drivers/gpu/host1x/intr.c

   1 /*
   2  * Tegra host1x Interrupt Management
   3  *
   4  * Copyright (c) 2010-2013, NVIDIA Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/clk.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/slab.h>
  22 #include <linux/irq.h>
  23
  24 #include <trace/events/host1x.h>
  25 #include "channel.h"
  26 #include "dev.h"
  27 #include "intr.h"
  28
  29 /* Wait list management */
  30
  31 enum waitlist_state {
  32         WLS_PENDING,
  33         WLS_REMOVED,
  34         WLS_CANCELLED,
  35         WLS_HANDLED
  36 };
  37
  38 static void waiter_release(struct kref *kref)
  39 {
  40         kfree(container_of(kref, struct host1x_waitlist, refcount));
  41 }
  42
  43 /*
  44  * add a waiter to a waiter queue, sorted by threshold
  45  * returns true if it was added at the head of the queue
  46  */
  47 static bool add_waiter_to_queue(struct host1x_waitlist *waiter,
  48                                 struct list_head *queue)
  49 {
  50         struct host1x_waitlist *pos;
  51         u32 thresh = waiter->thresh;
  52
  53         list_for_each_entry_reverse(pos, queue, list)
  54                 if ((s32)(pos->thresh - thresh) <= 0) {
  55                         list_add(&waiter->list, &pos->list);
  56                         return false;
  57                 }
  58
  59         list_add(&waiter->list, queue);
  60         return true;
  61 }
  62
  63 /*
  64  * run through a waiter queue for a single sync point ID
  65  * and gather all completed waiters into lists by actions
  66  */
  67 static void remove_completed_waiters(struct list_head *head, u32 sync,
  68                         struct list_head completed[HOST1X_INTR_ACTION_COUNT])
  69 {
  70         struct list_head *dest;
  71         struct host1x_waitlist *waiter, *next, *prev;
  72
  73         list_for_each_entry_safe(waiter, next, head, list) {
  74                 if ((s32)(waiter->thresh - sync) > 0)
  75                         break;
  76
  77                 dest = completed + waiter->action;
  78
  79                 /* consolidate submit cleanups */
  80                 if (waiter->action == HOST1X_INTR_ACTION_SUBMIT_COMPLETE &&
  81                     !list_empty(dest)) {
  82                         prev = list_entry(dest->prev,
  83                                           struct host1x_waitlist, list);
  84                         if (prev->data == waiter->data) {
  85                                 prev->count++;
  86                                 dest = NULL;
  87                         }
  88                 }
  89
  90                 /* PENDING->REMOVED or CANCELLED->HANDLED */
  91                 if (atomic_inc_return(&waiter->state) == WLS_HANDLED || !dest) {
  92                         list_del(&waiter->list);
  93                         kref_put(&waiter->refcount, waiter_release);
  94                 } else
  95                         list_move_tail(&waiter->list, dest);
  96         }
  97 }
  98
  99 static void reset_threshold_interrupt(struct host1x *host,
 100                                       struct list_head *head,
 101                                       unsigned int id)
 102 {
 103         u32 thresh =
 104                 list_first_entry(head, struct host1x_waitlist, list)->thresh;
 105
 106         host1x_hw_intr_set_syncpt_threshold(host, id, thresh);
 107         host1x_hw_intr_enable_syncpt_intr(host, id);
 108 }
 109
 110 static void action_submit_complete(struct host1x_waitlist *waiter)
 111 {
 112         struct host1x_channel *channel = waiter->data;
 113
 114         host1x_cdma_update(&channel->cdma);
 115
 116         /*  Add nr_completed to trace */
 117         trace_host1x_channel_submit_complete(dev_name(channel->dev),
 118                                              waiter->count, waiter->thresh);
 119
 120 }
 121
 122 static void action_wakeup(struct host1x_waitlist *waiter)
 123 {
 124         wait_queue_head_t *wq = waiter->data;
 125
 126         wake_up(wq);
 127 }
 128
 129 static void action_wakeup_interruptible(struct host1x_waitlist *waiter)
 130 {
 131         wait_queue_head_t *wq = waiter->data;
 132
 133         wake_up_interruptible(wq);
 134 }
 135
 136 typedef void (*action_handler)(struct host1x_waitlist *waiter);
 137
 138 static const action_handler action_handlers[HOST1X_INTR_ACTION_COUNT] = {
 139         action_submit_complete,
 140         action_wakeup,
 141         action_wakeup_interruptible,
 142 };
 143
 144 static void run_handlers(struct list_head completed[HOST1X_INTR_ACTION_COUNT])
 145 {
 146         struct list_head *head = completed;
 147         unsigned int i;
 148
 149         for (i = 0; i < HOST1X_INTR_ACTION_COUNT; ++i, ++head) {
 150                 action_handler handler = action_handlers[i];
 151                 struct host1x_waitlist *waiter, *next;
 152
 153                 list_for_each_entry_safe(waiter, next, head, list) {
 154                         list_del(&waiter->list);
 155                         handler(waiter);
 156                         WARN_ON(atomic_xchg(&waiter->state, WLS_HANDLED) !=
 157                                 WLS_REMOVED);
 158                         kref_put(&waiter->refcount, waiter_release);
 159                 }
 160         }
 161 }
 162
 163 /*
 164  * Remove & handle all waiters that have completed for the given syncpt
 165  */
 166 static int process_wait_list(struct host1x *host,
 167                              struct host1x_syncpt *syncpt,
 168                              u32 threshold)
 169 {
 170         struct list_head completed[HOST1X_INTR_ACTION_COUNT];
 171         unsigned int i;
 172         int empty;
 173
 174         for (i = 0; i < HOST1X_INTR_ACTION_COUNT; ++i)
 175                 INIT_LIST_HEAD(completed + i);
 176
 177         spin_lock(&syncpt->intr.lock);
 178
 179         remove_completed_waiters(&syncpt->intr.wait_head, threshold,
 180                                  completed);
 181
 182         empty = list_empty(&syncpt->intr.wait_head);
 183         if (empty)
 184                 host1x_hw_intr_disable_syncpt_intr(host, syncpt->id);
 185         else
 186                 reset_threshold_interrupt(host, &syncpt->intr.wait_head,
 187                                           syncpt->id);
 188
 189         spin_unlock(&syncpt->intr.lock);
 190
 191         run_handlers(completed);
 192
 193         return empty;
 194 }
 195
 196 /*
 197  * Sync point threshold interrupt service thread function
 198  * Handles sync point threshold triggers, in thread context
 199  */
 200
 201 static void syncpt_thresh_work(struct work_struct *work)
 202 {
 203         struct host1x_syncpt_intr *syncpt_intr =
 204                 container_of(work, struct host1x_syncpt_intr, work);
 205         struct host1x_syncpt *syncpt =
 206                 container_of(syncpt_intr, struct host1x_syncpt, intr);
 207         unsigned int id = syncpt->id;
 208         struct host1x *host = syncpt->host;
 209
 210         (void)process_wait_list(host, syncpt,
 211                                 host1x_syncpt_load(host->syncpt + id));
 212 }
 213
 214 int host1x_intr_add_action(struct host1x *host, struct host1x_syncpt *syncpt,
 215                            u32 thresh, enum host1x_intr_action action,
 216                            void *data, struct host1x_waitlist *waiter,
 217                            void **ref)
 218 {
 219         int queue_was_empty;
 220
 221         if (waiter == NULL) {
 222                 pr_warn("%s: NULL waiter\n", __func__);
 223                 return -EINVAL;
 224         }
 225
 226         /* initialize a new waiter */
 227         INIT_LIST_HEAD(&waiter->list);
 228         kref_init(&waiter->refcount);
 229         if (ref)
 230                 kref_get(&waiter->refcount);
 231         waiter->thresh = thresh;
 232         waiter->action = action;
 233         atomic_set(&waiter->state, WLS_PENDING);
 234         waiter->data = data;
 235         waiter->count = 1;
 236
 237         spin_lock(&syncpt->intr.lock);
 238
 239         queue_was_empty = list_empty(&syncpt->intr.wait_head);
 240
 241         if (add_waiter_to_queue(waiter, &syncpt->intr.wait_head)) {
 242                 /* added at head of list - new threshold value */
 243                 host1x_hw_intr_set_syncpt_threshold(host, syncpt->id, thresh);
 244
 245                 /* added as first waiter - enable interrupt */
 246                 if (queue_was_empty)
 247                         host1x_hw_intr_enable_syncpt_intr(host, syncpt->id);
 248         }
 249
 250         spin_unlock(&syncpt->intr.lock);
 251
 252         if (ref)
 253                 *ref = waiter;
 254         return 0;
 255 }
 256
 257 void host1x_intr_put_ref(struct host1x *host, unsigned int id, void *ref)
 258 {
 259         struct host1x_waitlist *waiter = ref;
 260         struct host1x_syncpt *syncpt;
 261
 262         while (atomic_cmpxchg(&waiter->state, WLS_PENDING, WLS_CANCELLED) ==
 263                WLS_REMOVED)
 264                 schedule();
 265
 266         syncpt = host->syncpt + id;
 267         (void)process_wait_list(host, syncpt,
 268                                 host1x_syncpt_load(host->syncpt + id));
 269
 270         kref_put(&waiter->refcount, waiter_release);
 271 }
 272
 273 int host1x_intr_init(struct host1x *host, unsigned int irq_sync)
 274 {
 275         unsigned int id;
 276         u32 nb_pts = host1x_syncpt_nb_pts(host);
 277
 278         mutex_init(&host->intr_mutex);
 279         host->intr_syncpt_irq = irq_sync;
 280
 281         for (id = 0; id < nb_pts; ++id) {
 282                 struct host1x_syncpt *syncpt = host->syncpt + id;
 283
 284                 spin_lock_init(&syncpt->intr.lock);
 285                 INIT_LIST_HEAD(&syncpt->intr.wait_head);
 286                 snprintf(syncpt->intr.thresh_irq_name,
 287                          sizeof(syncpt->intr.thresh_irq_name),
 288                          "host1x_sp_%02u", id);
 289         }
 290
 291         host1x_intr_start(host);
 292
 293         return 0;
 294 }
 295
 296 void host1x_intr_deinit(struct host1x *host)
 297 {
 298         host1x_intr_stop(host);
 299 }
 300
 301 void host1x_intr_start(struct host1x *host)
 302 {
 303         u32 hz = clk_get_rate(host->clk);
 304         int err;
 305
 306         mutex_lock(&host->intr_mutex);
 307         err = host1x_hw_intr_init_host_sync(host, DIV_ROUND_UP(hz, 1000000),
 308                                             syncpt_thresh_work);
 309         if (err) {
 310                 mutex_unlock(&host->intr_mutex);
 311                 return;
 312         }
 313         mutex_unlock(&host->intr_mutex);
 314 }
 315
 316 void host1x_intr_stop(struct host1x *host)
 317 {
 318         unsigned int id;
 319         struct host1x_syncpt *syncpt = host->syncpt;
 320         u32 nb_pts = host1x_syncpt_nb_pts(host);
 321
 322         mutex_lock(&host->intr_mutex);
 323
 324         host1x_hw_intr_disable_all_syncpt_intrs(host);
 325
 326         for (id = 0; id < nb_pts; ++id) {
 327                 struct host1x_waitlist *waiter, *next;
 328
 329                 list_for_each_entry_safe(waiter, next,
 330                         &syncpt[id].intr.wait_head, list) {
 331                         if (atomic_cmpxchg(&waiter->state,
 332                             WLS_CANCELLED, WLS_HANDLED) == WLS_CANCELLED) {
 333                                 list_del(&waiter->list);
 334                                 kref_put(&waiter->refcount, waiter_release);
 335                         }
 336                 }
 337
 338                 if (!list_empty(&syncpt[id].intr.wait_head)) {
 339                         /* output diagnostics */
 340                         mutex_unlock(&host->intr_mutex);
 341                         pr_warn("%s cannot stop syncpt intr id=%u\n",
 342                                 __func__, id);
 343                         return;
 344                 }
 345         }
 346
 347         host1x_hw_intr_free_syncpt_irq(host);
 348
 349         mutex_unlock(&host->intr_mutex);
 350 }