From patchwork Fri Jan 8 09:43:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 360013 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, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 50882C43381 for ; Fri, 8 Jan 2021 09:44:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C954233EA for ; Fri, 8 Jan 2021 09:44:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727864AbhAHJoa (ORCPT ); Fri, 8 Jan 2021 04:44:30 -0500 Received: from mx2.suse.de ([195.135.220.15]:35860 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727649AbhAHJo1 (ORCPT ); Fri, 8 Jan 2021 04:44:27 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 914E5AE1C; Fri, 8 Jan 2021 09:43:45 +0000 (UTC) From: Thomas Zimmermann To: sumit.semwal@linaro.org, christian.koenig@amd.com, airlied@redhat.com, daniel@ffwll.ch, maarten.lankhorst@linux.intel.com, mripard@kernel.org, kraxel@redhat.com, hdegoede@redhat.com, sean@poorly.run, eric@anholt.net, sam@ravnborg.org Cc: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, virtualization@lists.linux-foundation.org, Thomas Zimmermann , Daniel Vetter Subject: [PATCH v4 03/13] drm/cma-helper: Provide a vmap function for short-term mappings Date: Fri, 8 Jan 2021 10:43:30 +0100 Message-Id: <20210108094340.15290-4-tzimmermann@suse.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210108094340.15290-1-tzimmermann@suse.de> References: <20210108094340.15290-1-tzimmermann@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Implementations of the vmap/vunmap GEM callbacks may perform pinning of the BO and may acquire the associated reservation object's lock. Callers that only require a mapping of the contained memory can thus interfere with other tasks that require exact pinning, such as scanout. This is less of an issue with private CMA buffers, but may happen with imported ones. Therefore provide the new interface drm_gem_cma_vmap_local(), which only performs the vmap operations. Callers have to hold the reservation lock while the mapping persists. This patch also connects GEM CMA helpers to the GEM object function with equivalent functionality. v4: * vc4: don't wrap drm_gem_cma_vmap_local() in BO funcs (Daniel) * remove the TODO comment (Daniel) Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Vetter --- drivers/gpu/drm/drm_gem_cma_helper.c | 27 +++++++++++++++++++++++++++ drivers/gpu/drm/vc4/vc4_bo.c | 1 + include/drm/drm_gem_cma_helper.h | 1 + 3 files changed, 29 insertions(+) diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index 7942cf05cd93..f854027fa01f 100644 --- a/drivers/gpu/drm/drm_gem_cma_helper.c +++ b/drivers/gpu/drm/drm_gem_cma_helper.c @@ -38,6 +38,7 @@ static const struct drm_gem_object_funcs drm_gem_cma_default_funcs = { .print_info = drm_gem_cma_print_info, .get_sg_table = drm_gem_cma_get_sg_table, .vmap = drm_gem_cma_vmap, + .vmap_local = drm_gem_cma_vmap_local, .mmap = drm_gem_cma_mmap, .vm_ops = &drm_gem_cma_vm_ops, }; @@ -471,6 +472,32 @@ int drm_gem_cma_vmap(struct drm_gem_object *obj, struct dma_buf_map *map) } EXPORT_SYMBOL_GPL(drm_gem_cma_vmap); +/** + * drm_gem_cma_vmap_local - map a CMA GEM object into the kernel's virtual + * address space + * @obj: GEM object + * @map: Returns the kernel virtual address of the CMA GEM object's backing + * store. + * + * This function maps a buffer into the kernel's + * virtual address space. Since the CMA buffers are already mapped into the + * kernel virtual address space this simply returns the cached virtual + * address. Drivers using the CMA helpers should set this as their DRM + * driver's &drm_gem_object_funcs.vmap_local callback. + * + * Returns: + * 0 on success, or a negative error code otherwise. + */ +int drm_gem_cma_vmap_local(struct drm_gem_object *obj, struct dma_buf_map *map) +{ + struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); + + dma_buf_map_set_vaddr(map, cma_obj->vaddr); + + return 0; +} +EXPORT_SYMBOL_GPL(drm_gem_cma_vmap_local); + /** * drm_gem_cma_mmap - memory-map an exported CMA GEM object * @obj: GEM object diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c index dc316cb79e00..7283c018dbaf 100644 --- a/drivers/gpu/drm/vc4/vc4_bo.c +++ b/drivers/gpu/drm/vc4/vc4_bo.c @@ -387,6 +387,7 @@ static const struct drm_gem_object_funcs vc4_gem_object_funcs = { .export = vc4_prime_export, .get_sg_table = drm_gem_cma_get_sg_table, .vmap = vc4_prime_vmap, + .vmap_local = drm_gem_cma_vmap_local, .vm_ops = &vc4_vm_ops, }; diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h index 0a9711caa3e8..05122e71bc6d 100644 --- a/include/drm/drm_gem_cma_helper.h +++ b/include/drm/drm_gem_cma_helper.h @@ -99,6 +99,7 @@ drm_gem_cma_prime_import_sg_table(struct drm_device *dev, struct dma_buf_attachment *attach, struct sg_table *sgt); int drm_gem_cma_vmap(struct drm_gem_object *obj, struct dma_buf_map *map); +int drm_gem_cma_vmap_local(struct drm_gem_object *obj, struct dma_buf_map *map); int drm_gem_cma_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma); /**