target/linux/generic/backport-5.15/766-v5.18-15-net-dsa-qca8k-add-support-for-larger-read-write-size.patch

   1 From 90386223f44e2a751d7e9e9ac8f78ea33358a891 Mon Sep 17 00:00:00 2001
   2 From: Ansuel Smith <ansuelsmth@gmail.com>
   3 Date: Wed, 2 Feb 2022 01:03:34 +0100
   4 Subject: [PATCH 15/16] net: dsa: qca8k: add support for larger read/write size
   5  with mgmt Ethernet
   6
   7 mgmt Ethernet packet can read/write up to 16byte at times. The len reg
   8 is limited to 15 (0xf). The switch actually sends and accepts data in 4
   9 different steps of len values.
  10 Len steps:
  11 - 0: nothing
  12 - 1-4: first 4 byte
  13 - 5-6: first 12 byte
  14 - 7-15: all 16 byte
  15
  16 In the alloc skb function we check if the len is 16 and we fix it to a
  17 len of 15. It the read/write function interest to extract the real asked
  18 data. The tagger handler will always copy the fully 16byte with a READ
  19 command. This is useful for some big regs like the fdb reg that are
  20 more than 4byte of data. This permits to introduce a bulk function that
  21 will send and request the entire entry in one go.
  22 Write function is changed and it does now require to pass the pointer to
  23 val to also handle array val.
  24
  25 Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
  26 Signed-off-by: David S. Miller <davem@davemloft.net>
  27 ---
  28  drivers/net/dsa/qca8k.c | 61 +++++++++++++++++++++++++++--------------
  29  1 file changed, 41 insertions(+), 20 deletions(-)
  30
  31 --- a/drivers/net/dsa/qca8k.c
  32 +++ b/drivers/net/dsa/qca8k.c
  33 @@ -222,7 +222,9 @@ static void qca8k_rw_reg_ack_handler(str
  34         if (cmd == MDIO_READ) {
  35                 mgmt_eth_data->data[0] = mgmt_ethhdr->mdio_data;
  36
  37 -               /* Get the rest of the 12 byte of data */
  38 +               /* Get the rest of the 12 byte of data.
  39 +                * The read/write function will extract the requested data.
  40 +                */
  41                 if (len > QCA_HDR_MGMT_DATA1_LEN)
  42                         memcpy(mgmt_eth_data->data + 1, skb->data,
  43                                QCA_HDR_MGMT_DATA2_LEN);
  44 @@ -232,16 +234,30 @@ static void qca8k_rw_reg_ack_handler(str
  45  }
  46
  47  static struct sk_buff *qca8k_alloc_mdio_header(enum mdio_cmd cmd, u32 reg, u32 *val,
  48 -                                              int priority)
  49 +                                              int priority, unsigned int len)
  50  {
  51         struct qca_mgmt_ethhdr *mgmt_ethhdr;
  52 +       unsigned int real_len;
  53         struct sk_buff *skb;
  54 +       u32 *data2;
  55         u16 hdr;
  56
  57         skb = dev_alloc_skb(QCA_HDR_MGMT_PKT_LEN);
  58         if (!skb)
  59                 return NULL;
  60
  61 +       /* Max value for len reg is 15 (0xf) but the switch actually return 16 byte
  62 +        * Actually for some reason the steps are:
  63 +        * 0: nothing
  64 +        * 1-4: first 4 byte
  65 +        * 5-6: first 12 byte
  66 +        * 7-15: all 16 byte
  67 +        */
  68 +       if (len == 16)
  69 +               real_len = 15;
  70 +       else
  71 +               real_len = len;
  72 +
  73         skb_reset_mac_header(skb);
  74         skb_set_network_header(skb, skb->len);
  75
  76 @@ -254,7 +270,7 @@ static struct sk_buff *qca8k_alloc_mdio_
  77         hdr |= FIELD_PREP(QCA_HDR_XMIT_CONTROL, QCA_HDR_XMIT_TYPE_RW_REG);
  78
  79         mgmt_ethhdr->command = FIELD_PREP(QCA_HDR_MGMT_ADDR, reg);
  80 -       mgmt_ethhdr->command |= FIELD_PREP(QCA_HDR_MGMT_LENGTH, 4);
  81 +       mgmt_ethhdr->command |= FIELD_PREP(QCA_HDR_MGMT_LENGTH, real_len);
  82         mgmt_ethhdr->command |= FIELD_PREP(QCA_HDR_MGMT_CMD, cmd);
  83         mgmt_ethhdr->command |= FIELD_PREP(QCA_HDR_MGMT_CHECK_CODE,
  84                                            QCA_HDR_MGMT_CHECK_CODE_VAL);
  85 @@ -264,7 +280,9 @@ static struct sk_buff *qca8k_alloc_mdio_
  86
  87         mgmt_ethhdr->hdr = htons(hdr);
  88
  89 -       skb_put_zero(skb, QCA_HDR_MGMT_DATA2_LEN + QCA_HDR_MGMT_PADDING_LEN);
  90 +       data2 = skb_put_zero(skb, QCA_HDR_MGMT_DATA2_LEN + QCA_HDR_MGMT_PADDING_LEN);
  91 +       if (cmd == MDIO_WRITE && len > QCA_HDR_MGMT_DATA1_LEN)
  92 +               memcpy(data2, val + 1, len - QCA_HDR_MGMT_DATA1_LEN);
  93
  94         return skb;
  95  }
  96 @@ -277,7 +295,7 @@ static void qca8k_mdio_header_fill_seq_n
  97         mgmt_ethhdr->seq = FIELD_PREP(QCA_HDR_MGMT_SEQ_NUM, seq_num);
  98  }
  99
 100 -static int qca8k_read_eth(struct qca8k_priv *priv, u32 reg, u32 *val)
 101 +static int qca8k_read_eth(struct qca8k_priv *priv, u32 reg, u32 *val, int len)
 102  {
 103         struct qca8k_mgmt_eth_data *mgmt_eth_data = &priv->mgmt_eth_data;
 104         struct sk_buff *skb;
 105 @@ -285,7 +303,7 @@ static int qca8k_read_eth(struct qca8k_p
 106         int ret;
 107
 108         skb = qca8k_alloc_mdio_header(MDIO_READ, reg, NULL,
 109 -                                     QCA8K_ETHERNET_MDIO_PRIORITY);
 110 +                                     QCA8K_ETHERNET_MDIO_PRIORITY, len);
 111         if (!skb)
 112                 return -ENOMEM;
 113
 114 @@ -313,6 +331,9 @@ static int qca8k_read_eth(struct qca8k_p
 115                                           msecs_to_jiffies(QCA8K_ETHERNET_TIMEOUT));
 116
 117         *val = mgmt_eth_data->data[0];
 118 +       if (len > QCA_HDR_MGMT_DATA1_LEN)
 119 +               memcpy(val + 1, mgmt_eth_data->data + 1, len - QCA_HDR_MGMT_DATA1_LEN);
 120 +
 121         ack = mgmt_eth_data->ack;
 122
 123         mutex_unlock(&mgmt_eth_data->mutex);
 124 @@ -326,15 +347,15 @@ static int qca8k_read_eth(struct qca8k_p
 125         return 0;
 126  }
 127
 128 -static int qca8k_write_eth(struct qca8k_priv *priv, u32 reg, u32 val)
 129 +static int qca8k_write_eth(struct qca8k_priv *priv, u32 reg, u32 *val, int len)
 130  {
 131         struct qca8k_mgmt_eth_data *mgmt_eth_data = &priv->mgmt_eth_data;
 132         struct sk_buff *skb;
 133         bool ack;
 134         int ret;
 135
 136 -       skb = qca8k_alloc_mdio_header(MDIO_WRITE, reg, &val,
 137 -                                     QCA8K_ETHERNET_MDIO_PRIORITY);
 138 +       skb = qca8k_alloc_mdio_header(MDIO_WRITE, reg, val,
 139 +                                     QCA8K_ETHERNET_MDIO_PRIORITY, len);
 140         if (!skb)
 141                 return -ENOMEM;
 142
 143 @@ -380,14 +401,14 @@ qca8k_regmap_update_bits_eth(struct qca8
 144         u32 val = 0;
 145         int ret;
 146
 147 -       ret = qca8k_read_eth(priv, reg, &val);
 148 +       ret = qca8k_read_eth(priv, reg, &val, sizeof(val));
 149         if (ret)
 150                 return ret;
 151
 152         val &= ~mask;
 153         val |= write_val;
 154
 155 -       return qca8k_write_eth(priv, reg, val);
 156 +       return qca8k_write_eth(priv, reg, &val, sizeof(val));
 157  }
 158
 159  static int
 160 @@ -398,7 +419,7 @@ qca8k_regmap_read(void *ctx, uint32_t re
 161         u16 r1, r2, page;
 162         int ret;
 163
 164 -       if (!qca8k_read_eth(priv, reg, val))
 165 +       if (!qca8k_read_eth(priv, reg, val, sizeof(val)))
 166                 return 0;
 167
 168         qca8k_split_addr(reg, &r1, &r2, &page);
 169 @@ -424,7 +445,7 @@ qca8k_regmap_write(void *ctx, uint32_t r
 170         u16 r1, r2, page;
 171         int ret;
 172
 173 -       if (!qca8k_write_eth(priv, reg, val))
 174 +       if (!qca8k_write_eth(priv, reg, &val, sizeof(val)))
 175                 return 0;
 176
 177         qca8k_split_addr(reg, &r1, &r2, &page);
 178 @@ -959,21 +980,21 @@ qca8k_phy_eth_command(struct qca8k_priv
 179         }
 180
 181         /* Prealloc all the needed skb before the lock */
 182 -       write_skb = qca8k_alloc_mdio_header(MDIO_WRITE, QCA8K_MDIO_MASTER_CTRL,
 183 -                                           &write_val, QCA8K_ETHERNET_PHY_PRIORITY);
 184 +       write_skb = qca8k_alloc_mdio_header(MDIO_WRITE, QCA8K_MDIO_MASTER_CTRL, &write_val,
 185 +                                           QCA8K_ETHERNET_PHY_PRIORITY, sizeof(write_val));
 186         if (!write_skb)
 187                 return -ENOMEM;
 188
 189 -       clear_skb = qca8k_alloc_mdio_header(MDIO_WRITE, QCA8K_MDIO_MASTER_CTRL,
 190 -                                           &clear_val, QCA8K_ETHERNET_PHY_PRIORITY);
 191 +       clear_skb = qca8k_alloc_mdio_header(MDIO_WRITE, QCA8K_MDIO_MASTER_CTRL, &clear_val,
 192 +                                           QCA8K_ETHERNET_PHY_PRIORITY, sizeof(clear_val));
 193         if (!write_skb) {
 194                 ret = -ENOMEM;
 195                 goto err_clear_skb;
 196         }
 197
 198 -       read_skb = qca8k_alloc_mdio_header(MDIO_READ, QCA8K_MDIO_MASTER_CTRL,
 199 -                                          &clear_val, QCA8K_ETHERNET_PHY_PRIORITY);
 200 -       if (!write_skb) {
 201 +       read_skb = qca8k_alloc_mdio_header(MDIO_READ, QCA8K_MDIO_MASTER_CTRL, &clear_val,
 202 +                                          QCA8K_ETHERNET_PHY_PRIORITY, sizeof(clear_val));
 203 +       if (!read_skb) {
 204                 ret = -ENOMEM;
 205                 goto err_read_skb;
 206         }