drivers/gator/gator_pmu.c - LeafOS-Devices/android_kernel_samsung_universal7904 - Gitiles

 /**
  * Copyright (C) Arm Limited 2015-2016. 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 version 2 as
  * published by the Free Software Foundation.
  */

 #include <linux/cpumask.h>

 #ifdef CONFIG_64BIT
 #   define  GATOR_ATOMIC_T          atomic64_t
 #   define  GATOR_ATOMIC_CMPXCHG    atomic64_cmpxchg
 #   define  GATOR_ATOMIC_READ       atomic64_read
 #else
 #   define  GATOR_ATOMIC_T          atomic_t
 #   define  GATOR_ATOMIC_CMPXCHG    atomic_cmpxchg
 #   define  GATOR_ATOMIC_READ       atomic_read
 #endif

 #define GATOR_ATOMIC_PTR_TO_COUNTER(ptr)    ((unsigned long) (ptr))

 struct uncore_pmu {
     struct list_head list;
     unsigned long pmnc_counters;
     unsigned long has_cycles_counter;
     /* Perf PMU name */
     char pmnc_name[MAXSIZE_CORE_NAME];
     /* gatorfs event name */
     char core_name[MAXSIZE_CORE_NAME];
     /* cpumask - actually an atomic so we can CAS the pointer once without lock*/
     GATOR_ATOMIC_T cpumask_atomic;
 };

 static LIST_HEAD(uncore_pmus);
 static LIST_HEAD(gator_cpus);
 static DEFINE_MUTEX(pmu_mutex);

 static struct super_block *gator_sb;
 static struct dentry *gator_events_dir;

 static const struct gator_cpu gator_pmu_other = {
     .pmnc_name = "Other",
     .cpuid = 0xfffff,
     .core_name = "Other",
     .pmnc_counters = 6,
 };

 const struct gator_cpu *gator_clusters[GATOR_CLUSTER_COUNT];
 int gator_cluster_count;
 static ulong gator_cluster_ids[GATOR_CLUSTER_COUNT];

 static const struct gator_cpu *gator_find_cpu_by_cpuid(const u32 cpuid)
 {
     const struct gator_cpu *gator_cpu;

     list_for_each_entry(gator_cpu, &gator_cpus, list) {
         if (gator_cpu->cpuid == cpuid)
             return gator_cpu;
     }

     return NULL;
 }

 static const char OLD_PMU_PREFIX[] = "ARMv7 Cortex-";
 static const char NEW_PMU_PREFIX[] = "ARMv7_Cortex_";

 __maybe_unused
 static const struct gator_cpu *gator_find_cpu_by_pmu_name(const char *const name)
 {
     const struct gator_cpu *gator_cpu;

     list_for_each_entry(gator_cpu, &gator_cpus, list) {
         if (gator_cpu->pmnc_name != NULL &&
             /* Do the names match exactly? */
             (strcasecmp(gator_cpu->pmnc_name, name) == 0 ||
              /* Do these names match but have the old vs new prefix? */
              ((strncasecmp(name, OLD_PMU_PREFIX, sizeof(OLD_PMU_PREFIX) - 1) == 0 &&
                strncasecmp(gator_cpu->pmnc_name, NEW_PMU_PREFIX, sizeof(NEW_PMU_PREFIX) - 1) == 0 &&
                strcasecmp(name + sizeof(OLD_PMU_PREFIX) - 1, gator_cpu->pmnc_name + sizeof(NEW_PMU_PREFIX) - 1) == 0))))
             return gator_cpu;
     }

     return NULL;
 }

 __maybe_unused
 static const struct uncore_pmu *gator_find_uncore_pmu(const char *const name)
 {
     const struct uncore_pmu *uncore_pmu;

     list_for_each_entry(uncore_pmu, &uncore_pmus, list) {
         if (uncore_pmu->pmnc_name != NULL && strcasecmp(uncore_pmu->pmnc_name, name) == 0)
             return uncore_pmu;
     }

     return NULL;
 }

 static ssize_t gator_pmu_init_write(struct file *file, char const __user *buf, size_t count, loff_t *offset)
 {
     struct gator_interface *gi;
     int i;

     if (gator_events_perf_pmu_reread() != 0 ||
             gator_events_perf_pmu_create_files(gator_sb, gator_events_dir) != 0)
         return -EINVAL;

     if (gator_cluster_count == 0)
       gator_clusters[gator_cluster_count++] = &gator_pmu_other;

     /* cluster information */
     {
         struct dentry *dir;

         dir = gatorfs_mkdir(gator_sb, file->f_path.dentry->d_parent, "clusters");
         for (i = 0; i < gator_cluster_count; i++) {
             gator_cluster_ids[i] = i;
             gatorfs_create_ro_ulong(gator_sb, dir, gator_clusters[i]->pmnc_name, &gator_cluster_ids[i]);
         }
     }

     /* needs PMU info, so initialize afterwards */
     gator_trace_power_init();
     if (gator_trace_power_create_files(gator_sb, gator_events_dir) != 0)
         return -EINVAL;

     gator_trace_sched_init();
     if (sched_trace_create_files(gator_sb, gator_events_dir) != 0)
         return -EINVAL;

     /* events sources */
     for (i = 0; i < ARRAY_SIZE(gator_events_list); i++)
         if (gator_events_list[i])
             gator_events_list[i]();

     list_for_each_entry(gi, &gator_events, list)
         if (gi->create_files)
             if (gi->create_files(gator_sb, gator_events_dir) != 0)
                 pr_err("gator: create_files failed for %s\n", gi->name);

     return count;
 }

 static const struct file_operations gator_pmu_init_fops = {
     .write = gator_pmu_init_write,
 };

 static ssize_t gator_pmu_str_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
 {
     char *const val = file->private_data;

     return simple_read_from_buffer(buf, count, offset, val, strlen(val));
 }

 static ssize_t gator_pmu_str_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset)
 {
     char *value = file->private_data;

     if (*offset)
         return -EINVAL;

     if (count >= MAXSIZE_CORE_NAME)
         return -EINVAL;
     if (copy_from_user(value, buf, count))
         return -EFAULT;
     value[count] = 0;
     value = strstrip(value);

     return count;
 }

 static const struct file_operations gator_pmu_str_fops = {
     .read = gator_pmu_str_read_file,
     .write = gator_pmu_str_write_file,
     .open = default_open,
 };

 static int gator_pmu_create_str(struct super_block *sb, struct dentry *root, char const *name, char *const val)
 {
     struct dentry *d = __gatorfs_create_file(sb, root, name, &gator_pmu_str_fops, 0644);
     if (!d)
         return -EFAULT;

     d->d_inode->i_private = val;
     return 0;
 }

 #define GATOR_NONE_STRING "(none)"

 static ssize_t gator_pmu_cpumask_read(struct file *file, char __user *buf, size_t count, loff_t *offset)
 {
     struct uncore_pmu * uncore_pmu = NULL;
     struct cpumask * cpumask = NULL;
     int cpu = 0;
     int bpos = 0;
     char buffer[128];

     uncore_pmu = (struct uncore_pmu *) file->private_data;
     if (!uncore_pmu)
         return -EFAULT;

     cpumask = (struct cpumask *) GATOR_ATOMIC_READ(&(uncore_pmu->cpumask_atomic));
     if (!cpumask)
         return simple_read_from_buffer(buf, count, offset, GATOR_NONE_STRING, strlen(GATOR_NONE_STRING));

     for_each_cpu(cpu, cpumask) {
         bpos = snprintf(buffer + bpos, sizeof(buffer) - bpos, (bpos > 0 ? ",%d" : "%d"), cpu);
         if (bpos >= (sizeof(buffer) - 1))
             break;
     }

     return simple_read_from_buffer(buf, count, offset, buffer, strlen(buffer));
 }

 static ssize_t gator_pmu_cpumask_write(struct file *file, char const __user *ubuf, size_t count, loff_t *offset)
 {
     struct uncore_pmu * uncore_pmu = NULL;
     struct cpumask * cpumask = NULL;
     unsigned long value = 0;
     int retval = 0;

     uncore_pmu = (struct uncore_pmu *) file->private_data;
     if (!uncore_pmu)
         return -EFAULT;

     /* validate args */
     if (*offset)
         return -EINVAL;

     /* parse ulong */
     retval = gatorfs_ulong_from_user(&value, ubuf, count);
     if (retval)
         return retval;
     if (value >= nr_cpu_ids)
         return -EINVAL;

     /* allocate the mask if it does not already exist */
     cpumask = (struct cpumask *) GATOR_ATOMIC_READ(&(uncore_pmu->cpumask_atomic));
     if (!cpumask) {
         struct cpumask * ret = NULL;

         cpumask = kzalloc(cpumask_size(), GFP_KERNEL);
         if (!cpumask)
             return -ENOMEM;

         ret = (struct cpumask * ) GATOR_ATOMIC_CMPXCHG(&(uncore_pmu->cpumask_atomic), GATOR_ATOMIC_PTR_TO_COUNTER(NULL), GATOR_ATOMIC_PTR_TO_COUNTER(cpumask));
         if (ret != NULL) {
             /* someone else got there first, free the one we allocated and use the existing instead */
             kfree(cpumask);
             cpumask = ret;
         }
     }

     cpumask_set_cpu(value, cpumask);
     return count;
 }

 static const struct file_operations cpumask_fops = {
     .read = gator_pmu_cpumask_read,
     .write = gator_pmu_cpumask_write,
     .open = default_open,
 };

 static ssize_t gator_pmu_export_write(struct file *file, char const __user *ubuf, size_t count, loff_t *offset)
 {
     struct dentry *dir;
     struct dentry *parent;
     char buf[MAXSIZE_CORE_NAME];
     const char *str;

     if (*offset)
         return -EINVAL;

     if (count >= sizeof(buf))
         return -EINVAL;
     if (copy_from_user(&buf, ubuf, count))
         return -EFAULT;
     buf[count] = 0;
     str = strstrip(buf);

     parent = file->f_path.dentry->d_parent;
     dir = gatorfs_mkdir(gator_sb, parent, buf);
     if (!dir)
         return -EINVAL;

     if (strcmp("pmu", parent->d_name.name) == 0) {
         struct gator_cpu *gator_cpu;

         gator_cpu = kmalloc(sizeof(*gator_cpu), GFP_KERNEL);
         if (gator_cpu == NULL)
             return -ENOMEM;
         memset(gator_cpu, 0, sizeof(*gator_cpu));

         gatorfs_create_ulong(gator_sb, dir, "cpuid", &gator_cpu->cpuid);
         gator_pmu_create_str(gator_sb, dir, "core_name", gator_cpu->core_name);
         strcpy(gator_cpu->pmnc_name, str);
         gator_pmu_create_str(gator_sb, dir, "dt_name", gator_cpu->dt_name);
         gatorfs_create_ulong(gator_sb, dir, "pmnc_counters", &gator_cpu->pmnc_counters);

         mutex_lock(&pmu_mutex);
         list_add_tail(&gator_cpu->list, &gator_cpus); /* mutex */
         mutex_unlock(&pmu_mutex);
     } else {
         struct uncore_pmu *uncore_pmu;

         uncore_pmu = kmalloc(sizeof(*uncore_pmu), GFP_KERNEL);
         if (uncore_pmu == NULL)
             return -ENOMEM;
         memset(uncore_pmu, 0, sizeof(*uncore_pmu));

         strcpy(uncore_pmu->pmnc_name, str);
         gator_pmu_create_str(gator_sb, dir, "core_name", uncore_pmu->core_name);
         gatorfs_create_ulong(gator_sb, dir, "pmnc_counters", &uncore_pmu->pmnc_counters);
         gatorfs_create_ulong(gator_sb, dir, "has_cycles_counter", &uncore_pmu->has_cycles_counter);
         gatorfs_create_file_data(gator_sb, dir, "cpumask", &cpumask_fops, uncore_pmu);

         mutex_lock(&pmu_mutex);
         list_add_tail(&uncore_pmu->list, &uncore_pmus); /* mutex */
         mutex_unlock(&pmu_mutex);
     }

     return count;
 }

 static const struct file_operations export_fops = {
     .write = gator_pmu_export_write,
 };

 static int gator_pmu_create_files(struct super_block *sb, struct dentry *root, struct dentry *events)
 {
     struct dentry *dir;

     gator_sb = sb;
     gator_events_dir = events;

     gatorfs_create_file(sb, root, "pmu_init", &gator_pmu_init_fops);

     dir = gatorfs_mkdir(sb, root, "pmu");
     if (!dir)
         return -1;

     gatorfs_create_file(sb, dir, "export", &export_fops);

     dir = gatorfs_mkdir(sb, root, "uncore_pmu");
     if (!dir)
         return -1;

     gatorfs_create_file(sb, dir, "export", &export_fops);

     return 0;
 }

 static void gator_pmu_exit(void)
 {
     mutex_lock(&pmu_mutex);
     {
         struct gator_cpu *gator_cpu;
         struct gator_cpu *next;

         list_for_each_entry_safe(gator_cpu, next, &gator_cpus, list) {
             kfree(gator_cpu);
         }
     }
     {
         struct uncore_pmu *uncore_pmu;
         struct uncore_pmu *next;

         list_for_each_entry_safe(uncore_pmu, next, &uncore_pmus, list) {
             struct cpumask * cpumask = (struct cpumask *) GATOR_ATOMIC_READ(&(uncore_pmu->cpumask_atomic));
             if (cpumask) {
                 kfree(cpumask);
             }

             kfree(uncore_pmu);
         }
     }
     mutex_unlock(&pmu_mutex);
 }
	/**
	* Copyright (C) Arm Limited 2015-2016. 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 version 2 as
	* published by the Free Software Foundation.
	*/

	#include <linux/cpumask.h>

	#ifdef CONFIG_64BIT
	# define GATOR_ATOMIC_T atomic64_t
	# define GATOR_ATOMIC_CMPXCHG atomic64_cmpxchg
	# define GATOR_ATOMIC_READ atomic64_read
	#else
	# define GATOR_ATOMIC_T atomic_t
	# define GATOR_ATOMIC_CMPXCHG atomic_cmpxchg
	# define GATOR_ATOMIC_READ atomic_read
	#endif

	#define GATOR_ATOMIC_PTR_TO_COUNTER(ptr) ((unsigned long) (ptr))

	struct uncore_pmu {
	struct list_head list;
	unsigned long pmnc_counters;
	unsigned long has_cycles_counter;
	/* Perf PMU name */
	char pmnc_name[MAXSIZE_CORE_NAME];
	/* gatorfs event name */
	char core_name[MAXSIZE_CORE_NAME];
	/* cpumask - actually an atomic so we can CAS the pointer once without lock*/
	GATOR_ATOMIC_T cpumask_atomic;
	};

	static LIST_HEAD(uncore_pmus);
	static LIST_HEAD(gator_cpus);
	static DEFINE_MUTEX(pmu_mutex);

	static struct super_block *gator_sb;
	static struct dentry *gator_events_dir;

	static const struct gator_cpu gator_pmu_other = {
	.pmnc_name = "Other",
	.cpuid = 0xfffff,
	.core_name = "Other",
	.pmnc_counters = 6,
	};

	const struct gator_cpu *gator_clusters[GATOR_CLUSTER_COUNT];
	int gator_cluster_count;
	static ulong gator_cluster_ids[GATOR_CLUSTER_COUNT];

	static const struct gator_cpu *gator_find_cpu_by_cpuid(const u32 cpuid)
	{
	const struct gator_cpu *gator_cpu;

	list_for_each_entry(gator_cpu, &gator_cpus, list) {
	if (gator_cpu->cpuid == cpuid)
	return gator_cpu;
	}

	return NULL;
	}

	static const char OLD_PMU_PREFIX[] = "ARMv7 Cortex-";
	static const char NEW_PMU_PREFIX[] = "ARMv7_Cortex_";

	__maybe_unused
	static const struct gator_cpu gator_find_cpu_by_pmu_name(const char const name)
	{
	const struct gator_cpu *gator_cpu;

	list_for_each_entry(gator_cpu, &gator_cpus, list) {
	if (gator_cpu->pmnc_name != NULL &&
	/* Do the names match exactly? */
	(strcasecmp(gator_cpu->pmnc_name, name) == 0 \|\|
	/* Do these names match but have the old vs new prefix? */
	((strncasecmp(name, OLD_PMU_PREFIX, sizeof(OLD_PMU_PREFIX) - 1) == 0 &&
	strncasecmp(gator_cpu->pmnc_name, NEW_PMU_PREFIX, sizeof(NEW_PMU_PREFIX) - 1) == 0 &&
	strcasecmp(name + sizeof(OLD_PMU_PREFIX) - 1, gator_cpu->pmnc_name + sizeof(NEW_PMU_PREFIX) - 1) == 0))))
	return gator_cpu;
	}

	return NULL;
	}

	__maybe_unused
	static const struct uncore_pmu gator_find_uncore_pmu(const char const name)
	{
	const struct uncore_pmu *uncore_pmu;

	list_for_each_entry(uncore_pmu, &uncore_pmus, list) {
	if (uncore_pmu->pmnc_name != NULL && strcasecmp(uncore_pmu->pmnc_name, name) == 0)
	return uncore_pmu;
	}

	return NULL;
	}

	static ssize_t gator_pmu_init_write(struct file file, char const __user buf, size_t count, loff_t *offset)
	{
	struct gator_interface *gi;
	int i;

	if (gator_events_perf_pmu_reread() != 0 \|\|
	gator_events_perf_pmu_create_files(gator_sb, gator_events_dir) != 0)
	return -EINVAL;

	if (gator_cluster_count == 0)
	gator_clusters[gator_cluster_count++] = &gator_pmu_other;

	/* cluster information */
	{
	struct dentry *dir;

	dir = gatorfs_mkdir(gator_sb, file->f_path.dentry->d_parent, "clusters");
	for (i = 0; i < gator_cluster_count; i++) {
	gator_cluster_ids[i] = i;
	gatorfs_create_ro_ulong(gator_sb, dir, gator_clusters[i]->pmnc_name, &gator_cluster_ids[i]);
	}
	}

	/* needs PMU info, so initialize afterwards */
	gator_trace_power_init();
	if (gator_trace_power_create_files(gator_sb, gator_events_dir) != 0)
	return -EINVAL;

	gator_trace_sched_init();
	if (sched_trace_create_files(gator_sb, gator_events_dir) != 0)
	return -EINVAL;

	/* events sources */
	for (i = 0; i < ARRAY_SIZE(gator_events_list); i++)
	if (gator_events_list[i])
	gator_events_list[i]();

	list_for_each_entry(gi, &gator_events, list)
	if (gi->create_files)
	if (gi->create_files(gator_sb, gator_events_dir) != 0)
	pr_err("gator: create_files failed for %s\n", gi->name);

	return count;
	}

	static const struct file_operations gator_pmu_init_fops = {
	.write = gator_pmu_init_write,
	};

	static ssize_t gator_pmu_str_read_file(struct file file, char __user buf, size_t count, loff_t *offset)
	{
	char *const val = file->private_data;

	return simple_read_from_buffer(buf, count, offset, val, strlen(val));
	}

	static ssize_t gator_pmu_str_write_file(struct file file, char const __user buf, size_t count, loff_t *offset)
	{
	char *value = file->private_data;

	if (*offset)
	return -EINVAL;

	if (count >= MAXSIZE_CORE_NAME)
	return -EINVAL;
	if (copy_from_user(value, buf, count))
	return -EFAULT;
	value[count] = 0;
	value = strstrip(value);

	return count;
	}

	static const struct file_operations gator_pmu_str_fops = {
	.read = gator_pmu_str_read_file,
	.write = gator_pmu_str_write_file,
	.open = default_open,
	};

	static int gator_pmu_create_str(struct super_block sb, struct dentry root, char const name, char const val)
	{
	struct dentry *d = __gatorfs_create_file(sb, root, name, &gator_pmu_str_fops, 0644);
	if (!d)
	return -EFAULT;

	d->d_inode->i_private = val;
	return 0;
	}

	#define GATOR_NONE_STRING "(none)"

	static ssize_t gator_pmu_cpumask_read(struct file file, char __user buf, size_t count, loff_t *offset)
	{
	struct uncore_pmu * uncore_pmu = NULL;
	struct cpumask * cpumask = NULL;
	int cpu = 0;
	int bpos = 0;
	char buffer[128];

	uncore_pmu = (struct uncore_pmu *) file->private_data;
	if (!uncore_pmu)
	return -EFAULT;

	cpumask = (struct cpumask *) GATOR_ATOMIC_READ(&(uncore_pmu->cpumask_atomic));
	if (!cpumask)
	return simple_read_from_buffer(buf, count, offset, GATOR_NONE_STRING, strlen(GATOR_NONE_STRING));

	for_each_cpu(cpu, cpumask) {
	bpos = snprintf(buffer + bpos, sizeof(buffer) - bpos, (bpos > 0 ? ",%d" : "%d"), cpu);
	if (bpos >= (sizeof(buffer) - 1))
	break;
	}

	return simple_read_from_buffer(buf, count, offset, buffer, strlen(buffer));
	}

	static ssize_t gator_pmu_cpumask_write(struct file file, char const __user ubuf, size_t count, loff_t *offset)
	{
	struct uncore_pmu * uncore_pmu = NULL;
	struct cpumask * cpumask = NULL;
	unsigned long value = 0;
	int retval = 0;

	uncore_pmu = (struct uncore_pmu *) file->private_data;
	if (!uncore_pmu)
	return -EFAULT;

	/* validate args */
	if (*offset)
	return -EINVAL;

	/* parse ulong */
	retval = gatorfs_ulong_from_user(&value, ubuf, count);
	if (retval)
	return retval;
	if (value >= nr_cpu_ids)
	return -EINVAL;

	/* allocate the mask if it does not already exist */
	cpumask = (struct cpumask *) GATOR_ATOMIC_READ(&(uncore_pmu->cpumask_atomic));
	if (!cpumask) {
	struct cpumask * ret = NULL;

	cpumask = kzalloc(cpumask_size(), GFP_KERNEL);
	if (!cpumask)
	return -ENOMEM;

	ret = (struct cpumask * ) GATOR_ATOMIC_CMPXCHG(&(uncore_pmu->cpumask_atomic), GATOR_ATOMIC_PTR_TO_COUNTER(NULL), GATOR_ATOMIC_PTR_TO_COUNTER(cpumask));
	if (ret != NULL) {
	/* someone else got there first, free the one we allocated and use the existing instead */
	kfree(cpumask);
	cpumask = ret;
	}
	}

	cpumask_set_cpu(value, cpumask);
	return count;
	}

	static const struct file_operations cpumask_fops = {
	.read = gator_pmu_cpumask_read,
	.write = gator_pmu_cpumask_write,
	.open = default_open,
	};

	static ssize_t gator_pmu_export_write(struct file file, char const __user ubuf, size_t count, loff_t *offset)
	{
	struct dentry *dir;
	struct dentry *parent;
	char buf[MAXSIZE_CORE_NAME];
	const char *str;

	if (*offset)
	return -EINVAL;

	if (count >= sizeof(buf))
	return -EINVAL;
	if (copy_from_user(&buf, ubuf, count))
	return -EFAULT;
	buf[count] = 0;
	str = strstrip(buf);

	parent = file->f_path.dentry->d_parent;
	dir = gatorfs_mkdir(gator_sb, parent, buf);
	if (!dir)
	return -EINVAL;

	if (strcmp("pmu", parent->d_name.name) == 0) {
	struct gator_cpu *gator_cpu;

	gator_cpu = kmalloc(sizeof(*gator_cpu), GFP_KERNEL);
	if (gator_cpu == NULL)
	return -ENOMEM;
	memset(gator_cpu, 0, sizeof(*gator_cpu));

	gatorfs_create_ulong(gator_sb, dir, "cpuid", &gator_cpu->cpuid);
	gator_pmu_create_str(gator_sb, dir, "core_name", gator_cpu->core_name);
	strcpy(gator_cpu->pmnc_name, str);
	gator_pmu_create_str(gator_sb, dir, "dt_name", gator_cpu->dt_name);
	gatorfs_create_ulong(gator_sb, dir, "pmnc_counters", &gator_cpu->pmnc_counters);

	mutex_lock(&pmu_mutex);
	list_add_tail(&gator_cpu->list, &gator_cpus); /* mutex */
	mutex_unlock(&pmu_mutex);
	} else {
	struct uncore_pmu *uncore_pmu;

	uncore_pmu = kmalloc(sizeof(*uncore_pmu), GFP_KERNEL);
	if (uncore_pmu == NULL)
	return -ENOMEM;
	memset(uncore_pmu, 0, sizeof(*uncore_pmu));

	strcpy(uncore_pmu->pmnc_name, str);
	gator_pmu_create_str(gator_sb, dir, "core_name", uncore_pmu->core_name);
	gatorfs_create_ulong(gator_sb, dir, "pmnc_counters", &uncore_pmu->pmnc_counters);
	gatorfs_create_ulong(gator_sb, dir, "has_cycles_counter", &uncore_pmu->has_cycles_counter);
	gatorfs_create_file_data(gator_sb, dir, "cpumask", &cpumask_fops, uncore_pmu);

	mutex_lock(&pmu_mutex);
	list_add_tail(&uncore_pmu->list, &uncore_pmus); /* mutex */
	mutex_unlock(&pmu_mutex);
	}

	return count;
	}

	static const struct file_operations export_fops = {
	.write = gator_pmu_export_write,
	};

	static int gator_pmu_create_files(struct super_block sb, struct dentry root, struct dentry *events)
	{
	struct dentry *dir;

	gator_sb = sb;
	gator_events_dir = events;

	gatorfs_create_file(sb, root, "pmu_init", &gator_pmu_init_fops);

	dir = gatorfs_mkdir(sb, root, "pmu");
	if (!dir)
	return -1;

	gatorfs_create_file(sb, dir, "export", &export_fops);

	dir = gatorfs_mkdir(sb, root, "uncore_pmu");
	if (!dir)
	return -1;

	gatorfs_create_file(sb, dir, "export", &export_fops);

	return 0;
	}

	static void gator_pmu_exit(void)
	{
	mutex_lock(&pmu_mutex);
	{
	struct gator_cpu *gator_cpu;
	struct gator_cpu *next;

	list_for_each_entry_safe(gator_cpu, next, &gator_cpus, list) {
	kfree(gator_cpu);
	}
	}
	{
	struct uncore_pmu *uncore_pmu;
	struct uncore_pmu *next;

	list_for_each_entry_safe(uncore_pmu, next, &uncore_pmus, list) {
	struct cpumask * cpumask = (struct cpumask *) GATOR_ATOMIC_READ(&(uncore_pmu->cpumask_atomic));
	if (cpumask) {
	kfree(cpumask);
	}

	kfree(uncore_pmu);
	}
	}
	mutex_unlock(&pmu_mutex);
	}