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
 100                 td = &qset->qtd[qset->td_start];
 101                 status = le32_to_cpu(td->status);
 102
 103                 /*
 104                  * Nothing to do with a still active qTD.
 105                  */
 106                 if (status & QTD_STS_ACTIVE)
 107                         break;
 108
 109                 if (status & QTD_STS_HALTED) {
 110                         /* Ug, an error. */
 111                         process_halted_qtd(whc, qset, td);
 112                         /* A halted qTD always triggers an update
 113                            because the qset was either removed or
 114                            reactivated. */
 115                         update |= WHC_UPDATE_UPDATED;
 116                         goto done;
 117                 }
 118
 119                 /* Mmm, a completed qTD. */
 120                 process_inactive_qtd(whc, qset, td);
 121         }
 122
 123         if (!qset->remove)
 124                 update |= qset_add_qtds(whc, qset);
 125
 126 done:
 127         /*
 128          * If there are no qTDs in this qset, remove it from the PZL.
 129          */
 130         if (qset->remove && qset->ntds == 0) {
 131                 pzl_qset_remove(whc, qset);
 132                 update |= WHC_UPDATE_REMOVED;
 133         }
 134
 135         return update;
 136 }
 137
 138 /**
 139  * pzl_start - start the periodic schedule
 140  * @whc: the WHCI host controller
 141  *
 142  * The PZL must be valid (e.g., all entries in the list should have
 143  * the T bit set).
 144  */
 145 void pzl_start(struct whc *whc)
 146 {
 147         le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
 148
 149         whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, WUSBCMD_PERIODIC_EN);
 150         whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 151                       WUSBSTS_PERIODIC_SCHED, WUSBSTS_PERIODIC_SCHED,
 152                       1000, "start PZL");
 153 }
 154
 155 /**
 156  * pzl_stop - stop the periodic schedule
 157  * @whc: the WHCI host controller
 158  */
 159 void pzl_stop(struct whc *whc)
 160 {
 161         whc_write_wusbcmd(whc, WUSBCMD_PERIODIC_EN, 0);
 162         whci_wait_for(&whc->umc->dev, whc->base + WUSBSTS,
 163                       WUSBSTS_PERIODIC_SCHED, 0,
 164                       1000, "stop PZL");
 165 }
 166
 167 /**
 168  * pzl_update - request a PZL update and wait for the hardware to be synced
 169  * @whc: the WHCI HC
 170  * @wusbcmd: WUSBCMD value to start the update.
 171  *
 172  * If the WUSB HC is inactive (i.e., the PZL is stopped) then the
 173  * update must be skipped as the hardware may not respond to update
 174  * requests.
 175  */
 176 void pzl_update(struct whc *whc, uint32_t wusbcmd)
 177 {
 178         struct wusbhc *wusbhc = &whc->wusbhc;
 179         long t;
 180
 181         mutex_lock(&wusbhc->mutex);
 182         if (wusbhc->active) {
 183                 whc_write_wusbcmd(whc, wusbcmd, wusbcmd);
 184                 t = wait_event_timeout(
 185                         whc->periodic_list_wq,
 186                         (le_readl(whc->base + WUSBCMD) & WUSBCMD_PERIODIC_UPDATED) == 0,
 187                         msecs_to_jiffies(1000));
 188                 if (t == 0)
 189                         whc_hw_error(whc, "PZL update timeout");
 190         }
 191         mutex_unlock(&wusbhc->mutex);
 192 }
 193
 194 static void update_pzl_hw_view(struct whc *whc)
 195 {
 196         struct whc_qset *qset, *t;
 197         int period;
 198         u64 tmp_qh = 0;
 199
 200         for (period = 0; period < 5; period++) {
 201                 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
 202                         whc_qset_set_link_ptr(&qset->qh.link, tmp_qh);
 203                         tmp_qh = qset->qset_dma;
 204                         qset->in_hw_list = true;
 205                 }
 206                 update_pzl_pointers(whc, period, tmp_qh);
 207         }
 208 }
 209
 210 /**
 211  * scan_periodic_work - scan the PZL for qsets to process.
 212  *
 213  * Process each qset in the PZL in turn and then signal the WHC that
 214  * the PZL has been updated.
 215  *
 216  * Then start, stop or update the periodic schedule as required.
 217  */
 218 void scan_periodic_work(struct work_struct *work)
 219 {
 220         struct whc *whc = container_of(work, struct whc, periodic_work);
 221         struct whc_qset *qset, *t;
 222         enum whc_update update = 0;
 223         int period;
 224
 225         spin_lock_irq(&whc->lock);
 226
 227         for (period = 4; period >= 0; period--) {
 228                 list_for_each_entry_safe(qset, t, &whc->periodic_list[period], list_node) {
 229                         if (!qset->in_hw_list)
 230                                 update |= WHC_UPDATE_ADDED;
 231                         update |= pzl_process_qset(whc, qset);
 232                 }
 233         }
 234
 235         if (update & (WHC_UPDATE_ADDED | WHC_UPDATE_REMOVED))
 236                 update_pzl_hw_view(whc);
 237
 238         spin_unlock_irq(&whc->lock);
 239
 240         if (update) {
 241                 uint32_t wusbcmd = WUSBCMD_PERIODIC_UPDATED | WUSBCMD_PERIODIC_SYNCED_DB;
 242                 if (update & WHC_UPDATE_REMOVED)
 243                         wusbcmd |= WUSBCMD_PERIODIC_QSET_RM;
 244                 pzl_update(whc, wusbcmd);
 245         }
 246
 247         /*
 248          * Now that the PZL is updated, complete the removal of any
 249          * removed qsets.
 250          *
 251          * If the qset was to be reset, do so and reinsert it into the
 252          * PZL if it has pending transfers.
 253          */
 254         spin_lock_irq(&whc->lock);
 255
 256         list_for_each_entry_safe(qset, t, &whc->periodic_removed_list, list_node) {
 257                 qset_remove_complete(whc, qset);
 258                 if (qset->reset) {
 259                         qset_reset(whc, qset);
 260                         if (!list_empty(&qset->stds)) {
 261                                 qset_insert_in_sw_list(whc, qset);
 262                                 queue_work(whc->workqueue, &whc->periodic_work);
 263                         }
 264                 }
 265         }
 266
 267         spin_unlock_irq(&whc->lock);
 268 }
 269
 270 /**
 271  * pzl_urb_enqueue - queue an URB onto the periodic list (PZL)
 272  * @whc: the WHCI host controller
 273  * @urb: the URB to enqueue
 274  * @mem_flags: flags for any memory allocations
 275  *
 276  * The qset for the endpoint is obtained and the urb queued on to it.
 277  *
 278  * Work is scheduled to update the hardware's view of the PZL.
 279  */
 280 int pzl_urb_enqueue(struct whc *whc, struct urb *urb, gfp_t mem_flags)
 281 {
 282         struct whc_qset *qset;
 283         int err;
 284         unsigned long flags;
 285
 286         spin_lock_irqsave(&whc->lock, flags);
 287
 288         err = usb_hcd_link_urb_to_ep(&whc->wusbhc.usb_hcd, urb);
 289         if (err < 0) {
 290                 spin_unlock_irqrestore(&whc->lock, flags);
 291                 return err;
 292         }
 293
 294         qset = get_qset(whc, urb, GFP_ATOMIC);
 295         if (qset == NULL)
 296                 err = -ENOMEM;
 297         else
 298                 err = qset_add_urb(whc, qset, urb, GFP_ATOMIC);
 299         if (!err) {
 300                 if (!qset->in_sw_list && !qset->remove)
 301                         qset_insert_in_sw_list(whc, qset);
 302         } else
 303                 usb_hcd_unlink_urb_from_ep(&whc->wusbhc.usb_hcd, urb);
 304
 305         spin_unlock_irqrestore(&whc->lock, flags);
 306
 307         if (!err)
 308                 queue_work(whc->workqueue, &whc->periodic_work);
 309
 310         return err;
 311 }
 312
 313 /**
 314  * pzl_urb_dequeue - remove an URB (qset) from the periodic list
 315  * @whc: the WHCI host controller
 316  * @urb: the URB to dequeue
 317  * @status: the current status of the URB
 318  *
 319  * URBs that do yet have qTDs can simply be removed from the software
 320  * queue, otherwise the qset must be removed so the qTDs can be safely
 321  * removed.
 322  */
 323 int pzl_urb_dequeue(struct whc *whc, struct urb *urb, int status)
 324 {
 325         struct whc_urb *wurb = urb->hcpriv;
 326         struct whc_qset *qset = wurb->qset;
 327         struct whc_std *std, *t;
 328         bool has_qtd = false;
 329         int ret;
 330         unsigned long flags;
 331
 332         spin_lock_irqsave(&whc->lock, flags);
 333
 334         ret = usb_hcd_check_unlink_urb(&whc->wusbhc.usb_hcd, urb, status);
 335         if (ret < 0)
 336                 goto out;
 337
 338         list_for_each_entry_safe(std, t, &qset->stds, list_node) {
 339                 if (std->urb == urb) {
 340                         if (std->qtd)
 341                                 has_qtd = true;
 342                         qset_free_std(whc, std);
 343                 } else
 344                         std->qtd = NULL; /* so this std is re-added when the qset is */
 345         }
 346
 347         if (has_qtd) {
 348                 pzl_qset_remove(whc, qset);
 349                 update_pzl_hw_view(whc);
 350                 wurb->status = status;
 351                 wurb->is_async = false;
 352                 queue_work(whc->workqueue, &wurb->dequeue_work);
 353         } else
 354                 qset_remove_urb(whc, qset, urb, status);
 355 out:
 356         spin_unlock_irqrestore(&whc->lock, flags);
 357
 358         return ret;
 359 }
 360
 361 /**
 362  * pzl_qset_delete - delete a qset from the PZL
 363  */
 364 void pzl_qset_delete(struct whc *whc, struct whc_qset *qset)
 365 {
 366         qset->remove = 1;
 367         queue_work(whc->workqueue, &whc->periodic_work);
 368         qset_delete(whc, qset);
 369 }
 370
 371 /**
 372  * pzl_init - initialize the periodic zone list
 373  * @whc: the WHCI host controller
 374  */
 375 int pzl_init(struct whc *whc)
 376 {
 377         int i;
 378
 379         whc->pz_list = dma_alloc_coherent(&whc->umc->dev, sizeof(u64) * 16,
 380                                           &whc->pz_list_dma, GFP_KERNEL);
 381         if (whc->pz_list == NULL)
 382                 return -ENOMEM;
 383
 384         /* Set T bit on all elements in PZL. */
 385         for (i = 0; i < 16; i++)
 386                 whc->pz_list[i] = cpu_to_le64(QH_LINK_NTDS(8) | QH_LINK_T);
 387
 388         le_writeq(whc->pz_list_dma, whc->base + WUSBPERIODICLISTBASE);
 389
 390         return 0;
 391 }
 392
 393 /**
 394  * pzl_clean_up - free PZL resources
 395  * @whc: the WHCI host controller
 396  *
 397  * The PZL is stopped and empty.
 398  */
 399 void pzl_clean_up(struct whc *whc)
 400 {
 401         if (whc->pz_list)
 402                 dma_free_coherent(&whc->umc->dev,  sizeof(u64) * 16, whc->pz_list,
 403                                   whc->pz_list_dma);
 404 }