diff options
Diffstat (limited to 'arch/x86/kernel/cpuid.c')
| -rw-r--r-- | arch/x86/kernel/cpuid.c | 71 |
1 files changed, 42 insertions, 29 deletions
diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c index 0931a105ffe1..dae436253de4 100644 --- a/arch/x86/kernel/cpuid.c +++ b/arch/x86/kernel/cpuid.c @@ -1,13 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* ----------------------------------------------------------------------- * * * Copyright 2000-2008 H. Peter Anvin - All Rights Reserved * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139, - * USA; either version 2 of the License, or (at your option) any later - * version; incorporated herein by reference. - * * ----------------------------------------------------------------------- */ /* @@ -40,26 +35,34 @@ #include <linux/notifier.h> #include <linux/uaccess.h> #include <linux/gfp.h> +#include <linux/completion.h> #include <asm/processor.h> #include <asm/msr.h> -static struct class *cpuid_class; static enum cpuhp_state cpuhp_cpuid_state; +struct cpuid_regs_done { + struct cpuid_regs regs; + struct completion done; +}; + static void cpuid_smp_cpuid(void *cmd_block) { - struct cpuid_regs *cmd = (struct cpuid_regs *)cmd_block; + struct cpuid_regs_done *cmd = cmd_block; - cpuid_count(cmd->eax, cmd->ecx, - &cmd->eax, &cmd->ebx, &cmd->ecx, &cmd->edx); + cpuid_count(cmd->regs.eax, cmd->regs.ecx, + &cmd->regs.eax, &cmd->regs.ebx, + &cmd->regs.ecx, &cmd->regs.edx); + + complete(&cmd->done); } static ssize_t cpuid_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { char __user *tmp = buf; - struct cpuid_regs cmd; + struct cpuid_regs_done cmd; int cpu = iminor(file_inode(file)); u64 pos = *ppos; ssize_t bytes = 0; @@ -68,19 +71,27 @@ static ssize_t cpuid_read(struct file *file, char __user *buf, if (count % 16) return -EINVAL; /* Invalid chunk size */ + init_completion(&cmd.done); for (; count; count -= 16) { - cmd.eax = pos; - cmd.ecx = pos >> 32; - err = smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1); + call_single_data_t csd; + + INIT_CSD(&csd, cpuid_smp_cpuid, &cmd); + + cmd.regs.eax = pos; + cmd.regs.ecx = pos >> 32; + + err = smp_call_function_single_async(cpu, &csd); if (err) break; - if (copy_to_user(tmp, &cmd, 16)) { + wait_for_completion(&cmd.done); + if (copy_to_user(tmp, &cmd.regs, 16)) { err = -EFAULT; break; } tmp += 16; bytes += 16; *ppos = ++pos; + reinit_completion(&cmd.done); } return bytes ? bytes : err; @@ -112,26 +123,31 @@ static const struct file_operations cpuid_fops = { .open = cpuid_open, }; +static char *cpuid_devnode(const struct device *dev, umode_t *mode) +{ + return kasprintf(GFP_KERNEL, "cpu/%u/cpuid", MINOR(dev->devt)); +} + +static const struct class cpuid_class = { + .name = "cpuid", + .devnode = cpuid_devnode, +}; + static int cpuid_device_create(unsigned int cpu) { struct device *dev; - dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu), NULL, + dev = device_create(&cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu), NULL, "cpu%d", cpu); return PTR_ERR_OR_ZERO(dev); } static int cpuid_device_destroy(unsigned int cpu) { - device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu)); + device_destroy(&cpuid_class, MKDEV(CPUID_MAJOR, cpu)); return 0; } -static char *cpuid_devnode(struct device *dev, umode_t *mode) -{ - return kasprintf(GFP_KERNEL, "cpu/%u/cpuid", MINOR(dev->devt)); -} - static int __init cpuid_init(void) { int err; @@ -142,12 +158,9 @@ static int __init cpuid_init(void) CPUID_MAJOR); return -EBUSY; } - cpuid_class = class_create(THIS_MODULE, "cpuid"); - if (IS_ERR(cpuid_class)) { - err = PTR_ERR(cpuid_class); + err = class_register(&cpuid_class); + if (err) goto out_chrdev; - } - cpuid_class->devnode = cpuid_devnode; err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/cpuid:online", cpuid_device_create, cpuid_device_destroy); @@ -158,7 +171,7 @@ static int __init cpuid_init(void) return 0; out_class: - class_destroy(cpuid_class); + class_unregister(&cpuid_class); out_chrdev: __unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid"); return err; @@ -168,7 +181,7 @@ module_init(cpuid_init); static void __exit cpuid_exit(void) { cpuhp_remove_state(cpuhp_cpuid_state); - class_destroy(cpuid_class); + class_unregister(&cpuid_class); __unregister_chrdev(CPUID_MAJOR, 0, NR_CPUS, "cpu/cpuid"); } module_exit(cpuid_exit); |