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Commit ad8537cd authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'perf/x86-ibs' into perf/core

parents 149936a0 fab06992
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+5 −0
Original line number Original line Diff line number Diff line
@@ -134,6 +134,8 @@
#define MSR_AMD64_IBSFETCHCTL		0xc0011030
#define MSR_AMD64_IBSFETCHCTL		0xc0011030
#define MSR_AMD64_IBSFETCHLINAD		0xc0011031
#define MSR_AMD64_IBSFETCHLINAD		0xc0011031
#define MSR_AMD64_IBSFETCHPHYSAD	0xc0011032
#define MSR_AMD64_IBSFETCHPHYSAD	0xc0011032
#define MSR_AMD64_IBSFETCH_REG_COUNT	3
#define MSR_AMD64_IBSFETCH_REG_MASK	((1UL<<MSR_AMD64_IBSFETCH_REG_COUNT)-1)
#define MSR_AMD64_IBSOPCTL		0xc0011033
#define MSR_AMD64_IBSOPCTL		0xc0011033
#define MSR_AMD64_IBSOPRIP		0xc0011034
#define MSR_AMD64_IBSOPRIP		0xc0011034
#define MSR_AMD64_IBSOPDATA		0xc0011035
#define MSR_AMD64_IBSOPDATA		0xc0011035
@@ -141,8 +143,11 @@
#define MSR_AMD64_IBSOPDATA3		0xc0011037
#define MSR_AMD64_IBSOPDATA3		0xc0011037
#define MSR_AMD64_IBSDCLINAD		0xc0011038
#define MSR_AMD64_IBSDCLINAD		0xc0011038
#define MSR_AMD64_IBSDCPHYSAD		0xc0011039
#define MSR_AMD64_IBSDCPHYSAD		0xc0011039
#define MSR_AMD64_IBSOP_REG_COUNT	7
#define MSR_AMD64_IBSOP_REG_MASK	((1UL<<MSR_AMD64_IBSOP_REG_COUNT)-1)
#define MSR_AMD64_IBSCTL		0xc001103a
#define MSR_AMD64_IBSCTL		0xc001103a
#define MSR_AMD64_IBSBRTARGET		0xc001103b
#define MSR_AMD64_IBSBRTARGET		0xc001103b
#define MSR_AMD64_IBS_REG_COUNT_MAX	8 /* includes MSR_AMD64_IBSBRTARGET */


/* Fam 15h MSRs */
/* Fam 15h MSRs */
#define MSR_F15H_PERF_CTL		0xc0010200
#define MSR_F15H_PERF_CTL		0xc0010200
+2 −0
Original line number Original line Diff line number Diff line
@@ -178,6 +178,8 @@ struct x86_pmu_capability {
#define IBS_FETCH_MAX_CNT	0x0000FFFFULL
#define IBS_FETCH_MAX_CNT	0x0000FFFFULL


/* IbsOpCtl bits */
/* IbsOpCtl bits */
/* lower 4 bits of the current count are ignored: */
#define IBS_OP_CUR_CNT		(0xFFFF0ULL<<32)
#define IBS_OP_CNT_CTL		(1ULL<<19)
#define IBS_OP_CNT_CTL		(1ULL<<19)
#define IBS_OP_VAL		(1ULL<<18)
#define IBS_OP_VAL		(1ULL<<18)
#define IBS_OP_ENABLE		(1ULL<<17)
#define IBS_OP_ENABLE		(1ULL<<17)
+431 −7
Original line number Original line Diff line number Diff line
@@ -16,36 +16,460 @@ static u32 ibs_caps;


#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD)
#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD)


static struct pmu perf_ibs;
#include <linux/kprobes.h>
#include <linux/hardirq.h>

#include <asm/nmi.h>

#define IBS_FETCH_CONFIG_MASK	(IBS_FETCH_RAND_EN | IBS_FETCH_MAX_CNT)
#define IBS_OP_CONFIG_MASK	IBS_OP_MAX_CNT

enum ibs_states {
	IBS_ENABLED	= 0,
	IBS_STARTED	= 1,
	IBS_STOPPING	= 2,

	IBS_MAX_STATES,
};

struct cpu_perf_ibs {
	struct perf_event	*event;
	unsigned long		state[BITS_TO_LONGS(IBS_MAX_STATES)];
};

struct perf_ibs {
	struct pmu	pmu;
	unsigned int	msr;
	u64		config_mask;
	u64		cnt_mask;
	u64		enable_mask;
	u64		valid_mask;
	u64		max_period;
	unsigned long	offset_mask[1];
	int		offset_max;
	struct cpu_perf_ibs __percpu *pcpu;
	u64		(*get_count)(u64 config);
};

struct perf_ibs_data {
	u32		size;
	union {
		u32	data[0];	/* data buffer starts here */
		u32	caps;
	};
	u64		regs[MSR_AMD64_IBS_REG_COUNT_MAX];
};

static int
perf_event_set_period(struct hw_perf_event *hwc, u64 min, u64 max, u64 *count)
{
	s64 left = local64_read(&hwc->period_left);
	s64 period = hwc->sample_period;
	int overflow = 0;

	/*
	 * If we are way outside a reasonable range then just skip forward:
	 */
	if (unlikely(left <= -period)) {
		left = period;
		local64_set(&hwc->period_left, left);
		hwc->last_period = period;
		overflow = 1;
	}

	if (unlikely(left <= 0)) {
		left += period;
		local64_set(&hwc->period_left, left);
		hwc->last_period = period;
		overflow = 1;
	}

	if (unlikely(left < min))
		left = min;

	if (left > max)
		left = max;

	*count = (u64)left;

	return overflow;
}

static  int
perf_event_try_update(struct perf_event *event, u64 new_raw_count, int width)
{
	struct hw_perf_event *hwc = &event->hw;
	int shift = 64 - width;
	u64 prev_raw_count;
	u64 delta;

	/*
	 * Careful: an NMI might modify the previous event value.
	 *
	 * Our tactic to handle this is to first atomically read and
	 * exchange a new raw count - then add that new-prev delta
	 * count to the generic event atomically:
	 */
	prev_raw_count = local64_read(&hwc->prev_count);
	if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
					new_raw_count) != prev_raw_count)
		return 0;

	/*
	 * Now we have the new raw value and have updated the prev
	 * timestamp already. We can now calculate the elapsed delta
	 * (event-)time and add that to the generic event.
	 *
	 * Careful, not all hw sign-extends above the physical width
	 * of the count.
	 */
	delta = (new_raw_count << shift) - (prev_raw_count << shift);
	delta >>= shift;

	local64_add(delta, &event->count);
	local64_sub(delta, &hwc->period_left);

	return 1;
}

static struct perf_ibs perf_ibs_fetch;
static struct perf_ibs perf_ibs_op;

static struct perf_ibs *get_ibs_pmu(int type)
{
	if (perf_ibs_fetch.pmu.type == type)
		return &perf_ibs_fetch;
	if (perf_ibs_op.pmu.type == type)
		return &perf_ibs_op;
	return NULL;
}


static int perf_ibs_init(struct perf_event *event)
static int perf_ibs_init(struct perf_event *event)
{
{
	if (perf_ibs.type != event->attr.type)
	struct hw_perf_event *hwc = &event->hw;
	struct perf_ibs *perf_ibs;
	u64 max_cnt, config;

	perf_ibs = get_ibs_pmu(event->attr.type);
	if (!perf_ibs)
		return -ENOENT;
		return -ENOENT;

	config = event->attr.config;
	if (config & ~perf_ibs->config_mask)
		return -EINVAL;

	if (hwc->sample_period) {
		if (config & perf_ibs->cnt_mask)
			/* raw max_cnt may not be set */
			return -EINVAL;
		if (hwc->sample_period & 0x0f)
			/* lower 4 bits can not be set in ibs max cnt */
			return -EINVAL;
	} else {
		max_cnt = config & perf_ibs->cnt_mask;
		config &= ~perf_ibs->cnt_mask;
		event->attr.sample_period = max_cnt << 4;
		hwc->sample_period = event->attr.sample_period;
	}

	if (!hwc->sample_period)
		return -EINVAL;

	hwc->config_base = perf_ibs->msr;
	hwc->config = config;

	return 0;
	return 0;
}
}


static int perf_ibs_set_period(struct perf_ibs *perf_ibs,
			       struct hw_perf_event *hwc, u64 *period)
{
	int ret;

	/* ignore lower 4 bits in min count: */
	ret = perf_event_set_period(hwc, 1<<4, perf_ibs->max_period, period);
	local64_set(&hwc->prev_count, 0);

	return ret;
}

static u64 get_ibs_fetch_count(u64 config)
{
	return (config & IBS_FETCH_CNT) >> 12;
}

static u64 get_ibs_op_count(u64 config)
{
	return (config & IBS_OP_CUR_CNT) >> 32;
}

static void
perf_ibs_event_update(struct perf_ibs *perf_ibs, struct perf_event *event,
		      u64 config)
{
	u64 count = perf_ibs->get_count(config);

	while (!perf_event_try_update(event, count, 20)) {
		rdmsrl(event->hw.config_base, config);
		count = perf_ibs->get_count(config);
	}
}

/* Note: The enable mask must be encoded in the config argument. */
static inline void perf_ibs_enable_event(struct hw_perf_event *hwc, u64 config)
{
	wrmsrl(hwc->config_base, hwc->config | config);
}

/*
 * We cannot restore the ibs pmu state, so we always needs to update
 * the event while stopping it and then reset the state when starting
 * again. Thus, ignoring PERF_EF_RELOAD and PERF_EF_UPDATE flags in
 * perf_ibs_start()/perf_ibs_stop() and instead always do it.
 */
static void perf_ibs_start(struct perf_event *event, int flags)
{
	struct hw_perf_event *hwc = &event->hw;
	struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
	struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
	u64 config;

	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
		return;

	WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
	hwc->state = 0;

	perf_ibs_set_period(perf_ibs, hwc, &config);
	config = (config >> 4) | perf_ibs->enable_mask;
	set_bit(IBS_STARTED, pcpu->state);
	perf_ibs_enable_event(hwc, config);

	perf_event_update_userpage(event);
}

static void perf_ibs_stop(struct perf_event *event, int flags)
{
	struct hw_perf_event *hwc = &event->hw;
	struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
	struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
	u64 val;
	int stopping;

	stopping = test_and_clear_bit(IBS_STARTED, pcpu->state);

	if (!stopping && (hwc->state & PERF_HES_UPTODATE))
		return;

	rdmsrl(hwc->config_base, val);

	if (stopping) {
		set_bit(IBS_STOPPING, pcpu->state);
		val &= ~perf_ibs->enable_mask;
		wrmsrl(hwc->config_base, val);
		WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
		hwc->state |= PERF_HES_STOPPED;
	}

	if (hwc->state & PERF_HES_UPTODATE)
		return;

	perf_ibs_event_update(perf_ibs, event, val);
	hwc->state |= PERF_HES_UPTODATE;
}

static int perf_ibs_add(struct perf_event *event, int flags)
static int perf_ibs_add(struct perf_event *event, int flags)
{
{
	struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
	struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);

	if (test_and_set_bit(IBS_ENABLED, pcpu->state))
		return -ENOSPC;

	event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;

	pcpu->event = event;

	if (flags & PERF_EF_START)
		perf_ibs_start(event, PERF_EF_RELOAD);

	return 0;
	return 0;
}
}


static void perf_ibs_del(struct perf_event *event, int flags)
static void perf_ibs_del(struct perf_event *event, int flags)
{
{
	struct perf_ibs *perf_ibs = container_of(event->pmu, struct perf_ibs, pmu);
	struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);

	if (!test_and_clear_bit(IBS_ENABLED, pcpu->state))
		return;

	perf_ibs_stop(event, PERF_EF_UPDATE);

	pcpu->event = NULL;

	perf_event_update_userpage(event);
}
}


static struct pmu perf_ibs = {
static void perf_ibs_read(struct perf_event *event) { }

static struct perf_ibs perf_ibs_fetch = {
	.pmu = {
		.task_ctx_nr	= perf_invalid_context,

		.event_init	= perf_ibs_init,
		.add		= perf_ibs_add,
		.del		= perf_ibs_del,
		.start		= perf_ibs_start,
		.stop		= perf_ibs_stop,
		.read		= perf_ibs_read,
	},
	.msr			= MSR_AMD64_IBSFETCHCTL,
	.config_mask		= IBS_FETCH_CONFIG_MASK,
	.cnt_mask		= IBS_FETCH_MAX_CNT,
	.enable_mask		= IBS_FETCH_ENABLE,
	.valid_mask		= IBS_FETCH_VAL,
	.max_period		= IBS_FETCH_MAX_CNT << 4,
	.offset_mask		= { MSR_AMD64_IBSFETCH_REG_MASK },
	.offset_max		= MSR_AMD64_IBSFETCH_REG_COUNT,

	.get_count		= get_ibs_fetch_count,
};

static struct perf_ibs perf_ibs_op = {
	.pmu = {
		.task_ctx_nr	= perf_invalid_context,

		.event_init	= perf_ibs_init,
		.event_init	= perf_ibs_init,
		.add		= perf_ibs_add,
		.add		= perf_ibs_add,
		.del		= perf_ibs_del,
		.del		= perf_ibs_del,
		.start		= perf_ibs_start,
		.stop		= perf_ibs_stop,
		.read		= perf_ibs_read,
	},
	.msr			= MSR_AMD64_IBSOPCTL,
	.config_mask		= IBS_OP_CONFIG_MASK,
	.cnt_mask		= IBS_OP_MAX_CNT,
	.enable_mask		= IBS_OP_ENABLE,
	.valid_mask		= IBS_OP_VAL,
	.max_period		= IBS_OP_MAX_CNT << 4,
	.offset_mask		= { MSR_AMD64_IBSOP_REG_MASK },
	.offset_max		= MSR_AMD64_IBSOP_REG_COUNT,

	.get_count		= get_ibs_op_count,
};
};


static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
{
	struct cpu_perf_ibs *pcpu = this_cpu_ptr(perf_ibs->pcpu);
	struct perf_event *event = pcpu->event;
	struct hw_perf_event *hwc = &event->hw;
	struct perf_sample_data data;
	struct perf_raw_record raw;
	struct pt_regs regs;
	struct perf_ibs_data ibs_data;
	int offset, size, overflow, reenable;
	unsigned int msr;
	u64 *buf, config;

	if (!test_bit(IBS_STARTED, pcpu->state)) {
		/* Catch spurious interrupts after stopping IBS: */
		if (!test_and_clear_bit(IBS_STOPPING, pcpu->state))
			return 0;
		rdmsrl(perf_ibs->msr, *ibs_data.regs);
		return (*ibs_data.regs & perf_ibs->valid_mask) ? 1 : 0;
	}

	msr = hwc->config_base;
	buf = ibs_data.regs;
	rdmsrl(msr, *buf);
	if (!(*buf++ & perf_ibs->valid_mask))
		return 0;

	perf_sample_data_init(&data, 0);
	if (event->attr.sample_type & PERF_SAMPLE_RAW) {
		ibs_data.caps = ibs_caps;
		size = 1;
		offset = 1;
		do {
		    rdmsrl(msr + offset, *buf++);
		    size++;
		    offset = find_next_bit(perf_ibs->offset_mask,
					   perf_ibs->offset_max,
					   offset + 1);
		} while (offset < perf_ibs->offset_max);
		raw.size = sizeof(u32) + sizeof(u64) * size;
		raw.data = ibs_data.data;
		data.raw = &raw;
	}

	regs = *iregs; /* XXX: update ip from ibs sample */

	/*
	 * Emulate IbsOpCurCnt in MSRC001_1033 (IbsOpCtl), not
	 * supported in all cpus. As this triggered an interrupt, we
	 * set the current count to the max count.
	 */
	config = ibs_data.regs[0];
	if (perf_ibs == &perf_ibs_op && !(ibs_caps & IBS_CAPS_RDWROPCNT)) {
		config &= ~IBS_OP_CUR_CNT;
		config |= (config & IBS_OP_MAX_CNT) << 36;
	}

	perf_ibs_event_update(perf_ibs, event, config);

	overflow = perf_ibs_set_period(perf_ibs, hwc, &config);
	reenable = !(overflow && perf_event_overflow(event, &data, &regs));
	config = (config >> 4) | (reenable ? perf_ibs->enable_mask : 0);
	perf_ibs_enable_event(hwc, config);

	perf_event_update_userpage(event);

	return 1;
}

static int __kprobes
perf_ibs_nmi_handler(unsigned int cmd, struct pt_regs *regs)
{
	int handled = 0;

	handled += perf_ibs_handle_irq(&perf_ibs_fetch, regs);
	handled += perf_ibs_handle_irq(&perf_ibs_op, regs);

	if (handled)
		inc_irq_stat(apic_perf_irqs);

	return handled;
}

static __init int perf_ibs_pmu_init(struct perf_ibs *perf_ibs, char *name)
{
	struct cpu_perf_ibs __percpu *pcpu;
	int ret;

	pcpu = alloc_percpu(struct cpu_perf_ibs);
	if (!pcpu)
		return -ENOMEM;

	perf_ibs->pcpu = pcpu;

	ret = perf_pmu_register(&perf_ibs->pmu, name, -1);
	if (ret) {
		perf_ibs->pcpu = NULL;
		free_percpu(pcpu);
	}

	return ret;
}

static __init int perf_event_ibs_init(void)
static __init int perf_event_ibs_init(void)
{
{
	if (!ibs_caps)
	if (!ibs_caps)
		return -ENODEV;	/* ibs not supported by the cpu */
		return -ENODEV;	/* ibs not supported by the cpu */


	perf_pmu_register(&perf_ibs, "ibs", -1);
	perf_ibs_pmu_init(&perf_ibs_fetch, "ibs_fetch");
	perf_ibs_pmu_init(&perf_ibs_op, "ibs_op");
	register_nmi_handler(NMI_LOCAL, perf_ibs_nmi_handler, 0, "perf_ibs");
	printk(KERN_INFO "perf: AMD IBS detected (0x%08x)\n", ibs_caps);
	printk(KERN_INFO "perf: AMD IBS detected (0x%08x)\n", ibs_caps);


	return 0;
	return 0;