[net-next-2.6.git] / arch / arm / oprofile / common.c

/**
 * @file common.c
 *
 * @remark Copyright 2004 Oprofile Authors
 * @remark Copyright 2010 ARM Ltd.
 * @remark Read the file COPYING
 *
 * @author Zwane Mwaikambo
 * @author Will Deacon [move to perf]
 */

#include <linux/cpumask.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/oprofile.h>
#include <linux/perf_event.h>
#include <linux/slab.h>
#include <linux/sysdev.h>
#include <asm/stacktrace.h>
#include <linux/uaccess.h>

#include <asm/perf_event.h>
#include <asm/ptrace.h>

#ifdef CONFIG_HW_PERF_EVENTS
/*
 * Per performance monitor configuration as set via oprofilefs.
 */
struct op_counter_config {
	unsigned long count;
	unsigned long enabled;
	unsigned long event;
	unsigned long unit_mask;
	unsigned long kernel;
	unsigned long user;
	struct perf_event_attr attr;
};

static int op_arm_enabled;
static DEFINE_MUTEX(op_arm_mutex);

static struct op_counter_config *counter_config;
static struct perf_event **perf_events[nr_cpumask_bits];
static int perf_num_counters;

/*
 * Overflow callback for oprofile.
 */
static void op_overflow_handler(struct perf_event *event, int unused,
			struct perf_sample_data *data, struct pt_regs *regs)
{
	int id;
	u32 cpu = smp_processor_id();

	for (id = 0; id < perf_num_counters; ++id)
		if (perf_events[cpu][id] == event)
			break;

	if (id != perf_num_counters)
		oprofile_add_sample(regs, id);
	else
		pr_warning("oprofile: ignoring spurious overflow "
				"on cpu %u\n", cpu);
}

/*
 * Called by op_arm_setup to create perf attributes to mirror the oprofile
 * settings in counter_config. Attributes are created as `pinned' events and
 * so are permanently scheduled on the PMU.
 */
static void op_perf_setup(void)
{
	int i;
	u32 size = sizeof(struct perf_event_attr);
	struct perf_event_attr *attr;

	for (i = 0; i < perf_num_counters; ++i) {
		attr = &counter_config[i].attr;
		memset(attr, 0, size);
		attr->type		= PERF_TYPE_RAW;
		attr->size		= size;
		attr->config		= counter_config[i].event;
		attr->sample_period	= counter_config[i].count;
		attr->pinned		= 1;
	}
}

static int op_create_counter(int cpu, int event)
{
	int ret = 0;
	struct perf_event *pevent;

	if (!counter_config[event].enabled || (perf_events[cpu][event] != NULL))
		return ret;

	pevent = perf_event_create_kernel_counter(&counter_config[event].attr,
						  cpu, -1,
						  op_overflow_handler);

	if (IS_ERR(pevent)) {
		ret = PTR_ERR(pevent);
	} else if (pevent->state != PERF_EVENT_STATE_ACTIVE) {
		pr_warning("oprofile: failed to enable event %d "
				"on CPU %d\n", event, cpu);
		ret = -EBUSY;
	} else {
		perf_events[cpu][event] = pevent;
	}

	return ret;
}

static void op_destroy_counter(int cpu, int event)
{
	struct perf_event *pevent = perf_events[cpu][event];

	if (pevent) {
		perf_event_release_kernel(pevent);
		perf_events[cpu][event] = NULL;
	}
}

/*
 * Called by op_arm_start to create active perf events based on the
 * perviously configured attributes.
 */
static int op_perf_start(void)
{
	int cpu, event, ret = 0;

	for_each_online_cpu(cpu) {
		for (event = 0; event < perf_num_counters; ++event) {
			ret = op_create_counter(cpu, event);
			if (ret)
				goto out;
		}
	}

out:
	return ret;
}

/*
 * Called by op_arm_stop at the end of a profiling run.
 */
static void op_perf_stop(void)
{
	int cpu, event;

	for_each_online_cpu(cpu)
		for (event = 0; event < perf_num_counters; ++event)
			op_destroy_counter(cpu, event);
}


static char *op_name_from_perf_id(enum arm_perf_pmu_ids id)
{
	switch (id) {
	case ARM_PERF_PMU_ID_XSCALE1:
		return "arm/xscale1";
	case ARM_PERF_PMU_ID_XSCALE2:
		return "arm/xscale2";
	case ARM_PERF_PMU_ID_V6:
		return "arm/armv6";
	case ARM_PERF_PMU_ID_V6MP:
		return "arm/mpcore";
	case ARM_PERF_PMU_ID_CA8:
		return "arm/armv7";
	case ARM_PERF_PMU_ID_CA9:
		return "arm/armv7-ca9";
	default:
		return NULL;
	}
}

static int op_arm_create_files(struct super_block *sb, struct dentry *root)
{
	unsigned int i;

	for (i = 0; i < perf_num_counters; i++) {
		struct dentry *dir;
		char buf[4];

		snprintf(buf, sizeof buf, "%d", i);
		dir = oprofilefs_mkdir(sb, root, buf);
		oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
		oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);
		oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);
		oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
		oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
		oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
	}

	return 0;
}

static int op_arm_setup(void)
{
	spin_lock(&oprofilefs_lock);
	op_perf_setup();
	spin_unlock(&oprofilefs_lock);
	return 0;
}

static int op_arm_start(void)
{
	int ret = -EBUSY;

	mutex_lock(&op_arm_mutex);
	if (!op_arm_enabled) {
		ret = 0;
		op_perf_start();
		op_arm_enabled = 1;
	}
	mutex_unlock(&op_arm_mutex);
	return ret;
}

static void op_arm_stop(void)
{
	mutex_lock(&op_arm_mutex);
	if (op_arm_enabled)
		op_perf_stop();
	op_arm_enabled = 0;
	mutex_unlock(&op_arm_mutex);
}

#ifdef CONFIG_PM
static int op_arm_suspend(struct sys_device *dev, pm_message_t state)
{
	mutex_lock(&op_arm_mutex);
	if (op_arm_enabled)
		op_perf_stop();
	mutex_unlock(&op_arm_mutex);
	return 0;
}

static int op_arm_resume(struct sys_device *dev)
{
	mutex_lock(&op_arm_mutex);
	if (op_arm_enabled && op_perf_start())
		op_arm_enabled = 0;
	mutex_unlock(&op_arm_mutex);
	return 0;
}

static struct sysdev_class oprofile_sysclass = {
	.name		= "oprofile",
	.resume		= op_arm_resume,
	.suspend	= op_arm_suspend,
};

static struct sys_device device_oprofile = {
	.id		= 0,
	.cls		= &oprofile_sysclass,
};

static int __init init_driverfs(void)
{
	int ret;

	if (!(ret = sysdev_class_register(&oprofile_sysclass)))
		ret = sysdev_register(&device_oprofile);

	return ret;
}

static void  exit_driverfs(void)
{
	sysdev_unregister(&device_oprofile);
	sysdev_class_unregister(&oprofile_sysclass);
}
#else
#define init_driverfs()	do { } while (0)
#define exit_driverfs() do { } while (0)
#endif /* CONFIG_PM */

static int report_trace(struct stackframe *frame, void *d)
{
	unsigned int *depth = d;

	if (*depth) {
		oprofile_add_trace(frame->pc);
		(*depth)--;
	}

	return *depth == 0;
}

/*
 * The registers we're interested in are at the end of the variable
 * length saved register structure. The fp points at the end of this
 * structure so the address of this struct is:
 * (struct frame_tail *)(xxx->fp)-1
 */
struct frame_tail {
	struct frame_tail *fp;
	unsigned long sp;
	unsigned long lr;
} __attribute__((packed));

static struct frame_tail* user_backtrace(struct frame_tail *tail)
{
	struct frame_tail buftail[2];

	/* Also check accessibility of one struct frame_tail beyond */
	if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
		return NULL;
	if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
		return NULL;

	oprofile_add_trace(buftail[0].lr);

	/* frame pointers should strictly progress back up the stack
	 * (towards higher addresses) */
	if (tail >= buftail[0].fp)
		return NULL;

	return buftail[0].fp-1;
}

static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
{
	struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;

	if (!user_mode(regs)) {
		struct stackframe frame;
		frame.fp = regs->ARM_fp;
		frame.sp = regs->ARM_sp;
		frame.lr = regs->ARM_lr;
		frame.pc = regs->ARM_pc;
		walk_stackframe(&frame, report_trace, &depth);
		return;
	}

	while (depth-- && tail && !((unsigned long) tail & 3))
		tail = user_backtrace(tail);
}

int __init oprofile_arch_init(struct oprofile_operations *ops)
{
	int cpu, ret = 0;

	perf_num_counters = armpmu_get_max_events();

	counter_config = kcalloc(perf_num_counters,
			sizeof(struct op_counter_config), GFP_KERNEL);

	if (!counter_config) {
		pr_info("oprofile: failed to allocate %d "
				"counters\n", perf_num_counters);
		return -ENOMEM;
	}

	for_each_possible_cpu(cpu) {
		perf_events[cpu] = kcalloc(perf_num_counters,
				sizeof(struct perf_event *), GFP_KERNEL);
		if (!perf_events[cpu]) {
			pr_info("oprofile: failed to allocate %d perf events "
					"for cpu %d\n", perf_num_counters, cpu);
			while (--cpu >= 0)
				kfree(perf_events[cpu]);
			return -ENOMEM;
		}
	}

	init_driverfs();
	ops->backtrace		= arm_backtrace;
	ops->create_files	= op_arm_create_files;
	ops->setup		= op_arm_setup;
	ops->start		= op_arm_start;
	ops->stop		= op_arm_stop;
	ops->shutdown		= op_arm_stop;
	ops->cpu_type		= op_name_from_perf_id(armpmu_get_pmu_id());

	if (!ops->cpu_type)
		ret = -ENODEV;
	else
		pr_info("oprofile: using %s\n", ops->cpu_type);

	return ret;
}

void oprofile_arch_exit(void)
{
	int cpu, id;
	struct perf_event *event;

	if (*perf_events) {
		exit_driverfs();
		for_each_possible_cpu(cpu) {
			for (id = 0; id < perf_num_counters; ++id) {
				event = perf_events[cpu][id];
				if (event != NULL)
					perf_event_release_kernel(event);
			}
			kfree(perf_events[cpu]);
		}
	}

	if (counter_config)
		kfree(counter_config);
}
#else
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
	pr_info("oprofile: hardware counters not available\n");
	return -ENODEV;
}
void oprofile_arch_exit(void) {}
#endif /* CONFIG_HW_PERF_EVENTS */
Commit	Line	Data
1da177e4 LT	1	/**
	2	* @file common.c
	3	*
	4	* @remark Copyright 2004 Oprofile Authors
8c1fc96f	5	* @remark Copyright 2010 ARM Ltd.
1da177e4 LT	6	* @remark Read the file COPYING
	7	*
	8	* @author Zwane Mwaikambo
8c1fc96f	9	* @author Will Deacon [move to perf]
1da177e4 LT	10	*/
1da177e4 LT	11
8c1fc96f WD	12	#include <linux/cpumask.h>
8c1fc96f WD	13	#include <linux/errno.h>
1da177e4	14	#include <linux/init.h>
8c1fc96f	15	#include <linux/mutex.h>
1da177e4	16	#include <linux/oprofile.h>
8c1fc96f	17	#include <linux/perf_event.h>
ae92dc9f	18	#include <linux/slab.h>
1da177e4	19	#include <linux/sysdev.h>
8c1fc96f WD	20	#include <asm/stacktrace.h>
	21	#include <linux/uaccess.h>
	22
	23	#include <asm/perf_event.h>
	24	#include <asm/ptrace.h>
1da177e4	25
8c1fc96f WD	26	#ifdef CONFIG_HW_PERF_EVENTS
	27	/*
	28	* Per performance monitor configuration as set via oprofilefs.
	29	*/
	30	struct op_counter_config {
	31	unsigned long count;
	32	unsigned long enabled;
	33	unsigned long event;
	34	unsigned long unit_mask;
	35	unsigned long kernel;
	36	unsigned long user;
	37	struct perf_event_attr attr;
	38	};
1da177e4	39
55f05234	40	static int op_arm_enabled;
93ad7949	41	static DEFINE_MUTEX(op_arm_mutex);
1da177e4	42
8c1fc96f WD	43	static struct op_counter_config *counter_config;
	44	static struct perf_event **perf_events[nr_cpumask_bits];
	45	static int perf_num_counters;
	46
	47	/*
	48	* Overflow callback for oprofile.
	49	*/
	50	static void op_overflow_handler(struct perf_event *event, int unused,
	51	struct perf_sample_data data, struct pt_regs regs)
	52	{
	53	int id;
	54	u32 cpu = smp_processor_id();
	55
	56	for (id = 0; id < perf_num_counters; ++id)
	57	if (perf_events[cpu][id] == event)
	58	break;
	59
	60	if (id != perf_num_counters)
	61	oprofile_add_sample(regs, id);
	62	else
	63	pr_warning("oprofile: ignoring spurious overflow "
	64	"on cpu %u\n", cpu);
	65	}
	66
	67	/*
	68	* Called by op_arm_setup to create perf attributes to mirror the oprofile
	69	* settings in counter_config. Attributes are created as `pinned' events and
	70	* so are permanently scheduled on the PMU.
	71	*/
	72	static void op_perf_setup(void)
	73	{
	74	int i;
	75	u32 size = sizeof(struct perf_event_attr);
	76	struct perf_event_attr *attr;
	77
	78	for (i = 0; i < perf_num_counters; ++i) {
	79	attr = &counter_config[i].attr;
	80	memset(attr, 0, size);
	81	attr->type = PERF_TYPE_RAW;
	82	attr->size = size;
	83	attr->config = counter_config[i].event;
	84	attr->sample_period = counter_config[i].count;
	85	attr->pinned = 1;
	86	}
	87	}
	88
	89	static int op_create_counter(int cpu, int event)
	90	{
	91	int ret = 0;
	92	struct perf_event *pevent;
	93
	94	if (!counter_config[event].enabled \|\| (perf_events[cpu][event] != NULL))
	95	return ret;
	96
	97	pevent = perf_event_create_kernel_counter(&counter_config[event].attr,
	98	cpu, -1,
	99	op_overflow_handler);
	100
	101	if (IS_ERR(pevent)) {
	102	ret = PTR_ERR(pevent);
	103	} else if (pevent->state != PERF_EVENT_STATE_ACTIVE) {
	104	pr_warning("oprofile: failed to enable event %d "
	105	"on CPU %d\n", event, cpu);
	106	ret = -EBUSY;
107	} else {
108	perf_events[cpu][event] = pevent;
109	}
110
111	return ret;
112	}
113
114	static void op_destroy_counter(int cpu, int event)
115	{
116	struct perf_event *pevent = perf_events[cpu][event];
117
118	if (pevent) {
119	perf_event_release_kernel(pevent);
120	perf_events[cpu][event] = NULL;
121	}
122	}
123
124	/*
125	* Called by op_arm_start to create active perf events based on the
126	* perviously configured attributes.
127	*/
128	static int op_perf_start(void)
129	{
130	int cpu, event, ret = 0;
131
132	for_each_online_cpu(cpu) {
133	for (event = 0; event < perf_num_counters; ++event) {
134	ret = op_create_counter(cpu, event);
135	if (ret)
136	goto out;
137	}
138	}
139
140	out:
141	return ret;
142	}
143
144	/*
145	* Called by op_arm_stop at the end of a profiling run.
146	*/
147	static void op_perf_stop(void)
148	{
149	int cpu, event;
150
151	for_each_online_cpu(cpu)
152	for (event = 0; event < perf_num_counters; ++event)
153	op_destroy_counter(cpu, event);
154	}
155
156
157	static char *op_name_from_perf_id(enum arm_perf_pmu_ids id)
158	{
159	switch (id) {
160	case ARM_PERF_PMU_ID_XSCALE1:
161	return "arm/xscale1";
162	case ARM_PERF_PMU_ID_XSCALE2:
163	return "arm/xscale2";
164	case ARM_PERF_PMU_ID_V6:
165	return "arm/armv6";
166	case ARM_PERF_PMU_ID_V6MP:
167	return "arm/mpcore";
168	case ARM_PERF_PMU_ID_CA8:
169	return "arm/armv7";
170	case ARM_PERF_PMU_ID_CA9:
171	return "arm/armv7-ca9";
172	default:
173	return NULL;
174	}
175	}
1da177e4	176
55f05234	177	static int op_arm_create_files(struct super_block sb, struct dentry root)
1da177e4 LT	178	{
	179	unsigned int i;
	180
8c1fc96f	181	for (i = 0; i < perf_num_counters; i++) {
1da177e4	182	struct dentry *dir;
ae92dc9f	183	char buf[4];
1da177e4 LT	184
	185	snprintf(buf, sizeof buf, "%d", i);
	186	dir = oprofilefs_mkdir(sb, root, buf);
	187	oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
	188	oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);
	189	oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);
	190	oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
	191	oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
	192	oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
	193	}
	194
	195	return 0;
	196	}
	197
55f05234	198	static int op_arm_setup(void)
1da177e4	199	{
1da177e4	200	spin_lock(&oprofilefs_lock);
8c1fc96f	201	op_perf_setup();
1da177e4	202	spin_unlock(&oprofilefs_lock);
8c1fc96f	203	return 0;
1da177e4 LT	204	}
1da177e4 LT	205
55f05234	206	static int op_arm_start(void)
1da177e4 LT	207	{
	208	int ret = -EBUSY;
	209
93ad7949	210	mutex_lock(&op_arm_mutex);
55f05234	211	if (!op_arm_enabled) {
8c1fc96f WD	212	ret = 0;
	213	op_perf_start();
	214	op_arm_enabled = 1;
1da177e4	215	}
93ad7949	216	mutex_unlock(&op_arm_mutex);
1da177e4 LT	217	return ret;
	218	}
	219
55f05234	220	static void op_arm_stop(void)
1da177e4	221	{
93ad7949	222	mutex_lock(&op_arm_mutex);
55f05234	223	if (op_arm_enabled)
8c1fc96f	224	op_perf_stop();
55f05234	225	op_arm_enabled = 0;
93ad7949	226	mutex_unlock(&op_arm_mutex);
1da177e4 LT	227	}
1da177e4 LT	228
b5893c56	229	#ifdef CONFIG_PM
55f05234	230	static int op_arm_suspend(struct sys_device *dev, pm_message_t state)
b5893c56	231	{
93ad7949	232	mutex_lock(&op_arm_mutex);
55f05234	233	if (op_arm_enabled)
8c1fc96f	234	op_perf_stop();
93ad7949	235	mutex_unlock(&op_arm_mutex);
b5893c56 RK	236	return 0;
	237	}
	238
55f05234	239	static int op_arm_resume(struct sys_device *dev)
b5893c56	240	{
93ad7949	241	mutex_lock(&op_arm_mutex);
8c1fc96f	242	if (op_arm_enabled && op_perf_start())
55f05234	243	op_arm_enabled = 0;
93ad7949	244	mutex_unlock(&op_arm_mutex);
b5893c56 RK	245	return 0;
	246	}
	247
	248	static struct sysdev_class oprofile_sysclass = {
af5ca3f4	249	.name = "oprofile",
55f05234 RK	250	.resume = op_arm_resume,
55f05234 RK	251	.suspend = op_arm_suspend,
b5893c56 RK	252	};
	253
	254	static struct sys_device device_oprofile = {
	255	.id = 0,
	256	.cls = &oprofile_sysclass,
	257	};
	258
	259	static int __init init_driverfs(void)
	260	{
	261	int ret;
	262
	263	if (!(ret = sysdev_class_register(&oprofile_sysclass)))
	264	ret = sysdev_register(&device_oprofile);
	265
	266	return ret;
	267	}
	268
	269	static void exit_driverfs(void)
	270	{
	271	sysdev_unregister(&device_oprofile);
	272	sysdev_class_unregister(&oprofile_sysclass);
	273	}
	274	#else
	275	#define init_driverfs() do { } while (0)
	276	#define exit_driverfs() do { } while (0)
	277	#endif /* CONFIG_PM */
	278
8c1fc96f	279	static int report_trace(struct stackframe frame, void d)
1da177e4	280	{
8c1fc96f	281	unsigned int *depth = d;
c6b9dafc	282
8c1fc96f WD	283	if (*depth) {
	284	oprofile_add_trace(frame->pc);
	285	(*depth)--;
	286	}
1b7b5698	287
8c1fc96f WD	288	return *depth == 0;
8c1fc96f WD	289	}
c6b9dafc	290
8c1fc96f WD	291	/*
	292	* The registers we're interested in are at the end of the variable
	293	* length saved register structure. The fp points at the end of this
	294	* structure so the address of this struct is:
	295	* (struct frame_tail *)(xxx->fp)-1
	296	*/
	297	struct frame_tail {
	298	struct frame_tail *fp;
	299	unsigned long sp;
	300	unsigned long lr;
	301	} __attribute__((packed));
2d9e1ae0	302
8c1fc96f WD	303	static struct frame_tail* user_backtrace(struct frame_tail *tail)
	304	{
	305	struct frame_tail buftail[2];
10c03f69	306
8c1fc96f WD	307	/* Also check accessibility of one struct frame_tail beyond */
	308	if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
	309	return NULL;
	310	if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
	311	return NULL;
d7ac4e28	312
8c1fc96f	313	oprofile_add_trace(buftail[0].lr);
c6b9dafc	314
8c1fc96f WD	315	/* frame pointers should strictly progress back up the stack
	316	* (towards higher addresses) */
	317	if (tail >= buftail[0].fp)
	318	return NULL;
	319
	320	return buftail[0].fp-1;
	321	}
	322
	323	static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
	324	{
	325	struct frame_tail tail = ((struct frame_tail ) regs->ARM_fp) - 1;
	326
	327	if (!user_mode(regs)) {
	328	struct stackframe frame;
	329	frame.fp = regs->ARM_fp;
	330	frame.sp = regs->ARM_sp;
	331	frame.lr = regs->ARM_lr;
	332	frame.pc = regs->ARM_pc;
	333	walk_stackframe(&frame, report_trace, &depth);
	334	return;
	335	}
	336
	337	while (depth-- && tail && !((unsigned long) tail & 3))
	338	tail = user_backtrace(tail);
	339	}
	340
	341	int __init oprofile_arch_init(struct oprofile_operations *ops)
	342	{
	343	int cpu, ret = 0;
	344
	345	perf_num_counters = armpmu_get_max_events();
	346
	347	counter_config = kcalloc(perf_num_counters,
	348	sizeof(struct op_counter_config), GFP_KERNEL);
ae92dc9f	349
8c1fc96f WD	350	if (!counter_config) {
	351	pr_info("oprofile: failed to allocate %d "
	352	"counters\n", perf_num_counters);
	353	return -ENOMEM;
c6b9dafc	354	}
1da177e4	355
8c1fc96f WD	356	for_each_possible_cpu(cpu) {
	357	perf_events[cpu] = kcalloc(perf_num_counters,
	358	sizeof(struct perf_event *), GFP_KERNEL);
	359	if (!perf_events[cpu]) {
	360	pr_info("oprofile: failed to allocate %d perf events "
	361	"for cpu %d\n", perf_num_counters, cpu);
	362	while (--cpu >= 0)
	363	kfree(perf_events[cpu]);
	364	return -ENOMEM;
	365	}
	366	}
	367
	368	init_driverfs();
	369	ops->backtrace = arm_backtrace;
	370	ops->create_files = op_arm_create_files;
	371	ops->setup = op_arm_setup;
	372	ops->start = op_arm_start;
	373	ops->stop = op_arm_stop;
	374	ops->shutdown = op_arm_stop;
	375	ops->cpu_type = op_name_from_perf_id(armpmu_get_pmu_id());
	376
	377	if (!ops->cpu_type)
	378	ret = -ENODEV;
	379	else
	380	pr_info("oprofile: using %s\n", ops->cpu_type);
	381
c6b9dafc	382	return ret;
1da177e4 LT	383	}
1da177e4 LT	384
c6b9dafc	385	void oprofile_arch_exit(void)
1da177e4	386	{
8c1fc96f WD	387	int cpu, id;
	388	struct perf_event *event;
	389
	390	if (*perf_events) {
1da177e4	391	exit_driverfs();
8c1fc96f WD	392	for_each_possible_cpu(cpu) {
	393	for (id = 0; id < perf_num_counters; ++id) {
	394	event = perf_events[cpu][id];
	395	if (event != NULL)
	396	perf_event_release_kernel(event);
	397	}
	398	kfree(perf_events[cpu]);
	399	}
1da177e4	400	}
8c1fc96f WD	401
	402	if (counter_config)
	403	kfree(counter_config);
	404	}
	405	#else
	406	int __init oprofile_arch_init(struct oprofile_operations *ops)
	407	{
	408	pr_info("oprofile: hardware counters not available\n");
	409	return -ENODEV;
1da177e4	410	}
8c1fc96f WD	411	void oprofile_arch_exit(void) {}
8c1fc96f WD	412	#endif /* CONFIG_HW_PERF_EVENTS */