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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Tegra host1x Syncpoints
- *
- * Copyright (c) 2010-2015, NVIDIA Corporation.
- */
- #include <linux/module.h>
- #include <linux/device.h>
- #include <linux/slab.h>
- #include <trace/events/host1x.h>
- #include "syncpt.h"
- #include "dev.h"
- #include "intr.h"
- #include "debug.h"
- #define SYNCPT_CHECK_PERIOD (2 * HZ)
- #define MAX_STUCK_CHECK_COUNT 15
- static struct host1x_syncpt_base *
- host1x_syncpt_base_request(struct host1x *host)
- {
- struct host1x_syncpt_base *bases = host->bases;
- unsigned int i;
- for (i = 0; i < host->info->nb_bases; i++)
- if (!bases[i].requested)
- break;
- if (i >= host->info->nb_bases)
- return NULL;
- bases[i].requested = true;
- return &bases[i];
- }
- static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
- {
- if (base)
- base->requested = false;
- }
- static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
- struct host1x_client *client,
- unsigned long flags)
- {
- struct host1x_syncpt *sp = host->syncpt;
- unsigned int i;
- char *name;
- mutex_lock(&host->syncpt_mutex);
- for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
- ;
- if (i >= host->info->nb_pts)
- goto unlock;
- if (flags & HOST1X_SYNCPT_HAS_BASE) {
- sp->base = host1x_syncpt_base_request(host);
- if (!sp->base)
- goto unlock;
- }
- name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id,
- client ? dev_name(client->dev) : NULL);
- if (!name)
- goto free_base;
- sp->client = client;
- sp->name = name;
- if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
- sp->client_managed = true;
- else
- sp->client_managed = false;
- mutex_unlock(&host->syncpt_mutex);
- return sp;
- free_base:
- host1x_syncpt_base_free(sp->base);
- sp->base = NULL;
- unlock:
- mutex_unlock(&host->syncpt_mutex);
- return NULL;
- }
- /**
- * host1x_syncpt_id() - retrieve syncpoint ID
- * @sp: host1x syncpoint
- *
- * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
- * often used as a value to program into registers that control how hardware
- * blocks interact with syncpoints.
- */
- u32 host1x_syncpt_id(struct host1x_syncpt *sp)
- {
- return sp->id;
- }
- EXPORT_SYMBOL(host1x_syncpt_id);
- /**
- * host1x_syncpt_incr_max() - update the value sent to hardware
- * @sp: host1x syncpoint
- * @incrs: number of increments
- */
- u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
- {
- return (u32)atomic_add_return(incrs, &sp->max_val);
- }
- EXPORT_SYMBOL(host1x_syncpt_incr_max);
- /*
- * Write cached syncpoint and waitbase values to hardware.
- */
- void host1x_syncpt_restore(struct host1x *host)
- {
- struct host1x_syncpt *sp_base = host->syncpt;
- unsigned int i;
- for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
- host1x_hw_syncpt_restore(host, sp_base + i);
- for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
- host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
- wmb();
- }
- /*
- * Update the cached syncpoint and waitbase values by reading them
- * from the registers.
- */
- void host1x_syncpt_save(struct host1x *host)
- {
- struct host1x_syncpt *sp_base = host->syncpt;
- unsigned int i;
- for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
- if (host1x_syncpt_client_managed(sp_base + i))
- host1x_hw_syncpt_load(host, sp_base + i);
- else
- WARN_ON(!host1x_syncpt_idle(sp_base + i));
- }
- for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
- host1x_hw_syncpt_load_wait_base(host, sp_base + i);
- }
- /*
- * Updates the cached syncpoint value by reading a new value from the hardware
- * register
- */
- u32 host1x_syncpt_load(struct host1x_syncpt *sp)
- {
- u32 val;
- val = host1x_hw_syncpt_load(sp->host, sp);
- trace_host1x_syncpt_load_min(sp->id, val);
- return val;
- }
- /*
- * Get the current syncpoint base
- */
- u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
- {
- host1x_hw_syncpt_load_wait_base(sp->host, sp);
- return sp->base_val;
- }
- /**
- * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
- * @sp: host1x syncpoint
- */
- int host1x_syncpt_incr(struct host1x_syncpt *sp)
- {
- return host1x_hw_syncpt_cpu_incr(sp->host, sp);
- }
- EXPORT_SYMBOL(host1x_syncpt_incr);
- /*
- * Updated sync point form hardware, and returns true if syncpoint is expired,
- * false if we may need to wait
- */
- static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
- {
- host1x_hw_syncpt_load(sp->host, sp);
- return host1x_syncpt_is_expired(sp, thresh);
- }
- /**
- * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
- * @sp: host1x syncpoint
- * @thresh: threshold
- * @timeout: maximum time to wait for the syncpoint to reach the given value
- * @value: return location for the syncpoint value
- */
- int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
- u32 *value)
- {
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
- void *ref;
- struct host1x_waitlist *waiter;
- int err = 0, check_count = 0;
- u32 val;
- if (value)
- *value = 0;
- /* first check cache */
- if (host1x_syncpt_is_expired(sp, thresh)) {
- if (value)
- *value = host1x_syncpt_load(sp);
- return 0;
- }
- /* try to read from register */
- val = host1x_hw_syncpt_load(sp->host, sp);
- if (host1x_syncpt_is_expired(sp, thresh)) {
- if (value)
- *value = val;
- goto done;
- }
- if (!timeout) {
- err = -EAGAIN;
- goto done;
- }
- /* allocate a waiter */
- waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
- if (!waiter) {
- err = -ENOMEM;
- goto done;
- }
- /* schedule a wakeup when the syncpoint value is reached */
- err = host1x_intr_add_action(sp->host, sp, thresh,
- HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
- &wq, waiter, &ref);
- if (err)
- goto done;
- err = -EAGAIN;
- /* Caller-specified timeout may be impractically low */
- if (timeout < 0)
- timeout = LONG_MAX;
- /* wait for the syncpoint, or timeout, or signal */
- while (timeout) {
- long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
- int remain;
- remain = wait_event_interruptible_timeout(wq,
- syncpt_load_min_is_expired(sp, thresh),
- check);
- if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
- if (value)
- *value = host1x_syncpt_load(sp);
- err = 0;
- break;
- }
- if (remain < 0) {
- err = remain;
- break;
- }
- timeout -= check;
- if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
- dev_warn(sp->host->dev,
- "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
- current->comm, sp->id, sp->name,
- thresh, timeout);
- host1x_debug_dump_syncpts(sp->host);
- if (check_count == MAX_STUCK_CHECK_COUNT)
- host1x_debug_dump(sp->host);
- check_count++;
- }
- }
- host1x_intr_put_ref(sp->host, sp->id, ref);
- done:
- return err;
- }
- EXPORT_SYMBOL(host1x_syncpt_wait);
- /*
- * Returns true if syncpoint is expired, false if we may need to wait
- */
- bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
- {
- u32 current_val;
- u32 future_val;
- smp_rmb();
- current_val = (u32)atomic_read(&sp->min_val);
- future_val = (u32)atomic_read(&sp->max_val);
- /* Note the use of unsigned arithmetic here (mod 1<<32).
- *
- * c = current_val = min_val = the current value of the syncpoint.
- * t = thresh = the value we are checking
- * f = future_val = max_val = the value c will reach when all
- * outstanding increments have completed.
- *
- * Note that c always chases f until it reaches f.
- *
- * Dtf = (f - t)
- * Dtc = (c - t)
- *
- * Consider all cases:
- *
- * A) .....c..t..f..... Dtf < Dtc need to wait
- * B) .....c.....f..t.. Dtf > Dtc expired
- * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large)
- *
- * Any case where f==c: always expired (for any t). Dtf == Dcf
- * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0)
- * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0,
- * Dtc!=0)
- *
- * Other cases:
- *
- * A) .....t..f..c..... Dtf < Dtc need to wait
- * A) .....f..c..t..... Dtf < Dtc need to wait
- * A) .....f..t..c..... Dtf > Dtc expired
- *
- * So:
- * Dtf >= Dtc implies EXPIRED (return true)
- * Dtf < Dtc implies WAIT (return false)
- *
- * Note: If t is expired then we *cannot* wait on it. We would wait
- * forever (hang the system).
- *
- * Note: do NOT get clever and remove the -thresh from both sides. It
- * is NOT the same.
- *
- * If future valueis zero, we have a client managed sync point. In that
- * case we do a direct comparison.
- */
- if (!host1x_syncpt_client_managed(sp))
- return future_val - thresh >= current_val - thresh;
- else
- return (s32)(current_val - thresh) >= 0;
- }
- int host1x_syncpt_init(struct host1x *host)
- {
- struct host1x_syncpt_base *bases;
- struct host1x_syncpt *syncpt;
- unsigned int i;
- syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
- GFP_KERNEL);
- if (!syncpt)
- return -ENOMEM;
- bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
- GFP_KERNEL);
- if (!bases)
- return -ENOMEM;
- for (i = 0; i < host->info->nb_pts; i++) {
- syncpt[i].id = i;
- syncpt[i].host = host;
- /*
- * Unassign syncpt from channels for purposes of Tegra186
- * syncpoint protection. This prevents any channel from
- * accessing it until it is reassigned.
- */
- host1x_hw_syncpt_assign_to_channel(host, &syncpt[i], NULL);
- }
- for (i = 0; i < host->info->nb_bases; i++)
- bases[i].id = i;
- mutex_init(&host->syncpt_mutex);
- host->syncpt = syncpt;
- host->bases = bases;
- host1x_syncpt_restore(host);
- host1x_hw_syncpt_enable_protection(host);
- /* Allocate sync point to use for clearing waits for expired fences */
- host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);
- if (!host->nop_sp)
- return -ENOMEM;
- return 0;
- }
- /**
- * host1x_syncpt_request() - request a syncpoint
- * @client: client requesting the syncpoint
- * @flags: flags
- *
- * host1x client drivers can use this function to allocate a syncpoint for
- * subsequent use. A syncpoint returned by this function will be reserved for
- * use by the client exclusively. When no longer using a syncpoint, a host1x
- * client driver needs to release it using host1x_syncpt_free().
- */
- struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
- unsigned long flags)
- {
- struct host1x *host = dev_get_drvdata(client->parent->parent);
- return host1x_syncpt_alloc(host, client, flags);
- }
- EXPORT_SYMBOL(host1x_syncpt_request);
- /**
- * host1x_syncpt_free() - free a requested syncpoint
- * @sp: host1x syncpoint
- *
- * Release a syncpoint previously allocated using host1x_syncpt_request(). A
- * host1x client driver should call this when the syncpoint is no longer in
- * use. Note that client drivers must ensure that the syncpoint doesn't remain
- * under the control of hardware after calling this function, otherwise two
- * clients may end up trying to access the same syncpoint concurrently.
- */
- void host1x_syncpt_free(struct host1x_syncpt *sp)
- {
- if (!sp)
- return;
- mutex_lock(&sp->host->syncpt_mutex);
- host1x_syncpt_base_free(sp->base);
- kfree(sp->name);
- sp->base = NULL;
- sp->client = NULL;
- sp->name = NULL;
- sp->client_managed = false;
- mutex_unlock(&sp->host->syncpt_mutex);
- }
- EXPORT_SYMBOL(host1x_syncpt_free);
- void host1x_syncpt_deinit(struct host1x *host)
- {
- struct host1x_syncpt *sp = host->syncpt;
- unsigned int i;
- for (i = 0; i < host->info->nb_pts; i++, sp++)
- kfree(sp->name);
- }
- /**
- * host1x_syncpt_read_max() - read maximum syncpoint value
- * @sp: host1x syncpoint
- *
- * The maximum syncpoint value indicates how many operations there are in
- * queue, either in channel or in a software thread.
- */
- u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
- {
- smp_rmb();
- return (u32)atomic_read(&sp->max_val);
- }
- EXPORT_SYMBOL(host1x_syncpt_read_max);
- /**
- * host1x_syncpt_read_min() - read minimum syncpoint value
- * @sp: host1x syncpoint
- *
- * The minimum syncpoint value is a shadow of the current sync point value in
- * hardware.
- */
- u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
- {
- smp_rmb();
- return (u32)atomic_read(&sp->min_val);
- }
- EXPORT_SYMBOL(host1x_syncpt_read_min);
- /**
- * host1x_syncpt_read() - read the current syncpoint value
- * @sp: host1x syncpoint
- */
- u32 host1x_syncpt_read(struct host1x_syncpt *sp)
- {
- return host1x_syncpt_load(sp);
- }
- EXPORT_SYMBOL(host1x_syncpt_read);
- unsigned int host1x_syncpt_nb_pts(struct host1x *host)
- {
- return host->info->nb_pts;
- }
- unsigned int host1x_syncpt_nb_bases(struct host1x *host)
- {
- return host->info->nb_bases;
- }
- unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
- {
- return host->info->nb_mlocks;
- }
- /**
- * host1x_syncpt_get() - obtain a syncpoint by ID
- * @host: host1x controller
- * @id: syncpoint ID
- */
- struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id)
- {
- if (id >= host->info->nb_pts)
- return NULL;
- return host->syncpt + id;
- }
- EXPORT_SYMBOL(host1x_syncpt_get);
- /**
- * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
- * @sp: host1x syncpoint
- */
- struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
- {
- return sp ? sp->base : NULL;
- }
- EXPORT_SYMBOL(host1x_syncpt_get_base);
- /**
- * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
- * @base: host1x syncpoint wait base
- */
- u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
- {
- return base->id;
- }
- EXPORT_SYMBOL(host1x_syncpt_base_id);
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