1/* SPDX-License-Identifier: GPL-2.0-only */
2/*******************************************************************************
3 Header File to describe Normal/enhanced descriptor functions used for RING
4 and CHAINED modes.
5
6 Copyright(C) 2011 STMicroelectronics Ltd
7
8 It defines all the functions used to handle the normal/enhanced
9 descriptors in case of the DMA is configured to work in chained or
10 in ring mode.
11
12
13 Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
14*******************************************************************************/
15
16#ifndef __DESC_COM_H__
17#define __DESC_COM_H__
18
19/* Specific functions used for Ring mode */
20
21/* Enhanced descriptors */
22static inline void ehn_desc_rx_set_on_ring(struct dma_desc *p, int end,
23 int bfsize)
24{
25 if (bfsize == BUF_SIZE_16KiB)
26 p->des1 |= cpu_to_le32((BUF_SIZE_8KiB
27 << ERDES1_BUFFER2_SIZE_SHIFT)
28 & ERDES1_BUFFER2_SIZE_MASK);
29
30 if (end)
31 p->des1 |= cpu_to_le32(ERDES1_END_RING);
32}
33
34static inline void enh_desc_end_tx_desc_on_ring(struct dma_desc *p, int end)
35{
36 if (end)
37 p->des0 |= cpu_to_le32(ETDES0_END_RING);
38 else
39 p->des0 &= cpu_to_le32(~ETDES0_END_RING);
40}
41
42static inline void enh_set_tx_desc_len_on_ring(struct dma_desc *p, int len)
43{
44 if (unlikely(len > BUF_SIZE_4KiB)) {
45 p->des1 |= cpu_to_le32((((len - BUF_SIZE_4KiB)
46 << ETDES1_BUFFER2_SIZE_SHIFT)
47 & ETDES1_BUFFER2_SIZE_MASK) | (BUF_SIZE_4KiB
48 & ETDES1_BUFFER1_SIZE_MASK));
49 } else
50 p->des1 |= cpu_to_le32((len & ETDES1_BUFFER1_SIZE_MASK));
51}
52
53/* Normal descriptors */
54static inline void ndesc_rx_set_on_ring(struct dma_desc *p, int end, int bfsize)
55{
56 if (bfsize >= BUF_SIZE_2KiB) {
57 int bfsize2;
58
59 bfsize2 = min(bfsize - BUF_SIZE_2KiB + 1, BUF_SIZE_2KiB - 1);
60 p->des1 |= cpu_to_le32((bfsize2 << RDES1_BUFFER2_SIZE_SHIFT)
61 & RDES1_BUFFER2_SIZE_MASK);
62 }
63
64 if (end)
65 p->des1 |= cpu_to_le32(RDES1_END_RING);
66}
67
68static inline void ndesc_end_tx_desc_on_ring(struct dma_desc *p, int end)
69{
70 if (end)
71 p->des1 |= cpu_to_le32(TDES1_END_RING);
72 else
73 p->des1 &= cpu_to_le32(~TDES1_END_RING);
74}
75
76static inline void norm_set_tx_desc_len_on_ring(struct dma_desc *p, int len)
77{
78 if (unlikely(len > BUF_SIZE_2KiB)) {
79 unsigned int buffer1 = (BUF_SIZE_2KiB - 1)
80 & TDES1_BUFFER1_SIZE_MASK;
81 p->des1 |= cpu_to_le32((((len - buffer1)
82 << TDES1_BUFFER2_SIZE_SHIFT)
83 & TDES1_BUFFER2_SIZE_MASK) | buffer1);
84 } else
85 p->des1 |= cpu_to_le32((len & TDES1_BUFFER1_SIZE_MASK));
86}
87
88/* Specific functions used for Chain mode */
89
90/* Enhanced descriptors */
91static inline void ehn_desc_rx_set_on_chain(struct dma_desc *p)
92{
93 p->des1 |= cpu_to_le32(ERDES1_SECOND_ADDRESS_CHAINED);
94}
95
96static inline void enh_desc_end_tx_desc_on_chain(struct dma_desc *p)
97{
98 p->des0 |= cpu_to_le32(ETDES0_SECOND_ADDRESS_CHAINED);
99}
100
101static inline void enh_set_tx_desc_len_on_chain(struct dma_desc *p, int len)
102{
103 p->des1 |= cpu_to_le32(len & ETDES1_BUFFER1_SIZE_MASK);
104}
105
106/* Normal descriptors */
107static inline void ndesc_rx_set_on_chain(struct dma_desc *p, int end)
108{
109 p->des1 |= cpu_to_le32(RDES1_SECOND_ADDRESS_CHAINED);
110}
111
112static inline void ndesc_tx_set_on_chain(struct dma_desc *p)
113{
114 p->des1 |= cpu_to_le32(TDES1_SECOND_ADDRESS_CHAINED);
115}
116
117static inline void norm_set_tx_desc_len_on_chain(struct dma_desc *p, int len)
118{
119 p->des1 |= cpu_to_le32(len & TDES1_BUFFER1_SIZE_MASK);
120}
121#endif /* __DESC_COM_H__ */
122

source code of linux/drivers/net/ethernet/stmicro/stmmac/descs_com.h