linux/drivers/gpu/drm/i915/intel_context.c

271 lines
5.5 KiB
C

/*
* SPDX-License-Identifier: MIT
*
* Copyright © 2019 Intel Corporation
*/
#include "i915_drv.h"
#include "i915_gem_context.h"
#include "i915_globals.h"
#include "intel_context.h"
#include "intel_ringbuffer.h"
static struct i915_global_context {
struct i915_global base;
struct kmem_cache *slab_ce;
} global;
struct intel_context *intel_context_alloc(void)
{
return kmem_cache_zalloc(global.slab_ce, GFP_KERNEL);
}
void intel_context_free(struct intel_context *ce)
{
kmem_cache_free(global.slab_ce, ce);
}
struct intel_context *
intel_context_lookup(struct i915_gem_context *ctx,
struct intel_engine_cs *engine)
{
struct intel_context *ce = NULL;
struct rb_node *p;
spin_lock(&ctx->hw_contexts_lock);
p = ctx->hw_contexts.rb_node;
while (p) {
struct intel_context *this =
rb_entry(p, struct intel_context, node);
if (this->engine == engine) {
GEM_BUG_ON(this->gem_context != ctx);
ce = this;
break;
}
if (this->engine < engine)
p = p->rb_right;
else
p = p->rb_left;
}
spin_unlock(&ctx->hw_contexts_lock);
return ce;
}
struct intel_context *
__intel_context_insert(struct i915_gem_context *ctx,
struct intel_engine_cs *engine,
struct intel_context *ce)
{
struct rb_node **p, *parent;
int err = 0;
spin_lock(&ctx->hw_contexts_lock);
parent = NULL;
p = &ctx->hw_contexts.rb_node;
while (*p) {
struct intel_context *this;
parent = *p;
this = rb_entry(parent, struct intel_context, node);
if (this->engine == engine) {
err = -EEXIST;
ce = this;
break;
}
if (this->engine < engine)
p = &parent->rb_right;
else
p = &parent->rb_left;
}
if (!err) {
rb_link_node(&ce->node, parent, p);
rb_insert_color(&ce->node, &ctx->hw_contexts);
}
spin_unlock(&ctx->hw_contexts_lock);
return ce;
}
void __intel_context_remove(struct intel_context *ce)
{
struct i915_gem_context *ctx = ce->gem_context;
spin_lock(&ctx->hw_contexts_lock);
rb_erase(&ce->node, &ctx->hw_contexts);
spin_unlock(&ctx->hw_contexts_lock);
}
static struct intel_context *
intel_context_instance(struct i915_gem_context *ctx,
struct intel_engine_cs *engine)
{
struct intel_context *ce, *pos;
ce = intel_context_lookup(ctx, engine);
if (likely(ce))
return ce;
ce = intel_context_alloc();
if (!ce)
return ERR_PTR(-ENOMEM);
intel_context_init(ce, ctx, engine);
pos = __intel_context_insert(ctx, engine, ce);
if (unlikely(pos != ce)) /* Beaten! Use their HW context instead */
intel_context_free(ce);
GEM_BUG_ON(intel_context_lookup(ctx, engine) != pos);
return pos;
}
struct intel_context *
intel_context_pin_lock(struct i915_gem_context *ctx,
struct intel_engine_cs *engine)
__acquires(ce->pin_mutex)
{
struct intel_context *ce;
ce = intel_context_instance(ctx, engine);
if (IS_ERR(ce))
return ce;
if (mutex_lock_interruptible(&ce->pin_mutex))
return ERR_PTR(-EINTR);
return ce;
}
struct intel_context *
intel_context_pin(struct i915_gem_context *ctx,
struct intel_engine_cs *engine)
{
struct intel_context *ce;
int err;
ce = intel_context_instance(ctx, engine);
if (IS_ERR(ce))
return ce;
if (likely(atomic_inc_not_zero(&ce->pin_count)))
return ce;
if (mutex_lock_interruptible(&ce->pin_mutex))
return ERR_PTR(-EINTR);
if (likely(!atomic_read(&ce->pin_count))) {
err = ce->ops->pin(ce);
if (err)
goto err;
i915_gem_context_get(ctx);
GEM_BUG_ON(ce->gem_context != ctx);
mutex_lock(&ctx->mutex);
list_add(&ce->active_link, &ctx->active_engines);
mutex_unlock(&ctx->mutex);
intel_context_get(ce);
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! */
mutex_unlock(&ce->pin_mutex);
return ce;
err:
mutex_unlock(&ce->pin_mutex);
return ERR_PTR(err);
}
void intel_context_unpin(struct intel_context *ce)
{
if (likely(atomic_add_unless(&ce->pin_count, -1, 1)))
return;
/* We may be called from inside intel_context_pin() to evict another */
intel_context_get(ce);
mutex_lock_nested(&ce->pin_mutex, SINGLE_DEPTH_NESTING);
if (likely(atomic_dec_and_test(&ce->pin_count))) {
ce->ops->unpin(ce);
mutex_lock(&ce->gem_context->mutex);
list_del(&ce->active_link);
mutex_unlock(&ce->gem_context->mutex);
i915_gem_context_put(ce->gem_context);
intel_context_put(ce);
}
mutex_unlock(&ce->pin_mutex);
intel_context_put(ce);
}
static void intel_context_retire(struct i915_active_request *active,
struct i915_request *rq)
{
struct intel_context *ce =
container_of(active, typeof(*ce), active_tracker);
intel_context_unpin(ce);
}
void
intel_context_init(struct intel_context *ce,
struct i915_gem_context *ctx,
struct intel_engine_cs *engine)
{
kref_init(&ce->ref);
ce->gem_context = ctx;
ce->engine = engine;
ce->ops = engine->cops;
ce->saturated = 0;
INIT_LIST_HEAD(&ce->signal_link);
INIT_LIST_HEAD(&ce->signals);
mutex_init(&ce->pin_mutex);
/* Use the whole device by default */
ce->sseu = intel_device_default_sseu(ctx->i915);
i915_active_request_init(&ce->active_tracker,
NULL, intel_context_retire);
}
static void i915_global_context_shrink(void)
{
kmem_cache_shrink(global.slab_ce);
}
static void i915_global_context_exit(void)
{
kmem_cache_destroy(global.slab_ce);
}
static struct i915_global_context global = { {
.shrink = i915_global_context_shrink,
.exit = i915_global_context_exit,
} };
int __init i915_global_context_init(void)
{
global.slab_ce = KMEM_CACHE(intel_context, SLAB_HWCACHE_ALIGN);
if (!global.slab_ce)
return -ENOMEM;
i915_global_register(&global.base);
return 0;
}