On Fri, May 22, 2020 at 09:29:35AM +0300, Andra Paraschiv wrote: > +static char *ne_cpus; > +module_param(ne_cpus, charp, 0644); > +MODULE_PARM_DESC(ne_cpus, "<cpu-list> - CPU pool used for Nitro Enclaves"); This is not the 1990's, don't use module parameters if you can help it. Why is this needed, and where is it documented? > +/* CPU pool used for Nitro Enclaves. */ > +struct ne_cpu_pool { > + /* Available CPUs in the pool. */ > + cpumask_var_t avail; > + struct mutex mutex; > +}; > + > +static struct ne_cpu_pool ne_cpu_pool; > + > +static int ne_open(struct inode *node, struct file *file) > +{ > + return 0; > +} If open does nothing, just don't even provide it. > + > +static long ne_ioctl(struct file *file, unsigned int cmd, unsigned long arg) > +{ > + switch (cmd) { > + > + default: > + return -ENOTTY; > + } > + > + return 0; > +} Same for ioctl. > + > +static int ne_release(struct inode *inode, struct file *file) > +{ > + return 0; > +} Same for release. > + > +static const struct file_operations ne_fops = { > + .owner = THIS_MODULE, > + .llseek = noop_llseek, > + .unlocked_ioctl = ne_ioctl, > + .open = ne_open, > + .release = ne_release, > +}; > + > +struct miscdevice ne_miscdevice = { > + .minor = MISC_DYNAMIC_MINOR, > + .name = NE_DEV_NAME, > + .fops = &ne_fops, > + .mode = 0660, > +}; > + > +static int __init ne_init(void) > +{ > + unsigned int cpu = 0; > + unsigned int cpu_sibling = 0; > + int rc = -EINVAL; > + > + memset(&ne_cpu_pool, 0, sizeof(ne_cpu_pool)); Why did you just set a structure to 0 that was already initialized by the system to 0? Are you sure about this? > + > + if (!zalloc_cpumask_var(&ne_cpu_pool.avail, GFP_KERNEL)) > + return -ENOMEM; > + > + mutex_init(&ne_cpu_pool.mutex); > + > + rc = cpulist_parse(ne_cpus, ne_cpu_pool.avail); > + if (rc < 0) { > + pr_err_ratelimited(NE "Error in cpulist parse [rc=%d]\n", rc); Again, drop all ratelimited stuff please. thanks, greg k-h