From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA607C07E99 for ; Mon, 5 Jul 2021 13:53:33 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 73F1E6145D for ; Mon, 5 Jul 2021 13:53:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 73F1E6145D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B74CC89CF9; Mon, 5 Jul 2021 13:53:29 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3397489CF1; Mon, 5 Jul 2021 13:53:28 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10035"; a="207154267" X-IronPort-AV: E=Sophos;i="5.83,325,1616482800"; d="scan'208";a="207154267" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jul 2021 06:53:28 -0700 X-IronPort-AV: E=Sophos;i="5.83,325,1616482800"; d="scan'208";a="562596206" Received: from ricrossl-mobl.ger.corp.intel.com (HELO mwauld-desk1.intel.com) ([10.252.23.185]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jul 2021 06:53:25 -0700 From: Matthew Auld To: intel-gfx@lists.freedesktop.org Subject: [PATCH v3 2/5] drm/i915/uapi: convert drm_i915_gem_caching to kernel doc Date: Mon, 5 Jul 2021 14:53:07 +0100 Message-Id: <20210705135310.1502437-2-matthew.auld@intel.com> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210705135310.1502437-1-matthew.auld@intel.com> References: <20210705135310.1502437-1-matthew.auld@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , Jason Ekstrand , Tvrtko Ursulin , Jordan Justen , dri-devel@lists.freedesktop.org, Kenneth Graunke , Daniel Vetter Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Convert all the drm_i915_gem_caching bits to proper kernel doc. Suggested-by: Daniel Vetter Signed-off-by: Matthew Auld Cc: Thomas Hellström Cc: Maarten Lankhorst Cc: Tvrtko Ursulin Cc: Jordan Justen Cc: Kenneth Graunke Cc: Jason Ekstrand Cc: Daniel Vetter Cc: Ramalingam C --- include/uapi/drm/i915_drm.h | 70 +++++++++++++++++++++++-------------- 1 file changed, 43 insertions(+), 27 deletions(-) diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h index 2f70c48567c0..d13c6c5fad04 100644 --- a/include/uapi/drm/i915_drm.h +++ b/include/uapi/drm/i915_drm.h @@ -1363,43 +1363,59 @@ struct drm_i915_gem_busy { }; /** - * I915_CACHING_NONE + * struct drm_i915_gem_caching - Set or get the caching for given object + * handle. * - * GPU access is not coherent with cpu caches. Default for machines without an - * LLC. - */ -#define I915_CACHING_NONE 0 -/** - * I915_CACHING_CACHED + * Allow userspace to control the GTT caching bits for a given object when the + * object is later mapped through the ppGTT(or GGTT on older platforms lacking + * ppGTT support, or if the object is used for scanout). Note that this might + * require unbinding the object from the GTT first, if its current caching value + * doesn't match. * - * GPU access is coherent with cpu caches and furthermore the data is cached in - * last-level caches shared between cpu cores and the gpu GT. Default on - * machines with HAS_LLC. - */ -#define I915_CACHING_CACHED 1 -/** - * I915_CACHING_DISPLAY * - * Special GPU caching mode which is coherent with the scanout engines. - * Transparently falls back to I915_CACHING_NONE on platforms where no special - * cache mode (like write-through or gfdt flushing) is available. The kernel - * automatically sets this mode when using a buffer as a scanout target. - * Userspace can manually set this mode to avoid a costly stall and clflush in - * the hotpath of drawing the first frame. */ -#define I915_CACHING_DISPLAY 2 - struct drm_i915_gem_caching { /** - * Handle of the buffer to set/get the caching level of. */ + * @handle: Handle of the buffer to set/get the caching level. + */ __u32 handle; /** - * Cacheing level to apply or return value + * @caching: The GTT caching level to apply or possible return value. + * + * The supported @caching values: * - * bits0-15 are for generic caching control (i.e. the above defined - * values). bits16-31 are reserved for platform-specific variations - * (e.g. l3$ caching on gen7). */ + * I915_CACHING_NONE: + * + * GPU access is not coherent with CPU caches. Default for machines + * without an LLC. This means we need to manually clflush, if we want + * GPU access to be coherent. + * + * I915_CACHING_CACHED: + * + * GPU access is coherent with CPU caches and furthermore the data is + * cached in last-level caches shared between CPU cores and the GPU GT. + * Default on machines with HAS_LLC. In general the fast shared + * last-level cache(HAS_LLC) is considered much faster then platforms + * which only support snooping(HAS_SNOOP), hence by default + * + * I915_CACHING_DISPLAY: + * + * Special GPU caching mode which is coherent with the scanout engines. + * Transparently falls back to I915_CACHING_NONE on platforms where no + * special cache mode (like write-through or gfdt flushing) is + * available. The kernel automatically sets this mode when using a + * buffer as a scanout target. Userspace can manually set this mode to + * avoid a costly stall and clflush in the hotpath of drawing the first + * frame. + * + * Side note: On gen8+ this no longer does much since we lost the GGTT + * caching bits. Although setting this is harmless, since it still + * effectively falls back to I915_CACHING_NONE. + */ +#define I915_CACHING_NONE 0 +#define I915_CACHING_CACHED 1 +#define I915_CACHING_DISPLAY 2 __u32 caching; }; -- 2.26.3