1 // SPDX-License-Identifier: GPL-2.0-only
2 /*******************************************************************************
3 Specialised functions for managing Ring mode
4
5 Copyright(C) 2011 STMicroelectronics Ltd
6
7 It defines all the functions used to handle the normal/enhanced
8 descriptors in case of the DMA is configured to work in chained or
9 in ring mode.
10
11
12 Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
13 *******************************************************************************/
14
15 #include "stmmac.h"
16
jumbo_frm(void * p,struct sk_buff * skb,int csum)17 static int jumbo_frm(void *p, struct sk_buff *skb, int csum)
18 {
19 struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)p;
20 unsigned int nopaged_len = skb_headlen(skb);
21 struct stmmac_priv *priv = tx_q->priv_data;
22 unsigned int entry = tx_q->cur_tx;
23 unsigned int bmax, len, des2;
24 struct dma_desc *desc;
25
26 if (priv->extend_desc)
27 desc = (struct dma_desc *)(tx_q->dma_etx + entry);
28 else
29 desc = tx_q->dma_tx + entry;
30
31 if (priv->plat->enh_desc)
32 bmax = BUF_SIZE_8KiB;
33 else
34 bmax = BUF_SIZE_2KiB;
35
36 len = nopaged_len - bmax;
37
38 if (nopaged_len > BUF_SIZE_8KiB) {
39
40 des2 = dma_map_single(priv->device, skb->data, bmax,
41 DMA_TO_DEVICE);
42 desc->des2 = cpu_to_le32(des2);
43 if (dma_mapping_error(priv->device, des2))
44 return -1;
45
46 tx_q->tx_skbuff_dma[entry].buf = des2;
47 tx_q->tx_skbuff_dma[entry].len = bmax;
48 tx_q->tx_skbuff_dma[entry].is_jumbo = true;
49
50 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
51 stmmac_prepare_tx_desc(priv, desc, 1, bmax, csum,
52 STMMAC_RING_MODE, 0, false, skb->len);
53 tx_q->tx_skbuff[entry] = NULL;
54 entry = STMMAC_GET_ENTRY(entry, priv->dma_tx_size);
55
56 if (priv->extend_desc)
57 desc = (struct dma_desc *)(tx_q->dma_etx + entry);
58 else
59 desc = tx_q->dma_tx + entry;
60
61 des2 = dma_map_single(priv->device, skb->data + bmax, len,
62 DMA_TO_DEVICE);
63 desc->des2 = cpu_to_le32(des2);
64 if (dma_mapping_error(priv->device, des2))
65 return -1;
66 tx_q->tx_skbuff_dma[entry].buf = des2;
67 tx_q->tx_skbuff_dma[entry].len = len;
68 tx_q->tx_skbuff_dma[entry].is_jumbo = true;
69
70 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
71 stmmac_prepare_tx_desc(priv, desc, 0, len, csum,
72 STMMAC_RING_MODE, 1, !skb_is_nonlinear(skb),
73 skb->len);
74 } else {
75 des2 = dma_map_single(priv->device, skb->data,
76 nopaged_len, DMA_TO_DEVICE);
77 desc->des2 = cpu_to_le32(des2);
78 if (dma_mapping_error(priv->device, des2))
79 return -1;
80 tx_q->tx_skbuff_dma[entry].buf = des2;
81 tx_q->tx_skbuff_dma[entry].len = nopaged_len;
82 tx_q->tx_skbuff_dma[entry].is_jumbo = true;
83 desc->des3 = cpu_to_le32(des2 + BUF_SIZE_4KiB);
84 stmmac_prepare_tx_desc(priv, desc, 1, nopaged_len, csum,
85 STMMAC_RING_MODE, 0, !skb_is_nonlinear(skb),
86 skb->len);
87 }
88
89 tx_q->cur_tx = entry;
90
91 return entry;
92 }
93
is_jumbo_frm(int len,int enh_desc)94 static unsigned int is_jumbo_frm(int len, int enh_desc)
95 {
96 unsigned int ret = 0;
97
98 if (len >= BUF_SIZE_4KiB)
99 ret = 1;
100
101 return ret;
102 }
103
refill_desc3(void * priv_ptr,struct dma_desc * p)104 static void refill_desc3(void *priv_ptr, struct dma_desc *p)
105 {
106 struct stmmac_rx_queue *rx_q = priv_ptr;
107 struct stmmac_priv *priv = rx_q->priv_data;
108
109 /* Fill DES3 in case of RING mode */
110 if (priv->dma_buf_sz == BUF_SIZE_16KiB)
111 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
112 }
113
114 /* In ring mode we need to fill the desc3 because it is used as buffer */
init_desc3(struct dma_desc * p)115 static void init_desc3(struct dma_desc *p)
116 {
117 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
118 }
119
clean_desc3(void * priv_ptr,struct dma_desc * p)120 static void clean_desc3(void *priv_ptr, struct dma_desc *p)
121 {
122 struct stmmac_tx_queue *tx_q = (struct stmmac_tx_queue *)priv_ptr;
123 struct stmmac_priv *priv = tx_q->priv_data;
124 unsigned int entry = tx_q->dirty_tx;
125
126 /* des3 is only used for jumbo frames tx or time stamping */
127 if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo ||
128 (tx_q->tx_skbuff_dma[entry].last_segment &&
129 !priv->extend_desc && priv->hwts_tx_en)))
130 p->des3 = 0;
131 }
132
set_16kib_bfsize(int mtu)133 static int set_16kib_bfsize(int mtu)
134 {
135 int ret = 0;
136 if (unlikely(mtu > BUF_SIZE_8KiB))
137 ret = BUF_SIZE_16KiB;
138 return ret;
139 }
140
141 const struct stmmac_mode_ops ring_mode_ops = {
142 .is_jumbo_frm = is_jumbo_frm,
143 .jumbo_frm = jumbo_frm,
144 .refill_desc3 = refill_desc3,
145 .init_desc3 = init_desc3,
146 .clean_desc3 = clean_desc3,
147 .set_16kib_bfsize = set_16kib_bfsize,
148 };
149