X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2Fkernel%2Fcpuid.c;h=c10ebc4b8e4ba36b9d0d7ee72fefaf8bd07e21f9;hb=2347d933b158932cf2b8aeebae3e5cc16b200bd1;hp=5c2faa10e9fac42f604d0af086af0618835c289d;hpb=19f71153b9be219756c6b2757921433a69b7975c;p=linux-2.6 diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c index 5c2faa10e9..c10ebc4b8e 100644 --- a/arch/x86/kernel/cpuid.c +++ b/arch/x86/kernel/cpuid.c @@ -1,6 +1,6 @@ /* ----------------------------------------------------------------------- * - * - * Copyright 2000 H. Peter Anvin - All Rights Reserved + * + * 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 @@ -11,14 +11,16 @@ * ----------------------------------------------------------------------- */ /* - * cpuid.c - * * x86 CPUID access device * * This device is accessed by lseek() to the appropriate CPUID level * and then read in chunks of 16 bytes. A larger size means multiple * reads of consecutive levels. * + * The lower 32 bits of the file position is used as the incoming %eax, + * and the upper 32 bits of the file position as the incoming %ecx, + * the latter intended for "counting" eax levels like eax=4. + * * This driver uses /dev/cpu/%d/cpuid where %d is the minor number, and on * an SMP box will direct the access to CPU %d. */ @@ -45,45 +47,18 @@ static struct class *cpuid_class; -#ifdef CONFIG_SMP - -struct cpuid_command { - u32 reg; - u32 *data; +struct cpuid_regs { + u32 eax, ebx, ecx, edx; }; static void cpuid_smp_cpuid(void *cmd_block) { - struct cpuid_command *cmd = (struct cpuid_command *)cmd_block; - - cpuid(cmd->reg, &cmd->data[0], &cmd->data[1], &cmd->data[2], - &cmd->data[3]); -} - -static inline void do_cpuid(int cpu, u32 reg, u32 * data) -{ - struct cpuid_command cmd; - - preempt_disable(); - if (cpu == smp_processor_id()) { - cpuid(reg, &data[0], &data[1], &data[2], &data[3]); - } else { - cmd.reg = reg; - cmd.data = data; - - smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1); - } - preempt_enable(); -} -#else /* ! CONFIG_SMP */ + struct cpuid_regs *cmd = (struct cpuid_regs *)cmd_block; -static inline void do_cpuid(int cpu, u32 reg, u32 * data) -{ - cpuid(reg, &data[0], &data[1], &data[2], &data[3]); + cpuid_count(cmd->eax, cmd->ecx, + &cmd->eax, &cmd->ebx, &cmd->ecx, &cmd->edx); } -#endif /* ! CONFIG_SMP */ - static loff_t cpuid_seek(struct file *file, loff_t offset, int orig) { loff_t ret; @@ -111,19 +86,21 @@ static ssize_t cpuid_read(struct file *file, char __user *buf, size_t count, loff_t * ppos) { char __user *tmp = buf; - u32 data[4]; - u32 reg = *ppos; + struct cpuid_regs cmd; int cpu = iminor(file->f_path.dentry->d_inode); + u64 pos = *ppos; if (count % 16) return -EINVAL; /* Invalid chunk size */ for (; count; count -= 16) { - do_cpuid(cpu, reg, data); - if (copy_to_user(tmp, &data, 16)) + cmd.eax = pos; + cmd.ecx = pos >> 32; + smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1); + if (copy_to_user(tmp, &cmd, 16)) return -EFAULT; tmp += 16; - *ppos = reg++; + *ppos = ++pos; } return tmp - buf; @@ -132,7 +109,7 @@ static ssize_t cpuid_read(struct file *file, char __user *buf, static int cpuid_open(struct inode *inode, struct file *file) { unsigned int cpu = iminor(file->f_path.dentry->d_inode); - struct cpuinfo_x86 *c = &(cpu_data)[cpu]; + struct cpuinfo_x86 *c = &cpu_data(cpu); if (cpu >= NR_CPUS || !cpu_online(cpu)) return -ENXIO; /* No such CPU */ @@ -152,35 +129,43 @@ static const struct file_operations cpuid_fops = { .open = cpuid_open, }; -static int cpuid_device_create(int i) +static __cpuinit int cpuid_device_create(int cpu) { - int err = 0; struct device *dev; - dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, i), "cpu%d",i); - if (IS_ERR(dev)) - err = PTR_ERR(dev); - return err; + dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu), + "cpu%d", cpu); + return IS_ERR(dev) ? PTR_ERR(dev) : 0; } -static int cpuid_class_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) +static void cpuid_device_destroy(int cpu) +{ + device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu)); +} + +static int __cpuinit cpuid_class_cpu_callback(struct notifier_block *nfb, + unsigned long action, + void *hcpu) { unsigned int cpu = (unsigned long)hcpu; + int err = 0; switch (action) { - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - cpuid_device_create(cpu); + case CPU_UP_PREPARE: + err = cpuid_device_create(cpu); break; + case CPU_UP_CANCELED: case CPU_DEAD: - case CPU_DEAD_FROZEN: - device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu)); + cpuid_device_destroy(cpu); + break; + case CPU_UP_CANCELED_FROZEN: + destroy_suspended_device(cpuid_class, MKDEV(CPUID_MAJOR, cpu)); break; } - return NOTIFY_OK; + return err ? NOTIFY_BAD : NOTIFY_OK; } -static struct notifier_block __cpuinitdata cpuid_class_cpu_notifier = +static struct notifier_block __refdata cpuid_class_cpu_notifier = { .notifier_call = cpuid_class_cpu_callback, }; @@ -203,7 +188,7 @@ static int __init cpuid_init(void) } for_each_online_cpu(i) { err = cpuid_device_create(i); - if (err != 0) + if (err != 0) goto out_class; } register_hotcpu_notifier(&cpuid_class_cpu_notifier); @@ -214,11 +199,11 @@ static int __init cpuid_init(void) out_class: i = 0; for_each_online_cpu(i) { - device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, i)); + cpuid_device_destroy(i); } class_destroy(cpuid_class); out_chrdev: - unregister_chrdev(CPUID_MAJOR, "cpu/cpuid"); + unregister_chrdev(CPUID_MAJOR, "cpu/cpuid"); out: return err; } @@ -228,7 +213,7 @@ static void __exit cpuid_exit(void) int cpu = 0; for_each_online_cpu(cpu) - device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu)); + cpuid_device_destroy(cpu); class_destroy(cpuid_class); unregister_chrdev(CPUID_MAJOR, "cpu/cpuid"); unregister_hotcpu_notifier(&cpuid_class_cpu_notifier);