// SPDX-License-Identifier: MIT
/*
* Copyright © 2019 Intel Corporation
*/
#include "gem/i915_gem_context.h"
#include "gem/i915_gem_pm.h"
#include "i915_drm_client.h"
#include "i915_drv.h"
#include "i915_trace.h"
#include "intel_context.h"
#include "intel_engine.h"
#include "intel_engine_pm.h"
#include "intel_ring.h"
static struct kmem_cache *slab_ce;
static struct intel_context *intel_context_alloc(void)
{
return kmem_cache_zalloc(slab_ce, GFP_KERNEL);
}
static void rcu_context_free(struct rcu_head *rcu)
{
struct intel_context *ce = container_of(rcu, typeof(*ce), rcu);
trace_intel_context_free(ce);
if (intel_context_has_own_state(ce))
fput(ce->default_state);
kmem_cache_free(slab_ce, ce);
}
void intel_context_free(struct intel_context *ce)
{
call_rcu(&ce->rcu, rcu_context_free);
}
struct intel_context *
intel_context_create(struct intel_engine_cs *engine)
{
struct intel_context *ce;
ce = intel_context_alloc();
if (!ce)
return ERR_PTR(-ENOMEM);
intel_context_init(ce, engine);
trace_intel_context_create(ce);
return ce;
}
int intel_context_alloc_state(struct intel_context *ce)
{
struct i915_gem_context *ctx;
int err = 0;
if (mutex_lock_interruptible(&ce->pin_mutex))
return -EINTR;
if (!test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
if (intel_context_is_banned(ce)) {
err = -EIO;
goto unlock;
}
err = ce->ops->alloc(ce);
if (unlikely(err))
goto unlock;
set_bit(CONTEXT_ALLOC_BIT, &ce->flags);
rcu_read_lock();
ctx = rcu_dereference(ce->gem_context);
if (ctx && !kref_get_unless_zero(&ctx->ref))
ctx = NULL;
rcu_read_unlock();
if (ctx) {
if (ctx->client)
i915_drm_client_add_context_objects(ctx->client,
ce);
i915_gem_context_put(ctx);
}
}
unlock:
mutex_unlock(&ce->pin_mutex);
return err;
}
static int intel_context_active_acquire(struct intel_context *ce)
{
int err;
__i915_active_acquire(&ce->active);
if (intel_context_is_barrier(ce) || intel_engine_uses_guc(ce->engine) ||
intel_context_is_parallel(ce))
return 0;
/* Preallocate tracking nodes */
err = i915_active_acquire_preallocate_barrier(&ce->active,
ce->engine);
if (err)
i915_active_release(&ce->active);
return err;
}
static void intel_context_active_release(struct intel_context *ce)
{
/* Nodes preallocated in intel_context_active() */
i915_active_acquire_barrier(&ce->active);
i915_active_release(&ce->active);
}
static int __context_pin_state(struct i915_vma *vma, struct i915_gem_ww_ctx *ww)
{
unsigned int bias = i915_ggtt_pin_bias(vma) | PIN_OFFSET_BIAS;
int err;
err = i915_ggtt_pin(vma, ww, 0, bias | PIN_HIGH);
if (err)
return err;
err = i915_active_acquire(&vma->active);
if (err)
goto err_unpin;
/*
* And mark it as a globally pinned object to let the shrinker know
* it cannot reclaim the object until we release it.
*/
i915_vma_make_unshrinkable(vma);
vma->obj->mm.dirty = true;
return 0;
err_unpin:
i915_vma_unpin(vma);
return err;
}
static void __context_unpin_state(struct i915_vma *vma)
{
i915_vma_make_shrinkable(vma);
i915_active_release(&vma->active);
__i915_vma_unpin(vma);
}
static int __ring_active(struct intel_ring *ring,
struct i915_gem_ww_ctx *ww)
{
int err;
err = intel_ring_pin(ring, ww);
if (err)
return err;
err = i915_active_acquire(&ring->vma->active);
if (err)
goto err_pin;
return 0;
err_pin:
intel_ring_unpin(ring);
return err;
}
static void __ring_retire(struct intel_ring *ring)
{
i915_active_release(&ring->vma->active);
intel_ring_unpin(ring);
}
static int intel_context_pre_pin(struct intel_context *ce,
struct i915_gem_ww_ctx *ww)
{
int err;
CE_TRACE(ce, "active\n");
err = __ring_active(ce->ring, ww);
if (err)
return err;
err = intel_timeline_pin(ce->timeline, ww);
if (err)
goto err_ring;
if (!ce->state)
return 0;
err = __context_pin_state(ce->state, ww);
if (err)
goto err_timeline;
return 0;
err_timeline:
intel_timeline_unpin(ce->timeline);
err_ring:
__ring_retire(ce->ring);
return err;
}
static void intel_context_post_unpin(struct intel_context *ce)
{
if (ce->state)
__context_unpin_state(ce->state);
intel_timeline_unpin(ce->timeline);
__ring_retire(ce->ring);
}
int __intel_context_do_pin_ww(struct intel_context *ce,
struct i915_gem_ww_ctx *ww)
{
bool handoff = false;
void *vaddr;
int err = 0;
if (unlikely(!test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
err = intel_context_alloc_state(ce);
if (err)
return err;
}
/*
* We always pin the context/ring/timeline here, to ensure a pin
* refcount for __intel_context_active(), which prevent a lock
* inversion of ce->pin_mutex vs dma_resv_lock().
*/
err = i915_gem_object_lock(ce->timeline->hwsp_ggtt->obj, ww);
if (!err)
err = i915_gem_object_lock(ce->ring->vma->obj, ww);
if (!err && ce->state)
err = i915_gem_object_lock(ce->state->obj, ww);
if (!err)
err = intel_context_pre_pin(ce, ww);
if (err)
return err;
err = ce->ops->pre_pin(ce, ww, &vaddr);
if (err)
goto err_ctx_unpin;
err = i915_active_acquire(&ce->active);
if (err)
goto err_post_unpin;
err = mutex_lock_interruptible(&ce->pin_mutex);
if (err)
goto err_release;
intel_engine_pm_might_get(ce->engine);
if (unlikely(intel_context_is_closed(ce))) {
err = -ENOENT;
goto err_unlock;
}
if (likely(!atomic_add_unless(&ce->pin_count, 1, 0))) {
err = intel_context_active_acquire(ce);
if (unlikely(err))
goto err_unlock;
err = ce->ops->pin(ce, vaddr);
if (err) {
intel_context_active_release(ce);
goto err_unlock;
}
CE_TRACE(ce, "pin ring:{start:%08x, head:%04x, tail:%04x}\n",
i915_ggtt_offset(ce->ring->vma),
ce->ring->head, ce->ring->tail);
handoff = true;
smp_mb__before_atomic(); /* flush pin before it is visible */
atomic_inc(&ce->pin_count);
}
GEM_BUG_ON(!intel_context_is_pinned(ce)); /* no overflow! */
trace_intel_context_do_pin(ce);
err_unlock:
mutex_unlock(&ce->pin_mutex);
err_release:
i915_active_release(&ce->active);
err_post_unpin:
if (!handoff)
ce->ops->post_unpin(ce);
err_ctx_unpin:
intel_context_post_unpin(ce);
/*
* Unlock the hwsp_ggtt object since it's shared.
* In principle we can unlock all the global state locked above
* since it's pinned and doesn't need fencing, and will
* thus remain resident until it is explicitly unpinned.
*/
i915_gem_ww_unlock_single(ce->timeline->hwsp_ggtt->obj);
return err;
}
int __intel_context_do_pin(struct intel_context *ce)
{
struct i915_gem_ww_ctx ww;
int err;
i915_gem_ww_ctx_init(&ww, true);
retry:
err = __intel_context_do_pin_ww(ce, &ww);
if (err == -EDEADLK) {
err = i915_gem_ww_ctx_backoff(&ww);
if (!err)
goto retry;
}
i915_gem_ww_ctx_fini(&ww);
return err;
}
void __intel_context_do_unpin(struct intel_context *ce, int sub)
{
if (!atomic_sub_and_test(sub, &ce->pin_count))
return;
CE_TRACE(ce, "unpin\n");
ce->ops->unpin(ce);
ce->ops->post_unpin(ce);
/*
* Once released, we may asynchronously drop the active reference.
* As that may be the only reference keeping the context alive,
* take an extra now so that it is not freed before we finish
* dereferencing it.
*/
intel_context_get(ce);
intel_context_active_release(ce);
trace_intel_context_do_unpin(ce);
intel_context_put(ce);
}
static void __intel_context_retire(struct i915_active *active)
{
struct intel_context *ce = container_of(active, typeof(*ce), active);
CE_TRACE(ce, "retire runtime: { total:%lluns, avg:%lluns }\n",
intel_context_get_total_runtime_ns(ce),
intel_context_get_avg_runtime_ns(ce));
set_bit(CONTEXT_VALID_BIT, &ce->flags);
intel_context_post_unpin(ce);
intel_context_put(ce);
}
static int __intel_context_active(struct i915_active *active)
{
struct intel_context *ce = container_of(active, typeof(*ce), active);
intel_context_get(ce);
/* everything should already be activated by intel_context_pre_pin() */
GEM_WARN_ON(!i915_active_acquire_if_busy(&ce->ring->vma->active));
__intel_ring_pin(ce->ring);
__intel_timeline_pin(ce->timeline);
if (ce->state) {
GEM_WARN_ON(!i915_active_acquire_if_busy(&ce->state->active));
__i915_vma_pin(ce->state);
i915_vma_make_unshrinkable(ce->state);
}
return 0;
}
static int
sw_fence_dummy_notify(struct i915_sw_fence *sf,
enum i915_sw_fence_notify state)
{
return NOTIFY_DONE;
}
void
intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
{
GEM_BUG_ON(!engine->cops);
GEM_BUG_ON(!engine->gt->vm);
kref_init(&ce->ref);
ce->engine = engine;
ce->ops = engine->cops;
ce->sseu = engine->sseu;
ce->ring = NULL;
ce->ring_size = SZ_4K;
ewma_runtime_init(&ce->stats.runtime.avg);
ce->vm = i915_vm_get(engine->gt->vm);
/* NB ce->signal_link/lock is used under RCU */
spin_lock_init(&ce->signal_lock);
INIT_LIST_HEAD(&ce->signals);
mutex_init(&ce->pin_mutex);
spin_lock_init(&ce->guc_state.lock);
INIT_LIST_HEAD(&ce->guc_state.fences);
INIT_LIST_HEAD(&ce->guc_state.requests);
ce->guc_id.id = GUC_INVALID_CONTEXT_ID;
INIT_LIST_HEAD(&ce->guc_id.link);
INIT_LIST_HEAD(&ce->destroyed_link);
INIT_LIST_HEAD(&ce->parallel.child_list);
/*
* Initialize fence to be complete as this is expected to be complete
* unless there is a pending schedule disable outstanding.
*/
i915_sw_fence_init(&ce->guc_state.blocked,
sw_fence_dummy_notify);
i915_sw_fence_commit(&ce->guc_state.blocked);
i915_active_init(&ce->active,
__intel_context_active, __intel_context_retire, 0);
}
void intel_context_fini(struct intel_context *ce)
{
struct intel_context *child, *next;
if (ce->timeline)
intel_timeline_put(ce->timeline);
i915_vm_put(ce->vm);
/* Need to put the creation ref for the children */
if (intel_context_is_parent(ce))
for_each_child_safe(ce, child, next)
intel_context_put(child);
mutex_destroy(&ce->pin_mutex);
i915_active_fini(&ce->active);
i915_sw_fence_fini(&ce->guc_state.blocked);
}
void i915_context_module_exit(void)
{
kmem_cache_destroy(slab_ce);
}
int __init i915_context_module_init(void)
{
slab_ce = KMEM_CACHE(intel_context, SLAB_HWCACHE_ALIGN);
if (!slab_ce)
return -ENOMEM;
return 0;
}
void intel_context_enter_engine(struct intel_context *ce)
{
intel_engine_pm_get(ce->engine);
intel_timeline_enter(ce->timeline);
}
void intel_context_exit_engine(struct intel_context *ce)
{
intel_timeline_exit(ce->timeline);
intel_engine_pm_put(ce->engine);
}
int intel_context_prepare_remote_request(struct intel_context *ce,
struct i915_request *rq)
{
struct intel_timeline *tl = ce->timeline;
int err;
/* Only suitable for use in remotely modifying this context */
GEM_BUG_ON(rq->context == ce);
if (rcu_access_pointer(rq->timeline) != tl) { /* timeline sharing! */
/* Queue this switch after current activity by this context. */
err = i915_active_fence_set(&tl->last_request, rq);
if (err)
return err;
}
/*
* Guarantee context image and the timeline remains pinned until the
* modifying request is retired by setting the ce activity tracker.
*
* But we only need to take one pin on the account of it. Or in other
* words transfer the pinned ce object to tracked active request.
*/
GEM_BUG_ON(i915_active_is_idle(&ce->active));
return i915_active_add_request(&ce->active, rq);
}
struct i915_request *intel_context_create_request(struct intel_context *ce)
{
struct i915_gem_ww_ctx ww;
struct i915_request *rq;
int err;
i915_gem_ww_ctx_init(&ww, true);
retry:
err = intel_context_pin_ww(ce, &ww);
if (!err) {
rq = i915_request_create(ce);
intel_context_unpin(ce);
} else if (err == -EDEADLK) {
err = i915_gem_ww_ctx_backoff(&ww);
if (!err)
goto retry;
rq = ERR_PTR(err);
} else {
rq = ERR_PTR(err);
}
i915_gem_ww_ctx_fini(&ww);
if (IS_ERR(rq))
return rq;
/*
* timeline->mutex should be the inner lock, but is used as outer lock.
* Hack around this to shut up lockdep in selftests..
*/
lockdep_unpin_lock(&ce->timeline->mutex, rq->cookie);
mutex_release(&ce->timeline->mutex.dep_map, _RET_IP_);
mutex_acquire(&ce->timeline->mutex.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
rq->cookie = lockdep_pin_lock(&ce->timeline->mutex);
return rq;
}
struct i915_request *intel_context_get_active_request(struct intel_context *ce)
{
struct intel_context *parent = intel_context_to_parent(ce);
struct i915_request *rq, *active = NULL;
unsigned long flags;
GEM_BUG_ON(!intel_engine_uses_guc(ce->engine));
/*
* We search the parent list to find an active request on the submitted
* context. The parent list contains the requests for all the contexts
* in the relationship so we have to do a compare of each request's
* context.
*/
spin_lock_irqsave(&parent->guc_state.lock, flags);
list_for_each_entry_reverse(rq, &parent->guc_state.requests,
sched.link) {
if (rq->context != ce)
continue;
if (i915_request_completed(rq))
break;
active = rq;
}
if (active)
active = i915_request_get_rcu(active);
spin_unlock_irqrestore(&parent->guc_state.lock, flags);
return active;
}
void intel_context_bind_parent_child(struct intel_context *parent,
struct intel_context *child)
{
/*
* Callers responsibility to validate that this function is used
* correctly but we use GEM_BUG_ON here ensure that they do.
*/
GEM_BUG_ON(intel_context_is_pinned(parent));
GEM_BUG_ON(intel_context_is_child(parent));
GEM_BUG_ON(intel_context_is_pinned(child));
GEM_BUG_ON(intel_context_is_child(child));
GEM_BUG_ON(intel_context_is_parent(child));
parent->parallel.child_index = parent->parallel.number_children++;
list_add_tail(&child->parallel.child_link,
&parent->parallel.child_list);
child->parallel.parent = parent;
}
u64 intel_context_get_total_runtime_ns(struct intel_context *ce)
{
u64 total, active;
if (ce->ops->update_stats)
ce->ops->update_stats(ce);
total = ce->stats.runtime.total;
if (ce->ops->flags & COPS_RUNTIME_CYCLES)
total *= ce->engine->gt->clock_period_ns;
active = READ_ONCE(ce->stats.active);
if (active)
active = intel_context_clock() - active;
return total + active;
}
u64 intel_context_get_avg_runtime_ns(struct intel_context *ce)
{
u64 avg = ewma_runtime_read(&ce->stats.runtime.avg);
if (ce->ops->flags & COPS_RUNTIME_CYCLES)
avg *= ce->engine->gt->clock_period_ns;
return avg;
}
bool intel_context_ban(struct intel_context *ce, struct i915_request *rq)
{
bool ret = intel_context_set_banned(ce);
trace_intel_context_ban(ce);
if (ce->ops->revoke)
ce->ops->revoke(ce, rq,
INTEL_CONTEXT_BANNED_PREEMPT_TIMEOUT_MS);
return ret;
}
bool intel_context_revoke(struct intel_context *ce)
{
bool ret = intel_context_set_exiting(ce);
if (ce->ops->revoke)
ce->ops->revoke(ce, NULL, ce->engine->props.preempt_timeout_ms);
return ret;
}
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
#include "selftest_context.c"
#endif
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