[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/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/oprofile.h>
#include <linux/perf_event.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <asm/stacktrace.h>
#include <linux/uaccess.h>

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

#ifdef CONFIG_HW_PERF_EVENTS
char *op_name_from_perf_id(void)
{
	enum arm_perf_pmu_ids id = armpmu_get_pmu_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 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)
{
	ops->backtrace		= arm_backtrace;

	return oprofile_perf_init(ops);
}

void __exit oprofile_arch_exit(void)
{
	oprofile_perf_exit();
}
#else
int __init oprofile_arch_init(struct oprofile_operations *ops)
{
	pr_info("oprofile: hardware counters not available\n");
	return -ENODEV;
}
void __exit 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	12	#include <linux/cpumask.h>
d1e86d64	13	#include <linux/err.h>
8c1fc96f	14	#include <linux/errno.h>
1da177e4	15	#include <linux/init.h>
8c1fc96f	16	#include <linux/mutex.h>
1da177e4	17	#include <linux/oprofile.h>
8c1fc96f	18	#include <linux/perf_event.h>
d1e86d64	19	#include <linux/platform_device.h>
ae92dc9f	20	#include <linux/slab.h>
8c1fc96f WD	21	#include <asm/stacktrace.h>
	22	#include <linux/uaccess.h>
	23
	24	#include <asm/perf_event.h>
	25	#include <asm/ptrace.h>
1da177e4	26
8c1fc96f	27	#ifdef CONFIG_HW_PERF_EVENTS
56946331	28	char *op_name_from_perf_id(void)
8c1fc96f	29	{
56946331 MF	30	enum arm_perf_pmu_ids id = armpmu_get_pmu_id();
56946331 MF	31
8c1fc96f WD	32	switch (id) {
	33	case ARM_PERF_PMU_ID_XSCALE1:
	34	return "arm/xscale1";
	35	case ARM_PERF_PMU_ID_XSCALE2:
	36	return "arm/xscale2";
	37	case ARM_PERF_PMU_ID_V6:
	38	return "arm/armv6";
	39	case ARM_PERF_PMU_ID_V6MP:
	40	return "arm/mpcore";
	41	case ARM_PERF_PMU_ID_CA8:
	42	return "arm/armv7";
	43	case ARM_PERF_PMU_ID_CA9:
	44	return "arm/armv7-ca9";
	45	default:
	46	return NULL;
	47	}
	48	}
1da177e4	49
8c1fc96f	50	static int report_trace(struct stackframe frame, void d)
1da177e4	51	{
8c1fc96f	52	unsigned int *depth = d;
c6b9dafc	53
8c1fc96f WD	54	if (*depth) {
	55	oprofile_add_trace(frame->pc);
	56	(*depth)--;
	57	}
1b7b5698	58
8c1fc96f WD	59	return *depth == 0;
8c1fc96f WD	60	}
c6b9dafc	61
8c1fc96f WD	62	/*
	63	* The registers we're interested in are at the end of the variable
	64	* length saved register structure. The fp points at the end of this
	65	* structure so the address of this struct is:
	66	* (struct frame_tail *)(xxx->fp)-1
	67	*/
	68	struct frame_tail {
	69	struct frame_tail *fp;
	70	unsigned long sp;
	71	unsigned long lr;
	72	} __attribute__((packed));
2d9e1ae0	73
8c1fc96f WD	74	static struct frame_tail* user_backtrace(struct frame_tail *tail)
	75	{
	76	struct frame_tail buftail[2];
10c03f69	77
8c1fc96f WD	78	/* Also check accessibility of one struct frame_tail beyond */
	79	if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
	80	return NULL;
	81	if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
	82	return NULL;
d7ac4e28	83
8c1fc96f	84	oprofile_add_trace(buftail[0].lr);
c6b9dafc	85
8c1fc96f WD	86	/* frame pointers should strictly progress back up the stack
	87	* (towards higher addresses) */
	88	if (tail >= buftail[0].fp)
	89	return NULL;
	90
	91	return buftail[0].fp-1;
	92	}
	93
	94	static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
	95	{
	96	struct frame_tail tail = ((struct frame_tail ) regs->ARM_fp) - 1;
	97
	98	if (!user_mode(regs)) {
	99	struct stackframe frame;
	100	frame.fp = regs->ARM_fp;
	101	frame.sp = regs->ARM_sp;
	102	frame.lr = regs->ARM_lr;
	103	frame.pc = regs->ARM_pc;
	104	walk_stackframe(&frame, report_trace, &depth);
	105	return;
	106	}
	107
	108	while (depth-- && tail && !((unsigned long) tail & 3))
	109	tail = user_backtrace(tail);
	110	}
	111
58850e21 MF	112	int __init oprofile_arch_init(struct oprofile_operations *ops)
	113	{
	114	ops->backtrace = arm_backtrace;
	115
	116	return oprofile_perf_init(ops);
	117	}
	118
58850e21 MF	119	void __exit oprofile_arch_exit(void)
	120	{
	121	oprofile_perf_exit();
	122	}
8c1fc96f WD	123	#else
	124	int __init oprofile_arch_init(struct oprofile_operations *ops)
	125	{
	126	pr_info("oprofile: hardware counters not available\n");
	127	return -ENODEV;
1da177e4	128	}
c7fd239a	129	void __exit oprofile_arch_exit(void) {}
8c1fc96f	130	#endif /* CONFIG_HW_PERF_EVENTS */