Commit 94dee3b9 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/gem-vram: Acquire reservation lock in GEM pin/unpin callbacks 



Acquire the reservation lock directly in GEM pin callback. Same for
unpin. Prepares for further changes.

Dma-buf locking semantics require callers to hold the buffer's
reservation lock when invoking the pin and unpin callbacks. Prepare
gem-vram accordingly by pushing locking out of the implementation.
A follow-up patch will fix locking for all GEM code at once.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarDmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> # virtio-gpu
Acked-by: default avatarZack Rusin <zack.rusin@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240227113853.8464-3-tzimmermann@suse.de
parent ec144244

drivers/gpu/drm/drm_gem_vram_helper.c

+21 −3
Original line number Diff line number Diff line
@@ -283,6 +283,8 @@ static int drm_gem_vram_pin_locked(struct drm_gem_vram_object *gbo, 
	struct ttm_operation_ctx ctx = { false, false };

	int ret;



	dma_resv_assert_held(gbo->bo.base.resv);



	if (gbo->bo.pin_count)

		goto out;
@@ -338,6 +340,8 @@ EXPORT_SYMBOL(drm_gem_vram_pin); 


static void drm_gem_vram_unpin_locked(struct drm_gem_vram_object *gbo)

{

	dma_resv_assert_held(gbo->bo.base.resv);



	ttm_bo_unpin(&gbo->bo);

}
@@ -770,8 +774,14 @@ EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb); 
static int drm_gem_vram_object_pin(struct drm_gem_object *gem)

{

	struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);

	int ret;



	/* Fbdev console emulation is the use case of these PRIME

	ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);

	if (ret)

		return ret;



	/*

	 * Fbdev console emulation is the use case of these PRIME

	 * helpers. This may involve updating a hardware buffer from

	 * a shadow FB. We pin the buffer to it's current location

	 * (either video RAM or system memory) to prevent it from
@@ -779,7 +789,10 @@ static int drm_gem_vram_object_pin(struct drm_gem_object *gem) 
	 * the buffer to be pinned to VRAM, implement a callback that

	 * sets the flags accordingly.

	 */

	return drm_gem_vram_pin(gbo, 0);

	ret = drm_gem_vram_pin_locked(gbo, 0);

	ttm_bo_unreserve(&gbo->bo);



	return ret;

}



/**
@@ -790,8 +803,13 @@ static int drm_gem_vram_object_pin(struct drm_gem_object *gem) 
static void drm_gem_vram_object_unpin(struct drm_gem_object *gem)

{

	struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem);

	int ret;



	drm_gem_vram_unpin(gbo);

	ret = ttm_bo_reserve(&gbo->bo, true, false, NULL);

	if (ret)

		return;

	drm_gem_vram_unpin_locked(gbo);

	ttm_bo_unreserve(&gbo->bo);

}



/**