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 | |
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, 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(dev: priv->device, dma_addr: 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_conf.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(dev: priv->device, dma_addr: 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(dev: priv->device, dma_addr: 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 | |
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 | |
104 | static void refill_desc3(struct stmmac_rx_queue *rx_q, struct dma_desc *p) |
105 | { |
106 | struct stmmac_priv *priv = rx_q->priv_data; |
107 | |
108 | /* Fill DES3 in case of RING mode */ |
109 | if (priv->dma_conf.dma_buf_sz == BUF_SIZE_16KiB) |
110 | p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB); |
111 | } |
112 | |
113 | /* In ring mode we need to fill the desc3 because it is used as buffer */ |
114 | static void init_desc3(struct dma_desc *p) |
115 | { |
116 | p->des3 = cpu_to_le32(le32_to_cpu(p->des2) + BUF_SIZE_8KiB); |
117 | } |
118 | |
119 | static void clean_desc3(struct stmmac_tx_queue *tx_q, struct dma_desc *p) |
120 | { |
121 | struct stmmac_priv *priv = tx_q->priv_data; |
122 | unsigned int entry = tx_q->dirty_tx; |
123 | |
124 | /* des3 is only used for jumbo frames tx or time stamping */ |
125 | if (unlikely(tx_q->tx_skbuff_dma[entry].is_jumbo || |
126 | (tx_q->tx_skbuff_dma[entry].last_segment && |
127 | !priv->extend_desc && priv->hwts_tx_en))) |
128 | p->des3 = 0; |
129 | } |
130 | |
131 | static int set_16kib_bfsize(int mtu) |
132 | { |
133 | int ret = 0; |
134 | if (unlikely(mtu > BUF_SIZE_8KiB)) |
135 | ret = BUF_SIZE_16KiB; |
136 | return ret; |
137 | } |
138 | |
139 | const struct stmmac_mode_ops ring_mode_ops = { |
140 | .is_jumbo_frm = is_jumbo_frm, |
141 | .jumbo_frm = jumbo_frm, |
142 | .refill_desc3 = refill_desc3, |
143 | .init_desc3 = init_desc3, |
144 | .clean_desc3 = clean_desc3, |
145 | .set_16kib_bfsize = set_16kib_bfsize, |
146 | }; |
147 | |