blob: d8b206e53660a9d0457b0d790dc8d4e8ea5e2a0f [file] [log] [blame]
/*
* Copyright © 2015 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
*/
#include <linux/kthread.h>
#include <trace/events/dma_fence.h>
#include <uapi/linux/sched/types.h>
#include "i915_drv.h"
#include "i915_trace.h"
#include "intel_breadcrumbs.h"
#include "intel_context.h"
#include "intel_gt_pm.h"
#include "intel_gt_requests.h"
static void irq_enable(struct intel_engine_cs *engine)
{
if (!engine->irq_enable)
return;
/* Caller disables interrupts */
spin_lock(&engine->gt->irq_lock);
engine->irq_enable(engine);
spin_unlock(&engine->gt->irq_lock);
}
static void irq_disable(struct intel_engine_cs *engine)
{
if (!engine->irq_disable)
return;
/* Caller disables interrupts */
spin_lock(&engine->gt->irq_lock);
engine->irq_disable(engine);
spin_unlock(&engine->gt->irq_lock);
}
static void __intel_breadcrumbs_arm_irq(struct intel_breadcrumbs *b)
{
lockdep_assert_held(&b->irq_lock);
if (!b->irq_engine || b->irq_armed)
return;
if (!intel_gt_pm_get_if_awake(b->irq_engine->gt))
return;
/*
* The breadcrumb irq will be disarmed on the interrupt after the
* waiters are signaled. This gives us a single interrupt window in
* which we can add a new waiter and avoid the cost of re-enabling
* the irq.
*/
WRITE_ONCE(b->irq_armed, true);
/*
* Since we are waiting on a request, the GPU should be busy
* and should have its own rpm reference. This is tracked
* by i915->gt.awake, we can forgo holding our own wakref
* for the interrupt as before i915->gt.awake is released (when
* the driver is idle) we disarm the breadcrumbs.
*/
if (!b->irq_enabled++)
irq_enable(b->irq_engine);
}
static void __intel_breadcrumbs_disarm_irq(struct intel_breadcrumbs *b)
{
lockdep_assert_held(&b->irq_lock);
if (!b->irq_engine || !b->irq_armed)
return;
GEM_BUG_ON(!b->irq_enabled);
if (!--b->irq_enabled)
irq_disable(b->irq_engine);
WRITE_ONCE(b->irq_armed, false);
intel_gt_pm_put_async(b->irq_engine->gt);
}
static void add_signaling_context(struct intel_breadcrumbs *b,
struct intel_context *ce)
{
intel_context_get(ce);
list_add_tail(&ce->signal_link, &b->signalers);
if (list_is_first(&ce->signal_link, &b->signalers))
__intel_breadcrumbs_arm_irq(b);
}
static void remove_signaling_context(struct intel_breadcrumbs *b,
struct intel_context *ce)
{
list_del(&ce->signal_link);
intel_context_put(ce);
}
static inline bool __request_completed(const struct i915_request *rq)
{
return i915_seqno_passed(__hwsp_seqno(rq), rq->fence.seqno);
}
__maybe_unused static bool
check_signal_order(struct intel_context *ce, struct i915_request *rq)
{
if (rq->context != ce)
return false;
if (!list_is_last(&rq->signal_link, &ce->signals) &&
i915_seqno_passed(rq->fence.seqno,
list_next_entry(rq, signal_link)->fence.seqno))
return false;
if (!list_is_first(&rq->signal_link, &ce->signals) &&
i915_seqno_passed(list_prev_entry(rq, signal_link)->fence.seqno,
rq->fence.seqno))
return false;
return true;
}
static bool
__dma_fence_signal(struct dma_fence *fence)
{
return !test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags);
}
static void
__dma_fence_signal__timestamp(struct dma_fence *fence, ktime_t timestamp)
{
fence->timestamp = timestamp;
set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags);
trace_dma_fence_signaled(fence);
}
static void
__dma_fence_signal__notify(struct dma_fence *fence,
const struct list_head *list)
{
struct dma_fence_cb *cur, *tmp;
lockdep_assert_held(fence->lock);
list_for_each_entry_safe(cur, tmp, list, node) {
INIT_LIST_HEAD(&cur->node);
cur->func(fence, cur);
}
}
static void add_retire(struct intel_breadcrumbs *b, struct intel_timeline *tl)
{
if (b->irq_engine)
intel_engine_add_retire(b->irq_engine, tl);
}
static bool __signal_request(struct i915_request *rq, struct list_head *signals)
{
clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
if (!__dma_fence_signal(&rq->fence)) {
i915_request_put(rq);
return false;
}
list_add_tail(&rq->signal_link, signals);
return true;
}
static void signal_irq_work(struct irq_work *work)
{
struct intel_breadcrumbs *b = container_of(work, typeof(*b), irq_work);
const ktime_t timestamp = ktime_get();
struct intel_context *ce, *cn;
struct list_head *pos, *next;
LIST_HEAD(signal);
spin_lock(&b->irq_lock);
if (list_empty(&b->signalers))
__intel_breadcrumbs_disarm_irq(b);
list_splice_init(&b->signaled_requests, &signal);
list_for_each_entry_safe(ce, cn, &b->signalers, signal_link) {
GEM_BUG_ON(list_empty(&ce->signals));
list_for_each_safe(pos, next, &ce->signals) {
struct i915_request *rq =
list_entry(pos, typeof(*rq), signal_link);
GEM_BUG_ON(!check_signal_order(ce, rq));
if (!__request_completed(rq))
break;
/*
* Queue for execution after dropping the signaling
* spinlock as the callback chain may end up adding
* more signalers to the same context or engine.
*/
__signal_request(rq, &signal);
}
/*
* We process the list deletion in bulk, only using a list_add
* (not list_move) above but keeping the status of
* rq->signal_link known with the I915_FENCE_FLAG_SIGNAL bit.
*/
if (!list_is_first(pos, &ce->signals)) {
/* Advance the list to the first incomplete request */
__list_del_many(&ce->signals, pos);
if (&ce->signals == pos) { /* now empty */
add_retire(b, ce->timeline);
remove_signaling_context(b, ce);
}
}
}
spin_unlock(&b->irq_lock);
list_for_each_safe(pos, next, &signal) {
struct i915_request *rq =
list_entry(pos, typeof(*rq), signal_link);
struct list_head cb_list;
spin_lock(&rq->lock);
list_replace(&rq->fence.cb_list, &cb_list);
__dma_fence_signal__timestamp(&rq->fence, timestamp);
__dma_fence_signal__notify(&rq->fence, &cb_list);
spin_unlock(&rq->lock);
i915_request_put(rq);
}
}
struct intel_breadcrumbs *
intel_breadcrumbs_create(struct intel_engine_cs *irq_engine)
{
struct intel_breadcrumbs *b;
b = kzalloc(sizeof(*b), GFP_KERNEL);
if (!b)
return NULL;
spin_lock_init(&b->irq_lock);
INIT_LIST_HEAD(&b->signalers);
INIT_LIST_HEAD(&b->signaled_requests);
init_irq_work(&b->irq_work, signal_irq_work);
b->irq_engine = irq_engine;
return b;
}
void intel_breadcrumbs_reset(struct intel_breadcrumbs *b)
{
unsigned long flags;
if (!b->irq_engine)
return;
spin_lock_irqsave(&b->irq_lock, flags);
if (b->irq_enabled)
irq_enable(b->irq_engine);
else
irq_disable(b->irq_engine);
spin_unlock_irqrestore(&b->irq_lock, flags);
}
void intel_breadcrumbs_park(struct intel_breadcrumbs *b)
{
unsigned long flags;
if (!READ_ONCE(b->irq_armed))
return;
spin_lock_irqsave(&b->irq_lock, flags);
__intel_breadcrumbs_disarm_irq(b);
spin_unlock_irqrestore(&b->irq_lock, flags);
if (!list_empty(&b->signalers))
irq_work_queue(&b->irq_work);
}
void intel_breadcrumbs_free(struct intel_breadcrumbs *b)
{
kfree(b);
}
static void insert_breadcrumb(struct i915_request *rq,
struct intel_breadcrumbs *b)
{
struct intel_context *ce = rq->context;
struct list_head *pos;
if (test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags))
return;
i915_request_get(rq);
/*
* If the request is already completed, we can transfer it
* straight onto a signaled list, and queue the irq worker for
* its signal completion.
*/
if (__request_completed(rq)) {
if (__signal_request(rq, &b->signaled_requests))
irq_work_queue(&b->irq_work);
return;
}
if (list_empty(&ce->signals)) {
add_signaling_context(b, ce);
pos = &ce->signals;
} else {
/*
* We keep the seqno in retirement order, so we can break
* inside intel_engine_signal_breadcrumbs as soon as we've
* passed the last completed request (or seen a request that
* hasn't event started). We could walk the timeline->requests,
* but keeping a separate signalers_list has the advantage of
* hopefully being much smaller than the full list and so
* provides faster iteration and detection when there are no
* more interrupts required for this context.
*
* We typically expect to add new signalers in order, so we
* start looking for our insertion point from the tail of
* the list.
*/
list_for_each_prev(pos, &ce->signals) {
struct i915_request *it =
list_entry(pos, typeof(*it), signal_link);
if (i915_seqno_passed(rq->fence.seqno, it->fence.seqno))
break;
}
}
list_add(&rq->signal_link, pos);
GEM_BUG_ON(!check_signal_order(ce, rq));
set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
/* Check after attaching to irq, interrupt may have already fired. */
if (__request_completed(rq))
irq_work_queue(&b->irq_work);
}
bool i915_request_enable_breadcrumb(struct i915_request *rq)
{
struct intel_breadcrumbs *b;
/* Serialises with i915_request_retire() using rq->lock */
if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))
return true;
/*
* Peek at i915_request_submit()/i915_request_unsubmit() status.
*
* If the request is not yet active (and not signaled), we will
* attach the breadcrumb later.
*/
if (!test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags))
return true;
/*
* rq->engine is locked by rq->engine->active.lock. That however
* is not known until after rq->engine has been dereferenced and
* the lock acquired. Hence we acquire the lock and then validate
* that rq->engine still matches the lock we hold for it.
*
* Here, we are using the breadcrumb lock as a proxy for the
* rq->engine->active.lock, and we know that since the breadcrumb
* will be serialised within i915_request_submit/i915_request_unsubmit,
* the engine cannot change while active as long as we hold the
* breadcrumb lock on that engine.
*
* From the dma_fence_enable_signaling() path, we are outside of the
* request submit/unsubmit path, and so we must be more careful to
* acquire the right lock.
*/
b = READ_ONCE(rq->engine)->breadcrumbs;
spin_lock(&b->irq_lock);
while (unlikely(b != READ_ONCE(rq->engine)->breadcrumbs)) {
spin_unlock(&b->irq_lock);
b = READ_ONCE(rq->engine)->breadcrumbs;
spin_lock(&b->irq_lock);
}
/*
* Now that we are finally serialised with request submit/unsubmit,
* [with b->irq_lock] and with i915_request_retire() [via checking
* SIGNALED with rq->lock] confirm the request is indeed active. If
* it is no longer active, the breadcrumb will be attached upon
* i915_request_submit().
*/
if (test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags))
insert_breadcrumb(rq, b);
spin_unlock(&b->irq_lock);
return true;
}
void i915_request_cancel_breadcrumb(struct i915_request *rq)
{
struct intel_breadcrumbs *b = rq->engine->breadcrumbs;
/*
* We must wait for b->irq_lock so that we know the interrupt handler
* has released its reference to the intel_context and has completed
* the DMA_FENCE_FLAG_SIGNALED_BIT/I915_FENCE_FLAG_SIGNAL dance (if
* required).
*/
spin_lock(&b->irq_lock);
if (test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)) {
struct intel_context *ce = rq->context;
list_del(&rq->signal_link);
if (list_empty(&ce->signals))
remove_signaling_context(b, ce);
clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
i915_request_put(rq);
}
spin_unlock(&b->irq_lock);
}
static void print_signals(struct intel_breadcrumbs *b, struct drm_printer *p)
{
struct intel_context *ce;
struct i915_request *rq;
drm_printf(p, "Signals:\n");
spin_lock_irq(&b->irq_lock);
list_for_each_entry(ce, &b->signalers, signal_link) {
list_for_each_entry(rq, &ce->signals, signal_link) {
drm_printf(p, "\t[%llx:%llx%s] @ %dms\n",
rq->fence.context, rq->fence.seqno,
i915_request_completed(rq) ? "!" :
i915_request_started(rq) ? "*" :
"",
jiffies_to_msecs(jiffies - rq->emitted_jiffies));
}
}
spin_unlock_irq(&b->irq_lock);
}
void intel_engine_print_breadcrumbs(struct intel_engine_cs *engine,
struct drm_printer *p)
{
struct intel_breadcrumbs *b;
b = engine->breadcrumbs;
if (!b)
return;
drm_printf(p, "IRQ: %s\n", enableddisabled(b->irq_armed));
if (!list_empty(&b->signalers))
print_signals(b, p);
}