From patchwork Mon Jun 17 11:34:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Christian_K=C3=B6nig?= X-Patchwork-Id: 10998819 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 816F414BB for ; Mon, 17 Jun 2019 11:34:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7128B28517 for ; Mon, 17 Jun 2019 11:34:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 63A02288C5; Mon, 17 Jun 2019 11:34:28 +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,DKIM_ADSP_CUSTOM_MED, FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=unavailable 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 84F4B28517 for ; Mon, 17 Jun 2019 11:34:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1CA2F891AD; Mon, 17 Jun 2019 11:34:19 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by gabe.freedesktop.org (Postfix) with ESMTPS id EA16D89187; Mon, 17 Jun 2019 11:34:16 +0000 (UTC) Received: by mail-wm1-x341.google.com with SMTP id g135so8848565wme.4; Mon, 17 Jun 2019 04:34:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=6vIJVypIdCiKtnMi/GL5XD7d9M7bCA5ys3hvbjLIEWQ=; b=MASISfP168o71goJI3ANGXMPhi4JqjiqzpfH+RNg983hKwc7GsdNDjGOJ8ujTCq0wd sGKm9QN/2CLsM4ZQk3i7wdNQPTpJ1felXa+XSg0aiMQ/JiRRcqOcKqvvKyGXgObgcvcM +xxuYiuzoM4zSfZIuFJX7bfdO24lUNkoH+qoiOy+tdwRcsSVHufj88OwM2Pk3zhDGRvm RKNGF4NBuwD1jtwPtlfRmKbo1H1vtgh4MsbXjeY8SjkZhG3pEXZxawAla8yHAJ6Z5bEF DEdUT90xGkBwtE5GzAfoC3cXeZCUUt5kpMiM/7YFQOTImNjmBBzP+twZiFpuNkbx/pTO H7DQ== X-Gm-Message-State: APjAAAVpiblfkWyY4GD42oU3fkTyJ0Mek9oAiwB8TrOEBCRVL5Tz3OcP 90KFyfavpHgDlOBgU1+m/U7RybAa X-Google-Smtp-Source: APXvYqz0xgeVd7UrSBlvAd1YtI5hoMhQ89i8mcswZ4d8zje3TlEMqOsIQhdidHNmbEDUboBGHGml3w== X-Received: by 2002:a1c:44d7:: with SMTP id r206mr19174712wma.164.1560771255130; Mon, 17 Jun 2019 04:34:15 -0700 (PDT) Received: from abel.fritz.box ([2a02:908:1252:fb60:ad86:6268:1a78:d4c]) by smtp.gmail.com with ESMTPSA id s188sm12062110wmf.40.2019.06.17.04.34.14 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 17 Jun 2019 04:34:14 -0700 (PDT) From: " =?utf-8?q?Christian_K=C3=B6nig?= " X-Google-Original-From: =?utf-8?q?Christian_K=C3=B6nig?= To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org Date: Mon, 17 Jun 2019 13:34:08 +0200 Message-Id: <20190617113413.1869-1-christian.koenig@amd.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=6vIJVypIdCiKtnMi/GL5XD7d9M7bCA5ys3hvbjLIEWQ=; b=X6Fj5qT2MB6lcFr3xMo1tNauC65eRl6pl0eSHq7g/gKDWN+tqB640+E4VBVpTRpmz+ sI9ScgEu8+G0hnmR6ozcPtFwWaYlDnXw6iBPl6zwTp0b+zEOpCS6U+XhSeZnov5WIFe6 LcKPVmEPP+46N5xUXrK2flbJgXYwINNQGeMEZ49GOKmdt3FExR/2dLS1OaAaMc/dOrxa MPmiTsY2zO5JHwVKoSBW3qLvVolccpIBrxKCDWWEDFo7cqcFQ1TknweBhBxXVDsEEw/F b7cWPKTzbcJ8BJzBKiKWexCTlYNhqB0QmasEc4pd9LbxR1wvTkdMlCSuPmMo4eA2hFk+ 6rNQ== Subject: [Intel-gfx] [PATCH 1/6] dma-buf: add dynamic DMA-buf handling v10 X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP On the exporter side we add optional explicit pinning callbacks. If those callbacks are implemented the framework no longer caches sg tables and the map/unmap callbacks are always called with the lock of the reservation object held. On the importer side we add an optional invalidate callback. This callback is used by the exporter to inform the importers that their mappings should be destroyed as soon as possible. This allows the exporter to provide the mappings without the need to pin the backing store. v2: don't try to invalidate mappings when the callback is NULL, lock the reservation obj while using the attachments, add helper to set the callback v3: move flag for invalidation support into the DMA-buf, use new attach_info structure to set the callback v4: use importer_priv field instead of mangling exporter priv. v5: drop invalidation_supported flag v6: squash together with pin/unpin changes v7: pin/unpin takes an attachment now v8: nuke dma_buf_attachment_(map|unmap)_locked, everything is now handled backward compatible v9: always cache when export/importer don't agree on dynamic handling v10: minimal style cleanup Signed-off-by: Christian König --- drivers/dma-buf/dma-buf.c | 188 ++++++++++++++++++++++++++++++++++++-- include/linux/dma-buf.h | 109 ++++++++++++++++++++-- 2 files changed, 283 insertions(+), 14 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index a2d34c6b80a5..f756870ba509 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -409,6 +409,9 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) return ERR_PTR(-EINVAL); } + if (WARN_ON(exp_info->ops->cache_sgt_mapping && exp_info->ops->pin)) + return ERR_PTR(-EINVAL); + if (!try_module_get(exp_info->owner)) return ERR_PTR(-ENOENT); @@ -530,10 +533,12 @@ void dma_buf_put(struct dma_buf *dmabuf) EXPORT_SYMBOL_GPL(dma_buf_put); /** - * dma_buf_attach - Add the device to dma_buf's attachments list; optionally, + * dma_buf_dynamic_attach - Add the device to dma_buf's attachments list; optionally, * calls attach() of dma_buf_ops to allow device-specific attach functionality - * @dmabuf: [in] buffer to attach device to. - * @dev: [in] device to be attached. + * @dmabuf: [in] buffer to attach device to. + * @dev: [in] device to be attached. + * @importer_ops [in] importer operations for the attachment + * @importer_priv [in] importer private pointer for the attachment * * Returns struct dma_buf_attachment pointer for this attachment. Attachments * must be cleaned up by calling dma_buf_detach(). @@ -547,8 +552,10 @@ EXPORT_SYMBOL_GPL(dma_buf_put); * accessible to @dev, and cannot be moved to a more suitable place. This is * indicated with the error code -EBUSY. */ -struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, - struct device *dev) +struct dma_buf_attachment * +dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, + const struct dma_buf_attach_ops *importer_ops, + void *importer_priv) { struct dma_buf_attachment *attach; int ret; @@ -562,6 +569,8 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, attach->dev = dev; attach->dmabuf = dmabuf; + attach->importer_ops = importer_ops; + attach->importer_priv = importer_priv; mutex_lock(&dmabuf->lock); @@ -570,16 +579,72 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, if (ret) goto err_attach; } + reservation_object_lock(dmabuf->resv, NULL); list_add(&attach->node, &dmabuf->attachments); + reservation_object_unlock(dmabuf->resv); mutex_unlock(&dmabuf->lock); + /* When either the importer or the exporter can't handle dynamic + * mappings we cache the mapping here to avoid issues with the + * reservation object lock. + */ + if (dma_buf_attachment_is_dynamic(attach) != + dma_buf_is_dynamic(dmabuf)) { + struct sg_table *sgt; + + if (dma_buf_is_dynamic(attach->dmabuf)) { + reservation_object_lock(attach->dmabuf->resv, NULL); + ret = dma_buf_pin(attach); + if (ret) + goto err_unlock; + } + + sgt = dmabuf->ops->map_dma_buf(attach, DMA_BIDIRECTIONAL); + if (!sgt) + sgt = ERR_PTR(-ENOMEM); + if (IS_ERR(sgt)) { + ret = PTR_ERR(sgt); + goto err_unpin; + } + if (dma_buf_is_dynamic(attach->dmabuf)) + reservation_object_unlock(attach->dmabuf->resv); + attach->sgt = sgt; + attach->dir = DMA_BIDIRECTIONAL; + } + return attach; err_attach: kfree(attach); mutex_unlock(&dmabuf->lock); return ERR_PTR(ret); + +err_unpin: + if (dma_buf_is_dynamic(attach->dmabuf)) + dma_buf_unpin(attach); + +err_unlock: + if (dma_buf_is_dynamic(attach->dmabuf)) + reservation_object_unlock(attach->dmabuf->resv); + + dma_buf_detach(dmabuf, attach); + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(dma_buf_dynamic_attach); + +/** + * dma_buf_attach - Wrapper for dma_buf_dynamic_attach + * @dmabuf: [in] buffer to attach device to. + * @dev: [in] device to be attached. + * + * Wrapper to call dma_buf_dynamic_attach() for drivers which still use a static + * mapping. + */ +struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, + struct device *dev) +{ + return dma_buf_dynamic_attach(dmabuf, dev, NULL, NULL); } EXPORT_SYMBOL_GPL(dma_buf_attach); @@ -596,11 +661,22 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) if (WARN_ON(!dmabuf || !attach)) return; - if (attach->sgt) + if (attach->sgt) { + if (dma_buf_is_dynamic(attach->dmabuf)) + reservation_object_lock(attach->dmabuf->resv, NULL); + dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir); + if (dma_buf_is_dynamic(attach->dmabuf)) { + dma_buf_unpin(attach); + reservation_object_unlock(attach->dmabuf->resv); + } + } + mutex_lock(&dmabuf->lock); + reservation_object_lock(dmabuf->resv, NULL); list_del(&attach->node); + reservation_object_unlock(dmabuf->resv); if (dmabuf->ops->detach) dmabuf->ops->detach(dmabuf, attach); @@ -609,6 +685,44 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) } EXPORT_SYMBOL_GPL(dma_buf_detach); +/** + * dma_buf_pin - Lock down the DMA-buf + * + * @attach: [in] attachment which should be pinned + * + * Returns: + * 0 on success, negative error code on failure. + */ +int dma_buf_pin(struct dma_buf_attachment *attach) +{ + struct dma_buf *dmabuf = attach->dmabuf; + int ret = 0; + + reservation_object_assert_held(dmabuf->resv); + + if (dmabuf->ops->pin) + ret = dmabuf->ops->pin(attach); + + return ret; +} +EXPORT_SYMBOL_GPL(dma_buf_pin); + +/** + * dma_buf_unpin - Remove lock from DMA-buf + * + * @attach: [in] attachment which should be unpinned + */ +void dma_buf_unpin(struct dma_buf_attachment *attach) +{ + struct dma_buf *dmabuf = attach->dmabuf; + + reservation_object_assert_held(dmabuf->resv); + + if (dmabuf->ops->unpin) + dmabuf->ops->unpin(attach); +} +EXPORT_SYMBOL_GPL(dma_buf_unpin); + /** * dma_buf_map_attachment - Returns the scatterlist table of the attachment; * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the @@ -628,6 +742,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, enum dma_data_direction direction) { struct sg_table *sg_table; + int r; might_sleep(); @@ -646,10 +761,38 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, return attach->sgt; } + if (dma_buf_attachment_is_dynamic(attach)) { + reservation_object_assert_held(attach->dmabuf->resv); + + /* + * Mapping a DMA-buf can trigger its invalidation, prevent + * sending this event to the caller by temporary removing + * this attachment from the list. + */ + list_del(&attach->node); + + } else if (dma_buf_is_dynamic(attach->dmabuf)) { + reservation_object_lock(attach->dmabuf->resv, NULL); + r = dma_buf_pin(attach); + if (r) { + reservation_object_unlock(attach->dmabuf->resv); + return ERR_PTR(r); + } + } + sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); if (!sg_table) sg_table = ERR_PTR(-ENOMEM); + if (dma_buf_attachment_is_dynamic(attach)) { + list_add(&attach->node, &attach->dmabuf->attachments); + + } else if (dma_buf_is_dynamic(attach->dmabuf)) { + if (IS_ERR(sg_table)) + dma_buf_unpin(attach); + reservation_object_unlock(attach->dmabuf->resv); + } + if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) { attach->sgt = sg_table; attach->dir = direction; @@ -681,10 +824,41 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (attach->sgt == sg_table) return; + if (dma_buf_attachment_is_dynamic(attach)) + reservation_object_assert_held(attach->dmabuf->resv); + else if (dma_buf_is_dynamic(attach->dmabuf)) + reservation_object_lock(attach->dmabuf->resv, NULL); + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); + + if (dma_buf_is_dynamic(attach->dmabuf) && + !dma_buf_attachment_is_dynamic(attach)) { + dma_buf_unpin(attach); + reservation_object_unlock(attach->dmabuf->resv); + } } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); +/** + * dma_buf_invalidate_mappings - invalidate all mappings of this dma_buf + * + * @dmabuf: [in] buffer which mappings should be invalidated + * + * Informs all attachmenst that they need to destroy and recreated all their + * mappings. + */ +void dma_buf_invalidate_mappings(struct dma_buf *dmabuf) +{ + struct dma_buf_attachment *attach; + + reservation_object_assert_held(dmabuf->resv); + + list_for_each_entry(attach, &dmabuf->attachments, node) + if (attach->importer_ops && attach->importer_ops->invalidate) + attach->importer_ops->invalidate(attach); +} +EXPORT_SYMBOL_GPL(dma_buf_invalidate_mappings); + /** * DOC: cpu access * @@ -1097,10 +1271,12 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) seq_puts(s, "\tAttached Devices:\n"); attach_count = 0; + reservation_object_lock(buf_obj->resv, NULL); list_for_each_entry(attach_obj, &buf_obj->attachments, node) { seq_printf(s, "\t%s\n", dev_name(attach_obj->dev)); attach_count++; } + reservation_object_unlock(buf_obj->resv); seq_printf(s, "Total %d devices attached\n\n", attach_count); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 45b9767e67ec..90c3193be7a5 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -99,14 +99,40 @@ struct dma_buf_ops { */ void (*detach)(struct dma_buf *, struct dma_buf_attachment *); + /** + * @pin: + * + * This is called by dma_buf_pin and lets the exporter know that the + * DMA-buf can't be moved any more. + * + * This is called with the dmabuf->resv object locked. + * + * This callback is optional. + * + * Returns: + * + * 0 on success, negative error code on failure. + */ + int (*pin)(struct dma_buf_attachment *attach); + + /** + * @unpin: + * + * This is called by dma_buf_unpin and lets the exporter know that the + * DMA-buf can be moved again. + * + * This is called with the dmabuf->resv object locked. + * + * This callback is optional. + */ + void (*unpin)(struct dma_buf_attachment *attach); + /** * @map_dma_buf: * * This is called by dma_buf_map_attachment() and is used to map a * shared &dma_buf into device address space, and it is mandatory. It - * can only be called if @attach has been called successfully. This - * essentially pins the DMA buffer into place, and it cannot be moved - * any more + * can only be called if @attach has been called successfully. * * This call may sleep, e.g. when the backing storage first needs to be * allocated, or moved to a location suitable for all currently attached @@ -127,6 +153,9 @@ struct dma_buf_ops { * any other kind of sharing that the exporter might wish to make * available to buffer-users. * + * This is always called with the dmabuf->resv object locked when + * the pin/unpin callbacks are implemented. + * * Returns: * * A &sg_table scatter list of or the backing storage of the DMA buffer, @@ -144,9 +173,6 @@ struct dma_buf_ops { * * This is called by dma_buf_unmap_attachment() and should unmap and * release the &sg_table allocated in @map_dma_buf, and it is mandatory. - * It should also unpin the backing storage if this is the last mapping - * of the DMA buffer, it the exporter supports backing storage - * migration. */ void (*unmap_dma_buf)(struct dma_buf_attachment *, struct sg_table *, @@ -311,6 +337,35 @@ struct dma_buf { } cb_excl, cb_shared; }; +/** + * struct dma_buf_attach_ops - importer operations for an attachment + * @invalidate: [optional] invalidate all mappings made using this attachment. + * + * Attachment operations implemented by the importer. + */ +struct dma_buf_attach_ops { + /** + * @invalidate: + * + * If the invalidate callback is provided the framework can avoid + * pinning the backing store while mappings exists. + * + * This callback is called with the lock of the reservation object + * associated with the dma_buf held and the mapping function must be + * called with this lock held as well. This makes sure that no mapping + * is created concurrently with an ongoing invalidation. + * + * After the callback all existing mappings are still valid until all + * fences in the dma_bufs reservation object are signaled. After getting an + * invalidation callback all mappings should be destroyed by the importer using + * the normal dma_buf_unmap_attachment() function as soon as possible. + * + * New mappings can be created immediately, but can't be used before the + * exclusive fence in the dma_bufs reservation object is signaled. + */ + void (*invalidate)(struct dma_buf_attachment *attach); +}; + /** * struct dma_buf_attachment - holds device-buffer attachment data * @dmabuf: buffer for this attachment. @@ -319,6 +374,8 @@ struct dma_buf { * @sgt: cached mapping. * @dir: direction of cached mapping. * @priv: exporter specific attachment data. + * @importer_ops: importer operations for this attachment. + * @importer_priv: importer specific attachment data. * * This structure holds the attachment information between the dma_buf buffer * and its user device(s). The list contains one attachment struct per device @@ -336,6 +393,9 @@ struct dma_buf_attachment { struct sg_table *sgt; enum dma_data_direction dir; void *priv; + + const struct dma_buf_attach_ops *importer_ops; + void *importer_priv; }; /** @@ -386,10 +446,42 @@ static inline void get_dma_buf(struct dma_buf *dmabuf) get_file(dmabuf->file); } +/** + * dma_buf_is_dynamic - check if a DMA-buf uses dynamic mappings. + * @dmabuf: the DMA-buf to check + * + * Returns true if a DMA-buf exporter wants to create dynamic sg table mappings + * for each attachment. False if only a single static sg table should be used. + */ +static inline bool dma_buf_is_dynamic(struct dma_buf *dmabuf) +{ + return !!dmabuf->ops->pin; +} + +/** + * dma_buf_attachment_is_dynamic - check if a DMA-buf attachment uses dynamic + * mappinsg + * @attach: the DMA-buf attachment to check + * + * Returns true if a DMA-buf importer wants to use dynamic sg table mappings and + * calls the map/unmap functions with the reservation object locked. + */ +static inline bool +dma_buf_attachment_is_dynamic(struct dma_buf_attachment *attach) +{ + return attach->importer_ops && attach->importer_ops->invalidate; +} + struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, - struct device *dev); + struct device *dev); +struct dma_buf_attachment * +dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev, + const struct dma_buf_attach_ops *importer_ops, + void *importer_priv); void dma_buf_detach(struct dma_buf *dmabuf, - struct dma_buf_attachment *dmabuf_attach); + struct dma_buf_attachment *attach); +int dma_buf_pin(struct dma_buf_attachment *attach); +void dma_buf_unpin(struct dma_buf_attachment *attach); struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info); @@ -401,6 +493,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *, enum dma_data_direction); void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *, enum dma_data_direction); +void dma_buf_invalidate_mappings(struct dma_buf *dma_buf); int dma_buf_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction dir); int dma_buf_end_cpu_access(struct dma_buf *dma_buf,