drivers/net/ethernet/marvell/prestera/prestera_dsa.c

   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 }