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Commit 12c255b5 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Provide an i915_active.acquire callback 



If we introduce a callback for i915_active that is only called the first
time we use the i915_active and is symmetrically paired with the
i915_active.retire callback, we can replace the open-coded and
non-atomic implementations -- which will be very fragile (i.e. broken)
upon removing the struct_mutex serialisation.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621183801.23252-4-chris@chris-wilson.co.uk
parent a93615f9

drivers/gpu/drm/i915/gem/i915_gem_context.c

+6 −2
Original line number Diff line number Diff line
@@ -923,8 +923,12 @@ static int context_barrier_task(struct i915_gem_context *ctx, 
	if (!cb)

		return -ENOMEM;



	i915_active_init(i915, &cb->base, cb_retire);

	i915_active_acquire(&cb->base);

	i915_active_init(i915, &cb->base, NULL, cb_retire);

	err = i915_active_acquire(&cb->base);

	if (err) {

		kfree(cb);

		return err;

	}



	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {

		struct i915_request *rq;

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

+30 −35
Original line number Diff line number Diff line
@@ -95,11 +95,15 @@ void intel_context_unpin(struct intel_context *ce) 
	intel_context_put(ce);

}



static int __context_pin_state(struct i915_vma *vma, unsigned long flags)

static int __context_pin_state(struct i915_vma *vma)

{

	u64 flags;

	int err;



	err = i915_vma_pin(vma, 0, 0, flags | PIN_GLOBAL);

	flags = i915_ggtt_pin_bias(vma) | PIN_OFFSET_BIAS;

	flags |= PIN_HIGH | PIN_GLOBAL;



	err = i915_vma_pin(vma, 0, 0, flags);

	if (err)

		return err;
@@ -119,7 +123,7 @@ static void __context_unpin_state(struct i915_vma *vma) 
	__i915_vma_unpin(vma);

}



static void intel_context_retire(struct i915_active *active)

static void __intel_context_retire(struct i915_active *active)

{

	struct intel_context *ce = container_of(active, typeof(*ce), active);
@@ -130,35 +134,11 @@ static void intel_context_retire(struct i915_active *active) 
	intel_context_put(ce);

}



void

intel_context_init(struct intel_context *ce,

		   struct i915_gem_context *ctx,

		   struct intel_engine_cs *engine)

{

	GEM_BUG_ON(!engine->cops);



	kref_init(&ce->ref);



	ce->gem_context = ctx;

	ce->engine = engine;

	ce->ops = engine->cops;

	ce->sseu = engine->sseu;



	INIT_LIST_HEAD(&ce->signal_link);

	INIT_LIST_HEAD(&ce->signals);



	mutex_init(&ce->pin_mutex);



	i915_active_init(ctx->i915, &ce->active, intel_context_retire);

}



int intel_context_active_acquire(struct intel_context *ce, unsigned long flags)

static int __intel_context_active(struct i915_active *active)

{

	struct intel_context *ce = container_of(active, typeof(*ce), active);

	int err;



	if (!i915_active_acquire(&ce->active))

		return 0;



	intel_context_get(ce);



	err = intel_ring_pin(ce->ring);
@@ -168,7 +148,7 @@ int intel_context_active_acquire(struct intel_context *ce, unsigned long flags) 
	if (!ce->state)

		return 0;



	err = __context_pin_state(ce->state, flags);

	err = __context_pin_state(ce->state);

	if (err)

		goto err_ring;
@@ -188,15 +168,30 @@ int intel_context_active_acquire(struct intel_context *ce, unsigned long flags) 
	intel_ring_unpin(ce->ring);

err_put:

	intel_context_put(ce);

	i915_active_cancel(&ce->active);

	return err;

}



void intel_context_active_release(struct intel_context *ce)

void

intel_context_init(struct intel_context *ce,

		   struct i915_gem_context *ctx,

		   struct intel_engine_cs *engine)

{

	/* Nodes preallocated in intel_context_active() */

	i915_active_acquire_barrier(&ce->active);

	i915_active_release(&ce->active);

	GEM_BUG_ON(!engine->cops);



	kref_init(&ce->ref);



	ce->gem_context = ctx;

	ce->engine = engine;

	ce->ops = engine->cops;

	ce->sseu = engine->sseu;



	INIT_LIST_HEAD(&ce->signal_link);

	INIT_LIST_HEAD(&ce->signals);



	mutex_init(&ce->pin_mutex);



	i915_active_init(ctx->i915, &ce->active,

			 __intel_context_active, __intel_context_retire);

}



static void i915_global_context_shrink(void)

drivers/gpu/drm/i915/gt/intel_context.h

+12 −2
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 


#include <linux/lockdep.h>



#include "i915_active.h"

#include "intel_context_types.h"

#include "intel_engine_types.h"
@@ -102,8 +103,17 @@ static inline void intel_context_exit(struct intel_context *ce) 
		ce->ops->exit(ce);

}



int intel_context_active_acquire(struct intel_context *ce, unsigned long flags);

void intel_context_active_release(struct intel_context *ce);

static inline int intel_context_active_acquire(struct intel_context *ce)

{

	return i915_active_acquire(&ce->active);

}



static inline 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 inline struct intel_context *intel_context_get(struct intel_context *ce)

{

drivers/gpu/drm/i915/gt/intel_lrc.c

+2 −4
Original line number Diff line number Diff line
@@ -1542,12 +1542,10 @@ __execlists_context_pin(struct intel_context *ce, 
		goto err;

	GEM_BUG_ON(!ce->state);



	ret = intel_context_active_acquire(ce,

					   engine->i915->ggtt.pin_bias |

					   PIN_OFFSET_BIAS |

					   PIN_HIGH);

	ret = intel_context_active_acquire(ce);

	if (ret)

		goto err;

	GEM_BUG_ON(!i915_vma_is_pinned(ce->state));



	vaddr = i915_gem_object_pin_map(ce->state->obj,

					i915_coherent_map_type(engine->i915) |

drivers/gpu/drm/i915/gt/intel_ringbuffer.c

+1 −1
Original line number Diff line number Diff line
@@ -1455,7 +1455,7 @@ static int ring_context_pin(struct intel_context *ce) 
		ce->state = vma;

	}



	err = intel_context_active_acquire(ce, PIN_HIGH);

	err = intel_context_active_acquire(ce);

	if (err)

		return err;