1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* ----------------------------------------------------------------------- *
4  *   Copyright 2000-2008 H. Peter Anvin - All Rights Reserved
7  * ----------------------------------------------------------------------- */
17  * an SMP box will direct the access to CPU %d.
29 #include <linux/smp.h>
64 		return -EINVAL;	/* Invalid chunk size */  in msr_read()
66 	for (; count; count -= 8) {  in msr_read()
71 			err = -EFAULT;  in msr_read()
87 	 * It's possible to be smarter here and do it (for example) per-MSR, but  in filter_write()
95 	case MSR_WRITES_OFF: return -EPERM;  in filter_write()
106 	       reg, current->comm, current->pid);  in filter_write()
130 		return -EINVAL;	/* Invalid chunk size */  in msr_write()
132 	for (; count; count -= 8) {  in msr_write()
134 			err = -EFAULT;  in msr_write()
160 		if (!(file->f_mode & FMODE_READ)) {  in msr_ioctl()
161 			err = -EBADF;  in msr_ioctl()
165 			err = -EFAULT;  in msr_ioctl()
172 			err = -EFAULT;  in msr_ioctl()
176 		if (!(file->f_mode & FMODE_WRITE)) {  in msr_ioctl()
177 			err = -EBADF;  in msr_ioctl()
181 			err = -EFAULT;  in msr_ioctl()
191 			err = -EFAULT;  in msr_ioctl()
195 		err = -ENOTTY;  in msr_ioctl()
207 	if (!capable(CAP_SYS_RAWIO))  in msr_open()
208 		return -EPERM;  in msr_open()
211 		return -ENXIO;	/* No such CPU */  in msr_open()
215 		return -EIO;	/* MSR not supported */  in msr_open()
250 	return kasprintf(GFP_KERNEL, "cpu/%u/msr", MINOR(dev->devt));  in msr_devnode()
259 		return -EBUSY;  in msr_init()
266 	msr_class->devnode = msr_devnode;  in msr_init()
293 	/* val is NUL-terminated, see kernfs_fop_write() */  in module_exit()