From patchwork Mon Jan 23 12:37:55 2023 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: 646415 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1DE7C05027 for ; Mon, 23 Jan 2023 12:38:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231602AbjAWMiG (ORCPT ); Mon, 23 Jan 2023 07:38:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230245AbjAWMiE (ORCPT ); Mon, 23 Jan 2023 07:38:04 -0500 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65E56E073 for ; Mon, 23 Jan 2023 04:38:03 -0800 (PST) Received: by mail-wr1-x429.google.com with SMTP id h16so10642295wrz.12 for ; Mon, 23 Jan 2023 04:38:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=VXN5GkMQp7hu9CGhDS6OQxzJfUxb9ZcG/2PxTv2bgTk=; b=PRp+K8o/qTb7x4Y1T4vYADVymgsFKRTiEQUeIw441b4+7ksI/PO8lCH5nm/rIRROsn 4iDMmlJJZNdtKrxH21SPVt6hGd52qj7s5OsiIVfSlWaUeOpvfxE4TU3jF5kUaDJ+QCTx bQJgw6nfDkGfN0OoxfEebu0UfsuBEFMbcnTwXKOtuClRamGYCZr34BG8Iq+FuWPnorcK HxURxh6w1av0zX2Ly+9wrUaVN5sp+1l5/rl0FNBqrV9zbWJSc1njgdpi+lTy9NDlIrq+ aHFWcg9XG1+lAOOI1AivWVVwObRowL0aF72L3uePVBGdz+XMfNrRQ+KTbE97l1W5tm67 VrYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=VXN5GkMQp7hu9CGhDS6OQxzJfUxb9ZcG/2PxTv2bgTk=; b=17H/Xa6JHt3Mgv2dLY1MPG9d0Uv4Xo0FbfCakRog/nkqPnUPL6dUZjidCEw+o0Kgx1 uqYoo9wm6YXfLqW/YbiATl3ZWW2KfkoIA0pLRnti9cA/c9FtKgwsnOGzBg4TjMBzQLZZ xCSCGrZYoKkASd2PQ7jE/eKZTkUuv82ymBqn2Ikx7iO3G2cbLj5MfSIxcsO7OvI6I1K5 z8Bg+F//yQ4lzSd3bzeu3Qhs3tWvLy3aiodEp0WDBTDePSjTlyr4/QXW6+oWaw+SuDvw 1yjF/OrjOiM5wSTisCwg3qaAu7KVZoebzIYoeSVV1Ep17WljT05oJkz+iw/DQ2fQVXMV 1+SA== X-Gm-Message-State: AFqh2kqMF75Rxgj61cv5V6RX5vW9cBdLfw50cscae3WysyPgWQKBDtAf JlIw4UXqnn18mAv86r/81ocJJ9CrZqk= X-Google-Smtp-Source: AMrXdXvYyLMHWTRnrKqjQOgBOftzo1qbhvRaLIe14a7zX93YHo/yUYT9qtTwOY/d9I30A1VU7c/EMA== X-Received: by 2002:a05:6000:a03:b0:2bd:e036:6b1a with SMTP id co3-20020a0560000a0300b002bde0366b1amr24265990wrb.64.1674477481885; Mon, 23 Jan 2023 04:38:01 -0800 (PST) Received: from able.fritz.box (p5b0ea2e7.dip0.t-ipconnect.de. [91.14.162.231]) by smtp.gmail.com with ESMTPSA id k3-20020a5d6e83000000b00289bdda07b7sm4284510wrz.92.2023.01.23.04.38.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Jan 2023 04:38:01 -0800 (PST) From: " =?utf-8?q?Christian_K=C3=B6nig?= " X-Google-Original-From: =?utf-8?q?Christian_K=C3=B6nig?= To: l.stach@pengutronix.de, nicolas@ndufresne.ca, ppaalanen@gmail.com, sumit.semwal@linaro.org, daniel@ffwll.ch, robdclark@gmail.com, tfiga@chromium.org, sebastian.wick@redhat.com, hverkuil@xs4all.nl, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-media@vger.kernel.org, benjamin.gaignard@collabora.com, lmark@codeaurora.org, labbott@redhat.com, Brian.Starkey@arm.com, jstultz@google.com, laurent.pinchart@ideasonboard.com, mchehab@kernel.org Subject: [PATCH 1/2] dma-heap: add device link and unlink functions Date: Mon, 23 Jan 2023 13:37:55 +0100 Message-Id: <20230123123756.401692-2-christian.koenig@amd.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230123123756.401692-1-christian.koenig@amd.com> References: <20230123123756.401692-1-christian.koenig@amd.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org This allows device drivers to specify a DMA-heap where they want their buffers to be allocated from. This information is then exposed as sysfs link between the device and the DMA-heap. Useful for userspace when in need to decide from which provider to allocate a buffer. Signed-off-by: Christian König --- drivers/dma-buf/dma-heap.c | 41 ++++++++++++++++++++++++++++++-------- include/linux/dma-heap.h | 35 ++++++++++++++++++++++++++++++++ 2 files changed, 68 insertions(+), 8 deletions(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index c9e41e8a9e27..0f7cf713c22f 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -31,6 +31,7 @@ * @heap_devt heap device node * @list list head connecting to list of heaps * @heap_cdev heap char device + * @dev: heap device in sysfs * * Represents a heap of memory from which buffers can be made. */ @@ -41,6 +42,7 @@ struct dma_heap { dev_t heap_devt; struct list_head list; struct cdev heap_cdev; + struct device *dev; }; static LIST_HEAD(heap_list); @@ -49,6 +51,33 @@ static dev_t dma_heap_devt; static struct class *dma_heap_class; static DEFINE_XARRAY_ALLOC(dma_heap_minors); +int dma_heap_create_device_link(struct device *dev, const char *heap) +{ + struct dma_heap *h; + + /* check the name is valid */ + mutex_lock(&heap_list_lock); + list_for_each_entry(h, &heap_list, list) { + if (!strcmp(h->name, heap)) + break; + } + mutex_unlock(&heap_list_lock); + + if (list_entry_is_head(h, &heap_list, list)) { + pr_err("dma_heap: Link to invalid heap requested %s\n", heap); + return -EINVAL; + } + + return sysfs_create_link(&dev->kobj, &h->dev->kobj, DEVNAME); +} +EXPORT_SYMBOL(dma_heap_create_device_link); + +void dma_heap_remove_device_link(struct device *dev) +{ + sysfs_remove_link(&dev->kobj, DEVNAME); +} +EXPORT_SYMBOL(dma_heap_remove_device_link); + static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, unsigned int fd_flags, unsigned int heap_flags) @@ -219,7 +248,6 @@ const char *dma_heap_get_name(struct dma_heap *heap) struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) { struct dma_heap *heap, *h, *err_ret; - struct device *dev_ret; unsigned int minor; int ret; @@ -261,14 +289,11 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) goto err1; } - dev_ret = device_create(dma_heap_class, - NULL, - heap->heap_devt, - NULL, - heap->name); - if (IS_ERR(dev_ret)) { + heap->dev = device_create(dma_heap_class, NULL, heap->heap_devt, NULL, + heap->name); + if (IS_ERR(heap->dev)) { pr_err("dma_heap: Unable to create device\n"); - err_ret = ERR_CAST(dev_ret); + err_ret = ERR_CAST(heap->dev); goto err2; } diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h index 0c05561cad6e..097076766496 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -65,4 +65,39 @@ const char *dma_heap_get_name(struct dma_heap *heap); */ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info); +#ifdef CONFIG_DMABUF_HEAPS + +/** + * dma_heap_create_device_link() - add link between device and heap + * @dev: the device which should be linked to a heap + * @heap: name of the heap to link to + * + * Add a sysfs link between a device and a DMA-heap. This link can then be used + * by userspace to figure out from which DMA-heap a device wants it's buffers + * to be allocated. + */ +int dma_heap_create_device_link(struct device *dev, const char *heap); + +/** + * dma_heap_remove_device_link() - remove link between device and heap + * @dev: the device which should be unlinked + * + * Removes the sysfs link between the device and it's DMA-heap again when a + * driver is unloaded. + */ +void dma_heap_remove_device_link(struct device *dev); + +#else + +int dma_heap_create_device_link(struct device *dev, const char *heap) +{ + return 0; +} + +void dma_heap_remove_device_link(struct device *dev) +{ +} + +#endif + #endif /* _DMA_HEAPS_H */