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(struct stmmac_tx_queue * tx_q,struct sk_buff * skb,int csum)17 static int jumbo_frm(struct stmmac_tx_queue *tx_q, struct sk_buff *skb,
18 int csum)
19 {
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;
24 struct dma_desc *desc;
25 dma_addr_t des2;
26
27 if (priv->extend_desc)
28 desc = (struct dma_desc *)(tx_q->dma_etx + entry);
29 else
30 desc = tx_q->dma_tx + entry;
31
32 if (priv->plat->enh_desc)
33 bmax = BUF_SIZE_8KiB;
34 else
35 bmax = BUF_SIZE_2KiB;
36
37 len = nopaged_len - bmax;
38
39 if (nopaged_len > BUF_SIZE_8KiB) {
40
41 des2 = dma_map_single(priv->device, skb->data, bmax,
42 DMA_TO_DEVICE);
43 desc->des2 = cpu_to_le32(lower_32_bits(des2));
44 if (dma_mapping_error(priv->device, des2))
45 return -1;
46
47 tx_q->tx_skbuff_dma[entry].buf = des2;
48 tx_q->tx_skbuff_dma[entry].len = bmax;
49 tx_q->tx_skbuff_dma[entry].is_jumbo = true;
50
51 desc->des3 = cpu_to_le32(lower_32_bits(des2) + BUF_SIZE_4KiB);
52 stmmac_prepare_tx_desc(priv, desc, 1, bmax, csum,
53 STMMAC_RING_MODE, 0, false, skb->len);
54 tx_q->tx_skbuff[entry] = NULL;
55 entry = STMMAC_NEXT_ENTRY(entry, priv->dma_conf.dma_tx_size);
56
57 if (priv->extend_desc)
58 desc = (struct dma_desc *)(tx_q->dma_etx + entry);
59 else
60 desc = tx_q->dma_tx + entry;
61
62 des2 = dma_map_single(priv->device, skb->data + bmax, len,
63 DMA_TO_DEVICE);
64 desc->des2 = cpu_to_le32(lower_32_bits(des2));
65 if (dma_mapping_error(priv->device, des2))
66 return -1;
67 tx_q->tx_skbuff_dma[entry].buf = des2;
68 tx_q->tx_skbuff_dma[entry].len = len;
69 tx_q->tx_skbuff_dma[entry].is_jumbo = true;
70
71 desc->des3 = cpu_to_le32(lower_32_bits(des2) + BUF_SIZE_4KiB);
72 stmmac_prepare_tx_desc(priv, desc, 0, len, csum,
73 STMMAC_RING_MODE, 1, !skb_is_nonlinear(skb),
74 skb->len);
75 } else {
76 des2 = dma_map_single(priv->device, skb->data,
77 nopaged_len, DMA_TO_DEVICE);
78 desc->des2 = cpu_to_le32(lower_32_bits(des2));
79 if (dma_mapping_error(priv->device, des2))
80 return -1;
81 tx_q->tx_skbuff_dma[entry].buf = des2;
82 tx_q->tx_skbuff_dma[entry].len = nopaged_len;
83 tx_q->tx_skbuff_dma[entry].is_jumbo = true;
84 desc->des3 = cpu_to_le32(lower_32_bits(des2) + BUF_SIZE_4KiB);
85 stmmac_prepare_tx_desc(priv, desc, 1, nopaged_len, csum,
86 STMMAC_RING_MODE, 0, !skb_is_nonlinear(skb),
87 skb->len);
88 }
89
90 tx_q->cur_tx = entry;
91
92 return entry;
93 }
94
is_jumbo_frm(unsigned int len,bool enh_desc)95 static bool is_jumbo_frm(unsigned int len, bool enh_desc)
96 {
97 return len >= BUF_SIZE_4KiB;
98 }
99
refill_desc3(struct stmmac_rx_queue * rx_q,struct dma_desc * p)100 static void refill_desc3(struct stmmac_rx_queue *rx_q, struct dma_desc *p)
101 {
102 struct stmmac_priv *priv = rx_q->priv_data;
103
104 /* Fill DES3 in case of RING mode */
105 if (priv->dma_conf.dma_buf_sz == BUF_SIZE_16KiB)
106 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
107 }
108
109 /* In ring mode we need to fill the desc3 because it is used as buffer */
init_desc3(struct dma_desc * p)110 static void init_desc3(struct dma_desc *p)
111 {
112 p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB);
113 }
114
clean_desc3(struct stmmac_tx_queue * tx_q,struct dma_desc * p)115 static void clean_desc3(struct stmmac_tx_queue *tx_q, struct dma_desc *p)
116 {
117 struct stmmac_priv *priv = tx_q->priv_data;
118 unsigned int entry = tx_q->dirty_tx;
119
120 /* des3 is only used for jumbo frames tx or time stamping */
121 if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo ||
122 (tx_q->tx_skbuff_dma[entry].last_segment &&
123 !priv->extend_desc && priv->hwts_tx_en)))
124 p->des3 = 0;
125 }
126
set_16kib_bfsize(int mtu)127 static int set_16kib_bfsize(int mtu)
128 {
129 int ret = 0;
130 if (unlikely(mtu > BUF_SIZE_8KiB))
131 ret = BUF_SIZE_16KiB;
132 return ret;
133 }
134
135 const struct stmmac_mode_ops ring_mode_ops = {
136 .is_jumbo_frm = is_jumbo_frm,
137 .jumbo_frm = jumbo_frm,
138 .refill_desc3 = refill_desc3,
139 .init_desc3 = init_desc3,
140 .clean_desc3 = clean_desc3,
141 .set_16kib_bfsize = set_16kib_bfsize,
142 };
143