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) ? >> >>> + >>> + 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
