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author | Terje Bergstrom <tbergstrom@nvidia.com> | 2013-03-22 16:34:02 +0200 |
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committer | Thierry Reding <thierry.reding@avionic-design.de> | 2013-04-22 12:32:42 +0200 |
commit | 7ede0b0bf3e2595d40d6195b6fe4c4dcef438830 (patch) | |
tree | eb59a94a3892bd41ae810b1726f7e7ae9de96812 /drivers/gpu/host1x/intr.c | |
parent | 754716874389ccbea5ee03174df8ad9e72e41880 (diff) | |
download | linux-7ede0b0bf3e2595d40d6195b6fe4c4dcef438830.tar.bz2 |
gpu: host1x: Add syncpoint wait and interrupts
Add support for sync point interrupts, and sync point wait. Sync
point wait used interrupts for unblocking wait.
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Diffstat (limited to 'drivers/gpu/host1x/intr.c')
-rw-r--r-- | drivers/gpu/host1x/intr.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/drivers/gpu/host1x/intr.c b/drivers/gpu/host1x/intr.c new file mode 100644 index 000000000000..b1b5a80e3125 --- /dev/null +++ b/drivers/gpu/host1x/intr.c @@ -0,0 +1,328 @@ +/* + * Tegra host1x Interrupt Management + * + * Copyright (c) 2010-2013, NVIDIA Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/clk.h> +#include <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/irq.h> + +#include "dev.h" +#include "intr.h" + +/* Wait list management */ + +enum waitlist_state { + WLS_PENDING, + WLS_REMOVED, + WLS_CANCELLED, + WLS_HANDLED +}; + +static void waiter_release(struct kref *kref) +{ + kfree(container_of(kref, struct host1x_waitlist, refcount)); +} + +/* + * add a waiter to a waiter queue, sorted by threshold + * returns true if it was added at the head of the queue + */ +static bool add_waiter_to_queue(struct host1x_waitlist *waiter, + struct list_head *queue) +{ + struct host1x_waitlist *pos; + u32 thresh = waiter->thresh; + + list_for_each_entry_reverse(pos, queue, list) + if ((s32)(pos->thresh - thresh) <= 0) { + list_add(&waiter->list, &pos->list); + return false; + } + + list_add(&waiter->list, queue); + return true; +} + +/* + * run through a waiter queue for a single sync point ID + * and gather all completed waiters into lists by actions + */ +static void remove_completed_waiters(struct list_head *head, u32 sync, + struct list_head completed[HOST1X_INTR_ACTION_COUNT]) +{ + struct list_head *dest; + struct host1x_waitlist *waiter, *next; + + list_for_each_entry_safe(waiter, next, head, list) { + if ((s32)(waiter->thresh - sync) > 0) + break; + + dest = completed + waiter->action; + + /* PENDING->REMOVED or CANCELLED->HANDLED */ + if (atomic_inc_return(&waiter->state) == WLS_HANDLED || !dest) { + list_del(&waiter->list); + kref_put(&waiter->refcount, waiter_release); + } else + list_move_tail(&waiter->list, dest); + } +} + +static void reset_threshold_interrupt(struct host1x *host, + struct list_head *head, + unsigned int id) +{ + u32 thresh = + list_first_entry(head, struct host1x_waitlist, list)->thresh; + + host1x_hw_intr_set_syncpt_threshold(host, id, thresh); + host1x_hw_intr_enable_syncpt_intr(host, id); +} + +static void action_wakeup(struct host1x_waitlist *waiter) +{ + wait_queue_head_t *wq = waiter->data; + wake_up(wq); +} + +static void action_wakeup_interruptible(struct host1x_waitlist *waiter) +{ + wait_queue_head_t *wq = waiter->data; + wake_up_interruptible(wq); +} + +typedef void (*action_handler)(struct host1x_waitlist *waiter); + +static action_handler action_handlers[HOST1X_INTR_ACTION_COUNT] = { + action_wakeup, + action_wakeup_interruptible, +}; + +static void run_handlers(struct list_head completed[HOST1X_INTR_ACTION_COUNT]) +{ + struct list_head *head = completed; + int i; + + for (i = 0; i < HOST1X_INTR_ACTION_COUNT; ++i, ++head) { + action_handler handler = action_handlers[i]; + struct host1x_waitlist *waiter, *next; + + list_for_each_entry_safe(waiter, next, head, list) { + list_del(&waiter->list); + handler(waiter); + WARN_ON(atomic_xchg(&waiter->state, WLS_HANDLED) != + WLS_REMOVED); + kref_put(&waiter->refcount, waiter_release); + } + } +} + +/* + * Remove & handle all waiters that have completed for the given syncpt + */ +static int process_wait_list(struct host1x *host, + struct host1x_syncpt *syncpt, + u32 threshold) +{ + struct list_head completed[HOST1X_INTR_ACTION_COUNT]; + unsigned int i; + int empty; + + for (i = 0; i < HOST1X_INTR_ACTION_COUNT; ++i) + INIT_LIST_HEAD(completed + i); + + spin_lock(&syncpt->intr.lock); + + remove_completed_waiters(&syncpt->intr.wait_head, threshold, + completed); + + empty = list_empty(&syncpt->intr.wait_head); + if (empty) + host1x_hw_intr_disable_syncpt_intr(host, syncpt->id); + else + reset_threshold_interrupt(host, &syncpt->intr.wait_head, + syncpt->id); + + spin_unlock(&syncpt->intr.lock); + + run_handlers(completed); + + return empty; +} + +/* + * Sync point threshold interrupt service thread function + * Handles sync point threshold triggers, in thread context + */ + +static void syncpt_thresh_work(struct work_struct *work) +{ + struct host1x_syncpt_intr *syncpt_intr = + container_of(work, struct host1x_syncpt_intr, work); + struct host1x_syncpt *syncpt = + container_of(syncpt_intr, struct host1x_syncpt, intr); + unsigned int id = syncpt->id; + struct host1x *host = syncpt->host; + + (void)process_wait_list(host, syncpt, + host1x_syncpt_load(host->syncpt + id)); +} + +int host1x_intr_add_action(struct host1x *host, u32 id, u32 thresh, + enum host1x_intr_action action, void *data, + struct host1x_waitlist *waiter, void **ref) +{ + struct host1x_syncpt *syncpt; + int queue_was_empty; + + if (waiter == NULL) { + pr_warn("%s: NULL waiter\n", __func__); + return -EINVAL; + } + + /* initialize a new waiter */ + INIT_LIST_HEAD(&waiter->list); + kref_init(&waiter->refcount); + if (ref) + kref_get(&waiter->refcount); + waiter->thresh = thresh; + waiter->action = action; + atomic_set(&waiter->state, WLS_PENDING); + waiter->data = data; + waiter->count = 1; + + syncpt = host->syncpt + id; + + spin_lock(&syncpt->intr.lock); + + queue_was_empty = list_empty(&syncpt->intr.wait_head); + + if (add_waiter_to_queue(waiter, &syncpt->intr.wait_head)) { + /* added at head of list - new threshold value */ + host1x_hw_intr_set_syncpt_threshold(host, id, thresh); + + /* added as first waiter - enable interrupt */ + if (queue_was_empty) + host1x_hw_intr_enable_syncpt_intr(host, id); + } + + spin_unlock(&syncpt->intr.lock); + + if (ref) + *ref = waiter; + return 0; +} + +void host1x_intr_put_ref(struct host1x *host, u32 id, void *ref) +{ + struct host1x_waitlist *waiter = ref; + struct host1x_syncpt *syncpt; + + while (atomic_cmpxchg(&waiter->state, WLS_PENDING, WLS_CANCELLED) == + WLS_REMOVED) + schedule(); + + syncpt = host->syncpt + id; + (void)process_wait_list(host, syncpt, + host1x_syncpt_load(host->syncpt + id)); + + kref_put(&waiter->refcount, waiter_release); +} + +int host1x_intr_init(struct host1x *host, unsigned int irq_sync) +{ + unsigned int id; + u32 nb_pts = host1x_syncpt_nb_pts(host); + + mutex_init(&host->intr_mutex); + host->intr_syncpt_irq = irq_sync; + host->intr_wq = create_workqueue("host_syncpt"); + if (!host->intr_wq) + return -ENOMEM; + + for (id = 0; id < nb_pts; ++id) { + struct host1x_syncpt *syncpt = host->syncpt + id; + + spin_lock_init(&syncpt->intr.lock); + INIT_LIST_HEAD(&syncpt->intr.wait_head); + snprintf(syncpt->intr.thresh_irq_name, + sizeof(syncpt->intr.thresh_irq_name), + "host1x_sp_%02d", id); + } + + host1x_intr_start(host); + + return 0; +} + +void host1x_intr_deinit(struct host1x *host) +{ + host1x_intr_stop(host); + destroy_workqueue(host->intr_wq); +} + +void host1x_intr_start(struct host1x *host) +{ + u32 hz = clk_get_rate(host->clk); + int err; + + mutex_lock(&host->intr_mutex); + err = host1x_hw_intr_init_host_sync(host, DIV_ROUND_UP(hz, 1000000), + syncpt_thresh_work); + if (err) { + mutex_unlock(&host->intr_mutex); + return; + } + mutex_unlock(&host->intr_mutex); +} + +void host1x_intr_stop(struct host1x *host) +{ + unsigned int id; + struct host1x_syncpt *syncpt = host->syncpt; + u32 nb_pts = host1x_syncpt_nb_pts(host); + + mutex_lock(&host->intr_mutex); + + host1x_hw_intr_disable_all_syncpt_intrs(host); + + for (id = 0; id < nb_pts; ++id) { + struct host1x_waitlist *waiter, *next; + + list_for_each_entry_safe(waiter, next, + &syncpt[id].intr.wait_head, list) { + if (atomic_cmpxchg(&waiter->state, + WLS_CANCELLED, WLS_HANDLED) == WLS_CANCELLED) { + list_del(&waiter->list); + kref_put(&waiter->refcount, waiter_release); + } + } + + if (!list_empty(&syncpt[id].intr.wait_head)) { + /* output diagnostics */ + mutex_unlock(&host->intr_mutex); + pr_warn("%s cannot stop syncpt intr id=%d\n", + __func__, id); + return; + } + } + + host1x_hw_intr_free_syncpt_irq(host); + + mutex_unlock(&host->intr_mutex); +} |