drivers/staging/wfx/bh.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Interrupt bottom half (BH).
   4  *
   5  * Copyright (c) 2017-2019, Silicon Laboratories, Inc.
   6  * Copyright (c) 2010, ST-Ericsson
   7  */
   8 #include <linux/gpio/consumer.h>
   9 #include <net/mac80211.h>
  10
  11 #include "bh.h"
  12 #include "wfx.h"
  13 #include "hwio.h"
  14 #include "traces.h"
  15 #include "secure_link.h"
  16 #include "hif_rx.h"
  17 #include "hif_api_cmd.h"
  18
  19 static void device_wakeup(struct wfx_dev *wdev)
  20 {
  21         if (!wdev->pdata.gpio_wakeup)
  22                 return;
  23         if (gpiod_get_value(wdev->pdata.gpio_wakeup))
  24                 return;
  25
  26         gpiod_set_value(wdev->pdata.gpio_wakeup, 1);
  27         if (wfx_api_older_than(wdev, 1, 4)) {
  28                 if (!completion_done(&wdev->hif.ctrl_ready))
  29                         udelay(2000);
  30         } else {
  31                 // completion.h does not provide any function to wait
  32                 // completion without consume it (a kind of
  33                 // wait_for_completion_done_timeout()). So we have to emulate
  34                 // it.
  35                 if (wait_for_completion_timeout(&wdev->hif.ctrl_ready,
  36                                                 msecs_to_jiffies(2) + 1))
  37                         complete(&wdev->hif.ctrl_ready);
  38                 else
  39                         dev_err(wdev->dev, "timeout while wake up chip\n");
  40         }
  41 }
  42
  43 static void device_release(struct wfx_dev *wdev)
  44 {
  45         if (!wdev->pdata.gpio_wakeup)
  46                 return;
  47
  48         gpiod_set_value(wdev->pdata.gpio_wakeup, 0);
  49 }
  50
  51 static int rx_helper(struct wfx_dev *wdev, size_t read_len, int *is_cnf)
  52 {
  53         struct sk_buff *skb;
  54         struct hif_msg *hif;
  55         size_t alloc_len;
  56         size_t computed_len;
  57         int release_count;
  58         int piggyback = 0;
  59
  60         WARN(read_len < 4, "corrupted read");
  61         WARN(read_len > round_down(0xFFF, 2) * sizeof(u16),
  62              "%s: request exceed WFx capability", __func__);
  63
  64         // Add 2 to take into account piggyback size
  65         alloc_len = wdev->hwbus_ops->align_size(wdev->hwbus_priv, read_len + 2);
  66         skb = dev_alloc_skb(alloc_len);
  67         if (!skb)
  68                 return -ENOMEM;
  69
  70         if (wfx_data_read(wdev, skb->data, alloc_len))
  71                 goto err;
  72
  73         piggyback = le16_to_cpup((u16 *)(skb->data + alloc_len - 2));
  74         _trace_piggyback(piggyback, false);
  75
  76         hif = (struct hif_msg *)skb->data;
  77         WARN(hif->encrypted & 0x1, "unsupported encryption type");
  78         if (hif->encrypted == 0x2) {
  79                 if (wfx_sl_decode(wdev, (void *)hif)) {
  80                         dev_kfree_skb(skb);
  81                         // If frame was a confirmation, expect trouble in next
  82                         // exchange. However, it is harmless to fail to decode
  83                         // an indication frame, so try to continue. Anyway,
  84                         // piggyback is probably correct.
  85                         return piggyback;
  86                 }
  87                 le16_to_cpus(&hif->len);
  88                 computed_len = round_up(hif->len - sizeof(hif->len), 16)
  89                                + sizeof(struct hif_sl_msg)
  90                                + sizeof(struct hif_sl_tag);
  91         } else {
  92                 le16_to_cpus(&hif->len);
  93                 computed_len = round_up(hif->len, 2);
  94         }
  95         if (computed_len != read_len) {
  96                 dev_err(wdev->dev, "inconsistent message length: %zu != %zu\n",
  97                         computed_len, read_len);
  98                 print_hex_dump(KERN_INFO, "hif: ", DUMP_PREFIX_OFFSET, 16, 1,
  99                                hif, read_len, true);
 100                 goto err;
 101         }
 102
 103         if (!(hif->id & HIF_ID_IS_INDICATION)) {
 104                 (*is_cnf)++;
 105                 if (hif->id == HIF_CNF_ID_MULTI_TRANSMIT)
 106                         release_count = le32_to_cpu(((struct hif_cnf_multi_transmit *)hif->body)->num_tx_confs);
 107                 else
 108                         release_count = 1;
 109                 WARN(wdev->hif.tx_buffers_used < release_count, "corrupted buffer counter");
 110                 wdev->hif.tx_buffers_used -= release_count;
 111                 if (!wdev->hif.tx_buffers_used)
 112                         wake_up(&wdev->hif.tx_buffers_empty);
 113         }
 114         _trace_hif_recv(hif, wdev->hif.tx_buffers_used);
 115
 116         if (hif->id != HIF_IND_ID_EXCEPTION && hif->id != HIF_IND_ID_ERROR) {
 117                 if (hif->seqnum != wdev->hif.rx_seqnum)
 118                         dev_warn(wdev->dev, "wrong message sequence: %d != %d\n",
 119                                  hif->seqnum, wdev->hif.rx_seqnum);
 120                 wdev->hif.rx_seqnum = (hif->seqnum + 1) % (HIF_COUNTER_MAX + 1);
 121         }
 122
 123         skb_put(skb, hif->len);
 124         // wfx_handle_rx takes care on SKB livetime
 125         wfx_handle_rx(wdev, skb);
 126
 127         return piggyback;
 128
 129 err:
 130         if (skb)
 131                 dev_kfree_skb(skb);
 132         return -EIO;
 133 }
 134
 135 static int bh_work_rx(struct wfx_dev *wdev, int max_msg, int *num_cnf)
 136 {
 137         size_t len;
 138         int i;
 139         int ctrl_reg, piggyback;
 140
 141         piggyback = 0;
 142         for (i = 0; i < max_msg; i++) {
 143                 if (piggyback & CTRL_NEXT_LEN_MASK)
 144                         ctrl_reg = piggyback;
 145                 else if (try_wait_for_completion(&wdev->hif.ctrl_ready))
 146                         ctrl_reg = atomic_xchg(&wdev->hif.ctrl_reg, 0);
 147                 else
 148                         ctrl_reg = 0;
 149                 if (!(ctrl_reg & CTRL_NEXT_LEN_MASK))
 150                         return i;
 151                 // ctrl_reg units are 16bits words
 152                 len = (ctrl_reg & CTRL_NEXT_LEN_MASK) * 2;
 153                 piggyback = rx_helper(wdev, len, num_cnf);
 154                 if (piggyback < 0)
 155                         return i;
 156                 if (!(piggyback & CTRL_WLAN_READY))
 157                         dev_err(wdev->dev, "unexpected piggyback value: ready bit not set: %04x\n",
 158                                 piggyback);
 159         }
 160         if (piggyback & CTRL_NEXT_LEN_MASK) {
 161                 ctrl_reg = atomic_xchg(&wdev->hif.ctrl_reg, piggyback);
 162                 complete(&wdev->hif.ctrl_ready);
 163                 if (ctrl_reg)
 164                         dev_err(wdev->dev, "unexpected IRQ happened: %04x/%04x\n",
 165                                 ctrl_reg, piggyback);
 166         }
 167         return i;
 168 }
 169
 170 static void tx_helper(struct wfx_dev *wdev, struct hif_msg *hif)
 171 {
 172         int ret;
 173         void *data;
 174         bool is_encrypted = false;
 175         size_t len = le16_to_cpu(hif->len);
 176
 177         WARN(len < sizeof(*hif), "try to send corrupted data");
 178
 179         hif->seqnum = wdev->hif.tx_seqnum;
 180         wdev->hif.tx_seqnum = (wdev->hif.tx_seqnum + 1) % (HIF_COUNTER_MAX + 1);
 181
 182         if (wfx_is_secure_command(wdev, hif->id)) {
 183                 len = round_up(len - sizeof(hif->len), 16) + sizeof(hif->len) +
 184                         sizeof(struct hif_sl_msg_hdr) +
 185                         sizeof(struct hif_sl_tag);
 186                 // AES support encryption in-place. However, mac80211 access to
 187                 // 802.11 header after frame was sent (to get MAC addresses).
 188                 // So, keep origin buffer clear.
 189                 data = kmalloc(len, GFP_KERNEL);
 190                 if (!data)
 191                         goto end;
 192                 is_encrypted = true;
 193                 ret = wfx_sl_encode(wdev, hif, data);
 194                 if (ret)
 195                         goto end;
 196         } else {
 197                 data = hif;
 198         }
 199         WARN(len > wdev->hw_caps.size_inp_ch_buf,
 200              "%s: request exceed WFx capability: %zu > %d\n", __func__,
 201              len, wdev->hw_caps.size_inp_ch_buf);
 202         len = wdev->hwbus_ops->align_size(wdev->hwbus_priv, len);
 203         ret = wfx_data_write(wdev, data, len);
 204         if (ret)
 205                 goto end;
 206
 207         wdev->hif.tx_buffers_used++;
 208         _trace_hif_send(hif, wdev->hif.tx_buffers_used);
 209 end:
 210         if (is_encrypted)
 211                 kfree(data);
 212 }
 213
 214 static int bh_work_tx(struct wfx_dev *wdev, int max_msg)
 215 {
 216         struct hif_msg *hif;
 217         int i;
 218
 219         for (i = 0; i < max_msg; i++) {
 220                 hif = NULL;
 221                 if (wdev->hif.tx_buffers_used < wdev->hw_caps.num_inp_ch_bufs) {
 222                         if (try_wait_for_completion(&wdev->hif_cmd.ready)) {
 223                                 WARN(!mutex_is_locked(&wdev->hif_cmd.lock), "data locking error");
 224                                 hif = wdev->hif_cmd.buf_send;
 225                         } else {
 226                                 hif = wfx_tx_queues_get(wdev);
 227                         }
 228                 }
 229                 if (!hif)
 230                         return i;
 231                 tx_helper(wdev, hif);
 232         }
 233         return i;
 234 }
 235
 236 /* In SDIO mode, it is necessary to make an access to a register to acknowledge
 237  * last received message. It could be possible to restrict this acknowledge to
 238  * SDIO mode and only if last operation was rx.
 239  */
 240 static void ack_sdio_data(struct wfx_dev *wdev)
 241 {
 242         u32 cfg_reg;
 243
 244         config_reg_read(wdev, &cfg_reg);
 245         if (cfg_reg & 0xFF) {
 246                 dev_warn(wdev->dev, "chip reports errors: %02x\n",
 247                          cfg_reg & 0xFF);
 248                 config_reg_write_bits(wdev, 0xFF, 0x00);
 249         }
 250 }
 251
 252 static void bh_work(struct work_struct *work)
 253 {
 254         struct wfx_dev *wdev = container_of(work, struct wfx_dev, hif.bh);
 255         int stats_req = 0, stats_cnf = 0, stats_ind = 0;
 256         bool release_chip = false, last_op_is_rx = false;
 257         int num_tx, num_rx;
 258
 259         device_wakeup(wdev);
 260         do {
 261                 num_tx = bh_work_tx(wdev, 32);
 262                 stats_req += num_tx;
 263                 if (num_tx)
 264                         last_op_is_rx = false;
 265                 num_rx = bh_work_rx(wdev, 32, &stats_cnf);
 266                 stats_ind += num_rx;
 267                 if (num_rx)
 268                         last_op_is_rx = true;
 269         } while (num_rx || num_tx);
 270         stats_ind -= stats_cnf;
 271
 272         if (last_op_is_rx)
 273                 ack_sdio_data(wdev);
 274         if (!wdev->hif.tx_buffers_used && !work_pending(work)) {
 275                 device_release(wdev);
 276                 release_chip = true;
 277         }
 278         _trace_bh_stats(stats_ind, stats_req, stats_cnf,
 279                         wdev->hif.tx_buffers_used, release_chip);
 280 }
 281
 282 /*
 283  * An IRQ from chip did occur
 284  */
 285 void wfx_bh_request_rx(struct wfx_dev *wdev)
 286 {
 287         u32 cur, prev;
 288
 289         control_reg_read(wdev, &cur);
 290         prev = atomic_xchg(&wdev->hif.ctrl_reg, cur);
 291         complete(&wdev->hif.ctrl_ready);
 292         queue_work(system_highpri_wq, &wdev->hif.bh);
 293
 294         if (!(cur & CTRL_NEXT_LEN_MASK))
 295                 dev_err(wdev->dev, "unexpected control register value: length field is 0: %04x\n",
 296                         cur);
 297         if (prev != 0)
 298                 dev_err(wdev->dev, "received IRQ but previous data was not (yet) read: %04x/%04x\n",
 299                         prev, cur);
 300 }
 301
 302 /*
 303  * Driver want to send data
 304  */
 305 void wfx_bh_request_tx(struct wfx_dev *wdev)
 306 {
 307         queue_work(system_highpri_wq, &wdev->hif.bh);
 308 }
 309
 310 void wfx_bh_register(struct wfx_dev *wdev)
 311 {
 312         INIT_WORK(&wdev->hif.bh, bh_work);
 313         init_completion(&wdev->hif.ctrl_ready);
 314         init_waitqueue_head(&wdev->hif.tx_buffers_empty);
 315 }
 316
 317 void wfx_bh_unregister(struct wfx_dev *wdev)
 318 {
 319         flush_work(&wdev->hif.bh);
 320 }