gpu/host1x/syncpt.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Tegra host1x Syncpoints
0004  *
0005  * Copyright (c) 2010-2015, NVIDIA Corporation.
0006  */
0007
0008 #include <linux/module.h>
0009 #include <linux/device.h>
0010 #include <linux/slab.h>
0011
0012 #include <trace/events/host1x.h>
0013
0014 #include "syncpt.h"
0015 #include "dev.h"
0016 #include "intr.h"
0017 #include "debug.h"
0018
0019 #define SYNCPT_CHECK_PERIOD (2 * HZ)
0020 #define MAX_STUCK_CHECK_COUNT 15
0021
0022 static struct host1x_syncpt_base *
0023 host1x_syncpt_base_request(struct host1x *host)
0024 {
0025     struct host1x_syncpt_base *bases = host->bases;
0026     unsigned int i;
0027
0028     for (i = 0; i < host->info->nb_bases; i++)
0029         if (!bases[i].requested)
0030             break;
0031
0032     if (i >= host->info->nb_bases)
0033         return NULL;
0034
0035     bases[i].requested = true;
0036     return &bases[i];
0037 }
0038
0039 static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
0040 {
0041     if (base)
0042         base->requested = false;
0043 }
0044
0045 /**
0046  * host1x_syncpt_alloc() - allocate a syncpoint
0047  * @host: host1x device data
0048  * @flags: bitfield of HOST1X_SYNCPT_* flags
0049  * @name: name for the syncpoint for use in debug prints
0050  *
0051  * Allocates a hardware syncpoint for the caller's use. The caller then has
0052  * the sole authority to mutate the syncpoint's value until it is freed again.
0053  *
0054  * If no free syncpoints are available, or a NULL name was specified, returns
0055  * NULL.
0056  */
0057 struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
0058                       unsigned long flags,
0059                       const char *name)
0060 {
0061     struct host1x_syncpt *sp = host->syncpt;
0062     char *full_name;
0063     unsigned int i;
0064
0065     if (!name)
0066         return NULL;
0067
0068     mutex_lock(&host->syncpt_mutex);
0069
0070     for (i = 0; i < host->info->nb_pts && kref_read(&sp->ref); i++, sp++)
0071         ;
0072
0073     if (i >= host->info->nb_pts)
0074         goto unlock;
0075
0076     if (flags & HOST1X_SYNCPT_HAS_BASE) {
0077         sp->base = host1x_syncpt_base_request(host);
0078         if (!sp->base)
0079             goto unlock;
0080     }
0081
0082     full_name = kasprintf(GFP_KERNEL, "%u-%s", sp->id, name);
0083     if (!full_name)
0084         goto free_base;
0085
0086     sp->name = full_name;
0087
0088     if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
0089         sp->client_managed = true;
0090     else
0091         sp->client_managed = false;
0092
0093     kref_init(&sp->ref);
0094
0095     mutex_unlock(&host->syncpt_mutex);
0096     return sp;
0097
0098 free_base:
0099     host1x_syncpt_base_free(sp->base);
0100     sp->base = NULL;
0101 unlock:
0102     mutex_unlock(&host->syncpt_mutex);
0103     return NULL;
0104 }
0105 EXPORT_SYMBOL(host1x_syncpt_alloc);
0106
0107 /**
0108  * host1x_syncpt_id() - retrieve syncpoint ID
0109  * @sp: host1x syncpoint
0110  *
0111  * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
0112  * often used as a value to program into registers that control how hardware
0113  * blocks interact with syncpoints.
0114  */
0115 u32 host1x_syncpt_id(struct host1x_syncpt *sp)
0116 {
0117     return sp->id;
0118 }
0119 EXPORT_SYMBOL(host1x_syncpt_id);
0120
0121 /**
0122  * host1x_syncpt_incr_max() - update the value sent to hardware
0123  * @sp: host1x syncpoint
0124  * @incrs: number of increments
0125  */
0126 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
0127 {
0128     return (u32)atomic_add_return(incrs, &sp->max_val);
0129 }
0130 EXPORT_SYMBOL(host1x_syncpt_incr_max);
0131
0132  /*
0133  * Write cached syncpoint and waitbase values to hardware.
0134  */
0135 void host1x_syncpt_restore(struct host1x *host)
0136 {
0137     struct host1x_syncpt *sp_base = host->syncpt;
0138     unsigned int i;
0139
0140     for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
0141         /*
0142          * Unassign syncpt from channels for purposes of Tegra186
0143          * syncpoint protection. This prevents any channel from
0144          * accessing it until it is reassigned.
0145          */
0146         host1x_hw_syncpt_assign_to_channel(host, sp_base + i, NULL);
0147         host1x_hw_syncpt_restore(host, sp_base + i);
0148     }
0149
0150     for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
0151         host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
0152
0153     host1x_hw_syncpt_enable_protection(host);
0154
0155     wmb();
0156 }
0157
0158 /*
0159  * Update the cached syncpoint and waitbase values by reading them
0160  * from the registers.
0161   */
0162 void host1x_syncpt_save(struct host1x *host)
0163 {
0164     struct host1x_syncpt *sp_base = host->syncpt;
0165     unsigned int i;
0166
0167     for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
0168         if (host1x_syncpt_client_managed(sp_base + i))
0169             host1x_hw_syncpt_load(host, sp_base + i);
0170         else
0171             WARN_ON(!host1x_syncpt_idle(sp_base + i));
0172     }
0173
0174     for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
0175         host1x_hw_syncpt_load_wait_base(host, sp_base + i);
0176 }
0177
0178 /*
0179  * Updates the cached syncpoint value by reading a new value from the hardware
0180  * register
0181  */
0182 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
0183 {
0184     u32 val;
0185
0186     val = host1x_hw_syncpt_load(sp->host, sp);
0187     trace_host1x_syncpt_load_min(sp->id, val);
0188
0189     return val;
0190 }
0191
0192 /*
0193  * Get the current syncpoint base
0194  */
0195 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
0196 {
0197     host1x_hw_syncpt_load_wait_base(sp->host, sp);
0198
0199     return sp->base_val;
0200 }
0201
0202 /**
0203  * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
0204  * @sp: host1x syncpoint
0205  */
0206 int host1x_syncpt_incr(struct host1x_syncpt *sp)
0207 {
0208     return host1x_hw_syncpt_cpu_incr(sp->host, sp);
0209 }
0210 EXPORT_SYMBOL(host1x_syncpt_incr);
0211
0212 /*
0213  * Updated sync point form hardware, and returns true if syncpoint is expired,
0214  * false if we may need to wait
0215  */
0216 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
0217 {
0218     host1x_hw_syncpt_load(sp->host, sp);
0219
0220     return host1x_syncpt_is_expired(sp, thresh);
0221 }
0222
0223 /**
0224  * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
0225  * @sp: host1x syncpoint
0226  * @thresh: threshold
0227  * @timeout: maximum time to wait for the syncpoint to reach the given value
0228  * @value: return location for the syncpoint value
0229  */
0230 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
0231                u32 *value)
0232 {
0233     DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
0234     void *ref;
0235     struct host1x_waitlist *waiter;
0236     int err = 0, check_count = 0;
0237
0238     if (value)
0239         *value = host1x_syncpt_load(sp);
0240
0241     if (host1x_syncpt_is_expired(sp, thresh))
0242         return 0;
0243
0244     if (!timeout) {
0245         err = -EAGAIN;
0246         goto done;
0247     }
0248
0249     /* allocate a waiter */
0250     waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
0251     if (!waiter) {
0252         err = -ENOMEM;
0253         goto done;
0254     }
0255
0256     /* schedule a wakeup when the syncpoint value is reached */
0257     err = host1x_intr_add_action(sp->host, sp, thresh,
0258                      HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
0259                      &wq, waiter, &ref);
0260     if (err)
0261         goto done;
0262
0263     err = -EAGAIN;
0264     /* Caller-specified timeout may be impractically low */
0265     if (timeout < 0)
0266         timeout = LONG_MAX;
0267
0268     /* wait for the syncpoint, or timeout, or signal */
0269     while (timeout) {
0270         long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
0271         int remain;
0272
0273         remain = wait_event_interruptible_timeout(wq,
0274                 syncpt_load_min_is_expired(sp, thresh),
0275                 check);
0276         if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
0277             if (value)
0278                 *value = host1x_syncpt_load(sp);
0279
0280             err = 0;
0281
0282             break;
0283         }
0284
0285         if (remain < 0) {
0286             err = remain;
0287             break;
0288         }
0289
0290         timeout -= check;
0291
0292         if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
0293             dev_warn(sp->host->dev,
0294                 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
0295                  current->comm, sp->id, sp->name,
0296                  thresh, timeout);
0297
0298             host1x_debug_dump_syncpts(sp->host);
0299
0300             if (check_count == MAX_STUCK_CHECK_COUNT)
0301                 host1x_debug_dump(sp->host);
0302
0303             check_count++;
0304         }
0305     }
0306
0307     host1x_intr_put_ref(sp->host, sp->id, ref, true);
0308
0309 done:
0310     return err;
0311 }
0312 EXPORT_SYMBOL(host1x_syncpt_wait);
0313
0314 /*
0315  * Returns true if syncpoint is expired, false if we may need to wait
0316  */
0317 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
0318 {
0319     u32 current_val;
0320
0321     smp_rmb();
0322
0323     current_val = (u32)atomic_read(&sp->min_val);
0324
0325     return ((current_val - thresh) & 0x80000000U) == 0U;
0326 }
0327
0328 int host1x_syncpt_init(struct host1x *host)
0329 {
0330     struct host1x_syncpt_base *bases;
0331     struct host1x_syncpt *syncpt;
0332     unsigned int i;
0333
0334     syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
0335                   GFP_KERNEL);
0336     if (!syncpt)
0337         return -ENOMEM;
0338
0339     bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
0340                  GFP_KERNEL);
0341     if (!bases)
0342         return -ENOMEM;
0343
0344     for (i = 0; i < host->info->nb_pts; i++) {
0345         syncpt[i].id = i;
0346         syncpt[i].host = host;
0347     }
0348
0349     for (i = 0; i < host->info->nb_bases; i++)
0350         bases[i].id = i;
0351
0352     mutex_init(&host->syncpt_mutex);
0353     host->syncpt = syncpt;
0354     host->bases = bases;
0355
0356     /* Allocate sync point to use for clearing waits for expired fences */
0357     host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
0358     if (!host->nop_sp)
0359         return -ENOMEM;
0360
0361     if (host->info->reserve_vblank_syncpts) {
0362         kref_init(&host->syncpt[26].ref);
0363         kref_init(&host->syncpt[27].ref);
0364     }
0365
0366     return 0;
0367 }
0368
0369 /**
0370  * host1x_syncpt_request() - request a syncpoint
0371  * @client: client requesting the syncpoint
0372  * @flags: flags
0373  *
0374  * host1x client drivers can use this function to allocate a syncpoint for
0375  * subsequent use. A syncpoint returned by this function will be reserved for
0376  * use by the client exclusively. When no longer using a syncpoint, a host1x
0377  * client driver needs to release it using host1x_syncpt_put().
0378  */
0379 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
0380                         unsigned long flags)
0381 {
0382     struct host1x *host = dev_get_drvdata(client->host->parent);
0383
0384     return host1x_syncpt_alloc(host, flags, dev_name(client->dev));
0385 }
0386 EXPORT_SYMBOL(host1x_syncpt_request);
0387
0388 static void syncpt_release(struct kref *ref)
0389 {
0390     struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
0391
0392     atomic_set(&sp->max_val, host1x_syncpt_read(sp));
0393
0394     sp->locked = false;
0395
0396     mutex_lock(&sp->host->syncpt_mutex);
0397
0398     host1x_syncpt_base_free(sp->base);
0399     kfree(sp->name);
0400     sp->base = NULL;
0401     sp->name = NULL;
0402     sp->client_managed = false;
0403
0404     mutex_unlock(&sp->host->syncpt_mutex);
0405 }
0406
0407 /**
0408  * host1x_syncpt_put() - free a requested syncpoint
0409  * @sp: host1x syncpoint
0410  *
0411  * Release a syncpoint previously allocated using host1x_syncpt_request(). A
0412  * host1x client driver should call this when the syncpoint is no longer in
0413  * use.
0414  */
0415 void host1x_syncpt_put(struct host1x_syncpt *sp)
0416 {
0417     if (!sp)
0418         return;
0419
0420     kref_put(&sp->ref, syncpt_release);
0421 }
0422 EXPORT_SYMBOL(host1x_syncpt_put);
0423
0424 void host1x_syncpt_deinit(struct host1x *host)
0425 {
0426     struct host1x_syncpt *sp = host->syncpt;
0427     unsigned int i;
0428
0429     for (i = 0; i < host->info->nb_pts; i++, sp++)
0430         kfree(sp->name);
0431 }
0432
0433 /**
0434  * host1x_syncpt_read_max() - read maximum syncpoint value
0435  * @sp: host1x syncpoint
0436  *
0437  * The maximum syncpoint value indicates how many operations there are in
0438  * queue, either in channel or in a software thread.
0439  */
0440 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
0441 {
0442     smp_rmb();
0443
0444     return (u32)atomic_read(&sp->max_val);
0445 }
0446 EXPORT_SYMBOL(host1x_syncpt_read_max);
0447
0448 /**
0449  * host1x_syncpt_read_min() - read minimum syncpoint value
0450  * @sp: host1x syncpoint
0451  *
0452  * The minimum syncpoint value is a shadow of the current sync point value in
0453  * hardware.
0454  */
0455 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
0456 {
0457     smp_rmb();
0458
0459     return (u32)atomic_read(&sp->min_val);
0460 }
0461 EXPORT_SYMBOL(host1x_syncpt_read_min);
0462
0463 /**
0464  * host1x_syncpt_read() - read the current syncpoint value
0465  * @sp: host1x syncpoint
0466  */
0467 u32 host1x_syncpt_read(struct host1x_syncpt *sp)
0468 {
0469     return host1x_syncpt_load(sp);
0470 }
0471 EXPORT_SYMBOL(host1x_syncpt_read);
0472
0473 unsigned int host1x_syncpt_nb_pts(struct host1x *host)
0474 {
0475     return host->info->nb_pts;
0476 }
0477
0478 unsigned int host1x_syncpt_nb_bases(struct host1x *host)
0479 {
0480     return host->info->nb_bases;
0481 }
0482
0483 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
0484 {
0485     return host->info->nb_mlocks;
0486 }
0487
0488 /**
0489  * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
0490  * @host: host1x controller
0491  * @id: syncpoint ID
0492  */
0493 struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
0494                           unsigned int id)
0495 {
0496     if (id >= host->info->nb_pts)
0497         return NULL;
0498
0499     if (kref_get_unless_zero(&host->syncpt[id].ref))
0500         return &host->syncpt[id];
0501     else
0502         return NULL;
0503 }
0504 EXPORT_SYMBOL(host1x_syncpt_get_by_id);
0505
0506 /**
0507  * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
0508  *  increase the refcount.
0509  * @host: host1x controller
0510  * @id: syncpoint ID
0511  */
0512 struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
0513                             unsigned int id)
0514 {
0515     if (id >= host->info->nb_pts)
0516         return NULL;
0517
0518     return &host->syncpt[id];
0519 }
0520 EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
0521
0522 /**
0523  * host1x_syncpt_get() - increment syncpoint refcount
0524  * @sp: syncpoint
0525  */
0526 struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
0527 {
0528     kref_get(&sp->ref);
0529
0530     return sp;
0531 }
0532 EXPORT_SYMBOL(host1x_syncpt_get);
0533
0534 /**
0535  * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
0536  * @sp: host1x syncpoint
0537  */
0538 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
0539 {
0540     return sp ? sp->base : NULL;
0541 }
0542 EXPORT_SYMBOL(host1x_syncpt_get_base);
0543
0544 /**
0545  * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
0546  * @base: host1x syncpoint wait base
0547  */
0548 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
0549 {
0550     return base->id;
0551 }
0552 EXPORT_SYMBOL(host1x_syncpt_base_id);
0553
0554 static void do_nothing(struct kref *ref)
0555 {
0556 }
0557
0558 /**
0559  * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
0560  *   available for allocation
0561  *
0562  * @client: host1x bus client
0563  * @syncpt_id: syncpoint ID to make available
0564  *
0565  * Makes VBLANK<i> syncpoint available for allocatation if it was
0566  * reserved at initialization time. This should be called by the display
0567  * driver after it has ensured that any VBLANK increment programming configured
0568  * by the boot chain has been disabled.
0569  */
0570 void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
0571                           u32 syncpt_id)
0572 {
0573     struct host1x *host = dev_get_drvdata(client->host->parent);
0574
0575     if (!host->info->reserve_vblank_syncpts)
0576         return;
0577
0578     kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
0579 }
0580 EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);