+
+void profile_hit(int type, void *__pc)
+{
+ unsigned long pc;
+
+ if (prof_on != type || !prof_buffer)
+ return;
+ pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift;
+ atomic_inc(&prof_buffer[min(pc, prof_len - 1)]);
+}
+
+void profile_tick(int type, struct pt_regs *regs)
+{
+ if (type == CPU_PROFILING)
+ profile_hook(regs);
+ if (!user_mode(regs) && cpu_isset(smp_processor_id(), prof_cpu_mask))
+ profile_hit(type, (void *)profile_pc(regs));
+}
+
+#ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
+#include <asm/uaccess.h>
+#include <asm/ptrace.h>
+
+static int prof_cpu_mask_read_proc (char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len = cpumask_scnprintf(page, count, *(cpumask_t *)data);
+ if (count - len < 2)
+ return -EINVAL;
+ len += sprintf(page + len, "\n");
+ return len;
+}
+
+static int prof_cpu_mask_write_proc (struct file *file, const char __user *buffer,
+ unsigned long count, void *data)
+{
+ cpumask_t *mask = (cpumask_t *)data;
+ unsigned long full_count = count, err;
+ cpumask_t new_value;
+
+ err = cpumask_parse(buffer, count, new_value);
+ if (err)
+ return err;
+
+ *mask = new_value;
+ return full_count;
+}
+
+void create_prof_cpu_mask(struct proc_dir_entry *root_irq_dir)
+{
+ struct proc_dir_entry *entry;
+
+ /* create /proc/irq/prof_cpu_mask */
+ if (!(entry = create_proc_entry("prof_cpu_mask", 0600, root_irq_dir)))
+ return;
+ entry->nlink = 1;
+ entry->data = (void *)&prof_cpu_mask;
+ entry->read_proc = prof_cpu_mask_read_proc;
+ entry->write_proc = prof_cpu_mask_write_proc;
+}
+
+/*
+ * This function accesses profiling information. The returned data is
+ * binary: the sampling step and the actual contents of the profile
+ * buffer. Use of the program readprofile is recommended in order to
+ * get meaningful info out of these data.
+ */
+static ssize_t
+read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+ unsigned long p = *ppos;
+ ssize_t read;
+ char * pnt;
+ unsigned int sample_step = 1 << prof_shift;
+
+ if (p >= (prof_len+1)*sizeof(unsigned int))
+ return 0;
+ if (count > (prof_len+1)*sizeof(unsigned int) - p)
+ count = (prof_len+1)*sizeof(unsigned int) - p;
+ read = 0;
+
+ while (p < sizeof(unsigned int) && count > 0) {
+ put_user(*((char *)(&sample_step)+p),buf);
+ buf++; p++; count--; read++;
+ }
+ pnt = (char *)prof_buffer + p - sizeof(atomic_t);
+ if (copy_to_user(buf,(void *)pnt,count))
+ return -EFAULT;
+ read += count;
+ *ppos += read;
+ return read;
+}
+
+/*
+ * Writing to /proc/profile resets the counters
+ *
+ * Writing a 'profiling multiplier' value into it also re-sets the profiling
+ * interrupt frequency, on architectures that support this.
+ */
+static ssize_t write_profile(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+#ifdef CONFIG_SMP
+ extern int setup_profiling_timer (unsigned int multiplier);
+
+ if (count == sizeof(int)) {
+ unsigned int multiplier;
+
+ if (copy_from_user(&multiplier, buf, sizeof(int)))
+ return -EFAULT;
+
+ if (setup_profiling_timer(multiplier))
+ return -EINVAL;
+ }
+#endif
+
+ memset(prof_buffer, 0, prof_len * sizeof(atomic_t));
+ return count;
+}
+
+static struct file_operations proc_profile_operations = {
+ .read = read_profile,
+ .write = write_profile,
+};
+
+static int __init create_proc_profile(void)
+{
+ struct proc_dir_entry *entry;
+
+ if (!prof_on)
+ return 0;
+ if (!(entry = create_proc_entry("profile", S_IWUSR | S_IRUGO, NULL)))
+ return 0;
+ entry->proc_fops = &proc_profile_operations;
+ entry->size = (1+prof_len) * sizeof(atomic_t);
+ return 0;
+}
+module_init(create_proc_profile);
+#endif /* CONFIG_PROC_FS */