drivers/usb/host/whci/pzl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Wireless Host Controller (WHC) periodic schedule management.
   4  *
   5  * Copyright (C) 2007 Cambridge Silicon Radio Ltd.
   6  */
   7 #include <linux/kernel.h>
   8 #include <linux/gfp.h>
   9 #include <linux/dma-mapping.h>
  10 #include <linux/uwb/umc.h>
  11 #include <linux/usb.h>
  12
  13 #include "../../wusbcore/wusbhc.h"
  14
  15 #include "whcd.h"
  16
  17 static void update_pzl_pointers(struct whc *whc, int period, u64 addr)
  18 {
  19         switch (period) {
  20         case 0:
  21                 whc_qset_set_link_ptr(&whc->pz_list[0], addr);
  22                 whc_qset_set_link_ptr(&whc->pz_list[2], addr);
  23                 whc_qset_set_link_ptr(&whc->pz_list[4], addr);
  24                 whc_qset_set_link_ptr(&whc->pz_list[6], addr);
  25                 whc_qset_set_link_ptr(&whc->pz_list[8], addr);
  26                 whc_qset_set_link_ptr(&whc->pz_list[10], addr);
  27                 whc_qset_set_link_ptr(&whc->pz_list[12], addr);
  28                 whc_qset_set_link_ptr(&whc->pz_list[14], addr);
  29                 break;
  30         case 1:
  31                 whc_qset_set_link_ptr(&whc->pz_list[1], addr);
  32                 whc_qset_set_link_ptr(&whc->pz_list[5], addr);
  33                 whc_qset_set_link_ptr(&whc->pz_list[9], addr);
  34                 whc_qset_set_link_ptr(&whc->pz_list[13], addr);
  35                 break;
  36         case 2:
  37                 whc_qset_set_link_ptr(&whc->pz_list[3], addr);
  38                 whc_qset_set_link_ptr(&whc->pz_list[11], addr);
  39                 break;
  40         case 3:
  41                 whc_qset_set_link_ptr(&whc->pz_list[7], addr);
  42                 break;
  43         case 4:
  44                 whc_qset_set_link_ptr(&whc->pz_list[15], addr);
  45                 break;
  46         }
  47 }
  48
  49 /*
  50  * Return the 'period' to use for this qset.  The minimum interval for
  51  * the endpoint is used so whatever urbs are submitted the device is
  52  * polled often enough.
  53  */
  54 static int qset_get_period(struct whc *whc, struct whc_qset *qset)
  55 {
  56         uint8_t bInterval = qset->ep->desc.bInterval;
  57
  58         if (bInterval < 6)
  59                 bInterval = 6;
  60         if (bInterval > 10)
  61                 bInterval = 10;
  62         return bInterval - 6;
  63 }
  64
  65 static void qset_insert_in_sw_list(struct whc *whc, struct whc_qset *qset)
  66 {
  67         int period;
  68
  69         period = qset_get_period(whc, qset);
  70
  71         qset_clear(whc, qset);
  72         list_move(&qset->list_node, &whc->periodic_list[period]);
  73         qset->in_sw_list = true;
  74 }
  75
  76 static void pzl_qset_remove(struct whc *whc, struct whc_qset *qset)
  77 {
  78         list_move(&qset->list_node, &whc->periodic_removed_list);
  79         qset->in_hw_list = false;
  80         qset->in_sw_list = false;
  81 }
  82
  83 /**
  84  * pzl_process_qset - process any recently inactivated or halted qTDs
  85  * in a qset.
  86  *
  87  * After inactive qTDs are removed, new qTDs can be added if the
  88  * urb queue still contains URBs.
  89  *
  90  * Returns the schedule updates required.
  91  */
  92 static enum whc_update pzl_process_qset(struct whc *whc, struct whc_qset *qset)
  93 {
  94         enum whc_update update = 0;
  95         uint32_t status = 0;
  96
  97         while (qset->ntds) {
  98                 struct whc_qtd *td;
  99                 int t;
 100
 101                 t = qset->td_start;
 102                 td = &qset->qtd[qset->td_start];
 103                 status = le32_to_cpu(td->status);
 104
 105                 /*
 106                  * Nothing to do with a still active qTD.
 107                  */
 108                 if (status & QTD_STS_ACTIVE)
 109                         break;
 110
 111                 if (status & QTD_STS_HALTED) {
 112                         /* Ug, an error. */
 113                         process_halted_qtd(whc, qset, td);
 114                         /* A halted qTD always triggers an update
 115                            because the qset was either removed or
 116                            reactivated. */
 117                         update |= WHC_UPDATE_UPDATED;
 118                         goto done;
 119                 }
 120
 121                 /* Mmm, a completed qTD. */
 122                 process_inactive_qtd(whc, qset, td);
 123         }
 124
 125         if (!qset->remove)
 126                 update |= qset_add_qtds(whc, qset);
 127
 128 done:
 129         /*
 130          * If there are no qTDs in this qset, remove it from the PZL.
 131          */
 132         if (qset->remove && qset->ntds == 0) {
 133                 pzl_qset_remove(whc, qset);
 134                 update |= WHC_UPDATE_REMOVED;
 135         }
 136
 137         return update;
 138 }
 139
 140 /**
 141  * pzl_start - start the periodic schedule
 142  * @whc: the WHCI host controller
 143  *
 144  * The PZL must be valid (e.g., all entries in the list should have
 145  * the T bit set).
 146  */
 147 void pzl_start(struct whc *whc)
 148 {
 149         le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
 150
 151         whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, WUSBCMD_PERIODIC_EN);
 152         whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 153                       WUSBSTS_PERIODIC_SCHED, WUSBSTS_PERIODIC_SCHED,
 154                       1000, "start PZL");
 155 }
 156
 157 /**
 158  * pzl_stop - stop the periodic schedule
 159  * @whc: the WHCI host controller
 160  */
 161 void pzl_stop(struct whc *whc)
 162 {
 163         whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, 0);
 164         whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 165                       WUSBSTS_PERIODIC_SCHED, 0,
 166                       1000, "stop PZL");
 167 }
 168
 169 /**
 170  * pzl_update - request a PZL update and wait for the hardware to be synced
 171  * @whc: the WHCI HC
 172  * @wusbcmd: WUSBCMD value to start the update.
 173  *
 174  * If the WUSB HC is inactive (i.e., the PZL is stopped) then the
 175  * update must be skipped as the hardware may not respond to update
 176  * requests.
 177  */
 178 void pzl_update(struct whc *whc, uint32_t wusbcmd)
 179 {
 180         struct wusbhc *wusbhc = &whc->wusbhc;
 181         long t;
 182
 183         mutex_lock(&wusbhc->mutex);
 184         if (wusbhc->active) {
 185                 whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
 186                 t = wait_event_timeout(
 187                         whc->periodic_list_wq,
 188                         (le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0,
 189                         msecs_to_jiffies(1000));
 190                 if (t == 0)
 191                         whc_hw_error(whc, "PZL update timeout");
 192         }
 193         mutex_unlock(&wusbhc->mutex);
 194 }
 195
 196 static void update_pzl_hw_view(struct whc *whc)
 197 {
 198         struct whc_qset *qset, *t;
 199         int period;
 200         u64 tmp_qh = 0;
 201
 202         for (period = 0; period < 5; period++) {
 203                 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
 204                         whc_qset_set_link_ptr(&qset->qh.link, tmp_qh);
 205                         tmp_qh = qset->qset_dma;
 206                         qset->in_hw_list = true;
 207                 }
 208                 update_pzl_pointers(whc, period, tmp_qh);
 209         }
 210 }
 211
 212 /**
 213  * scan_periodic_work - scan the PZL for qsets to process.
 214  *
 215  * Process each qset in the PZL in turn and then signal the WHC that
 216  * the PZL has been updated.
 217  *
 218  * Then start, stop or update the periodic schedule as required.
 219  */
 220 void scan_periodic_work(struct work_struct *work)
 221 {
 222         struct whc *whc = container_of(work, struct whc, periodic_work);
 223         struct whc_qset *qset, *t;
 224         enum whc_update update = 0;
 225         int period;
 226
 227         spin_lock_irq(&whc->lock);
 228
 229         for (period = 4; period >= 0; period--) {
 230                 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
 231                         if (!qset->in_hw_list)
 232                                 update |= WHC_UPDATE_ADDED;
 233                         update |= pzl_process_qset(whc, qset);
 234                 }
 235         }
 236
 237         if (update & (WHC_UPDATE_ADDED | WHC_UPDATE_REMOVED))
 238                 update_pzl_hw_view(whc);
 239
 240         spin_unlock_irq(&whc->lock);
 241
 242         if (update) {
 243                 uint32_t wusbcmd = WUSBCMD_PERIODIC_UPDATED | WUSBCMD_PERIODIC_SYNCED_DB;
 244                 if (update & WHC_UPDATE_REMOVED)
 245                         wusbcmd |= WUSBCMD_PERIODIC_QSET_RM;
 246                 pzl_update(whc, wusbcmd);
 247         }
 248
 249         /*
 250          * Now that the PZL is updated, complete the removal of any
 251          * removed qsets.
 252          *
 253          * If the qset was to be reset, do so and reinsert it into the
 254          * PZL if it has pending transfers.
 255          */
 256         spin_lock_irq(&whc->lock);
 257
 258         list_for_each_entry_safe(qset, t, &whc->periodic_removed_list, list_node) {
 259                 qset_remove_complete(whc, qset);
 260                 if (qset->reset) {
 261                         qset_reset(whc, qset);
 262                         if (!list_empty(&qset->stds)) {
 263                                 qset_insert_in_sw_list(whc, qset);
 264                                 queue_work(whc->workqueue, &whc->periodic_work);
 265                         }
 266                 }
 267         }
 268
 269         spin_unlock_irq(&whc->lock);
 270 }
 271
 272 /**
 273  * pzl_urb_enqueue - queue an URB onto the periodic list (PZL)
 274  * @whc: the WHCI host controller
 275  * @urb: the URB to enqueue
 276  * @mem_flags: flags for any memory allocations
 277  *
 278  * The qset for the endpoint is obtained and the urb queued on to it.
 279  *
 280  * Work is scheduled to update the hardware's view of the PZL.
 281  */
 282 int pzl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
 283 {
 284         struct whc_qset *qset;
 285         int err;
 286         unsigned long flags;
 287
 288         spin_lock_irqsave(&whc->lock, flags);
 289
 290         err = usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
 291         if (err < 0) {
 292                 spin_unlock_irqrestore(&whc->lock, flags);
 293                 return err;
 294         }
 295
 296         qset = get_qset(whc, urb, GFP_ATOMIC);
 297         if (qset == NULL)
 298                 err = -ENOMEM;
 299         else
 300                 err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
 301         if (!err) {
 302                 if (!qset->in_sw_list && !qset->remove)
 303                         qset_insert_in_sw_list(whc, qset);
 304         } else
 305                 usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);
 306
 307         spin_unlock_irqrestore(&whc->lock, flags);
 308
 309         if (!err)
 310                 queue_work(whc->workqueue, &whc->periodic_work);
 311
 312         return err;
 313 }
 314
 315 /**
 316  * pzl_urb_dequeue - remove an URB (qset) from the periodic list
 317  * @whc: the WHCI host controller
 318  * @urb: the URB to dequeue
 319  * @status: the current status of the URB
 320  *
 321  * URBs that do yet have qTDs can simply be removed from the software
 322  * queue, otherwise the qset must be removed so the qTDs can be safely
 323  * removed.
 324  */
 325 int pzl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
 326 {
 327         struct whc_urb *wurb = urb->hcpriv;
 328         struct whc_qset *qset = wurb->qset;
 329         struct whc_std *std, *t;
 330         bool has_qtd = false;
 331         int ret;
 332         unsigned long flags;
 333
 334         spin_lock_irqsave(&whc->lock, flags);
 335
 336         ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
 337         if (ret < 0)
 338                 goto out;
 339
 340         list_for_each_entry_safe(std, t, &qset->stds, list_node) {
 341                 if (std->urb == urb) {
 342                         if (std->qtd)
 343                                 has_qtd = true;
 344                         qset_free_std(whc, std);
 345                 } else
 346                         std->qtd = NULL; /* so this std is re-added when the qset is */
 347         }
 348
 349         if (has_qtd) {
 350                 pzl_qset_remove(whc, qset);
 351                 update_pzl_hw_view(whc);
 352                 wurb->status = status;
 353                 wurb->is_async = false;
 354                 queue_work(whc->workqueue, &wurb->dequeue_work);
 355         } else
 356                 qset_remove_urb(whc, qset, urb, status);
 357 out:
 358         spin_unlock_irqrestore(&whc->lock, flags);
 359
 360         return ret;
 361 }
 362
 363 /**
 364  * pzl_qset_delete - delete a qset from the PZL
 365  */
 366 void pzl_qset_delete(struct whc *whc, struct whc_qset *qset)
 367 {
 368         qset->remove = 1;
 369         queue_work(whc->workqueue, &whc->periodic_work);
 370         qset_delete(whc, qset);
 371 }
 372
 373 /**
 374  * pzl_init - initialize the periodic zone list
 375  * @whc: the WHCI host controller
 376  */
 377 int pzl_init(struct whc *whc)
 378 {
 379         int i;
 380
 381         whc->pz_list = dma_alloc_coherent(&whc->umc->dev, sizeof(u64) * 16,
 382                                           &whc->pz_list_dma, GFP_KERNEL);
 383         if (whc->pz_list == NULL)
 384                 return -ENOMEM;
 385
 386         /* Set T bit on all elements in PZL. */
 387         for (i = 0; i < 16; i++)
 388                 whc->pz_list[i] = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
 389
 390         le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
 391
 392         return 0;
 393 }
 394
 395 /**
 396  * pzl_clean_up - free PZL resources
 397  * @whc: the WHCI host controller
 398  *
 399  * The PZL is stopped and empty.
 400  */
 401 void pzl_clean_up(struct whc *whc)
 402 {
 403         if (whc->pz_list)
 404                 dma_free_coherent(&whc->umc->dev,  sizeof(u64) * 16, whc->pz_list,
 405                                   whc->pz_list_dma);
 406 }