From patchwork Fri Jul 5 09:26:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 11032269 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9641A13B1 for ; Fri, 5 Jul 2019 09:26:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8513028A78 for ; Fri, 5 Jul 2019 09:26:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7985E28A7E; Fri, 5 Jul 2019 09:26:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 1816C28A78 for ; Fri, 5 Jul 2019 09:26:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DB6846E451; Fri, 5 Jul 2019 09:26:20 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id D7D1B6E029 for ; Fri, 5 Jul 2019 09:26:18 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 37797ADE5; Fri, 5 Jul 2019 09:26:17 +0000 (UTC) From: Thomas Zimmermann To: airlied@redhat.com, daniel@ffwll.ch, kraxel@redhat.com, maarten.lankhorst@linux.intel.com, maxime.ripard@bootlin.com, sean@poorly.run, noralf@tronnes.org, sam@ravnborg.org, yc_chen@aspeedtech.com Subject: [PATCH v2 1/6] drm/client: Support unmapping of DRM client buffers Date: Fri, 5 Jul 2019 11:26:08 +0200 Message-Id: <20190705092613.7621-2-tzimmermann@suse.de> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190705092613.7621-1-tzimmermann@suse.de> References: <20190705092613.7621-1-tzimmermann@suse.de> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Zimmermann , dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP DRM clients, such as the fbdev emulation, have their buffer objects mapped by default. Mapping a buffer implicitly prevents its relocation. Hence, the buffer may permanently consume video memory while it's allocated. This is a problem for drivers of low-memory devices, such as ast, mgag200 or older framebuffer hardware, which will then not have enough memory to display other content (e.g., X11). This patch introduces drm_client_buffer_vmap() and _vunmap(). Internal DRM clients can use these functions to unmap and remap buffer objects as needed. There's no reference counting for vmap operations. Callers are expected to either keep buffers mapped (as it is now), or call vmap and vunmap in pairs around code that accesses the mapped memory. v2: * remove several duplicated NULL-pointer checks Signed-off-by: Thomas Zimmermann Reviewed-by: Noralf Trønnes --- drivers/gpu/drm/drm_client.c | 67 ++++++++++++++++++++++++++++++------ include/drm/drm_client.h | 3 ++ 2 files changed, 60 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c index 410572f14257..66d8d645ac79 100644 --- a/drivers/gpu/drm/drm_client.c +++ b/drivers/gpu/drm/drm_client.c @@ -281,6 +281,43 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u buffer->gem = obj; + vaddr = drm_client_buffer_vmap(buffer); + if (IS_ERR(vaddr)) { + ret = PTR_ERR(vaddr); + goto err_delete; + } + + return buffer; + +err_delete: + drm_client_buffer_delete(buffer); + + return ERR_PTR(ret); +} + +/** + * drm_client_buffer_vmap - Map DRM client buffer into address space + * @buffer: DRM client buffer + * + * This function maps a client buffer into kernel address space. If the + * buffer is already mapped, it returns the mapping's address. + * + * Client buffer mappings are not ref'counted. Each call to + * drm_client_buffer_vmap() should be followed by a call to + * drm_client_buffer_vunmap(); or the client buffer should be mapped + * throughout its lifetime. The latter is the default. + * + * Returns: + * The mapped memory's address + */ +void * +drm_client_buffer_vmap(struct drm_client_buffer *buffer) +{ + void *vaddr; + + if (buffer->vaddr) + return buffer->vaddr; + /* * FIXME: The dependency on GEM here isn't required, we could * convert the driver handle to a dma-buf instead and use the @@ -289,21 +326,31 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u * fd_install step out of the driver backend hooks, to make that * final step optional for internal users. */ - vaddr = drm_gem_vmap(obj); - if (IS_ERR(vaddr)) { - ret = PTR_ERR(vaddr); - goto err_delete; - } + vaddr = drm_gem_vmap(buffer->gem); + if (IS_ERR(vaddr)) + return vaddr; buffer->vaddr = vaddr; - return buffer; - -err_delete: - drm_client_buffer_delete(buffer); + return vaddr; +} +EXPORT_SYMBOL(drm_client_buffer_vmap); - return ERR_PTR(ret); +/** + * drm_client_buffer_vunmap - Unmap DRM client buffer + * @buffer: DRM client buffer + * + * This function removes a client buffer's memory mmapping. This + * function is only required by clients that manage their buffers + * by themselves. By default, DRM client buffers are mapped throughout + * their entire lifetime. + */ +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer) +{ + drm_gem_vunmap(buffer->gem, buffer->vaddr); + buffer->vaddr = NULL; } +EXPORT_SYMBOL(drm_client_buffer_vunmap); static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer) { diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h index 72d51d1e9dd9..e1db1d9da0bf 100644 --- a/include/drm/drm_client.h +++ b/include/drm/drm_client.h @@ -149,6 +149,9 @@ struct drm_client_buffer { struct drm_client_buffer * drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format); void drm_client_framebuffer_delete(struct drm_client_buffer *buffer); +void * +drm_client_buffer_vmap(struct drm_client_buffer *buffer); +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer); int drm_client_modeset_create(struct drm_client_dev *client); void drm_client_modeset_free(struct drm_client_dev *client);