#include <linux/smp_lock.h>
#include <linux/major.h>
#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
#include <asm/processor.h>
#include <asm/msr.h>
#include <asm/uaccess.h>
#include <asm/system.h>
-/* Note: "err" is handled in a funny way below. Otherwise one version
- of gcc or another breaks. */
+static struct class *msr_class;
static inline int wrmsr_eio(u32 reg, u32 eax, u32 edx)
{
- int err;
-
- asm volatile(
- "1: wrmsr\n"
- "2:\n"
- ".section .fixup,\"ax\"\n"
- "3: movl %4,%0\n"
- " jmp 2b\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- " .align 4\n"
- " .long 1b,3b\n"
- ".previous"
- : "=&bDS" (err)
- : "a" (eax), "d" (edx), "c" (reg), "i" (-EIO), "0" (0));
-
- return err;
+ int err;
+
+ err = wrmsr_safe(reg, eax, edx);
+ if (err)
+ err = -EIO;
+ return err;
}
static inline int rdmsr_eio(u32 reg, u32 *eax, u32 *edx)
{
- int err;
-
- asm volatile(
- "1: rdmsr\n"
- "2:\n"
- ".section .fixup,\"ax\"\n"
- "3: movl %4,%0\n"
- " jmp 2b\n"
- ".previous\n"
- ".section __ex_table,\"a\"\n"
- " .align 4\n"
- " .long 1b,3b\n"
- ".previous"
- : "=&bDS" (err), "=a" (*eax), "=d" (*edx)
- : "c" (reg), "i" (-EIO), "0" (0));
-
- return err;
+ int err;
+
+ err = rdmsr_safe(reg, eax, edx);
+ if (err)
+ err = -EIO;
+ return err;
}
#ifdef CONFIG_SMP
struct msr_command {
- int cpu;
- int err;
- u32 reg;
- u32 data[2];
+ int cpu;
+ int err;
+ u32 reg;
+ u32 data[2];
};
static void msr_smp_wrmsr(void *cmd_block)
{
- struct msr_command *cmd = (struct msr_command *) cmd_block;
-
- if ( cmd->cpu == smp_processor_id() )
- cmd->err = wrmsr_eio(cmd->reg, cmd->data[0], cmd->data[1]);
+ struct msr_command *cmd = (struct msr_command *)cmd_block;
+
+ if (cmd->cpu == smp_processor_id())
+ cmd->err = wrmsr_eio(cmd->reg, cmd->data[0], cmd->data[1]);
}
static void msr_smp_rdmsr(void *cmd_block)
{
- struct msr_command *cmd = (struct msr_command *) cmd_block;
-
- if ( cmd->cpu == smp_processor_id() )
- cmd->err = rdmsr_eio(cmd->reg, &cmd->data[0], &cmd->data[1]);
+ struct msr_command *cmd = (struct msr_command *)cmd_block;
+
+ if (cmd->cpu == smp_processor_id())
+ cmd->err = rdmsr_eio(cmd->reg, &cmd->data[0], &cmd->data[1]);
}
static inline int do_wrmsr(int cpu, u32 reg, u32 eax, u32 edx)
{
- struct msr_command cmd;
- int ret;
-
- preempt_disable();
- if ( cpu == smp_processor_id() ) {
- ret = wrmsr_eio(reg, eax, edx);
- } else {
- cmd.cpu = cpu;
- cmd.reg = reg;
- cmd.data[0] = eax;
- cmd.data[1] = edx;
-
- smp_call_function(msr_smp_wrmsr, &cmd, 1, 1);
- ret = cmd.err;
- }
- preempt_enable();
- return ret;
+ struct msr_command cmd;
+ int ret;
+
+ preempt_disable();
+ if (cpu == smp_processor_id()) {
+ ret = wrmsr_eio(reg, eax, edx);
+ } else {
+ cmd.cpu = cpu;
+ cmd.reg = reg;
+ cmd.data[0] = eax;
+ cmd.data[1] = edx;
+
+ smp_call_function(msr_smp_wrmsr, &cmd, 1, 1);
+ ret = cmd.err;
+ }
+ preempt_enable();
+ return ret;
}
-static inline int do_rdmsr(int cpu, u32 reg, u32 *eax, u32 *edx)
+static inline int do_rdmsr(int cpu, u32 reg, u32 * eax, u32 * edx)
{
- struct msr_command cmd;
- int ret;
-
- preempt_disable();
- if ( cpu == smp_processor_id() ) {
- ret = rdmsr_eio(reg, eax, edx);
- } else {
- cmd.cpu = cpu;
- cmd.reg = reg;
-
- smp_call_function(msr_smp_rdmsr, &cmd, 1, 1);
-
- *eax = cmd.data[0];
- *edx = cmd.data[1];
-
- ret = cmd.err;
- }
- preempt_enable();
- return ret;
+ struct msr_command cmd;
+ int ret;
+
+ preempt_disable();
+ if (cpu == smp_processor_id()) {
+ ret = rdmsr_eio(reg, eax, edx);
+ } else {
+ cmd.cpu = cpu;
+ cmd.reg = reg;
+
+ smp_call_function(msr_smp_rdmsr, &cmd, 1, 1);
+
+ *eax = cmd.data[0];
+ *edx = cmd.data[1];
+
+ ret = cmd.err;
+ }
+ preempt_enable();
+ return ret;
}
-#else /* ! CONFIG_SMP */
+#else /* ! CONFIG_SMP */
static inline int do_wrmsr(int cpu, u32 reg, u32 eax, u32 edx)
{
- return wrmsr_eio(reg, eax, edx);
+ return wrmsr_eio(reg, eax, edx);
}
static inline int do_rdmsr(int cpu, u32 reg, u32 *eax, u32 *edx)
{
- return rdmsr_eio(reg, eax, edx);
+ return rdmsr_eio(reg, eax, edx);
}
-#endif /* ! CONFIG_SMP */
+#endif /* ! CONFIG_SMP */
static loff_t msr_seek(struct file *file, loff_t offset, int orig)
{
- loff_t ret = -EINVAL;
- lock_kernel();
- switch (orig) {
- case 0:
- file->f_pos = offset;
- ret = file->f_pos;
- break;
- case 1:
- file->f_pos += offset;
- ret = file->f_pos;
- }
- unlock_kernel();
- return ret;
+ loff_t ret = -EINVAL;
+
+ lock_kernel();
+ switch (orig) {
+ case 0:
+ file->f_pos = offset;
+ ret = file->f_pos;
+ break;
+ case 1:
+ file->f_pos += offset;
+ ret = file->f_pos;
+ }
+ unlock_kernel();
+ return ret;
}
-static ssize_t msr_read(struct file * file, char __user * buf,
- size_t count, loff_t *ppos)
+static ssize_t msr_read(struct file *file, char __user * buf,
+ size_t count, loff_t * ppos)
{
- u32 *tmp = (u32 *)buf;
- u32 data[2];
- size_t rv;
- u32 reg = *ppos;
- int cpu = iminor(file->f_dentry->d_inode);
- int err;
-
- if ( count % 8 )
- return -EINVAL; /* Invalid chunk size */
-
- for ( rv = 0 ; count ; count -= 8 ) {
- err = do_rdmsr(cpu, reg, &data[0], &data[1]);
- if ( err )
- return err;
- if ( copy_to_user(tmp,&data,8) )
- return -EFAULT;
- tmp += 2;
- }
-
- return ((char *)tmp) - buf;
+ u32 __user *tmp = (u32 __user *) buf;
+ u32 data[2];
+ u32 reg = *ppos;
+ int cpu = iminor(file->f_dentry->d_inode);
+ int err;
+
+ if (count % 8)
+ return -EINVAL; /* Invalid chunk size */
+
+ for (; count; count -= 8) {
+ err = do_rdmsr(cpu, reg, &data[0], &data[1]);
+ if (err)
+ return err;
+ if (copy_to_user(tmp, &data, 8))
+ return -EFAULT;
+ tmp += 2;
+ }
+
+ return ((char __user *)tmp) - buf;
}
-static ssize_t msr_write(struct file * file, const char __user * buf,
+static ssize_t msr_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
- const u32 *tmp = (const u32 *)buf;
- u32 data[2];
- size_t rv;
- u32 reg = *ppos;
- int cpu = iminor(file->f_dentry->d_inode);
- int err;
-
- if ( count % 8 )
- return -EINVAL; /* Invalid chunk size */
-
- for ( rv = 0 ; count ; count -= 8 ) {
- if ( copy_from_user(&data,tmp,8) )
- return -EFAULT;
- err = do_wrmsr(cpu, reg, data[0], data[1]);
- if ( err )
- return err;
- tmp += 2;
- }
-
- return ((char *)tmp) - buf;
+ const u32 __user *tmp = (const u32 __user *)buf;
+ u32 data[2];
+ size_t rv;
+ u32 reg = *ppos;
+ int cpu = iminor(file->f_dentry->d_inode);
+ int err;
+
+ if (count % 8)
+ return -EINVAL; /* Invalid chunk size */
+
+ for (rv = 0; count; count -= 8) {
+ if (copy_from_user(&data, tmp, 8))
+ return -EFAULT;
+ err = do_wrmsr(cpu, reg, data[0], data[1]);
+ if (err)
+ return err;
+ tmp += 2;
+ }
+
+ return ((char __user *)tmp) - buf;
}
static int msr_open(struct inode *inode, struct file *file)
{
- int cpu = iminor(file->f_dentry->d_inode);
- struct cpuinfo_x86 *c = &(cpu_data)[cpu];
-
- if (!cpu_online(cpu))
- return -ENXIO; /* No such CPU */
- if ( !cpu_has(c, X86_FEATURE_MSR) )
- return -EIO; /* MSR not supported */
-
- return 0;
+ unsigned int cpu = iminor(file->f_dentry->d_inode);
+ struct cpuinfo_x86 *c = &(cpu_data)[cpu];
+
+ if (cpu >= NR_CPUS || !cpu_online(cpu))
+ return -ENXIO; /* No such CPU */
+ if (!cpu_has(c, X86_FEATURE_MSR))
+ return -EIO; /* MSR not supported */
+
+ return 0;
}
/*
* File operations we support
*/
static struct file_operations msr_fops = {
- .owner = THIS_MODULE,
- .llseek = msr_seek,
- .read = msr_read,
- .write = msr_write,
- .open = msr_open,
+ .owner = THIS_MODULE,
+ .llseek = msr_seek,
+ .read = msr_read,
+ .write = msr_write,
+ .open = msr_open,
+};
+
+static int msr_class_device_create(int i)
+{
+ int err = 0;
+ struct class_device *class_err;
+
+ class_err = class_device_create(msr_class, NULL, MKDEV(MSR_MAJOR, i), NULL, "msr%d",i);
+ if (IS_ERR(class_err))
+ err = PTR_ERR(class_err);
+ return err;
+}
+
+static int msr_class_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+
+ switch (action) {
+ case CPU_ONLINE:
+ msr_class_device_create(cpu);
+ break;
+ case CPU_DEAD:
+ class_device_destroy(msr_class, MKDEV(MSR_MAJOR, cpu));
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block msr_class_cpu_notifier =
+{
+ .notifier_call = msr_class_cpu_callback,
};
-int __init msr_init(void)
+static int __init msr_init(void)
{
- if (register_chrdev(MSR_MAJOR, "cpu/msr", &msr_fops)) {
- printk(KERN_ERR "msr: unable to get major %d for msr\n",
- MSR_MAJOR);
- return -EBUSY;
- }
-
- return 0;
+ int i, err = 0;
+ i = 0;
+
+ if (register_chrdev(MSR_MAJOR, "cpu/msr", &msr_fops)) {
+ printk(KERN_ERR "msr: unable to get major %d for msr\n",
+ MSR_MAJOR);
+ err = -EBUSY;
+ goto out;
+ }
+ msr_class = class_create(THIS_MODULE, "msr");
+ if (IS_ERR(msr_class)) {
+ err = PTR_ERR(msr_class);
+ goto out_chrdev;
+ }
+ for_each_online_cpu(i) {
+ err = msr_class_device_create(i);
+ if (err != 0)
+ goto out_class;
+ }
+ register_cpu_notifier(&msr_class_cpu_notifier);
+
+ err = 0;
+ goto out;
+
+out_class:
+ i = 0;
+ for_each_online_cpu(i)
+ class_device_destroy(msr_class, MKDEV(MSR_MAJOR, i));
+ class_destroy(msr_class);
+out_chrdev:
+ unregister_chrdev(MSR_MAJOR, "cpu/msr");
+out:
+ return err;
}
-void __exit msr_exit(void)
+static void __exit msr_exit(void)
{
- unregister_chrdev(MSR_MAJOR, "cpu/msr");
+ int cpu = 0;
+ for_each_online_cpu(cpu)
+ class_device_destroy(msr_class, MKDEV(MSR_MAJOR, cpu));
+ class_destroy(msr_class);
+ unregister_chrdev(MSR_MAJOR, "cpu/msr");
+ unregister_cpu_notifier(&msr_class_cpu_notifier);
}
module_init(msr_init);