 } else {
85 desc->des2 = dma_map_single(priv->device, skb->data,
86 nopaged_len, DMA_TO_DEVICE);
87 if (dma_mapping_error(priv->device, desc->des2))
88 return -1;
89 priv->tx_skbuff_dma[entry].buf = desc->des2;
90 priv->tx_skbuff_dma[entry].len = nopaged_len;
91 priv->tx_skbuff_dma[entry].is_jumbo = true;
92 desc->des3 = desc->des2 + BUF_SIZE_4KiB;
93 priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len, csum,
94 STMMAC_RING_MODE, 0, true);
95 }
96
97 priv->cur_tx = entry;
98
99 return entry;
100 }
101
stmmac_is_jumbo_frm(int len,int enh_desc)102 static unsigned int stmmac_is_jumbo_frm(int len, int enh_desc)
103 {
104 unsigned int ret = 0;
105
106 if (len >= BUF_SIZE_4KiB)
107 ret = 1;
108
109 return ret;
110 }
111
stmmac_refill_desc3(void * priv_ptr,struct dma_desc * p)112 static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p)
113 {
114 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
115
116 /* Fill DES3 in case of RING mode */
117 if (priv->dma_buf_sz >= BUF_SIZE_8KiB)
118 p->des3 = p->des2 + BUF_SIZE_8KiB;
119 }
120
121 /* In ring mode we need to fill the desc3 because it is used as buffer */
stmmac_init_desc3(struct dma_desc * p)122 static void stmmac_init_desc3(struct dma_desc *p)
123 {
124 p->des3 = p->des2 + BUF_SIZE_8KiB;
125 }
126
stmmac_clean_desc3(void * priv_ptr,struct dma_desc * p)127 static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
128 {
129 struct stmmac_priv *priv = (struct stmmac_priv *)priv_ptr;
130 unsigned int entry = priv->dirty_tx;
131
132 /* des3 is only used for jumbo frames tx or time stamping */
133 if (unlikely(priv->tx_skbuff_dma[entry].is_jumbo ||
134 (priv->tx_skbuff_dma[entry].last_segment &&
135 !priv->extend_desc && priv->hwts_tx_en)))
136 p->des3 = 0;
137 }
138
stmmac_set_16kib_bfsize(int mtu)139 static int stmmac_set_16kib_bfsize(int mtu)
140 {
141 int ret = 0;
142 if (unlikely(mtu >= BUF_SIZE_8KiB))
143 ret = BUF_SIZE_16KiB;
144 return ret;
145 }
146
147 const struct stmmac_mode_ops ring_mode_ops = {
148 .is_jumbo_frm = stmmac_is_jumbo_frm,
149 .jumbo_frm = stmmac_jumbo_frm,
150 .refill_desc3 = stmmac_refill_desc3,
151 .init_desc3 = stmmac_init_desc3,
152 .clean_desc3 = stmmac_clean_desc3,
153 .set_16kib_bfsize = stmmac_set_16kib_bfsize,
154 };
155