From nobody Thu Apr 9 16:37:33 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E310D36212E for ; Fri, 6 Mar 2026 10:37:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793442; cv=none; b=XaWZtfztlwIEOq+q3JkIRhl9J8y3h7bFKKXZPrgnA3dpkw+7cfWqthKNpIytnI/SgMSchSkGyXkpe19/G0v5IBVQYOzlokPookMwXYgxuixYx5XJsC8vGl13eAzO/DBFqqj/EhhF5thMXZ+iKo6GWoChupW/80iH9vAL5m0m9Es= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793442; c=relaxed/simple; bh=jEcsosu4FVff7wQTzKWFyuvhOs9GdLa7SAJlZveaz5I=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=qGkwE3OpLFP+jYZbqGpJIF3kbKxSsihB+B/vd482r+Ai/g1LXWBuYGPWt0EvIUxlPsDuBvkDE4V+hkjoRLkP6Dkp6XSvcRxpVN8BIXeDD/WYmOP22acGZ6BXQ6ZM9SrhN+baPhOOi0s15MtHQeVS1AuoXzspG/4Y2zHRloTnU4c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=OBlLtmZt; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OBlLtmZt" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772793439; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gJYSzg9vNyDy8YIRC70niUvoXuiagt/nl4vhegwZQ4I=; b=OBlLtmZtPgDmUvzNKWNvGxfGgrGLYXNoE5ZZKWHyJPYsw6I4EU1W+M+09vOZQ8UwfDbho5 NGRaPahw2ZGjWGlOFfeRw+a4ZEogLJAc/DvYqSNxEwDyzup1RPdqiWcZHWhI/TVekVNRG6 iarrWn3vsZqQlX+SA08DH9YSSCnMTA0= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-367-ylLWy7D1MiK14lBlXpaTbg-1; Fri, 06 Mar 2026 05:37:15 -0500 X-MC-Unique: ylLWy7D1MiK14lBlXpaTbg-1 X-Mimecast-MFC-AGG-ID: ylLWy7D1MiK14lBlXpaTbg_1772793433 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D891E1800344; Fri, 6 Mar 2026 10:37:12 +0000 (UTC) Received: from [192.168.1.153] (unknown [10.45.226.103]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 033FE1800576; Fri, 6 Mar 2026 10:37:05 +0000 (UTC) From: Albert Esteve Date: Fri, 06 Mar 2026 11:36:32 +0100 Subject: [PATCH v3 1/6] dma-buf: dma-heap: Keep track of the heap device struct Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260306-b4-dmabuf-heap-coherent-rmem-v3-1-3d00d36c9bc4@redhat.com> References: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> In-Reply-To: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> To: Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , =?utf-8?q?Christian_K=C3=B6nig?= , Marek Szyprowski , Robin Murphy , Rob Herring , Saravana Kannan Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, Albert Esteve , mripard@redhat.com, echanude@redhat.com, John Stultz , Maxime Ripard X-Developer-Signature: v=1; a=ed25519-sha256; t=1772793417; l=3407; i=aesteve@redhat.com; s=20260303; h=from:subject:message-id; bh=+cQjQX7wWYHly3CqYJA61GMkvrlvlEzfu2d2CAj6odw=; b=En+VXoYTUj9Wv8NJOCjiJ2RfNcXww6oL8TirckFIGLBYTejfT3hcTJrdgb6B6KgRDqrUo0tN9 FelEna3sZ9ZD6c7cS4dja3evP5ZoiN/f//EuT4Ak6aRC+21Ljf0dHsJ X-Developer-Key: i=aesteve@redhat.com; a=ed25519; pk=YSFz6sOHd2L45+Fr8DIvHTi6lSIjhLZ5T+rkxspJt1s= X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 From: John Stultz Keep track of the heap device struct. This will be useful for special DMA allocations and actions. Signed-off-by: John Stultz Reviewed-by: Maxime Ripard Signed-off-by: Albert Esteve --- drivers/dma-buf/dma-heap.c | 34 ++++++++++++++++++++++++++-------- include/linux/dma-heap.h | 2 ++ 2 files changed, 28 insertions(+), 8 deletions(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index ac5f8685a6494..1124d63eb1398 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 + * @heap_dev: heap device * * 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 *heap_dev; }; =20 static LIST_HEAD(heap_list); @@ -223,6 +225,19 @@ const char *dma_heap_get_name(struct dma_heap *heap) } EXPORT_SYMBOL_NS_GPL(dma_heap_get_name, "DMA_BUF_HEAP"); =20 +/** + * dma_heap_get_dev() - get device struct for the heap + * @heap: DMA-Heap to retrieve device struct from + * + * Returns: + * The device struct for the heap. + */ +struct device *dma_heap_get_dev(struct dma_heap *heap) +{ + return heap->heap_dev; +} +EXPORT_SYMBOL_NS_GPL(dma_heap_get_dev, "DMA_BUF_HEAP"); + /** * dma_heap_add - adds a heap to dmabuf heaps * @exp_info: information needed to register this heap @@ -230,7 +245,6 @@ EXPORT_SYMBOL_NS_GPL(dma_heap_get_name, "DMA_BUF_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; =20 @@ -272,14 +286,14 @@ struct dma_heap *dma_heap_add(const struct dma_heap_e= xport_info *exp_info) goto err1; } =20 - dev_ret =3D device_create(dma_heap_class, - NULL, - heap->heap_devt, - NULL, - heap->name); - if (IS_ERR(dev_ret)) { + heap->heap_dev =3D device_create(dma_heap_class, + NULL, + heap->heap_devt, + NULL, + heap->name); + if (IS_ERR(heap->heap_dev)) { pr_err("dma_heap: Unable to create device\n"); - err_ret =3D ERR_CAST(dev_ret); + err_ret =3D ERR_CAST(heap->heap_dev); goto err2; } =20 @@ -295,6 +309,10 @@ struct dma_heap *dma_heap_add(const struct dma_heap_ex= port_info *exp_info) } } =20 + /* Make sure it doesn't disappear on us */ + heap->heap_dev =3D get_device(heap->heap_dev); + + /* Add heap to the list */ list_add(&heap->list, &heap_list); mutex_unlock(&heap_list_lock); diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h index 648328a64b27e..493085e69b70e 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -12,6 +12,7 @@ #include =20 struct dma_heap; +struct device; =20 /** * struct dma_heap_ops - ops to operate on a given heap @@ -43,6 +44,7 @@ struct dma_heap_export_info { void *dma_heap_get_drvdata(struct dma_heap *heap); =20 const char *dma_heap_get_name(struct dma_heap *heap); +struct device *dma_heap_get_dev(struct dma_heap *heap); =20 struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info); =20 --=20 2.52.0 From nobody Thu Apr 9 16:37:33 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AFB6937DE8F for ; Fri, 6 Mar 2026 10:37:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793451; cv=none; b=EnlGMlnVenPQgKhvvzy5kLxGc4u3D32Zh7sCr6ukMQdh6UBRPvpVrbgsgjlPaBALEwlaIrFiGNyEREb3u9eOO9ipFlMusLXgfdIZapQ5BW/Bjt2lhIYyY3Tc8EdEbU0kPxPJZorePG/Q8oup+5J+EhW9rqdswBKz/22/vLyVesE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793451; c=relaxed/simple; bh=jnEWfPpzZhM9PT5/4IIyDdYQm5qsF5MEa9uiNa9/840=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ageCHetnCSlsSLb63v5HIW/3LYgPM0iEtsZ2+gTsHcV5esh9rfPapDzRDh+pgWMIm6CkIGnNFswN2f+yZqNjpLb+bCyk8uXzfbfhHB1xRVsza8cDmllDMS9zqrcAM5fg+RC2Gr3myB6ggMl4+J1CDU0G/8dm7PsAEKsLkqT4YsY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=fnZkILcE; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fnZkILcE" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772793446; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OZ1uxUMfdvEVIiXLLllIOCQX5Y7WK3c/GBbiTWtJcUU=; b=fnZkILcExJ8pgXy8ARNbW0urQwj3E9hEaq57RfM2MTyLjEAaFrcywR/hBKFSImgDPi+5/B B0Pl3qLfJdFslY64p5vuz3Rt0g4eCV+SHoEwrgwS5kjMJVxTA77dUrzVeI/YGT9V7g+Jm4 enuKaiTYyTVeVAKQ02Ba4K+IL5zu1RE= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-294-AAMy9kKQN4eRmXL4ZNJgAg-1; Fri, 06 Mar 2026 05:37:22 -0500 X-MC-Unique: AAMy9kKQN4eRmXL4ZNJgAg-1 X-Mimecast-MFC-AGG-ID: AAMy9kKQN4eRmXL4ZNJgAg_1772793440 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 43CE718005B9; Fri, 6 Mar 2026 10:37:20 +0000 (UTC) Received: from [192.168.1.153] (unknown [10.45.226.103]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7E1CA180058B; Fri, 6 Mar 2026 10:37:13 +0000 (UTC) From: Albert Esteve Date: Fri, 06 Mar 2026 11:36:33 +0100 Subject: [PATCH v3 2/6] dma-buf: dma-heap: split dma_heap_add Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260306-b4-dmabuf-heap-coherent-rmem-v3-2-3d00d36c9bc4@redhat.com> References: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> In-Reply-To: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> To: Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , =?utf-8?q?Christian_K=C3=B6nig?= , Marek Szyprowski , Robin Murphy , Rob Herring , Saravana Kannan Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, Albert Esteve , mripard@redhat.com, echanude@redhat.com X-Developer-Signature: v=1; a=ed25519-sha256; t=1772793417; l=6927; i=aesteve@redhat.com; s=20260303; h=from:subject:message-id; bh=jnEWfPpzZhM9PT5/4IIyDdYQm5qsF5MEa9uiNa9/840=; b=Uq16kJks+H+M48RJxOWpGu8dbWraHuDz9VUhJlh3teNs+cTNDwHXuQtrqIYX0saef7gs9UfOD kjuetUfxw/5A+RGtAyaCBo6FmPDtCDuojyos6wX0xUOjdQR0OgL/nth X-Developer-Key: i=aesteve@redhat.com; a=ed25519; pk=YSFz6sOHd2L45+Fr8DIvHTi6lSIjhLZ5T+rkxspJt1s= X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Split dma_heap_add() into creation and registration phases while preserving the ordering between cdev_add() and device_add(), and ensuring all device fields are initialised. This lets callers build a heap and its device, bind reserved memory, and cleanly unwind on failure before the heap is registered. It also avoids a window where userspace can see a heap that exists but isn=E2=80=99t fully functional. The coherent heap will need this to bind rmem to the heap device prior to registration. Signed-off-by: Albert Esteve --- drivers/dma-buf/dma-heap.c | 126 +++++++++++++++++++++++++++++++++++------= ---- include/linux/dma-heap.h | 3 ++ 2 files changed, 103 insertions(+), 26 deletions(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 1124d63eb1398..ba87e5ac16ae2 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -238,15 +238,30 @@ struct device *dma_heap_get_dev(struct dma_heap *heap) } EXPORT_SYMBOL_NS_GPL(dma_heap_get_dev, "DMA_BUF_HEAP"); =20 +static void dma_heap_dev_release(struct device *dev) +{ + struct dma_heap *heap; + + pr_debug("heap device: '%s': %s\n", dev_name(dev), __func__); + heap =3D dev_get_drvdata(dev); + kfree(heap->name); + kfree(heap); + kfree(dev); +} + /** - * dma_heap_add - adds a heap to dmabuf heaps - * @exp_info: information needed to register this heap + * dma_heap_create() - allocate and initialize a heap object + * @exp_info: information needed to create a heap + * + * Creates a heap instance but does not register it or create device nodes. + * Use dma_heap_register() to make it visible to userspace, or + * dma_heap_destroy() to release it. + * + * Returns a heap on success or ERR_PTR(-errno) on failure. */ -struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) +struct dma_heap *dma_heap_create(const struct dma_heap_export_info *exp_in= fo) { - struct dma_heap *heap, *h, *err_ret; - unsigned int minor; - int ret; + struct dma_heap *heap; =20 if (!exp_info->name || !strcmp(exp_info->name, "")) { pr_err("dma_heap: Cannot add heap without a name\n"); @@ -265,13 +280,41 @@ struct dma_heap *dma_heap_add(const struct dma_heap_e= xport_info *exp_info) heap->name =3D exp_info->name; heap->ops =3D exp_info->ops; heap->priv =3D exp_info->priv; + heap->heap_dev =3D kzalloc_obj(*heap->heap_dev); + if (!heap->heap_dev) { + kfree(heap); + return ERR_PTR(-ENOMEM); + } + + device_initialize(heap->heap_dev); + dev_set_drvdata(heap->heap_dev, heap); + + dev_set_name(heap->heap_dev, heap->name); + heap->heap_dev->class =3D dma_heap_class; + heap->heap_dev->release =3D dma_heap_dev_release; + + return heap; +} +EXPORT_SYMBOL_NS_GPL(dma_heap_create, "DMA_BUF_HEAP"); + +/** + * dma_heap_register() - register a heap with the dma-heap framework + * @heap: heap instance created with dma_heap_create() + * + * Registers the heap, creating its device node and adding it to the heap + * list. Returns 0 on success or a negative error code on failure. + */ +int dma_heap_register(struct dma_heap *heap) +{ + struct dma_heap *h; + unsigned int minor; + int ret; =20 /* Find unused minor number */ ret =3D xa_alloc(&dma_heap_minors, &minor, heap, XA_LIMIT(0, NUM_HEAP_MINORS - 1), GFP_KERNEL); if (ret < 0) { pr_err("dma_heap: Unable to get minor number for heap\n"); - err_ret =3D ERR_PTR(ret); goto err0; } =20 @@ -282,42 +325,34 @@ struct dma_heap *dma_heap_add(const struct dma_heap_e= xport_info *exp_info) ret =3D cdev_add(&heap->heap_cdev, heap->heap_devt, 1); if (ret < 0) { pr_err("dma_heap: Unable to add char device\n"); - err_ret =3D ERR_PTR(ret); goto err1; } =20 - heap->heap_dev =3D device_create(dma_heap_class, - NULL, - heap->heap_devt, - NULL, - heap->name); - if (IS_ERR(heap->heap_dev)) { - pr_err("dma_heap: Unable to create device\n"); - err_ret =3D ERR_CAST(heap->heap_dev); + heap->heap_dev->devt =3D heap->heap_devt; + + ret =3D device_add(heap->heap_dev); + if (ret) { + pr_err("dma_heap: Unable to add device\n"); goto err2; } =20 mutex_lock(&heap_list_lock); /* check the name is unique */ list_for_each_entry(h, &heap_list, list) { - if (!strcmp(h->name, exp_info->name)) { + if (!strcmp(h->name, heap->name)) { mutex_unlock(&heap_list_lock); pr_err("dma_heap: Already registered heap named %s\n", - exp_info->name); - err_ret =3D ERR_PTR(-EINVAL); + heap->name); + ret =3D -EINVAL; goto err3; } } =20 - /* Make sure it doesn't disappear on us */ - heap->heap_dev =3D get_device(heap->heap_dev); - - /* Add heap to the list */ list_add(&heap->list, &heap_list); mutex_unlock(&heap_list_lock); =20 - return heap; + return 0; =20 err3: device_destroy(dma_heap_class, heap->heap_devt); @@ -326,8 +361,47 @@ struct dma_heap *dma_heap_add(const struct dma_heap_ex= port_info *exp_info) err1: xa_erase(&dma_heap_minors, minor); err0: - kfree(heap); - return err_ret; + dma_heap_destroy(heap); + return ret; +} +EXPORT_SYMBOL_NS_GPL(dma_heap_register, "DMA_BUF_HEAP"); + +/** + * dma_heap_destroy() - release a heap created by dma_heap_create() + * @heap: heap instance to release + * + * Drops the heap device reference; the heap and its device are freed in t= he + * device release path when the last reference is gone. + */ +void dma_heap_destroy(struct dma_heap *heap) +{ + put_device(heap->heap_dev); +} +EXPORT_SYMBOL_NS_GPL(dma_heap_destroy, "DMA_BUF_HEAP"); + +/** + * dma_heap_add - adds a heap to dmabuf heaps + * @exp_info: information needed to register this heap + */ +struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) +{ + struct dma_heap *heap; + int ret; + + heap =3D dma_heap_create(exp_info); + if (IS_ERR(heap)) { + pr_err("dma_heap: failed to create heap (%ld)\n", PTR_ERR(heap)); + return ERR_CAST(heap); + } + + ret =3D dma_heap_register(heap); + if (ret) { + pr_err("dma_heap: failed to register heap (%d)\n", ret); + dma_heap_destroy(heap); + return ERR_PTR(ret); + } + + return heap; } EXPORT_SYMBOL_NS_GPL(dma_heap_add, "DMA_BUF_HEAP"); =20 diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h index 493085e69b70e..1b0ea43ba66c3 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -46,6 +46,9 @@ void *dma_heap_get_drvdata(struct dma_heap *heap); const char *dma_heap_get_name(struct dma_heap *heap); struct device *dma_heap_get_dev(struct dma_heap *heap); =20 +struct dma_heap *dma_heap_create(const struct dma_heap_export_info *exp_in= fo); +int dma_heap_register(struct dma_heap *heap); +void dma_heap_destroy(struct dma_heap *heap); struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info); =20 extern bool mem_accounting; --=20 2.52.0 From nobody Thu Apr 9 16:37:33 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 28FB237E30E for ; Fri, 6 Mar 2026 10:37:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793455; cv=none; b=NKUdxQuoeRLyQSzbBkgrdt7qzlLHHNLNYx5nbkAoOm391R+xrpkGYzjrggpXerZE4AvSZ5ISrOCIBwGozuuz5zd5qqmRyBDcwbpQlgHma9CYS+1cESOK3YETPykArnxqnYfUBsIa4Z1Yimy0TI7dirwQP1bi7nMl9DaRsOI6X8U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793455; c=relaxed/simple; bh=rgrqri/qil5mD0TqCg7stpgdjtBE6SE/MHI+utJVZN0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=C9+udXaJc3P2654xoEe5JSWF6dPGpd34KEfOWIUWycNQoEZ6iCxwyYgOTmFr4Ad2uG3TkmyaxUsXlCSFB9MjAPaBFrHmlqCgCCHZaqVMsTYONUpLbF3KZ5hdN/q1+sC1sXy47vAxcJ8Sq7sbjdKnYDN0E70T0XBFll13oNSjs3c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=MDD7Nisy; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MDD7Nisy" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772793453; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=suRtAZrxz3OO0NlvM3Q3uQcnaecb9vHR4v4iJlgEyR8=; b=MDD7Nisy1KTDco5tnhHjF7zOmmpGSiCgd/w8koOdKTJK2mp3aiXBvMlWkHj+hB9AzTtrvD GpU2sUG21MQXTbHlza9LmwwIA2+x+MgYVR2Tjh3buGYZGOZ4LCem62CKGtXdgwQzIgzLRS vnxHGJSfNCtIJQgJQhb6LrCTzIdYoo8= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-327-xTjywzMWNs6YmfKnZZPkig-1; Fri, 06 Mar 2026 05:37:29 -0500 X-MC-Unique: xTjywzMWNs6YmfKnZZPkig-1 X-Mimecast-MFC-AGG-ID: xTjywzMWNs6YmfKnZZPkig_1772793447 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B23F51956095; Fri, 6 Mar 2026 10:37:26 +0000 (UTC) Received: from [192.168.1.153] (unknown [10.45.226.103]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D16FF1800576; Fri, 6 Mar 2026 10:37:20 +0000 (UTC) From: Albert Esteve Date: Fri, 06 Mar 2026 11:36:34 +0100 Subject: [PATCH v3 3/6] of_reserved_mem: add a helper for rmem device_init op Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260306-b4-dmabuf-heap-coherent-rmem-v3-3-3d00d36c9bc4@redhat.com> References: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> In-Reply-To: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> To: Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , =?utf-8?q?Christian_K=C3=B6nig?= , Marek Szyprowski , Robin Murphy , Rob Herring , Saravana Kannan Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, Albert Esteve , mripard@redhat.com, echanude@redhat.com X-Developer-Signature: v=1; a=ed25519-sha256; t=1772793417; l=4434; i=aesteve@redhat.com; s=20260303; h=from:subject:message-id; bh=rgrqri/qil5mD0TqCg7stpgdjtBE6SE/MHI+utJVZN0=; b=/9NHwRWbwX4ljPKtYhgTcPVxYkxoBoVNNBgLyQk3ultqrgYvfZaohRku503CZAnxdi2GQrCDJ nuJ5HYgcUNyDgdH+gO0uk9X4NPANrQnY0hXLw41OgZNS7WS/AMYTTyJ X-Developer-Key: i=aesteve@redhat.com; a=ed25519; pk=YSFz6sOHd2L45+Fr8DIvHTi6lSIjhLZ5T+rkxspJt1s= X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Add a helper function wrapping internal reserved memory device_init call and expose it externally. Use the new helper function within of_reserved_mem_device_init_by_idx(). Signed-off-by: Albert Esteve --- drivers/of/of_reserved_mem.c | 68 ++++++++++++++++++++++++++-----------= ---- include/linux/of_reserved_mem.h | 8 +++++ 2 files changed, 52 insertions(+), 24 deletions(-) diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index 1fd28f8056108..26ca871f7f919 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -605,6 +605,49 @@ struct rmem_assigned_device { static LIST_HEAD(of_rmem_assigned_device_list); static DEFINE_MUTEX(of_rmem_assigned_device_mutex); =20 +/** + * of_reserved_mem_device_init_with_mem() - assign reserved memory region = to + * given device + * @dev: Pointer to the device to configure + * @rmem: Reserved memory region to assign + * + * This function assigns respective DMA-mapping operations based on the + * reserved memory region already provided in @rmem to the @dev device, + * without walking DT nodes. + * + * Returns error code or zero on success. + */ +int of_reserved_mem_device_init_with_mem(struct device *dev, + struct reserved_mem *rmem) +{ + struct rmem_assigned_device *rd; + int ret; + + if (!dev || !rmem || !rmem->ops || !rmem->ops->device_init) + return -EINVAL; + + rd =3D kmalloc_obj(struct rmem_assigned_device); + if (!rd) + return -ENOMEM; + + ret =3D rmem->ops->device_init(rmem, dev); + if (ret =3D=3D 0) { + rd->dev =3D dev; + rd->rmem =3D rmem; + + mutex_lock(&of_rmem_assigned_device_mutex); + list_add(&rd->list, &of_rmem_assigned_device_list); + mutex_unlock(&of_rmem_assigned_device_mutex); + + dev_info(dev, "assigned reserved memory node %s\n", rmem->name); + } else { + kfree(rd); + } + + return ret; +} +EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_with_mem); + /** * of_reserved_mem_device_init_by_idx() - assign reserved memory region to * given device @@ -623,10 +666,8 @@ static DEFINE_MUTEX(of_rmem_assigned_device_mutex); int of_reserved_mem_device_init_by_idx(struct device *dev, struct device_node *np, int idx) { - struct rmem_assigned_device *rd; struct device_node *target; struct reserved_mem *rmem; - int ret; =20 if (!np || !dev) return -EINVAL; @@ -643,28 +684,7 @@ int of_reserved_mem_device_init_by_idx(struct device *= dev, rmem =3D of_reserved_mem_lookup(target); of_node_put(target); =20 - if (!rmem || !rmem->ops || !rmem->ops->device_init) - return -EINVAL; - - rd =3D kmalloc_obj(struct rmem_assigned_device); - if (!rd) - return -ENOMEM; - - ret =3D rmem->ops->device_init(rmem, dev); - if (ret =3D=3D 0) { - rd->dev =3D dev; - rd->rmem =3D rmem; - - mutex_lock(&of_rmem_assigned_device_mutex); - list_add(&rd->list, &of_rmem_assigned_device_list); - mutex_unlock(&of_rmem_assigned_device_mutex); - - dev_info(dev, "assigned reserved memory node %s\n", rmem->name); - } else { - kfree(rd); - } - - return ret; + return of_reserved_mem_device_init_with_mem(dev, rmem); } EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx); =20 diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_me= m.h index f573423359f48..12f7ddb7ee61f 100644 --- a/include/linux/of_reserved_mem.h +++ b/include/linux/of_reserved_mem.h @@ -32,6 +32,8 @@ typedef int (*reservedmem_of_init_fn)(struct reserved_mem= *rmem); #define RESERVEDMEM_OF_DECLARE(name, compat, init) \ _OF_DECLARE(reservedmem, name, compat, init, reservedmem_of_init_fn) =20 +int of_reserved_mem_device_init_with_mem(struct device *dev, + struct reserved_mem *rmem); int of_reserved_mem_device_init_by_idx(struct device *dev, struct device_node *np, int idx); int of_reserved_mem_device_init_by_name(struct device *dev, @@ -51,6 +53,12 @@ int of_reserved_mem_region_count(const struct device_nod= e *np); #define RESERVEDMEM_OF_DECLARE(name, compat, init) \ _OF_DECLARE_STUB(reservedmem, name, compat, init, reservedmem_of_init_fn) =20 +static inline int of_reserved_mem_device_init_with_mem(struct device *dev, + struct reserved_mem *rmem) +{ + return -EOPNOTSUPP; +} + static inline int of_reserved_mem_device_init_by_idx(struct device *dev, struct device_node *np, int idx) { --=20 2.52.0 From nobody Thu Apr 9 16:37:33 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C524537D10C for ; Fri, 6 Mar 2026 10:37:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793461; cv=none; b=u3fvkpo5FdeYewG+cQt/r1AzMezSCkuPnXrbR/h114nF40iHyOvGtmhlPBFhEECCFZcsOAYhT0i0HAPVavilfhYcKiPoKLEo/qwbQzdU0XcvraDFumL38gJvX3JHT7I1Sz6xFCG3c/t5qLEkZd593Be2prS/F0Wk13bK/SSYRkc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793461; c=relaxed/simple; bh=u/febRDM30JzV4zi0O2oWhXMCmjL4J3mUC+OUI296Uo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=SNTL8RaUfqTk/6iVPAs33d1O4O9WsChwFAMLXgtHoGSlbVpfUJUdoEp2TX1rDZbWZtdSGHz80EaIPL4EpEGYs7sc0bEwYrq953R/tAe0dbAVOOsHhZx4eqZDDXx+DwRzavxDc8w1fLMFayEqEvgzywRz5KYm62WVOyQBJDelLw0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=KEq+BUnV; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KEq+BUnV" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772793458; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=X1W1JFb09fQZLTmuNIkzg7O2smMWNXHTw+tCky9f0yA=; b=KEq+BUnVkHxl/L0p1EM+AxkKe3jjglS6pzG/mtt8rHL5Rz++l7RXq+xQUMO9e6zed0F/A+ Z18LQA0snMtKfs+9xXpp45yslAIF7B/cTOArvCqkl6eR5FNMR2gA8gePAzZ/1FGqXa1YBZ w1W8RIbAtF8IPD+Yw/b6VnlQcfB4YkA= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-220-MnqftG4TNyCRK-vj5TQNCg-1; Fri, 06 Mar 2026 05:37:34 -0500 X-MC-Unique: MnqftG4TNyCRK-vj5TQNCg-1 X-Mimecast-MFC-AGG-ID: MnqftG4TNyCRK-vj5TQNCg_1772793452 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A0F7D18005B0; Fri, 6 Mar 2026 10:37:32 +0000 (UTC) Received: from [192.168.1.153] (unknown [10.45.226.103]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4C717180035F; Fri, 6 Mar 2026 10:37:27 +0000 (UTC) From: Albert Esteve Date: Fri, 06 Mar 2026 11:36:35 +0100 Subject: [PATCH v3 4/6] dma: coherent: store reserved memory coherent regions Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260306-b4-dmabuf-heap-coherent-rmem-v3-4-3d00d36c9bc4@redhat.com> References: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> In-Reply-To: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> To: Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , =?utf-8?q?Christian_K=C3=B6nig?= , Marek Szyprowski , Robin Murphy , Rob Herring , Saravana Kannan Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, Albert Esteve , mripard@redhat.com, echanude@redhat.com X-Developer-Signature: v=1; a=ed25519-sha256; t=1772793417; l=3959; i=aesteve@redhat.com; s=20260303; h=from:subject:message-id; bh=u/febRDM30JzV4zi0O2oWhXMCmjL4J3mUC+OUI296Uo=; b=ox/FLKFGG37y3D4eZEeuwpjANM+kMoZ40TSyVRxSl1Ey8IISOiKa4rN8VqUqJSo2qSnDVNqH6 fpEmrmFeDwyCRLDpE2qyCTx7NCMG7X+GpX6EubQV3mDuWjEh1pthLL6 X-Developer-Key: i=aesteve@redhat.com; a=ed25519; pk=YSFz6sOHd2L45+Fr8DIvHTi6lSIjhLZ5T+rkxspJt1s= X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Create the logic to store coherent reserved memory regions within the coherent DMA code; and provide an iterator (i.e., dma_coherent_get_reserved_region()) to allow consumers of this API retrieving the regions. Note: since the consumer of this iterator is going to be the specific coherent memory dmabuf heap module, this commit introduces a check for CONFIG_DMABUF_HEAPS_COHERENT, which is defined in the subsequent patch, to maintain a clean split between the kernel code and the heap module code. Signed-off-by: Albert Esteve --- include/linux/dma-map-ops.h | 7 +++++++ kernel/dma/coherent.c | 34 ++++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index 60b63756df821..c87e5e44e5383 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -12,6 +12,7 @@ =20 struct cma; struct iommu_ops; +struct reserved_mem; =20 struct dma_map_ops { void *(*alloc)(struct device *dev, size_t size, @@ -161,6 +162,7 @@ int dma_alloc_from_dev_coherent(struct device *dev, ssi= ze_t size, int dma_release_from_dev_coherent(struct device *dev, int order, void *vad= dr); int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *= vma, void *cpu_addr, size_t size, int *ret); +struct reserved_mem *dma_coherent_get_reserved_region(unsigned int idx); #else static inline int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, dma_addr_t device_addr, size_t size) @@ -172,6 +174,11 @@ static inline int dma_declare_coherent_memory(struct d= evice *dev, #define dma_release_from_dev_coherent(dev, order, vaddr) (0) #define dma_mmap_from_dev_coherent(dev, vma, vaddr, order, ret) (0) static inline void dma_release_coherent_memory(struct device *dev) { } +static inline +struct reserved_mem *dma_coherent_get_reserved_region(unsigned int idx) +{ + return NULL; +} #endif /* CONFIG_DMA_DECLARE_COHERENT */ =20 #ifdef CONFIG_DMA_GLOBAL_POOL diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 1147497bc512c..d0d0979ffb153 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -9,6 +9,7 @@ #include #include #include +#include =20 struct dma_coherent_mem { void *virt_base; @@ -334,6 +335,31 @@ static phys_addr_t dma_reserved_default_memory_base __= initdata; static phys_addr_t dma_reserved_default_memory_size __initdata; #endif =20 +#define MAX_COHERENT_REGIONS 64 + +static struct reserved_mem *rmem_coherent_areas[MAX_COHERENT_REGIONS]; +static unsigned int rmem_coherent_areas_num; + +static int rmem_coherent_insert_area(struct reserved_mem *rmem) +{ + if (rmem_coherent_areas_num >=3D MAX_COHERENT_REGIONS) { + pr_warn("Deferred heap areas list full, dropping %s\n", + rmem->name ? rmem->name : "unknown"); + return -EINVAL; + } + rmem_coherent_areas[rmem_coherent_areas_num++] =3D rmem; + return 0; +} + +struct reserved_mem *dma_coherent_get_reserved_region(unsigned int idx) +{ + if (idx >=3D rmem_coherent_areas_num) + return NULL; + + return rmem_coherent_areas[idx]; +} +EXPORT_SYMBOL_GPL(dma_coherent_get_reserved_region); + static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *= dev) { struct dma_coherent_mem *mem =3D rmem->priv; @@ -393,6 +419,14 @@ static int __init rmem_dma_setup(struct reserved_mem *= rmem) rmem->ops =3D &rmem_dma_ops; pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n", &rmem->base, (unsigned long)rmem->size / SZ_1M); + + if (IS_ENABLED(CONFIG_DMABUF_HEAPS_COHERENT)) { + int ret =3D rmem_coherent_insert_area(rmem); + + if (ret) + pr_warn("Reserved memory: failed to store coherent area for %s (%d)\n", + rmem->name ? rmem->name : "unknown", ret); + } return 0; } =20 --=20 2.52.0 From nobody Thu Apr 9 16:37:33 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CE8C836309A for ; Fri, 6 Mar 2026 10:37:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793470; cv=none; b=SVhdOPeXTaPxU9VQwcHcCMmCF1xuvFNxP7dFWn1c5qTyCw/MZMbXpdfysgZpm/HeA9HrFnItjGgsGcCKxEdoimL7HCJaWW5GBOcRpqOoqya5rAu++GVpZ8xFMHu/mDBN7SaDoB22Td78H21XpThRAPPk188OLnR9bUhF7sbREV0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793470; c=relaxed/simple; bh=kg7v50c/flgdrIKZTgprBZYfSYOYoRG93RIqsiK+UG4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=KReisDOdlDq2XpM8WpOFgvxQxsQYmG32kOE0T811c2aJ/6l+oUG7tleorR/y7q7aOOKSSlNdvHaI33jdXdHs/tTHhvsZehNiARYy5TSKbc2WSEBfmDIWWclA+OzkNF4ovTSkTkCZJ1A5DuoiMdrCtb11QCMl+rQimNvYCuxI2bw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=XcdPHp4D; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XcdPHp4D" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772793468; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3GaZ0Gxwr7V6iRLWanA72Vhzb8OR1VOC64yNTo9eMhE=; b=XcdPHp4DHxbjG9tURig4gwnBpBS/IimqK1mjWheJgwJQuYoZpgfGL0xBsltoKx8L+kxrbV tkQkwvXW5K3fQn03OrL4v+nnxkiMKU/2XA9+a0nIWj48ubRTS+aEZzk0O6F2WWGgkZTof8 CW1cqFhNmcpvrZsLBnW3GKMK98G3YwQ= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-80-Odv7rigsP1-zrUB-y2fFCw-1; Fri, 06 Mar 2026 05:37:41 -0500 X-MC-Unique: Odv7rigsP1-zrUB-y2fFCw-1 X-Mimecast-MFC-AGG-ID: Odv7rigsP1-zrUB-y2fFCw_1772793459 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5D81D1956063; Fri, 6 Mar 2026 10:37:39 +0000 (UTC) Received: from [192.168.1.153] (unknown [10.45.226.103]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 30CD01800576; Fri, 6 Mar 2026 10:37:32 +0000 (UTC) From: Albert Esteve Date: Fri, 06 Mar 2026 11:36:36 +0100 Subject: [PATCH v3 5/6] dma-buf: heaps: Add Coherent heap to dmabuf heaps Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260306-b4-dmabuf-heap-coherent-rmem-v3-5-3d00d36c9bc4@redhat.com> References: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> In-Reply-To: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> To: Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , =?utf-8?q?Christian_K=C3=B6nig?= , Marek Szyprowski , Robin Murphy , Rob Herring , Saravana Kannan Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, Albert Esteve , mripard@redhat.com, echanude@redhat.com X-Developer-Signature: v=1; a=ed25519-sha256; t=1772793417; l=12946; i=aesteve@redhat.com; s=20260303; h=from:subject:message-id; bh=kg7v50c/flgdrIKZTgprBZYfSYOYoRG93RIqsiK+UG4=; b=DCFgmPif9LMVPvQq3TQyWAwfQLGxptuqTbHlhHQ99DjIcwsBfb9nF/tNDxypZiH+iCg5otnZ7 UY9S5DyFLMrCo7cwomveRiiUeoHZpp/ma1WjxMeFNYC66DELxg03654 X-Developer-Key: i=aesteve@redhat.com; a=ed25519; pk=YSFz6sOHd2L45+Fr8DIvHTi6lSIjhLZ5T+rkxspJt1s= X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Expose DT coherent reserved-memory pools ("shared-dma-pool" without "reusable") as dma-buf heaps, creating one heap per region so userspace can allocate from the exact device-local pool intended for coherent DMA. This is a missing backend in the long-term effort to steer userspace buffer allocations (DRM, v4l2, dma-buf heaps) through heaps for clearer cgroup accounting. CMA and system heaps already exist; non-reusable coherent reserved memory did not. The heap binds the heap device to each memory region so coherent allocations use the correct dev->dma_mem, and it defers registration until module_init when normal allocators are available. Signed-off-by: Albert Esteve --- drivers/dma-buf/heaps/Kconfig | 9 + drivers/dma-buf/heaps/Makefile | 1 + drivers/dma-buf/heaps/coherent_heap.c | 414 ++++++++++++++++++++++++++++++= ++++ 3 files changed, 424 insertions(+) diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig index a5eef06c42264..aeb475e585048 100644 --- a/drivers/dma-buf/heaps/Kconfig +++ b/drivers/dma-buf/heaps/Kconfig @@ -12,3 +12,12 @@ config DMABUF_HEAPS_CMA Choose this option to enable dma-buf CMA heap. This heap is backed by the Contiguous Memory Allocator (CMA). If your system has these regions, you should say Y here. + +config DMABUF_HEAPS_COHERENT + bool "DMA-BUF Coherent Reserved-Memory Heap" + depends on DMABUF_HEAPS && OF_RESERVED_MEM && DMA_DECLARE_COHERENT + help + Choose this option to enable coherent reserved-memory dma-buf heaps. + This heap is backed by non-reusable DT "shared-dma-pool" regions. + If your system defines coherent reserved-memory regions, you should + say Y here. diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile index 974467791032f..96bda7a65f041 100644 --- a/drivers/dma-buf/heaps/Makefile +++ b/drivers/dma-buf/heaps/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) +=3D system_heap.o obj-$(CONFIG_DMABUF_HEAPS_CMA) +=3D cma_heap.o +obj-$(CONFIG_DMABUF_HEAPS_COHERENT) +=3D coherent_heap.o diff --git a/drivers/dma-buf/heaps/coherent_heap.c b/drivers/dma-buf/heaps/= coherent_heap.c new file mode 100644 index 0000000000000..55f53f87c4c15 --- /dev/null +++ b/drivers/dma-buf/heaps/coherent_heap.c @@ -0,0 +1,414 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DMABUF heap for coherent reserved-memory regions + * + * Copyright (C) 2026 Red Hat, Inc. + * Author: Albert Esteve + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct coherent_heap { + struct dma_heap *heap; + struct reserved_mem *rmem; + char *name; +}; + +struct coherent_heap_buffer { + struct coherent_heap *heap; + struct list_head attachments; + struct mutex lock; + unsigned long len; + dma_addr_t dma_addr; + void *alloc_vaddr; + struct page **pages; + pgoff_t pagecount; + int vmap_cnt; + void *vaddr; +}; + +struct dma_heap_attachment { + struct device *dev; + struct sg_table table; + struct list_head list; + bool mapped; +}; + +static int coherent_heap_attach(struct dma_buf *dmabuf, + struct dma_buf_attachment *attachment) +{ + struct coherent_heap_buffer *buffer =3D dmabuf->priv; + struct dma_heap_attachment *a; + int ret; + + a =3D kzalloc_obj(*a); + if (!a) + return -ENOMEM; + + ret =3D sg_alloc_table_from_pages(&a->table, buffer->pages, + buffer->pagecount, 0, + buffer->pagecount << PAGE_SHIFT, + GFP_KERNEL); + if (ret) { + kfree(a); + return ret; + } + + a->dev =3D attachment->dev; + INIT_LIST_HEAD(&a->list); + a->mapped =3D false; + + attachment->priv =3D a; + + mutex_lock(&buffer->lock); + list_add(&a->list, &buffer->attachments); + mutex_unlock(&buffer->lock); + + return 0; +} + +static void coherent_heap_detach(struct dma_buf *dmabuf, + struct dma_buf_attachment *attachment) +{ + struct coherent_heap_buffer *buffer =3D dmabuf->priv; + struct dma_heap_attachment *a =3D attachment->priv; + + mutex_lock(&buffer->lock); + list_del(&a->list); + mutex_unlock(&buffer->lock); + + sg_free_table(&a->table); + kfree(a); +} + +static struct sg_table *coherent_heap_map_dma_buf(struct dma_buf_attachmen= t *attachment, + enum dma_data_direction direction) +{ + struct dma_heap_attachment *a =3D attachment->priv; + struct sg_table *table =3D &a->table; + int ret; + + ret =3D dma_map_sgtable(attachment->dev, table, direction, 0); + if (ret) + return ERR_PTR(-ENOMEM); + a->mapped =3D true; + + return table; +} + +static void coherent_heap_unmap_dma_buf(struct dma_buf_attachment *attachm= ent, + struct sg_table *table, + enum dma_data_direction direction) +{ + struct dma_heap_attachment *a =3D attachment->priv; + + a->mapped =3D false; + dma_unmap_sgtable(attachment->dev, table, direction, 0); +} + +static int coherent_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, + enum dma_data_direction direction) +{ + struct coherent_heap_buffer *buffer =3D dmabuf->priv; + struct dma_heap_attachment *a; + + mutex_lock(&buffer->lock); + if (buffer->vmap_cnt) + invalidate_kernel_vmap_range(buffer->vaddr, buffer->len); + + list_for_each_entry(a, &buffer->attachments, list) { + if (!a->mapped) + continue; + dma_sync_sgtable_for_cpu(a->dev, &a->table, direction); + } + mutex_unlock(&buffer->lock); + + return 0; +} + +static int coherent_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, + enum dma_data_direction direction) +{ + struct coherent_heap_buffer *buffer =3D dmabuf->priv; + struct dma_heap_attachment *a; + + mutex_lock(&buffer->lock); + if (buffer->vmap_cnt) + flush_kernel_vmap_range(buffer->vaddr, buffer->len); + + list_for_each_entry(a, &buffer->attachments, list) { + if (!a->mapped) + continue; + dma_sync_sgtable_for_device(a->dev, &a->table, direction); + } + mutex_unlock(&buffer->lock); + + return 0; +} + +static int coherent_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struc= t *vma) +{ + struct coherent_heap_buffer *buffer =3D dmabuf->priv; + struct coherent_heap *coh_heap =3D buffer->heap; + struct device *heap_dev =3D dma_heap_get_dev(coh_heap->heap); + + return dma_mmap_coherent(heap_dev, vma, buffer->alloc_vaddr, + buffer->dma_addr, buffer->len); +} + +static void *coherent_heap_do_vmap(struct coherent_heap_buffer *buffer) +{ + void *vaddr; + + vaddr =3D vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL); + if (!vaddr) + return ERR_PTR(-ENOMEM); + + return vaddr; +} + +static int coherent_heap_vmap(struct dma_buf *dmabuf, struct iosys_map *ma= p) +{ + struct coherent_heap_buffer *buffer =3D dmabuf->priv; + void *vaddr; + int ret =3D 0; + + mutex_lock(&buffer->lock); + if (buffer->vmap_cnt) { + buffer->vmap_cnt++; + iosys_map_set_vaddr(map, buffer->vaddr); + goto out; + } + + vaddr =3D coherent_heap_do_vmap(buffer); + if (IS_ERR(vaddr)) { + ret =3D PTR_ERR(vaddr); + goto out; + } + + buffer->vaddr =3D vaddr; + buffer->vmap_cnt++; + iosys_map_set_vaddr(map, buffer->vaddr); +out: + mutex_unlock(&buffer->lock); + + return ret; +} + +static void coherent_heap_vunmap(struct dma_buf *dmabuf, struct iosys_map = *map) +{ + struct coherent_heap_buffer *buffer =3D dmabuf->priv; + + mutex_lock(&buffer->lock); + if (!--buffer->vmap_cnt) { + vunmap(buffer->vaddr); + buffer->vaddr =3D NULL; + } + mutex_unlock(&buffer->lock); + iosys_map_clear(map); +} + +static void coherent_heap_dma_buf_release(struct dma_buf *dmabuf) +{ + struct coherent_heap_buffer *buffer =3D dmabuf->priv; + struct coherent_heap *coh_heap =3D buffer->heap; + struct device *heap_dev =3D dma_heap_get_dev(coh_heap->heap); + + if (buffer->vmap_cnt > 0) { + WARN(1, "%s: buffer still mapped in the kernel\n", __func__); + vunmap(buffer->vaddr); + buffer->vaddr =3D NULL; + buffer->vmap_cnt =3D 0; + } + + if (buffer->alloc_vaddr) + dma_free_coherent(heap_dev, buffer->len, buffer->alloc_vaddr, + buffer->dma_addr); + kfree(buffer->pages); + kfree(buffer); +} + +static const struct dma_buf_ops coherent_heap_buf_ops =3D { + .attach =3D coherent_heap_attach, + .detach =3D coherent_heap_detach, + .map_dma_buf =3D coherent_heap_map_dma_buf, + .unmap_dma_buf =3D coherent_heap_unmap_dma_buf, + .begin_cpu_access =3D coherent_heap_dma_buf_begin_cpu_access, + .end_cpu_access =3D coherent_heap_dma_buf_end_cpu_access, + .mmap =3D coherent_heap_mmap, + .vmap =3D coherent_heap_vmap, + .vunmap =3D coherent_heap_vunmap, + .release =3D coherent_heap_dma_buf_release, +}; + +static struct dma_buf *coherent_heap_allocate(struct dma_heap *heap, + unsigned long len, + u32 fd_flags, + u64 heap_flags) +{ + struct coherent_heap *coh_heap; + struct coherent_heap_buffer *buffer; + struct device *heap_dev; + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + size_t size =3D PAGE_ALIGN(len); + pgoff_t pagecount =3D size >> PAGE_SHIFT; + struct dma_buf *dmabuf; + int ret =3D -ENOMEM; + pgoff_t pg; + + coh_heap =3D dma_heap_get_drvdata(heap); + if (!coh_heap) + return ERR_PTR(-EINVAL); + + heap_dev =3D dma_heap_get_dev(coh_heap->heap); + if (!heap_dev) + return ERR_PTR(-ENODEV); + + buffer =3D kzalloc_obj(*buffer); + if (!buffer) + return ERR_PTR(-ENOMEM); + + INIT_LIST_HEAD(&buffer->attachments); + mutex_init(&buffer->lock); + buffer->len =3D size; + buffer->heap =3D coh_heap; + buffer->pagecount =3D pagecount; + + buffer->alloc_vaddr =3D dma_alloc_coherent(heap_dev, buffer->len, + &buffer->dma_addr, GFP_KERNEL); + if (!buffer->alloc_vaddr) { + ret =3D -ENOMEM; + goto free_buffer; + } + + buffer->pages =3D kmalloc_array(pagecount, sizeof(*buffer->pages), + GFP_KERNEL); + if (!buffer->pages) { + ret =3D -ENOMEM; + goto free_dma; + } + + for (pg =3D 0; pg < pagecount; pg++) + buffer->pages[pg] =3D virt_to_page((char *)buffer->alloc_vaddr + + (pg * PAGE_SIZE)); + + /* create the dmabuf */ + exp_info.exp_name =3D dma_heap_get_name(heap); + exp_info.ops =3D &coherent_heap_buf_ops; + exp_info.size =3D buffer->len; + exp_info.flags =3D fd_flags; + exp_info.priv =3D buffer; + dmabuf =3D dma_buf_export(&exp_info); + if (IS_ERR(dmabuf)) { + ret =3D PTR_ERR(dmabuf); + goto free_pages; + } + return dmabuf; + +free_pages: + kfree(buffer->pages); +free_dma: + dma_free_coherent(heap_dev, buffer->len, buffer->alloc_vaddr, + buffer->dma_addr); +free_buffer: + kfree(buffer); + return ERR_PTR(ret); +} + +static const struct dma_heap_ops coherent_heap_ops =3D { + .allocate =3D coherent_heap_allocate, +}; + +static int __coherent_heap_register(struct reserved_mem *rmem) +{ + struct dma_heap_export_info exp_info; + struct coherent_heap *coh_heap; + struct device *heap_dev; + int ret; + + if (!rmem || !rmem->name) + return -EINVAL; + + coh_heap =3D kzalloc_obj(*coh_heap); + if (!coh_heap) + return -ENOMEM; + + coh_heap->rmem =3D rmem; + coh_heap->name =3D kstrdup(rmem->name, GFP_KERNEL); + if (!coh_heap->name) { + ret =3D -ENOMEM; + goto free_coherent_heap; + } + + exp_info.name =3D coh_heap->name; + exp_info.ops =3D &coherent_heap_ops; + exp_info.priv =3D coh_heap; + + coh_heap->heap =3D dma_heap_create(&exp_info); + if (IS_ERR(coh_heap->heap)) { + ret =3D PTR_ERR(coh_heap->heap); + goto free_name; + } + + heap_dev =3D dma_heap_get_dev(coh_heap->heap); + ret =3D dma_coerce_mask_and_coherent(heap_dev, DMA_BIT_MASK(64)); + if (ret) { + pr_err("coherent_heap: failed to set DMA mask (%d)\n", ret); + goto destroy_heap; + } + + ret =3D of_reserved_mem_device_init_with_mem(heap_dev, rmem); + if (ret) { + pr_err("coherent_heap: failed to initialize memory (%d)\n", ret); + goto destroy_heap; + } + + ret =3D dma_heap_register(coh_heap->heap); + if (ret) { + pr_err("coherent_heap: failed to register heap (%d)\n", ret); + goto destroy_heap; + } + + return 0; + +destroy_heap: + dma_heap_destroy(coh_heap->heap); + coh_heap->heap =3D NULL; +free_name: + kfree(coh_heap->name); +free_coherent_heap: + kfree(coh_heap); + + return ret; +} + +static int __init coherent_heap_register(void) +{ + struct reserved_mem *rmem; + unsigned int i; + int ret; + + for (i =3D 0; (rmem =3D dma_coherent_get_reserved_region(i)) !=3D NULL; i= ++) { + ret =3D __coherent_heap_register(rmem); + if (ret) { + pr_warn("Failed to add coherent heap %s", + rmem->name ? rmem->name : "unknown"); + continue; + } + } + + return 0; +} +module_init(coherent_heap_register); +MODULE_DESCRIPTION("DMA-BUF heap for coherent reserved-memory regions"); --=20 2.52.0 From nobody Thu Apr 9 16:37:33 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 12CB637CD49 for ; Fri, 6 Mar 2026 10:37:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793474; cv=none; b=Ip4oO4rrtUsT8ulthUGAD8DO97gW2Sr3lKHkN0GIQ6baq9bnF6l63G96sGYM+O7JZsW2McpPxlSZodZuIsinv4em9n+tBDLvuqlgqoYCbFCtWREWK4sbI9C7QT68LWRYH1TDmxNwtUbAexTKzbqJxmD/9dww3Lv8Z13VeO4z+B8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772793474; c=relaxed/simple; bh=8dYJXakMo93Mc3lLZ5xLZ8QfYkIluXNTvVn7oLOYyd0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=WHppWRbLJ4uHaFpSJr4fW6iz91m66vsSx7WDywsafnEHENnriE5LNOE6GOTnLaNWSbtRsBaQ08BlKzt5B3DxT5CuE/YNk0yEmTYWI0yU7E4AJO7iQvYl03PUAEiL0GFM6Snw3HRS36scrF6O+sCSn4NO8ycQDAaf1v9N18btfpg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=g5Nud/PN; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="g5Nud/PN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772793472; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QlzQWM0pQarIoPqm3Nl91hQ8QPCgoigzmRIhUlpi9M8=; b=g5Nud/PNpHQhAqBQZ+SiSiMu7cu4hpRbgFPrGt1YkZqYPsxLIxE7fjo1buAcNcMQ7qXvae 2/ucyyWLqaqdAbZHvkJDg4UKDNKrTLanqnq+RBQ+cspPM2FCcUQmgpsqAiYTRAvv/E+R7T xNEURcSnWDDGBxJ31Tw47mEMoQDzzWU= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-588-UUtSeqiXMbu1DAjH5sRbQg-1; Fri, 06 Mar 2026 05:37:47 -0500 X-MC-Unique: UUtSeqiXMbu1DAjH5sRbQg-1 X-Mimecast-MFC-AGG-ID: UUtSeqiXMbu1DAjH5sRbQg_1772793465 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BBFDE1956088; Fri, 6 Mar 2026 10:37:45 +0000 (UTC) Received: from [192.168.1.153] (unknown [10.45.226.103]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D4D89180035F; Fri, 6 Mar 2026 10:37:39 +0000 (UTC) From: Albert Esteve Date: Fri, 06 Mar 2026 11:36:37 +0100 Subject: [PATCH v3 6/6] dma-buf: heaps: coherent: Turn heap into a module Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260306-b4-dmabuf-heap-coherent-rmem-v3-6-3d00d36c9bc4@redhat.com> References: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> In-Reply-To: <20260306-b4-dmabuf-heap-coherent-rmem-v3-0-3d00d36c9bc4@redhat.com> To: Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , =?utf-8?q?Christian_K=C3=B6nig?= , Marek Szyprowski , Robin Murphy , Rob Herring , Saravana Kannan Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, Albert Esteve , mripard@redhat.com, echanude@redhat.com X-Developer-Signature: v=1; a=ed25519-sha256; t=1772793417; l=1661; i=aesteve@redhat.com; s=20260303; h=from:subject:message-id; bh=8dYJXakMo93Mc3lLZ5xLZ8QfYkIluXNTvVn7oLOYyd0=; b=Qm2/NTv+NibwQ4NUgIiBv1ELR84Zemc1608Ij5MBU+ZNmcVHDkvPQnkB17rRPklxBL/kLazKf 4Fi3uUXQDF+CAD44A2H9aDZK/GjsuL7JYH0er/9W85JKFYPQp+70MJH X-Developer-Key: i=aesteve@redhat.com; a=ed25519; pk=YSFz6sOHd2L45+Fr8DIvHTi6lSIjhLZ5T+rkxspJt1s= X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Following the current efforts to make CMA heap as module, we can do the same and turn the Coherent heap into a module as well, by changing the Kconfig into a tristate and importing the proper dma-buf namespaces. This heap won't be able to unload (same as happens with the CMA heap), since we're missing a big part of the infrastructure that would allow to make it safe. Signed-off-by: Albert Esteve --- drivers/dma-buf/heaps/Kconfig | 2 +- drivers/dma-buf/heaps/coherent_heap.c | 3 +++ 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig index aeb475e585048..2f84a1018b900 100644 --- a/drivers/dma-buf/heaps/Kconfig +++ b/drivers/dma-buf/heaps/Kconfig @@ -14,7 +14,7 @@ config DMABUF_HEAPS_CMA regions, you should say Y here. =20 config DMABUF_HEAPS_COHERENT - bool "DMA-BUF Coherent Reserved-Memory Heap" + tristate "DMA-BUF Coherent Reserved-Memory Heap" depends on DMABUF_HEAPS && OF_RESERVED_MEM && DMA_DECLARE_COHERENT help Choose this option to enable coherent reserved-memory dma-buf heaps. diff --git a/drivers/dma-buf/heaps/coherent_heap.c b/drivers/dma-buf/heaps/= coherent_heap.c index 55f53f87c4c15..fdb3f5d907e88 100644 --- a/drivers/dma-buf/heaps/coherent_heap.c +++ b/drivers/dma-buf/heaps/coherent_heap.c @@ -412,3 +412,6 @@ static int __init coherent_heap_register(void) } module_init(coherent_heap_register); MODULE_DESCRIPTION("DMA-BUF heap for coherent reserved-memory regions"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS("DMA_BUF"); +MODULE_IMPORT_NS("DMA_BUF_HEAP"); --=20 2.52.0