Commit a6397e63 authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm/gem: Convert to drm_exec 



Replace the ww_mutex locking dance with the drm_exec helper.

v2: Error path fixes, move drm_exec_fini so we only call it once (and
    only if we have drm_exec_init()

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/568342/
parent 05d24935

drivers/gpu/drm/msm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ config DRM_MSM 
	select DRM_DP_AUX_BUS

	select DRM_DISPLAY_DP_HELPER

	select DRM_DISPLAY_HELPER

	select DRM_EXEC

	select DRM_KMS_HELPER

	select DRM_PANEL

	select DRM_BRIDGE

drivers/gpu/drm/msm/msm_gem.h

+2 −3
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 


#include <linux/kref.h>

#include <linux/dma-resv.h>

#include "drm/drm_exec.h"

#include "drm/gpu_scheduler.h"

#include "msm_drv.h"
@@ -258,7 +259,7 @@ struct msm_gem_submit { 
	struct msm_gpu *gpu;

	struct msm_gem_address_space *aspace;

	struct list_head node;   /* node in ring submit list */

	struct ww_acquire_ctx ticket;

	struct drm_exec exec;

	uint32_t seqno;		/* Sequence number of the submit on the ring */



	/* Hw fence, which is created when the scheduler executes the job, and
@@ -291,8 +292,6 @@ struct msm_gem_submit { 
		struct drm_msm_gem_submit_reloc *relocs;

	} *cmd;  /* array of size nr_cmds */

	struct {

/* make sure these don't conflict w/ MSM_SUBMIT_BO_x */

#define BO_LOCKED	0x4000	/* obj lock is held */

		uint32_t flags;

		union {

			struct drm_gem_object *obj;

drivers/gpu/drm/msm/msm_gem_submit.c

+21 −98
Original line number Diff line number Diff line
@@ -248,85 +248,30 @@ static int submit_lookup_cmds(struct msm_gem_submit *submit, 
	return ret;

}



static void submit_unlock_bo(struct msm_gem_submit *submit, int i)

{

	struct drm_gem_object *obj = submit->bos[i].obj;

	unsigned cleanup_flags = BO_LOCKED;

	unsigned flags = submit->bos[i].flags & cleanup_flags;



	/*

	 * Clear flags bit before dropping lock, so that the msm_job_run()

	 * path isn't racing with submit_cleanup() (ie. the read/modify/

	 * write is protected by the obj lock in all paths)

	 */

	submit->bos[i].flags &= ~cleanup_flags;



	if (flags & BO_LOCKED)

		dma_resv_unlock(obj->resv);

}



/* This is where we make sure all the bo's are reserved and pin'd: */

static int submit_lock_objects(struct msm_gem_submit *submit)

{

	int contended, slow_locked = -1, i, ret = 0;



retry:

	for (i = 0; i < submit->nr_bos; i++) {

		struct drm_gem_object *obj = submit->bos[i].obj;



		if (slow_locked == i)

			slow_locked = -1;

	int ret;



		contended = i;

	drm_exec_init(&submit->exec, DRM_EXEC_INTERRUPTIBLE_WAIT, submit->nr_bos);



		if (!(submit->bos[i].flags & BO_LOCKED)) {

			ret = dma_resv_lock_interruptible(obj->resv,

							  &submit->ticket);

	drm_exec_until_all_locked (&submit->exec) {

		for (unsigned i = 0; i < submit->nr_bos; i++) {

			struct drm_gem_object *obj = submit->bos[i].obj;

			ret = drm_exec_prepare_obj(&submit->exec, obj, 1);

			drm_exec_retry_on_contention(&submit->exec);

			if (ret)

				goto fail;

			submit->bos[i].flags |= BO_LOCKED;

				goto error;

		}

	}



	ww_acquire_done(&submit->ticket);



	return 0;



fail:

	if (ret == -EALREADY) {

		SUBMIT_ERROR(submit, "handle %u at index %u already on submit list\n",

			     submit->bos[i].handle, i);

		ret = -EINVAL;

	}



	for (; i >= 0; i--)

		submit_unlock_bo(submit, i);



	if (slow_locked > 0)

		submit_unlock_bo(submit, slow_locked);



	if (ret == -EDEADLK) {

		struct drm_gem_object *obj = submit->bos[contended].obj;

		/* we lost out in a seqno race, lock and retry.. */

		ret = dma_resv_lock_slow_interruptible(obj->resv,

						       &submit->ticket);

		if (!ret) {

			submit->bos[contended].flags |= BO_LOCKED;

			slow_locked = contended;

			goto retry;

		}



		/* Not expecting -EALREADY here, if the bo was already

		 * locked, we should have gotten -EALREADY already from

		 * the dma_resv_lock_interruptable() call.

		 */

		WARN_ON_ONCE(ret == -EALREADY);

	}



error:

	return ret;

}



static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit)

static int submit_fence_sync(struct msm_gem_submit *submit)

{

	int i, ret = 0;
@@ -334,22 +279,6 @@ static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit) 
		struct drm_gem_object *obj = submit->bos[i].obj;

		bool write = submit->bos[i].flags & MSM_SUBMIT_BO_WRITE;



		/* NOTE: _reserve_shared() must happen before

		 * _add_shared_fence(), which makes this a slightly

		 * strange place to call it.  OTOH this is a

		 * convenient can-fail point to hook it in.

		 */

		ret = dma_resv_reserve_fences(obj->resv, 1);

		if (ret)

			return ret;



		/* If userspace has determined that explicit fencing is

		 * used, it can disable implicit sync on the entire

		 * submit:

		 */

		if (no_implicit)

			continue;



		/* Otherwise userspace can ask for implicit sync to be

		 * disabled on specific buffers.  This is useful for internal

		 * usermode driver managed buffers, suballocation, etc.
@@ -529,17 +458,14 @@ static int submit_reloc(struct msm_gem_submit *submit, struct drm_gem_object *ob 
 */

static void submit_cleanup(struct msm_gem_submit *submit, bool error)

{

	unsigned i;



	if (error)

	if (error) {

		submit_unpin_objects(submit);



	for (i = 0; i < submit->nr_bos; i++) {

		struct drm_gem_object *obj = submit->bos[i].obj;

		submit_unlock_bo(submit, i);

		if (error)

			drm_gem_object_put(obj);

		/* job wasn't enqueued to scheduler, so early retirement: */

		msm_submit_retire(submit);

	}



	if (submit->exec.objects)

		drm_exec_fini(&submit->exec);

}



void msm_submit_retire(struct msm_gem_submit *submit)
@@ -733,7 +659,6 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, 
	struct msm_submit_post_dep *post_deps = NULL;

	struct drm_syncobj **syncobjs_to_reset = NULL;

	int out_fence_fd = -1;

	bool has_ww_ticket = false;

	unsigned i;

	int ret;
@@ -839,15 +764,15 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, 
		goto out;



	/* copy_*_user while holding a ww ticket upsets lockdep */

	ww_acquire_init(&submit->ticket, &reservation_ww_class);

	has_ww_ticket = true;

	ret = submit_lock_objects(submit);

	if (ret)

		goto out;



	ret = submit_fence_sync(submit, !!(args->flags & MSM_SUBMIT_NO_IMPLICIT));

	if (!(args->flags & MSM_SUBMIT_NO_IMPLICIT)) {

		ret = submit_fence_sync(submit);

		if (ret)

			goto out;

	}



	ret = submit_pin_objects(submit);

	if (ret)
@@ -975,8 +900,6 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, 


out:

	submit_cleanup(submit, !!ret);

	if (has_ww_ticket)

		ww_acquire_fini(&submit->ticket);

out_unlock:

	mutex_unlock(&queue->lock);

out_post_unlock: