From nobody Wed Dec 17 08:51:02 2025 Received: from out-189.mta0.migadu.com (out-189.mta0.migadu.com [91.218.175.189]) (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 2031F237176 for ; Fri, 9 May 2025 16:00:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.189 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746806429; cv=none; b=PPtbu9AwQqKRX4AocxFLhX9eSr+baRHaDScFFZ0vnc+KzzoJFOd47aOf63f3isn8NHcBGNoMcnYuZMvqTLMpXLHP7bxfDa+DkfRq6jhLKje67ZY0fFMJeOFtPcBSgWE7Ne60jS7U4sa2U8hnI/pcLBOM6k+GBRnJn+sVB8Hl2C8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746806429; c=relaxed/simple; bh=heGBJ3SeFAFWjkC+/u9VZBpvC4hEwAlPEmXlIY/Cze0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=GKPZv+Vhx6P91mCpxUjzRy95RKdU6dex/w9oLDbPaPSs/wDALtoXMIPuw5fFVGy0DOJmnYPg0mFmHvfWnPjSP7unAKfuO+HobooRtzLwuHfWBP5T4PqwrhydEOolEAsKxqQk/KTHndcZ+Lj3YBd40IpUB6V7tCvo5Jk7HYUE8R8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=euyjOW7W; arc=none smtp.client-ip=91.218.175.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="euyjOW7W" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1746806423; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=g9IyEqqXTR0rneb1m3RreWD1KdVSsI1Pzjo/c6NQGY0=; b=euyjOW7W0ASBc42Cp4GNoTRgM/lK6HVDnR8xfPcU+mtIhrLMGfT+Lfd8l5W5hq9pJ9lKXg n7HyDwcD5zrvcQOkZSGxB1HaiJAN0YGl7S0Uqm0cAUKyIyG2p5laTOMKDIdGXQloPIcSgl 7FdZHCdLeNIeY+ifBccmRPyWi7PZXq0= From: Dawei Li To: andersson@kernel.org, mathieu.poirier@linaro.org Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, dawei.li@linux.dev, set_pte_at@outlook.com Subject: [PATCH v2 1/3] rpmsg: char: Reuse eptdev logic for anon device Date: Fri, 9 May 2025 23:59:25 +0800 Message-Id: <20250509155927.109258-2-dawei.li@linux.dev> In-Reply-To: <20250509155927.109258-1-dawei.li@linux.dev> References: <20250509155927.109258-1-dawei.li@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Current uAPI implementation for rpmsg ctrl & char device manipulation is abstracted in procedures below: Current uAPI implementation for rpmsg ctrl & char device manipulation is abstracted in procedures below: - fd =3D open("/dev/rpmsg_ctrlX") - ioctl(fd, RPMSG_CREATE_EPT_IOCTL, &info); /dev/rpmsgY devnode is generated. - fd_ep =3D open("/dev/rpmsgY", O_RDWR) - operations on fd_ep(write, read, poll ioctl) - ioctl(fd_ep, RPMSG_DESTROY_EPT_IOCTL) - close(fd_ep) - close(fd) This /dev/rpmsgY abstraction is less favorable for: - Performance issue: It's time consuming for some operations are invovled: - Device node creation. Depends on specific config, especially CONFIG_DEVTMPFS, the overall overhead is based on coordination between DEVTMPFS and userspace tools such as udev and mdev. - Extra kernel-space switch cost. - Other major costs brought by heavy-weight logic like device_add(). - /dev/rpmsgY node can be opened only once. It doesn't make much sense that a dynamically created device node can be opened only once. - For some container application such as docker, a client can't access host's dev unless specified explicitly. But in case of /dev/rpmsgY, which is generated dynamically and whose existence is unknown for clients in advance, this uAPI based on device node doesn't fit well. An anon inode based approach is introduced to address the issues above. Rather than generating device node and opening it, rpmsg code just make a anon inode representing eptdev and return the fd to userspace. The legacy abstraction based on struct dev and struct cdev is honored for: - Avoid legacy uAPI break(RPMSG_CREATE_EPT_IOCTL) - Reuse existing logic: -- dev_err() and friends. -- Life cycle management of struct device. Signed-off-by: Dawei Li --- drivers/rpmsg/rpmsg_char.c | 80 ++++++++++++++++++++++++++------------ 1 file changed, 56 insertions(+), 24 deletions(-) diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c index eec7642d2686..5b2a883d6236 100644 --- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -91,7 +91,8 @@ int rpmsg_chrdev_eptdev_destroy(struct device *dev, void = *data) /* wake up any blocked readers */ wake_up_interruptible(&eptdev->readq); =20 - cdev_device_del(&eptdev->cdev, &eptdev->dev); + if (eptdev->dev.devt) + cdev_device_del(&eptdev->cdev, &eptdev->dev); put_device(&eptdev->dev); =20 return 0; @@ -132,21 +133,17 @@ static int rpmsg_ept_flow_cb(struct rpmsg_device *rpd= ev, void *priv, bool enable return 0; } =20 -static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) +static int __rpmsg_eptdev_open(struct rpmsg_eptdev *eptdev) { - struct rpmsg_eptdev *eptdev =3D cdev_to_eptdev(inode->i_cdev); struct rpmsg_endpoint *ept; struct rpmsg_device *rpdev =3D eptdev->rpdev; struct device *dev =3D &eptdev->dev; =20 - mutex_lock(&eptdev->ept_lock); if (eptdev->ept) { - mutex_unlock(&eptdev->ept_lock); return -EBUSY; } =20 if (!eptdev->rpdev) { - mutex_unlock(&eptdev->ept_lock); return -ENETRESET; } =20 @@ -164,21 +161,32 @@ static int rpmsg_eptdev_open(struct inode *inode, str= uct file *filp) if (!ept) { dev_err(dev, "failed to open %s\n", eptdev->chinfo.name); put_device(dev); - mutex_unlock(&eptdev->ept_lock); return -EINVAL; } =20 ept->flow_cb =3D rpmsg_ept_flow_cb; eptdev->ept =3D ept; - filp->private_data =3D eptdev; - mutex_unlock(&eptdev->ept_lock); =20 return 0; } =20 -static int rpmsg_eptdev_release(struct inode *inode, struct file *filp) +static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) { struct rpmsg_eptdev *eptdev =3D cdev_to_eptdev(inode->i_cdev); + int ret; + + mutex_lock(&eptdev->ept_lock); + ret =3D __rpmsg_eptdev_open(eptdev); + if (!ret) + filp->private_data =3D eptdev; + mutex_unlock(&eptdev->ept_lock); + + return ret; +} + +static int rpmsg_eptdev_release(struct inode *inode, struct file *filp) +{ + struct rpmsg_eptdev *eptdev =3D filp->private_data; struct device *dev =3D &eptdev->dev; =20 /* Close the endpoint, if it's not already destroyed by the parent */ @@ -400,12 +408,13 @@ static void rpmsg_eptdev_release_device(struct device= *dev) struct rpmsg_eptdev *eptdev =3D dev_to_eptdev(dev); =20 ida_free(&rpmsg_ept_ida, dev->id); - ida_free(&rpmsg_minor_ida, MINOR(eptdev->dev.devt)); + if (eptdev->dev.devt) + ida_free(&rpmsg_minor_ida, MINOR(eptdev->dev.devt)); kfree(eptdev); } =20 -static struct rpmsg_eptdev *rpmsg_chrdev_eptdev_alloc(struct rpmsg_device = *rpdev, - struct device *parent) +static struct rpmsg_eptdev *__rpmsg_chrdev_eptdev_alloc(struct rpmsg_devic= e *rpdev, + struct device *parent, bool cdev) { struct rpmsg_eptdev *eptdev; struct device *dev; @@ -428,33 +437,50 @@ static struct rpmsg_eptdev *rpmsg_chrdev_eptdev_alloc= (struct rpmsg_device *rpdev dev->groups =3D rpmsg_eptdev_groups; dev_set_drvdata(dev, eptdev); =20 - cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops); - eptdev->cdev.owner =3D THIS_MODULE; + if (cdev) { + cdev_init(&eptdev->cdev, &rpmsg_eptdev_fops); + eptdev->cdev.owner =3D THIS_MODULE; + } =20 return eptdev; } =20 -static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev *eptdev, struct rpm= sg_channel_info chinfo) +static struct rpmsg_eptdev *rpmsg_chrdev_eptdev_alloc(struct rpmsg_device = *rpdev, + struct device *parent) +{ + return __rpmsg_chrdev_eptdev_alloc(rpdev, parent, true); +} + +static int __rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev *eptdev, + struct rpmsg_channel_info chinfo, bool cdev) { struct device *dev =3D &eptdev->dev; int ret; =20 eptdev->chinfo =3D chinfo; =20 - ret =3D ida_alloc_max(&rpmsg_minor_ida, RPMSG_DEV_MAX - 1, GFP_KERNEL); - if (ret < 0) - goto free_eptdev; - dev->devt =3D MKDEV(MAJOR(rpmsg_major), ret); + if (cdev) { + ret =3D ida_alloc_max(&rpmsg_minor_ida, RPMSG_DEV_MAX - 1, GFP_KERNEL); + if (ret < 0) + goto free_eptdev; =20 + dev->devt =3D MKDEV(MAJOR(rpmsg_major), ret); + } + + /* Anon inode device still need dev name for dev_err() and friends */ ret =3D ida_alloc(&rpmsg_ept_ida, GFP_KERNEL); if (ret < 0) goto free_minor_ida; dev->id =3D ret; dev_set_name(dev, "rpmsg%d", ret); =20 - ret =3D cdev_device_add(&eptdev->cdev, &eptdev->dev); - if (ret) - goto free_ept_ida; + ret =3D 0; + + if (cdev) { + ret =3D cdev_device_add(&eptdev->cdev, &eptdev->dev); + if (ret) + goto free_ept_ida; + } =20 /* We can now rely on the release function for cleanup */ dev->release =3D rpmsg_eptdev_release_device; @@ -464,7 +490,8 @@ static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev = *eptdev, struct rpmsg_cha free_ept_ida: ida_free(&rpmsg_ept_ida, dev->id); free_minor_ida: - ida_free(&rpmsg_minor_ida, MINOR(dev->devt)); + if (cdev) + ida_free(&rpmsg_minor_ida, MINOR(dev->devt)); free_eptdev: put_device(dev); kfree(eptdev); @@ -472,6 +499,11 @@ static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev= *eptdev, struct rpmsg_cha return ret; } =20 +static int rpmsg_chrdev_eptdev_add(struct rpmsg_eptdev *eptdev, struct rpm= sg_channel_info chinfo) +{ + return __rpmsg_chrdev_eptdev_add(eptdev, chinfo, true); +} + int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *= parent, struct rpmsg_channel_info chinfo) { --=20 2.25.1 From nobody Wed Dec 17 08:51:02 2025 Received: from out-185.mta0.migadu.com (out-185.mta0.migadu.com [91.218.175.185]) (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 C69812367D1 for ; Fri, 9 May 2025 16:00:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.185 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746806435; cv=none; b=gQzsEEgDkWZiFHgE/lpipghqafuQuoBB+XlVqAwJWJnOr/pnw8WPP56xQtd4j0PaMMPFJ7dqyRMjVjn7/+XBcZyILDNurdDaZpQ8t1nNKYcSqg9NoB0TlR8qEBk25kvVYWUIiDpRhBUaJYqxHwT8rpe45A3C74Z0spGhEaPe5Ps= ARC-Message-Signature: i=1; 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DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1746806431; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=q6rNWKa3yBqbjYl0but82CIqRVti48Mb1G+HhwjvMLI=; b=amp9iI5ldtnWZe6TLLmjdWwTI5VFbsHP9pTu53NiBRPxA1q0iph7Dcgmi2ZjAzXdtW87K4 jWe5edtE1nTVXndNvCXCCLvQ4RcPwm5ROE2GW10fiVWsbM6jpfODGg8qiAJNrLdU06ifZQ Ut7FlJk4bOn3z2H6TdxtGohH5+K0H6c= From: Dawei Li To: andersson@kernel.org, mathieu.poirier@linaro.org Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, dawei.li@linux.dev, set_pte_at@outlook.com Subject: [PATCH v2 2/3] rpmsg: char: Implement eptdev based on anon inode Date: Fri, 9 May 2025 23:59:26 +0800 Message-Id: <20250509155927.109258-3-dawei.li@linux.dev> In-Reply-To: <20250509155927.109258-1-dawei.li@linux.dev> References: <20250509155927.109258-1-dawei.li@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Introduce new eptdev abstraction based on anon inode. The new API is exactly same with legacy one except: - It's anonymous and devnode/path free. - Its fops->open() is empty. Signed-off-by: Dawei Li --- drivers/rpmsg/rpmsg_char.c | 44 ++++++++++++++++++++++++++++++++++++++ drivers/rpmsg/rpmsg_char.h | 19 ++++++++++++++++ 2 files changed, 63 insertions(+) diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c index 5b2a883d6236..b0ec05f88013 100644 --- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -13,6 +13,7 @@ =20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt =20 +#include #include #include #include @@ -517,6 +518,49 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rp= dev, struct device *parent } EXPORT_SYMBOL(rpmsg_chrdev_eptdev_create); =20 +static const struct file_operations rpmsg_eptdev_anon_fops =3D { + .owner =3D THIS_MODULE, + .release =3D rpmsg_eptdev_release, + .read_iter =3D rpmsg_eptdev_read_iter, + .write_iter =3D rpmsg_eptdev_write_iter, + .poll =3D rpmsg_eptdev_poll, + .unlocked_ioctl =3D rpmsg_eptdev_ioctl, + .compat_ioctl =3D compat_ptr_ioctl, +}; + +int rpmsg_eptdev_create(struct rpmsg_device *rpdev, struct device *parent, + struct rpmsg_channel_info chinfo, int *pfd) +{ + struct rpmsg_eptdev *eptdev; + int ret, fd; + + eptdev =3D __rpmsg_chrdev_eptdev_alloc(rpdev, parent, false); + if (IS_ERR(eptdev)) + return PTR_ERR(eptdev); + + ret =3D __rpmsg_chrdev_eptdev_add(eptdev, chinfo, false); + if (ret) { + dev_err(&eptdev->dev, "failed to add %s\n", eptdev->chinfo.name); + return ret; + } + + fd =3D anon_inode_getfd("rpmsg-eptdev", &rpmsg_eptdev_anon_fops, eptdev, = O_RDWR | O_CLOEXEC); + if (fd < 0) { + put_device(&eptdev->dev); + return fd; + } + + mutex_lock(&eptdev->ept_lock); + ret =3D __rpmsg_eptdev_open(eptdev); + mutex_unlock(&eptdev->ept_lock); + + if (!ret) + *pfd =3D fd; + + return ret; +} +EXPORT_SYMBOL(rpmsg_eptdev_create); + static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev) { struct rpmsg_channel_info chinfo; diff --git a/drivers/rpmsg/rpmsg_char.h b/drivers/rpmsg/rpmsg_char.h index 117d9cbc52f0..8cc2c14537da 100644 --- a/drivers/rpmsg/rpmsg_char.h +++ b/drivers/rpmsg/rpmsg_char.h @@ -19,6 +19,19 @@ int rpmsg_chrdev_eptdev_create(struct rpmsg_device *rpdev, struct device *= parent, struct rpmsg_channel_info chinfo); =20 +/** + * rpmsg_eptdev_create() - register ep device and its associated fd based = on an endpoint + * @rpdev: prepared rpdev to be used for creating endpoints + * @parent: parent device + * @chinfo: associated endpoint channel information. + * @pfd: fd in represent of endpoint device + * + * This function create a new rpmsg endpoint device and its associated fd = to instantiate a new + * endpoint based on chinfo information. + */ +int rpmsg_eptdev_create(struct rpmsg_device *rpdev, struct device *parent, + struct rpmsg_channel_info chinfo, int *pfd); + /** * rpmsg_chrdev_eptdev_destroy() - destroy created char device endpoint. * @data: private data associated to the endpoint device @@ -36,6 +49,12 @@ static inline int rpmsg_chrdev_eptdev_create(struct rpms= g_device *rpdev, struct return -ENXIO; } =20 +static inline int rpmsg_eptdev_create(struct rpmsg_device *rpdev, struct d= evice *parent, + struct rpmsg_channel_info chinfo, int *pfd) +{ + return -ENXIO; +} + static inline int rpmsg_chrdev_eptdev_destroy(struct device *dev, void *da= ta) { return -ENXIO; --=20 2.25.1 From nobody Wed Dec 17 08:51:02 2025 Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) (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 5DD8F239E9E for ; Fri, 9 May 2025 16:00:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746806442; cv=none; b=GV956Z7OteBf8xF9uBowqjLg3kA/d3CAmHEyYnMcBuGVCIyuC2YsI7RHwD/hkYCU/HpNju0wLyB63uhuz+zSx7PDqHveKK+FEcaTZuymFwHdtFXZz7tZJlsNZS223TfokJolNeWkHC3W7OGdTDHvaSVt2Cbo6SVpd6f4CbVe3Es= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746806442; c=relaxed/simple; bh=z5pSE65ULIjqvpmH+J9vRAyHolUkWZ/Oap1Uu7HAaSU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Jl1oD0o2Smfe5AwJoDI5/YaTDLk1hWEdCLEBdOUk82TWSy1kHKXw6v5bZFtWMBzh5fZrrkEUiyqG675638tHkhLJncCZjQz2GdvXNX9zRCCRiVdX+h43qgsb8K/NQu46Xty+TTDu5nQh0x3iRgeWnZyJD1l6/RBV0lJR71vU5zw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=MkDZt0ZK; arc=none smtp.client-ip=91.218.175.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="MkDZt0ZK" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1746806437; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/32H+9/41lr99VTZd+rMmdnuXbjt0IaFlsmmN5aVGwc=; b=MkDZt0ZKwnqniuqIINNb5JaTMqYZ1HOcyWul37B7wU4wa4Ewfk41zTsJNC7dwAOW/8F7DT JcV6OhdsQRu9KIJG/18EgZ9BuemtH9SYGYxwM5doHlqstig6VXfkH2fO1DOleU1Cy155yp na4XK8Vb6gWys2Dl3fSLcVogono3vAA= From: Dawei Li To: andersson@kernel.org, mathieu.poirier@linaro.org Cc: linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, dawei.li@linux.dev, set_pte_at@outlook.com Subject: [PATCH v2 3/3] rpmsg: ctrl: Introduce RPMSG_CREATE_EPT_FD_IOCTL uAPI Date: Fri, 9 May 2025 23:59:27 +0800 Message-Id: <20250509155927.109258-4-dawei.li@linux.dev> In-Reply-To: <20250509155927.109258-1-dawei.li@linux.dev> References: <20250509155927.109258-1-dawei.li@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Implement RPMSG_CREATE_EPT_FD_IOCTL, new uAPI for rpmsg ctrl, which shares most of operations of RPMSG_CREATE_EPT_IOCTL except that it returns fd representing eptdev to userspace directly. Possible calling procedures for userspace are: - fd =3D open("/dev/rpmsg_ctrlX") - ioctl(fd, RPMSG_CREATE_EPT_FD_IOCTL, &info); - fd_ep =3D info.fd - operations on fd_ep(write, read, poll ioctl) - ioctl(fd_ep, RPMSG_DESTROY_EPT_IOCTL) - close(fd_ep) - close(fd) Signed-off-by: Dawei Li --- drivers/rpmsg/rpmsg_ctrl.c | 37 +++++++++++++++++++++++++++++-------- include/uapi/linux/rpmsg.h | 19 +++++++++++++++++++ 2 files changed, 48 insertions(+), 8 deletions(-) diff --git a/drivers/rpmsg/rpmsg_ctrl.c b/drivers/rpmsg/rpmsg_ctrl.c index 28f57945ccd9..c2cfdf46ccc6 100644 --- a/drivers/rpmsg/rpmsg_ctrl.c +++ b/drivers/rpmsg/rpmsg_ctrl.c @@ -75,19 +75,32 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsign= ed int cmd, unsigned long arg) { struct rpmsg_ctrldev *ctrldev =3D fp->private_data; + struct rpmsg_endpoint_fd_info ept_fd_info; void __user *argp =3D (void __user *)arg; struct rpmsg_endpoint_info eptinfo; struct rpmsg_channel_info chinfo; struct rpmsg_device *rpdev; int ret =3D 0; - - if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) - return -EFAULT; - - memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE); - chinfo.name[RPMSG_NAME_SIZE - 1] =3D '\0'; - chinfo.src =3D eptinfo.src; - chinfo.dst =3D eptinfo.dst; + int fd =3D -1; + + if (cmd =3D=3D RPMSG_CREATE_EPT_IOCTL || cmd =3D=3D RPMSG_CREATE_DEV_IOCT= L || + cmd =3D=3D RPMSG_RELEASE_DEV_IOCTL) { + if (copy_from_user(&eptinfo, argp, sizeof(eptinfo))) + return -EFAULT; + + memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE); + chinfo.name[RPMSG_NAME_SIZE - 1] =3D '\0'; + chinfo.src =3D eptinfo.src; + chinfo.dst =3D eptinfo.dst; + } else if (cmd =3D=3D RPMSG_CREATE_EPT_FD_IOCTL) { + if (copy_from_user(&ept_fd_info, argp, sizeof(ept_fd_info))) + return -EFAULT; + + memcpy(chinfo.name, ept_fd_info.name, RPMSG_NAME_SIZE); + chinfo.name[RPMSG_NAME_SIZE - 1] =3D '\0'; + chinfo.src =3D ept_fd_info.src; + chinfo.dst =3D ept_fd_info.dst; + } =20 mutex_lock(&ctrldev->ctrl_lock); switch (cmd) { @@ -110,6 +123,14 @@ static long rpmsg_ctrldev_ioctl(struct file *fp, unsig= ned int cmd, chinfo.name, ret); break; =20 + case RPMSG_CREATE_EPT_FD_IOCTL: + ret =3D rpmsg_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo, &fd); + if (!ret) { + ept_fd_info.fd =3D fd; + ret =3D copy_to_user(argp, &ept_fd_info, sizeof(ept_fd_info)); + } + break; + default: ret =3D -EINVAL; } diff --git a/include/uapi/linux/rpmsg.h b/include/uapi/linux/rpmsg.h index f0c8da2b185b..934c0e76bfe3 100644 --- a/include/uapi/linux/rpmsg.h +++ b/include/uapi/linux/rpmsg.h @@ -53,4 +53,23 @@ struct rpmsg_endpoint_info { */ #define RPMSG_SET_INCOMING_FLOWCONTROL _IOR(0xb5, 0x6, int) =20 +/** + * struct rpmsg_endpoint_fd_info - endpoint & fd info representation + * @name: name of service + * @src: local address. To set to RPMSG_ADDR_ANY if not used. + * @dst: destination address. To set to RPMSG_ADDR_ANY if not used. + * @fd: fd returned from driver + */ +struct rpmsg_endpoint_fd_info { + char name[32]; + __u32 src; + __u32 dst; + __s32 fd; +}; + +/** + * Instantiate a new rmpsg endpoint which is represented by fd + */ +#define RPMSG_CREATE_EPT_FD_IOCTL _IOWR(0xb5, 0x7, struct rpmsg_endpoint_f= d_info) + #endif --=20 2.25.1