xref: /linux/drivers/net/ethernet/marvell/prestera/prestera_dsa.c (revision 3c09ec59cdea5b132212d97154d625fd34e436dd)
1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /* Copyright (c) 2020 Marvell International Ltd. All rights reserved */
3 
4 #include <linux/bitfield.h>
5 #include <linux/bitops.h>
6 #include <linux/errno.h>
7 #include <linux/string.h>
8 
9 #include "prestera_dsa.h"
10 
11 #define PRESTERA_DSA_W0_CMD		GENMASK(31, 30)
12 #define PRESTERA_DSA_W0_IS_TAGGED	BIT(29)
13 #define PRESTERA_DSA_W0_DEV_NUM		GENMASK(28, 24)
14 #define PRESTERA_DSA_W0_PORT_NUM	GENMASK(23, 19)
15 #define PRESTERA_DSA_W0_VPT		GENMASK(15, 13)
16 #define PRESTERA_DSA_W0_EXT_BIT		BIT(12)
17 #define PRESTERA_DSA_W0_VID		GENMASK(11, 0)
18 
19 #define PRESTERA_DSA_W1_EXT_BIT		BIT(31)
20 #define PRESTERA_DSA_W1_CFI_BIT		BIT(30)
21 #define PRESTERA_DSA_W1_PORT_NUM	GENMASK(11, 10)
22 
23 #define PRESTERA_DSA_W2_EXT_BIT		BIT(31)
24 #define PRESTERA_DSA_W2_PORT_NUM	BIT(20)
25 
26 #define PRESTERA_DSA_W3_VID		GENMASK(30, 27)
27 #define PRESTERA_DSA_W3_DST_EPORT	GENMASK(23, 7)
28 #define PRESTERA_DSA_W3_DEV_NUM		GENMASK(6, 0)
29 
30 #define PRESTERA_DSA_VID		GENMASK(15, 12)
31 #define PRESTERA_DSA_DEV_NUM		GENMASK(11, 5)
32 
33 int prestera_dsa_parse(struct prestera_dsa *dsa, const u8 *dsa_buf)
34 {
35 	__be32 *dsa_words = (__be32 *)dsa_buf;
36 	enum prestera_dsa_cmd cmd;
37 	u32 words[4];
38 	u32 field;
39 
40 	words[0] = ntohl(dsa_words[0]);
41 	words[1] = ntohl(dsa_words[1]);
42 	words[2] = ntohl(dsa_words[2]);
43 	words[3] = ntohl(dsa_words[3]);
44 
45 	/* set the common parameters */
46 	cmd = (enum prestera_dsa_cmd)FIELD_GET(PRESTERA_DSA_W0_CMD, words[0]);
47 
48 	/* only to CPU is supported */
49 	if (unlikely(cmd != PRESTERA_DSA_CMD_TO_CPU))
50 		return -EINVAL;
51 
52 	if (FIELD_GET(PRESTERA_DSA_W0_EXT_BIT, words[0]) == 0)
53 		return -EINVAL;
54 	if (FIELD_GET(PRESTERA_DSA_W1_EXT_BIT, words[1]) == 0)
55 		return -EINVAL;
56 	if (FIELD_GET(PRESTERA_DSA_W2_EXT_BIT, words[2]) == 0)
57 		return -EINVAL;
58 
59 	field = FIELD_GET(PRESTERA_DSA_W3_VID, words[3]);
60 
61 	dsa->vlan.is_tagged = FIELD_GET(PRESTERA_DSA_W0_IS_TAGGED, words[0]);
62 	dsa->vlan.cfi_bit = FIELD_GET(PRESTERA_DSA_W1_CFI_BIT, words[1]);
63 	dsa->vlan.vpt = FIELD_GET(PRESTERA_DSA_W0_VPT, words[0]);
64 	dsa->vlan.vid = FIELD_GET(PRESTERA_DSA_W0_VID, words[0]);
65 	dsa->vlan.vid &= ~PRESTERA_DSA_VID;
66 	dsa->vlan.vid |= FIELD_PREP(PRESTERA_DSA_VID, field);
67 
68 	field = FIELD_GET(PRESTERA_DSA_W3_DEV_NUM, words[3]);
69 
70 	dsa->hw_dev_num = FIELD_GET(PRESTERA_DSA_W0_DEV_NUM, words[0]);
71 	dsa->hw_dev_num |= FIELD_PREP(PRESTERA_DSA_DEV_NUM, field);
72 
73 	dsa->port_num = (FIELD_GET(PRESTERA_DSA_W0_PORT_NUM, words[0]) << 0) |
74 			(FIELD_GET(PRESTERA_DSA_W1_PORT_NUM, words[1]) << 5) |
75 			(FIELD_GET(PRESTERA_DSA_W2_PORT_NUM, words[2]) << 7);
76 
77 	return 0;
78 }
79 
80 int prestera_dsa_build(const struct prestera_dsa *dsa, u8 *dsa_buf)
81 {
82 	__be32 *dsa_words = (__be32 *)dsa_buf;
83 	u32 dev_num = dsa->hw_dev_num;
84 	u32 words[4] = { 0 };
85 
86 	words[0] |= FIELD_PREP(PRESTERA_DSA_W0_CMD, PRESTERA_DSA_CMD_FROM_CPU);
87 
88 	words[0] |= FIELD_PREP(PRESTERA_DSA_W0_DEV_NUM, dev_num);
89 	dev_num = FIELD_GET(PRESTERA_DSA_DEV_NUM, dev_num);
90 	words[3] |= FIELD_PREP(PRESTERA_DSA_W3_DEV_NUM, dev_num);
91 
92 	words[3] |= FIELD_PREP(PRESTERA_DSA_W3_DST_EPORT, dsa->port_num);
93 
94 	words[0] |= FIELD_PREP(PRESTERA_DSA_W0_EXT_BIT, 1);
95 	words[1] |= FIELD_PREP(PRESTERA_DSA_W1_EXT_BIT, 1);
96 	words[2] |= FIELD_PREP(PRESTERA_DSA_W2_EXT_BIT, 1);
97 
98 	dsa_words[0] = htonl(words[0]);
99 	dsa_words[1] = htonl(words[1]);
100 	dsa_words[2] = htonl(words[2]);
101 	dsa_words[3] = htonl(words[3]);
102 
103 	return 0;
104 }
105