On 6/30/20 7:38 AM, Siddharth Gupta wrote: > > On 6/17/2020 1:44 AM, Arnaud POULIQUEN wrote: >> >> On 6/16/20 9:56 PM, rishabhb@xxxxxxxxxxxxxx wrote: >>> On 2020-04-30 01:30, Arnaud POULIQUEN wrote: >>>> Hi Rishabh, >>>> >>>> >>>> On 4/21/20 8:10 PM, Rishabh Bhatnagar wrote: >>>>> Add the character device interface into remoteproc framework. >>>>> This interface can be used in order to boot/shutdown remote >>>>> subsystems and provides a basic ioctl based interface to implement >>>>> supplementary functionality. An ioctl call is implemented to enable >>>>> the shutdown on release feature which will allow remote processors to >>>>> be shutdown when the controlling userpsace application crashes or >>>>> hangs. >>>>> >>>> Thanks for intruducing Ioctl, this will help for future evolutions. >>>> >>>>> Signed-off-by: Rishabh Bhatnagar <rishabhb@xxxxxxxxxxxxxx> >>>>> --- >>>>> Documentation/userspace-api/ioctl/ioctl-number.rst | 1 + >>>>> drivers/remoteproc/Kconfig | 9 ++ >>>>> drivers/remoteproc/Makefile | 1 + >>>>> drivers/remoteproc/remoteproc_cdev.c | 143 >>>>> +++++++++++++++++++++ >>>>> drivers/remoteproc/remoteproc_internal.h | 21 +++ >>>>> include/linux/remoteproc.h | 3 + >>>>> include/uapi/linux/remoteproc_cdev.h | 20 +++ >>>>> 7 files changed, 198 insertions(+) >>>>> create mode 100644 drivers/remoteproc/remoteproc_cdev.c >>>>> create mode 100644 include/uapi/linux/remoteproc_cdev.h >>>>> >>>>> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst >>>>> b/Documentation/userspace-api/ioctl/ioctl-number.rst >>>>> index 2e91370..412b2a0 100644 >>>>> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst >>>>> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst >>>>> @@ -337,6 +337,7 @@ Code Seq# Include File >>>>> Comments >>>>> 0xB4 00-0F linux/gpio.h >>>>> <mailto:linux-gpio@xxxxxxxxxxxxxxx> >>>>> 0xB5 00-0F uapi/linux/rpmsg.h >>>>> <mailto:linux-remoteproc@xxxxxxxxxxxxxxx> >>>>> 0xB6 all linux/fpga-dfl.h >>>>> +0xB7 all uapi/linux/remoteproc_cdev.h >>>>> <mailto:linux-remoteproc@xxxxxxxxxxxxxxx> >>>>> 0xC0 00-0F linux/usb/iowarrior.h >>>>> 0xCA 00-0F uapi/misc/cxl.h >>>>> 0xCA 10-2F uapi/misc/ocxl.h >>>>> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig >>>>> index de3862c..6374b79 100644 >>>>> --- a/drivers/remoteproc/Kconfig >>>>> +++ b/drivers/remoteproc/Kconfig >>>>> @@ -14,6 +14,15 @@ config REMOTEPROC >>>>> >>>>> if REMOTEPROC >>>>> >>>>> +config REMOTEPROC_CDEV >>>>> + bool "Remoteproc character device interface" >>>>> + help >>>>> + Say y here to have a character device interface for Remoteproc >>>>> + framework. Userspace can boot/shutdown remote processors through >>>>> + this interface. >>>>> + >>>>> + It's safe to say N if you don't want to use this interface. >>>>> + >>>>> config IMX_REMOTEPROC >>>>> tristate "IMX6/7 remoteproc support" >>>>> depends on ARCH_MXC >>>>> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile >>>>> index e30a1b1..b7d4f77 100644 >>>>> --- a/drivers/remoteproc/Makefile >>>>> +++ b/drivers/remoteproc/Makefile >>>>> @@ -9,6 +9,7 @@ remoteproc-y += remoteproc_debugfs.o >>>>> remoteproc-y += remoteproc_sysfs.o >>>>> remoteproc-y += remoteproc_virtio.o >>>>> remoteproc-y += remoteproc_elf_loader.o >>>>> +obj-$(CONFIG_REMOTEPROC_CDEV) += remoteproc_cdev.o >>>>> obj-$(CONFIG_IMX_REMOTEPROC) += imx_rproc.o >>>>> obj-$(CONFIG_MTK_SCP) += mtk_scp.o mtk_scp_ipi.o >>>>> obj-$(CONFIG_OMAP_REMOTEPROC) += omap_remoteproc.o >>>>> diff --git a/drivers/remoteproc/remoteproc_cdev.c >>>>> b/drivers/remoteproc/remoteproc_cdev.c >>>>> new file mode 100644 >>>>> index 0000000..65142ec >>>>> --- /dev/null >>>>> +++ b/drivers/remoteproc/remoteproc_cdev.c >>>>> @@ -0,0 +1,143 @@ >>>>> +// SPDX-License-Identifier: GPL-2.0-only >>>>> +/* >>>>> + * Character device interface driver for Remoteproc framework. >>>>> + * >>>>> + * Copyright (c) 2020, The Linux Foundation. All rights reserved. >>>>> + */ >>>>> + >>>>> +#include <linux/cdev.h> >>>>> +#include <linux/fs.h> >>>>> +#include <linux/module.h> >>>>> +#include <linux/mutex.h> >>>>> +#include <linux/remoteproc.h> >>>>> +#include <uapi/linux/remoteproc_cdev.h> >>>>> +#include <linux/uaccess.h> >>>>> + >>>>> +#include "remoteproc_internal.h" >>>>> + >>>>> +#define NUM_RPROC_DEVICES 64 >>>>> +static dev_t rproc_major; >>>>> + >>>>> +static ssize_t rproc_cdev_write(struct file *filp, const char __user >>>>> *buf, >>>>> + size_t len, loff_t *pos) >>>>> +{ >>>>> + struct rproc *rproc = container_of(filp->f_inode->i_cdev, >>>>> + struct rproc, char_dev); >>>>> + int ret = 0; >>>>> + char cmd[10]; >>>>> + >>>>> + if (!len || len > sizeof(cmd)) >>>>> + return -EINVAL; >>>>> + >>>>> + ret = copy_from_user(cmd, buf, sizeof(cmd)); >>>>> + if (ret) >>>>> + return -EFAULT; >>>>> + >>>>> + if (sysfs_streq(cmd, "start")) { >>>>> + if (rproc->state == RPROC_RUNNING) >>>>> + return -EBUSY; >>>>> + >>>>> + ret = rproc_boot(rproc); >>>>> + if (ret) >>>>> + dev_err(&rproc->dev, "Boot failed:%d\n", ret); >>>>> + } else if (sysfs_streq(cmd, "stop")) { >>>>> + if (rproc->state == RPROC_OFFLINE) >>>>> + return -ENXIO; >>>> returning ENXIO in this case seems to me no appropriate , what about >>>> EPERM or >>>> EINVAL (rproc_sysfs) ? > > I think EPERM would indicate the operation is not permitted on the > device, and > EINVAL would indicate that the command/string they wrote to the char device > is not a valid command/string. I guess even ENXIO may not be appropriate? > > In that case we could use EHOSTDOWN or ESHUTDOWN, thoughts? Regarding remoteproc_sysfs.c[1], seems that the -EINVAL return would be coherent. It would probably also be better to replace your condition with if (rproc->state != RPROC_RUNNING) [1] https://elixir.bootlin.com/linux/latest/source/drivers/remoteproc/remoteproc_sysfs.c#L104 Regards, Arnaud > > Thanks, > Sid > >>>> >>>>> + >>>>> + rproc_shutdown(rproc); >>>>> + } else { >>>>> + dev_err(&rproc->dev, "Unrecognized option\n"); >>>>> + ret = -EINVAL; >>>>> + } >>>>> + >>>>> + return ret ? ret : len; >>>>> +} >>>>> + >>>>> +static long rproc_device_ioctl(struct file *filp, unsigned int ioctl, >>>>> + unsigned long arg) >>>>> +{ >>>>> + struct rproc *rproc = container_of(filp->f_inode->i_cdev, >>>>> + struct rproc, char_dev); >>>>> + void __user *argp = (void __user *)arg; >>>>> + int ret; >>>>> + bool param; >>>>> + >>>>> + switch (ioctl) { >>>>> + case RPROC_SET_SHUTDOWN_ON_RELEASE: >>>>> + ret = copy_from_user(¶m, argp, sizeof(bool)); >>>>> + if (ret) { >>>>> + dev_err(&rproc->dev, "Data copy from userspace failed\n"); >>>>> + return -EINVAL; >>>>> + } >>>>> + rproc->cdev_put_on_release = param; >>>> argp is an void value, where cdev_put_on_release is a bool a check or >>>> a conversion seems >>>> missing >>>> >>>>> + break; >>>>> + case RPROC_GET_SHUTDOWN_ON_RELEASE: >>>>> + ret = copy_to_user(argp, &rproc->cdev_put_on_release, >>>>> + sizeof(bool)); >>>>> + if (ret) { >>>>> + dev_err(&rproc->dev, "Data copy to userspace failed\n"); >>>>> + return -EINVAL; >>>>> + } >>>>> + break; >>>>> + default: >>>>> + dev_err(&rproc->dev, "Unsupported ioctl\n"); >>>>> + return -EINVAL; >>>>> + } >>>>> + return 0; >>>>> +} >>>>> + >>>>> +static int rproc_cdev_release(struct inode *inode, struct file *filp) >>>>> +{ >>>>> + struct rproc *rproc = container_of(inode->i_cdev, struct rproc, >>>>> + char_dev); >>>>> + >>>>> + if (rproc->cdev_put_on_release && rproc->state != RPROC_OFFLINE) >>>>> + rproc_shutdown(rproc); >>>>> + >>>>> + return 0; >>>>> +} >>>>> + >>>>> + >>>>> +static const struct file_operations rproc_fops = { >>>>> + .write = rproc_cdev_write, >>>>> + .unlocked_ioctl = rproc_device_ioctl, >>>>> + .release = rproc_cdev_release, >>>>> +}; >>>>> + >>>>> +int rproc_char_device_add(struct rproc *rproc) >>>>> +{ >>>>> + int ret; >>>>> + dev_t cdevt; >>>>> + >>>>> + cdev_init(&rproc->char_dev, &rproc_fops); >>>>> + rproc->char_dev.owner = THIS_MODULE; >>>>> + >>>>> + cdevt = MKDEV(MAJOR(rproc_major), rproc->index); >>>>> + ret = cdev_add(&rproc->char_dev, cdevt, 1); >>>>> + if (ret < 0) >>>>> + goto out; >>>>> + >>>>> + rproc->dev.devt = cdevt; >>>>> +out: >>>>> + return ret; >>>>> +} >>>>> + >>>>> +void rproc_char_device_remove(struct rproc *rproc) >>>>> +{ >>>>> + __unregister_chrdev(MAJOR(rproc->dev.devt), rproc->index, 1, >>>>> "rproc"); >>>>> +} >>>>> + >>>>> +void __init rproc_init_cdev(void) >>>>> +{ >>>>> + int ret; >>>>> + >>>>> + ret = alloc_chrdev_region(&rproc_major, 0, NUM_RPROC_DEVICES, >>>>> "rproc"); >>>> "remoteproc"instead of "rproc" (in line with sysfs and debugfs naming) >>>> . >>>> >>>>> + if (ret < 0) >>>>> + pr_err("Failed to alloc rproc_cdev region, err %d\n", ret); >>>>> +} >>>>> + >>>>> +void __exit rproc_exit_cdev(void) >>>>> +{ >>>>> + unregister_chrdev_region(MKDEV(MAJOR(rproc_major), 0), >>>>> + NUM_RPROC_DEVICES); >>>>> +} >>>>> diff --git a/drivers/remoteproc/remoteproc_internal.h >>>>> b/drivers/remoteproc/remoteproc_internal.h >>>>> index 493ef92..fb9d891 100644 >>>>> --- a/drivers/remoteproc/remoteproc_internal.h >>>>> +++ b/drivers/remoteproc/remoteproc_internal.h >>>>> @@ -47,6 +47,27 @@ struct dentry *rproc_create_trace_file(const char >>>>> *name, struct rproc *rproc, >>>>> int rproc_init_sysfs(void); >>>>> void rproc_exit_sysfs(void); >>>>> >>>>> +#ifdef CONFIG_REMOTEPROC_CDEV >>>>> +void rproc_init_cdev(void); >>>>> +void rproc_exit_cdev(void); >>>>> +int rproc_char_device_add(struct rproc *rproc); >>>>> +void rproc_char_device_remove(struct rproc *rproc); >>>>> +#else >>>>> +static inline void rproc_init_cdev(void) >>>>> +{ >>>>> +} >>>>> +static inline void rproc_exit_cdev(void) >>>>> +{ >>>>> +} >>>>> +static inline int rproc_char_device_add(struct rproc *rproc) >>>>> +{ >>>>> + return 0; >>>>> +} >>>>> +static inline void rproc_char_device_remove(struct rproc *rproc) >>>>> +{ >>>>> +} >>>>> +#endif >>>>> + >>>>> void rproc_free_vring(struct rproc_vring *rvring); >>>>> int rproc_alloc_vring(struct rproc_vdev *rvdev, int i); >>>>> >>>>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h >>>>> index 16ad666..9bd2ff5 100644 >>>>> --- a/include/linux/remoteproc.h >>>>> +++ b/include/linux/remoteproc.h >>>>> @@ -40,6 +40,7 @@ >>>>> #include <linux/virtio.h> >>>>> #include <linux/completion.h> >>>>> #include <linux/idr.h> >>>>> +#include <linux/cdev.h> >>>>> #include <linux/of.h> >>>>> >>>>> /** >>>>> @@ -514,6 +515,8 @@ struct rproc { >>>>> bool auto_boot; >>>>> struct list_head dump_segments; >>>>> int nb_vdev; >>>>> + struct cdev char_dev; >>>>> + bool cdev_put_on_release; >>>>> }; >>>> These parameters are local variables of rproc_cdev. Could be defined >>>> in a separate structure. >>>> with a pointer in rproc to this structure. >>>> >>>>> /** >>>>> diff --git a/include/uapi/linux/remoteproc_cdev.h >>>>> b/include/uapi/linux/remoteproc_cdev.h >>>>> new file mode 100644 >>>>> index 0000000..3975120 >>>>> --- /dev/null >>>>> +++ b/include/uapi/linux/remoteproc_cdev.h >>>>> @@ -0,0 +1,20 @@ >>>>> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */ >>>>> +/* >>>>> + * IOCTLs for Remoteproc's character device interface. >>>>> + * >>>>> + * Copyright (c) 2020, The Linux Foundation. All rights reserved. >>>>> + */ >>>>> + >>>>> + >>>>> +#ifndef _UAPI_REMOTEPROC_CDEV_H_ >>>>> +#define _UAPI_REMOTEPROC_CDEV_H_ >>>>> + >>>>> +#include <linux/ioctl.h> >>>>> +#include <linux/types.h> >>>>> + >>>>> +#define RPROC_MAGIC 0xB7 >>>>> + >>>>> +#define RPROC_SET_SHUTDOWN_ON_RELEASE _IOW(RPROC_MAGIC, 1, int) >>>>> +#define RPROC_GET_SHUTDOWN_ON_RELEASE _IOR(RPROC_MAGIC, 2, int) >>>>> + >>>>> +#endif >>>>> >>>> IOCTLs should probaly be documented. >>> I have added documentation to >>> Documentation/userspace-api/ioctl/ioctl-number.rst >>> Is there another place where I need to add documentation for this? >> Could you add in this file comments that describe >> the IOCTL usage and associated parameter? >> >> Regards, >> Arnaud >> >>>> Thanks, >>>> Arnaud
