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From: Dmitry Osipenko <dmitry.osipenko@collabora.com>
To: David Airlie <airlied@gmail.com>,
	Gerd Hoffmann <kraxel@redhat.com>,
	Gurchetan Singh <gurchetansingh@chromium.org>,
	Chia-I Wu <olvaffe@gmail.com>,
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	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	=?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
	Qiang Yu <yuq825@gmail.com>,
	Steven Price <steven.price@arm.com>,
	Boris Brezillon <boris.brezillon@collabora.com>,
	Emma Anholt <emma@anholt.net>,
	Melissa Wen <mwen@igalia.com>
Cc: dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org,
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	virtualization@lists.linux-foundation.org
Subject: [PATCH v19 03/30] drm/gem: Document locking rule of vmap and evict callbacks
Date: Fri,  5 Jan 2024 21:45:57 +0300
Message-ID: <20240105184624.508603-4-dmitry.osipenko@collabora.com>
In-Reply-To: <20240105184624.508603-1-dmitry.osipenko@collabora.com>
References: <20240105184624.508603-1-dmitry.osipenko@collabora.com>
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The vmap/vunmap/evict GEM callbacks are always invoked with a held GEM's
reservation lock. Document this locking rule for clarity.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 include/drm/drm_gem.h | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index f835fdee6a5e..021f64371056 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -156,7 +156,8 @@ struct drm_gem_object_funcs {
 	 * @vmap:
 	 *
 	 * Returns a virtual address for the buffer. Used by the
-	 * drm_gem_dmabuf_vmap() helper.
+	 * drm_gem_dmabuf_vmap() helper. Called with a held GEM reservation
+	 * lock.
 	 *
 	 * This callback is optional.
 	 */
@@ -166,7 +167,8 @@ struct drm_gem_object_funcs {
 	 * @vunmap:
 	 *
 	 * Releases the address previously returned by @vmap. Used by the
-	 * drm_gem_dmabuf_vunmap() helper.
+	 * drm_gem_dmabuf_vunmap() helper. Called with a held GEM reservation
+	 * lock.
 	 *
 	 * This callback is optional.
 	 */
@@ -189,7 +191,8 @@ struct drm_gem_object_funcs {
 	 * @evict:
 	 *
 	 * Evicts gem object out from memory. Used by the drm_gem_object_evict()
-	 * helper. Returns 0 on success, -errno otherwise.
+	 * helper. Returns 0 on success, -errno otherwise. Called with a held
+	 * GEM reservation lock.
 	 *
 	 * This callback is optional.
 	 */
-- 
2.43.0