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
jumbo_frm(void * p,struct sk_buff * skb,int csum)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, 1, 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, true, skb->len);
83 } else {
84 des2 = dma_map_single(priv->device, skb->data,
85 nopaged_len, DMA_TO_DEVICE);
86 desc->des2 = cpu_to_le32(des2);
87 if (dma_mapping_error(priv->device, des2))
88 return -1;
89 tx_q->tx_skbuff_dma[entry].buf = des2;
90 tx_q->tx_skbuff_dma[entry].len = nopaged_len;
91 tx_q->tx_skbuff_dma[entry].is_jumbo = true;
92 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
93 stmmac_prepare_tx_desc(priv, desc, 1, nopaged_len, csum,
94 STMMAC_RING_MODE, 1, true, skb->len);
95 }
96
97 tx_q->cur_tx = entry;
98
99 return entry;
100 }
101
is_jumbo_frm(int len,int enh_desc)102 static unsigned int 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
refill_desc3(void * priv_ptr,struct dma_desc * p)112 static void refill_desc3(void *priv_ptr, struct dma_desc *p)
113 {
114 struct stmmac_rx_queue *rx_q = priv_ptr;
115 struct stmmac_priv *priv = rx_q->priv_data;
116
117 /* Fill DES3 in case of RING mode */
118 if (priv->dma_buf_sz == BUF_SIZE_16KiB)
119 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
120 }
121
122 /* In ring mode we need to fill the desc3 because it is used as buffer */
init_desc3(struct dma_desc * p)123 static void init_desc3(struct dma_desc *p)
124 {
125 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
126 }
127
clean_desc3(void * priv_ptr,struct dma_desc * p)128 static void clean_desc3(void *priv_ptr, struct dma_desc *p)
129 {
130 struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)priv_ptr;
131 struct stmmac_priv *priv = tx_q->priv_data;
132 unsigned int entry = tx_q->dirty_tx;
133
134 /* des3 is only used for jumbo frames tx or time stamping */
135 if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo ||
136 (tx_q->tx_skbuff_dma[entry].last_segment &&
137 !priv->extend_desc && priv->hwts_tx_en)))
138 p->des3 = 0;
139 }
140
set_16kib_bfsize(int mtu)141 static int set_16kib_bfsize(int mtu)
142 {
143 int ret = 0;
144 if (unlikely(mtu > BUF_SIZE_8KiB))
145 ret = BUF_SIZE_16KiB;
146 return ret;
147 }
148
149 const struct stmmac_mode_ops ring_mode_ops = {
150 .is_jumbo_frm = is_jumbo_frm,
151 .jumbo_frm = jumbo_frm,
152 .refill_desc3 = refill_desc3,
153 .init_desc3 = init_desc3,
154 .clean_desc3 = clean_desc3,
155 .set_16kib_bfsize = set_16kib_bfsize,
156 };
157