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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 78403C43457 for ; Fri, 16 Oct 2020 10:39:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 27D152084C for ; Fri, 16 Oct 2020 10:39:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395416AbgJPKjh convert rfc822-to-8bit (ORCPT ); Fri, 16 Oct 2020 06:39:37 -0400 Received: from mx2.suse.de ([195.135.220.15]:47686 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394467AbgJPKjh (ORCPT ); Fri, 16 Oct 2020 06:39:37 -0400 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 6C254AB5C; Fri, 16 Oct 2020 10:39:34 +0000 (UTC) Date: Fri, 16 Oct 2020 12:39:31 +0200 From: Thomas Zimmermann To: Sam Ravnborg Cc: luben.tuikov@amd.com, airlied@linux.ie, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, melissa.srw@gmail.com, ray.huang@amd.com, kraxel@redhat.com, emil.velikov@collabora.com, linux-samsung-soc@vger.kernel.org, jy0922.shim@samsung.com, lima@lists.freedesktop.org, oleksandr_andrushchenko@epam.com, krzk@kernel.org, steven.price@arm.com, linux-rockchip@lists.infradead.org, kgene@kernel.org, alyssa.rosenzweig@collabora.com, linux+etnaviv@armlinux.org.uk, spice-devel@lists.freedesktop.org, bskeggs@redhat.com, etnaviv@lists.freedesktop.org, hdegoede@redhat.com, xen-devel@lists.xenproject.org, virtualization@lists.linux-foundation.org, sean@poorly.run, apaneers@amd.com, linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, amd-gfx@lists.freedesktop.org, tomeu.vizoso@collabora.com, sw0312.kim@samsung.com, hjc@rock-chips.com, kyungmin.park@samsung.com, miaoqinglang@huawei.com, yuq825@gmail.com, alexander.deucher@amd.com, linux-media@vger.kernel.org, christian.koenig@amd.com Subject: Re: [PATCH v4 09/10] dma-buf-map: Add memcpy and pointer-increment interfaces Message-ID: <20201016123931.10dd3930@linux-uq9g> In-Reply-To: <20201016100854.GA1042954@ravnborg.org> References: <20201015123806.32416-1-tzimmermann@suse.de> <20201015123806.32416-10-tzimmermann@suse.de> <20201016100854.GA1042954@ravnborg.org> Organization: SUSE Software Solutions Germany GmbH X-Mailer: Claws Mail 3.17.7 (GTK+ 2.24.32; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Sam On Fri, 16 Oct 2020 12:08:54 +0200 Sam Ravnborg wrote: > Hi Thomas. > > On Thu, Oct 15, 2020 at 02:38:05PM +0200, Thomas Zimmermann wrote: > > To do framebuffer updates, one needs memcpy from system memory and a > > pointer-increment function. Add both interfaces with documentation. > > > > Signed-off-by: Thomas Zimmermann > > Looks good. > Reviewed-by: Sam Ravnborg Thanks. If you have the time, may I ask you to test this patchset on the bochs/sparc64 system that failed with the original code? Best regards Thomas > > > --- > > include/linux/dma-buf-map.h | 72 +++++++++++++++++++++++++++++++------ > > 1 file changed, 62 insertions(+), 10 deletions(-) > > > > diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h > > index 2e8bbecb5091..6ca0f304dda2 100644 > > --- a/include/linux/dma-buf-map.h > > +++ b/include/linux/dma-buf-map.h > > @@ -32,6 +32,14 @@ > > * accessing the buffer. Use the returned instance and the helper > > functions > > * to access the buffer's memory in the correct way. > > * > > + * The type :c:type:`struct dma_buf_map ` and its helpers > > are > > + * actually independent from the dma-buf infrastructure. When sharing > > buffers > > + * among devices, drivers have to know the location of the memory to > > access > > + * the buffers in a safe way. :c:type:`struct dma_buf_map ` > > + * solves this problem for dma-buf and its users. If other drivers or > > + * sub-systems require similar functionality, the type could be > > generalized > > + * and moved to a more prominent header file. > > + * > > * Open-coding access to :c:type:`struct dma_buf_map ` is > > * considered bad style. Rather then accessing its fields directly, use > > one > > * of the provided helper functions, or implement your own. For example, > > @@ -51,6 +59,14 @@ > > * > > * dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf); > > * > > + * Instances of struct dma_buf_map do not have to be cleaned up, but > > + * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings > > + * always refer to system memory. > > + * > > + * .. code-block:: c > > + * > > + * dma_buf_map_clear(&map); > > + * > > * Test if a mapping is valid with either dma_buf_map_is_set() or > > * dma_buf_map_is_null(). > > * > > @@ -73,17 +89,19 @@ > > * if (dma_buf_map_is_equal(&sys_map, &io_map)) > > * // always false > > * > > - * Instances of struct dma_buf_map do not have to be cleaned up, but > > - * can be cleared to NULL with dma_buf_map_clear(). Cleared mappings > > - * always refer to system memory. > > + * A set up instance of struct dma_buf_map can be used to access or > > manipulate > > + * the buffer memory. Depending on the location of the memory, the > > provided > > + * helpers will pick the correct operations. Data can be copied into the > > memory > > + * with dma_buf_map_memcpy_to(). The address can be manipulated with > > + * dma_buf_map_incr(). > > * > > - * The type :c:type:`struct dma_buf_map ` and its helpers > > are > > - * actually independent from the dma-buf infrastructure. When sharing > > buffers > > - * among devices, drivers have to know the location of the memory to > > access > > - * the buffers in a safe way. :c:type:`struct dma_buf_map ` > > - * solves this problem for dma-buf and its users. If other drivers or > > - * sub-systems require similar functionality, the type could be > > generalized > > - * and moved to a more prominent header file. > > + * .. code-block:: c > > + * > > + * const void *src = ...; // source buffer > > + * size_t len = ...; // length of src > > + * > > + * dma_buf_map_memcpy_to(&map, src, len); > > + * dma_buf_map_incr(&map, len); // go to first byte after the > > memcpy */ > > > > /** > > @@ -210,4 +228,38 @@ static inline void dma_buf_map_clear(struct > > dma_buf_map *map) } > > } > > > > +/** > > + * dma_buf_map_memcpy_to - Memcpy into dma-buf mapping > > + * @dst: The dma-buf mapping structure > > + * @src: The source buffer > > + * @len: The number of byte in src > > + * > > + * Copies data into a dma-buf mapping. The source buffer is in system > > + * memory. Depending on the buffer's location, the helper picks the > > correct > > + * method of accessing the memory. > > + */ > > +static inline void dma_buf_map_memcpy_to(struct dma_buf_map *dst, const > > void *src, size_t len) +{ > > + if (dst->is_iomem) > > + memcpy_toio(dst->vaddr_iomem, src, len); > > + else > > + memcpy(dst->vaddr, src, len); > > +} > > + > > +/** > > + * dma_buf_map_incr - Increments the address stored in a dma-buf mapping > > + * @map: The dma-buf mapping structure > > + * @incr: The number of bytes to increment > > + * > > + * Increments the address stored in a dma-buf mapping. Depending on the > > + * buffer's location, the correct value will be updated. > > + */ > > +static inline void dma_buf_map_incr(struct dma_buf_map *map, size_t incr) > > +{ > > + if (map->is_iomem) > > + map->vaddr_iomem += incr; > > + else > > + map->vaddr += incr; > > +} > > + > > #endif /* __DMA_BUF_MAP_H__ */ > > -- > > 2.28.0 > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer