1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /******************************************************************************* |
3 | Specialised functions for managing Chained 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, des2; |
24 | unsigned int i = 1, len; |
25 | struct dma_desc *desc; |
26 | |
27 | desc = tx_q->dma_tx + entry; |
28 | |
29 | if (priv->plat->enh_desc) |
30 | bmax = BUF_SIZE_8KiB; |
31 | else |
32 | bmax = BUF_SIZE_2KiB; |
33 | |
34 | len = nopaged_len - bmax; |
35 | |
36 | des2 = dma_map_single(priv->device, skb->data, |
37 | bmax, DMA_TO_DEVICE); |
38 | desc->des2 = cpu_to_le32(des2); |
39 | if (dma_mapping_error(dev: priv->device, dma_addr: des2)) |
40 | return -1; |
41 | tx_q->tx_skbuff_dma[entry].buf = des2; |
42 | tx_q->tx_skbuff_dma[entry].len = bmax; |
43 | /* do not close the descriptor and do not set own bit */ |
44 | stmmac_prepare_tx_desc(priv, desc, 1, bmax, csum, STMMAC_CHAIN_MODE, |
45 | 0, false, skb->len); |
46 | |
47 | while (len != 0) { |
48 | tx_q->tx_skbuff[entry] = NULL; |
49 | entry = STMMAC_GET_ENTRY(entry, priv->dma_conf.dma_tx_size); |
50 | desc = tx_q->dma_tx + entry; |
51 | |
52 | if (len > bmax) { |
53 | des2 = dma_map_single(priv->device, |
54 | (skb->data + bmax * i), |
55 | bmax, DMA_TO_DEVICE); |
56 | desc->des2 = cpu_to_le32(des2); |
57 | if (dma_mapping_error(dev: priv->device, dma_addr: des2)) |
58 | return -1; |
59 | tx_q->tx_skbuff_dma[entry].buf = des2; |
60 | tx_q->tx_skbuff_dma[entry].len = bmax; |
61 | stmmac_prepare_tx_desc(priv, desc, 0, bmax, csum, |
62 | STMMAC_CHAIN_MODE, 1, false, skb->len); |
63 | len -= bmax; |
64 | i++; |
65 | } else { |
66 | des2 = dma_map_single(priv->device, |
67 | (skb->data + bmax * i), len, |
68 | DMA_TO_DEVICE); |
69 | desc->des2 = cpu_to_le32(des2); |
70 | if (dma_mapping_error(dev: priv->device, dma_addr: des2)) |
71 | return -1; |
72 | tx_q->tx_skbuff_dma[entry].buf = des2; |
73 | tx_q->tx_skbuff_dma[entry].len = len; |
74 | /* last descriptor can be set now */ |
75 | stmmac_prepare_tx_desc(priv, desc, 0, len, csum, |
76 | STMMAC_CHAIN_MODE, 1, true, skb->len); |
77 | len = 0; |
78 | } |
79 | } |
80 | |
81 | tx_q->cur_tx = entry; |
82 | |
83 | return entry; |
84 | } |
85 | |
86 | static unsigned int is_jumbo_frm(int len, int enh_desc) |
87 | { |
88 | unsigned int ret = 0; |
89 | |
90 | if ((enh_desc && (len > BUF_SIZE_8KiB)) || |
91 | (!enh_desc && (len > BUF_SIZE_2KiB))) { |
92 | ret = 1; |
93 | } |
94 | |
95 | return ret; |
96 | } |
97 | |
98 | static void init_dma_chain(void *des, dma_addr_t phy_addr, |
99 | unsigned int size, unsigned int extend_desc) |
100 | { |
101 | /* |
102 | * In chained mode the des3 points to the next element in the ring. |
103 | * The latest element has to point to the head. |
104 | */ |
105 | int i; |
106 | dma_addr_t dma_phy = phy_addr; |
107 | |
108 | if (extend_desc) { |
109 | struct dma_extended_desc *p = (struct dma_extended_desc *)des; |
110 | for (i = 0; i < (size - 1); i++) { |
111 | dma_phy += sizeof(struct dma_extended_desc); |
112 | p->basic.des3 = cpu_to_le32((unsigned int)dma_phy); |
113 | p++; |
114 | } |
115 | p->basic.des3 = cpu_to_le32((unsigned int)phy_addr); |
116 | |
117 | } else { |
118 | struct dma_desc *p = (struct dma_desc *)des; |
119 | for (i = 0; i < (size - 1); i++) { |
120 | dma_phy += sizeof(struct dma_desc); |
121 | p->des3 = cpu_to_le32((unsigned int)dma_phy); |
122 | p++; |
123 | } |
124 | p->des3 = cpu_to_le32((unsigned int)phy_addr); |
125 | } |
126 | } |
127 | |
128 | static void refill_desc3(struct stmmac_rx_queue *rx_q, struct dma_desc *p) |
129 | { |
130 | struct stmmac_priv *priv = rx_q->priv_data; |
131 | |
132 | if (priv->hwts_rx_en && !priv->extend_desc) |
133 | /* NOTE: Device will overwrite des3 with timestamp value if |
134 | * 1588-2002 time stamping is enabled, hence reinitialize it |
135 | * to keep explicit chaining in the descriptor. |
136 | */ |
137 | p->des3 = cpu_to_le32((unsigned int)(rx_q->dma_rx_phy + |
138 | (((rx_q->dirty_rx) + 1) % |
139 | priv->dma_conf.dma_rx_size) * |
140 | sizeof(struct dma_desc))); |
141 | } |
142 | |
143 | static void clean_desc3(struct stmmac_tx_queue *tx_q, struct dma_desc *p) |
144 | { |
145 | struct stmmac_priv *priv = tx_q->priv_data; |
146 | unsigned int entry = tx_q->dirty_tx; |
147 | |
148 | if (tx_q->tx_skbuff_dma[entry].last_segment && !priv->extend_desc && |
149 | priv->hwts_tx_en) |
150 | /* NOTE: Device will overwrite des3 with timestamp value if |
151 | * 1588-2002 time stamping is enabled, hence reinitialize it |
152 | * to keep explicit chaining in the descriptor. |
153 | */ |
154 | p->des3 = cpu_to_le32((unsigned int)((tx_q->dma_tx_phy + |
155 | ((tx_q->dirty_tx + 1) % |
156 | priv->dma_conf.dma_tx_size)) |
157 | * sizeof(struct dma_desc))); |
158 | } |
159 | |
160 | const struct stmmac_mode_ops chain_mode_ops = { |
161 | .init = init_dma_chain, |
162 | .is_jumbo_frm = is_jumbo_frm, |
163 | .jumbo_frm = jumbo_frm, |
164 | .refill_desc3 = refill_desc3, |
165 | .clean_desc3 = clean_desc3, |
166 | }; |
167 | |