On 7/1/20 12:02 AM, Siddharth Gupta wrote: > > On 6/30/2020 12:43 AM, Arnaud POULIQUEN wrote: >> >> 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. > Okay sure. >> It would probably also be better to replace your condition with >> if (rproc->state != RPROC_RUNNING) > Will do. >> >> >> [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 > > I don't see any for of comments that describe in detail the IOCTL usage, > i.e., > input parameters, etc. Could you provide an example so I can follow it? > > If not, should I instead put them in Documentation/remoteproc.txt? Bjorn and Mathieu are the right persons to decide on the best place. Here are 2 exemples of "inline" documented IOCTRLs. https://elixir.bootlin.com/linux/latest/source/arch/s390/include/uapi/asm/tape390.h#L15 https://elixir.bootlin.com/linux/latest/source/drivers/net/wan/cosa.h#L63 Could be something like that: /* * The RPROC_SET_SHUTDOWN_ON_RELEASE ioctl allows to enable/disable the * automatic remote processors shutdown when the controlling userpsace * closes the char device interface. * * input parameter: integer * 0 : disable automatic shutdown * other: enable automatic shutdown */ #define RPROC_SET_SHUTDOWN_ON_RELEASE _IOW(RPROC_MAGIC, 1, int) /* * The RPROC_GET_SHUTDOWN_ON_RELEASE ioctl gets information about the * automatic remote processors shutdown when the controlling userpsace * closes the char device interface. * * output parameter: integer * 0: automatic shutdown disable * 1: automatic shutdown enable */ #define RPROC_GET_SHUTDOWN_ON_RELEASE _IOR(RPROC_MAGIC, 2, int) Regards, Arnaud > > Thanks, > Sid > >>>> >>>>>> Thanks, >>>>>> Arnaud
