From patchwork Fri Jan 8 09:43:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 360009 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 C7039C4332D for ; Fri, 8 Jan 2021 09:45:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8EDBB23435 for ; Fri, 8 Jan 2021 09:45:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728083AbhAHJpM (ORCPT ); Fri, 8 Jan 2021 04:45:12 -0500 Received: from mx2.suse.de ([195.135.220.15]:36790 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727993AbhAHJpL (ORCPT ); Fri, 8 Jan 2021 04:45:11 -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 3CFF4AFF0; Fri, 8 Jan 2021 09:43:52 +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 12/13] drm/fb-helper: Move BO locking from DRM client to fbdev damage worker Date: Fri, 8 Jan 2021 10:43:39 +0100 Message-Id: <20210108094340.15290-13-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 Fbdev emulation has to lock the BO into place while flushing the shadow buffer into the BO's memory. Remove any interference with pinning by using vmap_local functionality (instead of full vmap). This requires BO reservation locking in fbdev's damage worker. The new DRM client functions for locking and vmap_local functionality are added for consistency with the existing style. v4: * update documentation (Daniel) Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Vetter --- drivers/gpu/drm/drm_client.c | 94 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_fb_helper.c | 41 +++++++------- include/drm/drm_client.h | 4 ++ 3 files changed, 119 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c index ce45e380f4a2..0220165810aa 100644 --- a/drivers/gpu/drm/drm_client.c +++ b/drivers/gpu/drm/drm_client.c @@ -288,6 +288,37 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u return ERR_PTR(ret); } +/** + * drm_client_buffer_lock - Locks the DRM client buffer + * @buffer: DRM client buffer + * + * This function locks the client buffer by acquiring the buffer + * object's reservation lock. + * + * Unlock the buffer with drm_client_buffer_unlock(). + * + * Returns: + * 0 on success, or a negative errno code otherwise. + */ +int +drm_client_buffer_lock(struct drm_client_buffer *buffer) +{ + return dma_resv_lock(buffer->gem->resv, NULL); +} +EXPORT_SYMBOL(drm_client_buffer_lock); + +/** + * drm_client_buffer_unlock - Unlock DRM client buffer + * @buffer: DRM client buffer + * + * Unlocks a client buffer. See drm_client_buffer_lock(). + */ +void drm_client_buffer_unlock(struct drm_client_buffer *buffer) +{ + dma_resv_unlock(buffer->gem->resv); +} +EXPORT_SYMBOL(drm_client_buffer_unlock); + /** * drm_client_buffer_vmap - Map DRM client buffer into address space * @buffer: DRM client buffer @@ -305,6 +336,9 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u * other vmap interfaces, you don't need it for the client's vunmap * function. So you can modify it at will during blit and draw operations. * + * drm_client_buffer_vmap() is for permanent or long-term mappings. See + * drm_client_buffer_vmap_local() for short-term mappings. + * * Returns: * 0 on success, or a negative errno code otherwise. */ @@ -348,6 +382,66 @@ void drm_client_buffer_vunmap(struct drm_client_buffer *buffer) } EXPORT_SYMBOL(drm_client_buffer_vunmap); +/** + * drm_client_buffer_vmap_local - Map DRM client buffer into address space + * @buffer: DRM client buffer + * @map_copy: Returns the mapped memory's address + * + * This function maps a client buffer into kernel address space. If the + * buffer is already mapped, it returns the existing mapping's address. + * + * Client buffer mappings are not ref'counted. Each call to + * drm_client_buffer_vmap_local() should be followed by a call to + * drm_client_buffer_vunmap_local(); or the client buffer should be mapped + * throughout its lifetime. + * + * The returned address is a copy of the internal value. In contrast to + * other vmap interfaces, you don't need it for the client's vunmap + * function. So you can modify it at will during blit and draw operations. + * + * Returns: + * 0 on success, or a negative errno code otherwise. + */ +int +drm_client_buffer_vmap_local(struct drm_client_buffer *buffer, struct dma_buf_map *map_copy) +{ + struct dma_buf_map *map = &buffer->map; + int ret; + + /* + * FIXME: The dependency on GEM here isn't required, we could + * convert the driver handle to a dma-buf instead and use the + * backend-agnostic dma-buf vmap_local support instead. This would + * require that the handle2fd prime ioctl is reworked to pull the + * fd_install step out of the driver backend hooks, to make that + * final step optional for internal users. + */ + ret = drm_gem_vmap_local(buffer->gem, map); + if (ret) + return ret; + + *map_copy = *map; + + return 0; +} +EXPORT_SYMBOL(drm_client_buffer_vmap_local); + +/** + * drm_client_buffer_vunmap_local - Unmap DRM client buffer + * @buffer: DRM client buffer + * + * This function removes a client buffer's memory mapping. Calling this + * function is only required by clients that manage their buffer mappings + * by themselves. + */ +void drm_client_buffer_vunmap_local(struct drm_client_buffer *buffer) +{ + struct dma_buf_map *map = &buffer->map; + + drm_gem_vunmap_local(buffer->gem, map); +} +EXPORT_SYMBOL(drm_client_buffer_vunmap_local); + static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer) { int ret; diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index a44c3a438059..283d27f8fe67 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -399,28 +399,34 @@ static int drm_fb_helper_damage_blit(struct drm_fb_helper *fb_helper, int ret; /* - * We have to pin the client buffer to its current location while - * flushing the shadow buffer. In the general case, concurrent - * modesetting operations could try to move the buffer and would - * fail. The modeset has to be serialized by acquiring the reservation - * object of the underlying BO here. - * * For fbdev emulation, we only have to protect against fbdev modeset * operations. Nothing else will involve the client buffer's BO. So it * is sufficient to acquire struct drm_fb_helper.lock here. */ mutex_lock(&fb_helper->lock); - ret = drm_client_buffer_vmap(buffer, &map); + /* + * We have to keep the client buffer at its current location while + * flushing the shadow buffer. Concurrent operations could otherwise + * try to move the buffer. Therefore acquiring the reservation + * object of the underlying BO here. + */ + ret = drm_client_buffer_lock(buffer); + if (ret) + goto out_mutex_unlock; + + ret = drm_client_buffer_vmap_local(buffer, &map); if (ret) - goto out; + goto out_drm_client_buffer_unlock; dst = map; drm_fb_helper_damage_blit_real(fb_helper, clip, &dst); - drm_client_buffer_vunmap(buffer); + drm_client_buffer_vunmap_local(buffer); -out: +out_drm_client_buffer_unlock: + drm_client_buffer_unlock(buffer); +out_mutex_unlock: mutex_unlock(&fb_helper->lock); return ret; @@ -946,15 +952,11 @@ static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info) drm_modeset_lock_all(fb_helper->dev); drm_client_for_each_modeset(modeset, &fb_helper->client) { crtc = modeset->crtc; - if (!crtc->funcs->gamma_set || !crtc->gamma_size) { - ret = -EINVAL; - goto out; - } + if (!crtc->funcs->gamma_set || !crtc->gamma_size) + return -EINVAL; - if (cmap->start + cmap->len > crtc->gamma_size) { - ret = -EINVAL; - goto out; - } + if (cmap->start + cmap->len > crtc->gamma_size) + return -EINVAL; r = crtc->gamma_store; g = r + crtc->gamma_size; @@ -967,9 +969,8 @@ static int setcmap_legacy(struct fb_cmap *cmap, struct fb_info *info) ret = crtc->funcs->gamma_set(crtc, r, g, b, crtc->gamma_size, NULL); if (ret) - goto out; + return ret; } -out: drm_modeset_unlock_all(fb_helper->dev); return ret; diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h index f07f2fb02e75..df61e339a11c 100644 --- a/include/drm/drm_client.h +++ b/include/drm/drm_client.h @@ -156,8 +156,12 @@ 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); int drm_client_framebuffer_flush(struct drm_client_buffer *buffer, struct drm_rect *rect); +int drm_client_buffer_lock(struct drm_client_buffer *buffer); +void drm_client_buffer_unlock(struct drm_client_buffer *buffer); int drm_client_buffer_vmap(struct drm_client_buffer *buffer, struct dma_buf_map *map); void drm_client_buffer_vunmap(struct drm_client_buffer *buffer); +int drm_client_buffer_vmap_local(struct drm_client_buffer *buffer, struct dma_buf_map *map); +void drm_client_buffer_vunmap_local(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);