/arch/x86/kernel/cpu/perf_event.h

/*
 * Performance events x86 architecture header
 *
 *  Copyright (C) 2008 Thomas Gleixner <tglx@linutronix.de>
 *  Copyright (C) 2008-2009 Red Hat, Inc., Ingo Molnar
 *  Copyright (C) 2009 Jaswinder Singh Rajput
 *  Copyright (C) 2009 Advanced Micro Devices, Inc., Robert Richter
 *  Copyright (C) 2008-2009 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
 *  Copyright (C) 2009 Intel Corporation, <markus.t.metzger@intel.com>
 *  Copyright (C) 2009 Google, Inc., Stephane Eranian
 *
 *  For licencing details see kernel-base/COPYING
 */

#include <linux/perf_event.h>

/*
 *          |   NHM/WSM    |      SNB     |
 * register -------------------------------
 *          |  HT  | no HT |  HT  | no HT |
 *-----------------------------------------
 * offcore  | core | core  | cpu  | core  |
 * lbr_sel  | core | core  | cpu  | core  |
 * ld_lat   | cpu  | core  | cpu  | core  |
 *-----------------------------------------
 *
 * Given that there is a small number of shared regs,
 * we can pre-allocate their slot in the per-cpu
 * per-core reg tables.
 */
enum extra_reg_type {
	EXTRA_REG_NONE  = -1,	/* not used */

	EXTRA_REG_RSP_0 = 0,	/* offcore_response_0 */
	EXTRA_REG_RSP_1 = 1,	/* offcore_response_1 */

	EXTRA_REG_MAX		/* number of entries needed */
};

struct event_constraint {
	union {
		unsigned long	idxmsk[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
		u64		idxmsk64;
	};
	u64	code;
	u64	cmask;
	int	weight;
	int	overlap;
};

struct amd_nb {
	int nb_id;  /* NorthBridge id */
	int refcnt; /* reference count */
	struct perf_event *owners[X86_PMC_IDX_MAX];
	struct event_constraint event_constraints[X86_PMC_IDX_MAX];
};

/* The maximal number of PEBS events: */
#define MAX_PEBS_EVENTS		4

/*
 * A debug store configuration.
 *
 * We only support architectures that use 64bit fields.
 */
struct debug_store {
	u64	bts_buffer_base;
	u64	bts_index;
	u64	bts_absolute_maximum;
	u64	bts_interrupt_threshold;
	u64	pebs_buffer_base;
	u64	pebs_index;
	u64	pebs_absolute_maximum;
	u64	pebs_interrupt_threshold;
	u64	pebs_event_reset[MAX_PEBS_EVENTS];
};

/*
 * Per register state.
 */
struct er_account {
	raw_spinlock_t		lock;	/* per-core: protect structure */
	u64                 config;	/* extra MSR config */
	u64                 reg;	/* extra MSR number */
	atomic_t            ref;	/* reference count */
};

/*
 * Per core/cpu state
 *
 * Used to coordinate shared registers between HT threads or
 * among events on a single PMU.
 */
struct intel_shared_regs {
	struct er_account       regs[EXTRA_REG_MAX];
	int                     refcnt;		/* per-core: #HT threads */
	unsigned                core_id;	/* per-core: core id */
};

#define MAX_LBR_ENTRIES		16

struct cpu_hw_events {
	/*
	 * Generic x86 PMC bits
	 */
	struct perf_event	*events[X86_PMC_IDX_MAX]; /* in counter order */
	unsigned long		active_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
	unsigned long		running[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
	int			enabled;

	int			n_events;
	int			n_added;
	int			n_txn;
	int			assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
	u64			tags[X86_PMC_IDX_MAX];
	struct perf_event	*event_list[X86_PMC_IDX_MAX]; /* in enabled order */

	unsigned int		group_flag;

	/*
	 * Intel DebugStore bits
	 */
	struct debug_store	*ds;
	u64			pebs_enabled;

	/*
	 * Intel LBR bits
	 */
	int				lbr_users;
	void				*lbr_context;
	struct perf_branch_stack	lbr_stack;
	struct perf_branch_entry	lbr_entries[MAX_LBR_ENTRIES];

	/*
	 * Intel host/guest exclude bits
	 */
	u64				intel_ctrl_guest_mask;
	u64				intel_ctrl_host_mask;
	struct perf_guest_switch_msr	guest_switch_msrs[X86_PMC_IDX_MAX];

	/*
	 * manage shared (per-core, per-cpu) registers
	 * used on Intel NHM/WSM/SNB
	 */
	struct intel_shared_regs	*shared_regs;

	/*
	 * AMD specific bits
	 */
	struct amd_nb		*amd_nb;

	void				*kfree_on_online;
};

#define __EVENT_CONSTRAINT(c, n, m, w, o) {\
	{ .idxmsk64 = (n) },		\
	.code = (c),			\
	.cmask = (m),			\
	.weight = (w),			\
	.overlap = (o),			\
}

#define EVENT_CONSTRAINT(c, n, m)	\
	__EVENT_CONSTRAINT(c, n, m, HWEIGHT(n), 0)

/*
 * The overlap flag marks event constraints with overlapping counter
 * masks. This is the case if the counter mask of such an event is not
 * a subset of any other counter mask of a constraint with an equal or
 * higher weight, e.g.:
 *
 *  c_overlaps = EVENT_CONSTRAINT_OVERLAP(0, 0x09, 0);
 *  c_another1 = EVENT_CONSTRAINT(0, 0x07, 0);
 *  c_another2 = EVENT_CONSTRAINT(0, 0x38, 0);
 *
 * The event scheduler may not select the correct counter in the first
 * cycle because it needs to know which subsequent events will be
 * scheduled. It may fail to schedule the events then. So we set the
 * overlap flag for such constraints to give the scheduler a hint which
 * events to select for counter rescheduling.
 *
 * Care must be taken as the rescheduling algorithm is O(n!) which
 * will increase scheduling cycles for an over-commited system
 * dramatically.  The number of such EVENT_CONSTRAINT_OVERLAP() macros
 * and its counter masks must be kept at a minimum.
 */
#define EVENT_CONSTRAINT_OVERLAP(c, n, m)	\
	__EVENT_CONSTRAINT(c, n, m, HWEIGHT(n), 1)

/*
 * Constraint on the Event code.
 */
#define INTEL_EVENT_CONSTRAINT(c, n)	\
	EVENT_CONSTRAINT(c, n, ARCH_PERFMON_EVENTSEL_EVENT)

/*
 * Constraint on the Event code + UMask + fixed-mask
 *
 * filter mask to validate fixed counter events.
 * the following filters disqualify for fixed counters:
 *  - inv
 *  - edge
 *  - cnt-mask
 *  The other filters are supported by fixed counters.
 *  The any-thread option is supported starting with v3.
 */
#define FIXED_EVENT_CONSTRAINT(c, n)	\
	EVENT_CONSTRAINT(c, (1ULL << (32+n)), X86_RAW_EVENT_MASK)

/*
 * Constraint on the Event code + UMask
 */
#define INTEL_UEVENT_CONSTRAINT(c, n)	\
	EVENT_CONSTRAINT(c, n, INTEL_ARCH_EVENT_MASK)

#define EVENT_CONSTRAINT_END		\
	EVENT_CONSTRAINT(0, 0, 0)

#define for_each_event_constraint(e, c)	\
	for ((e) = (c); (e)->weight; (e)++)

/*
 * Extra registers for specific events.
 *
 * Some events need large masks and require external MSRs.
 * Those extra MSRs end up being shared for all events on
 * a PMU and sometimes between PMU of sibling HT threads.
 * In either case, the kernel needs to handle conflicting
 * accesses to those extra, shared, regs. The data structure
 * to manage those registers is stored in cpu_hw_event.
 */
struct extra_reg {
	unsigned int		event;
	unsigned int		msr;
	u64			config_mask;
	u64			valid_mask;
	int			idx;  /* per_xxx->regs[] reg index */
};

#define EVENT_EXTRA_REG(e, ms, m, vm, i) {	\
	.event = (e),		\
	.msr = (ms),		\
	.config_mask = (m),	\
	.valid_mask = (vm),	\
	.idx = EXTRA_REG_##i	\
	}

#define INTEL_EVENT_EXTRA_REG(event, msr, vm, idx)	\
	EVENT_EXTRA_REG(event, msr, ARCH_PERFMON_EVENTSEL_EVENT, vm, idx)

#define EVENT_EXTRA_END EVENT_EXTRA_REG(0, 0, 0, 0, RSP_0)

union perf_capabilities {
	struct {
		u64	lbr_format:6;
		u64	pebs_trap:1;
		u64	pebs_arch_reg:1;
		u64	pebs_format:4;
		u64	smm_freeze:1;
	};
	u64	capabilities;
};

struct x86_pmu_quirk {
	struct x86_pmu_quirk *next;
	void (*func)(void);
};

/*
 * struct x86_pmu - generic x86 pmu
 */
struct x86_pmu {
	/*
	 * Generic x86 PMC bits
	 */
	const char	*name;
	int		version;
	int		(*handle_irq)(struct pt_regs *);
	void		(*disable_all)(void);
	void		(*enable_all)(int added);
	void		(*enable)(struct perf_event *);
	void		(*disable)(struct perf_event *);
	int		(*hw_config)(struct perf_event *event);
	int		(*schedule_events)(struct cpu_hw_events *cpuc, int n, int *assign);
	unsigned	eventsel;
	unsigned	perfctr;
	u64		(*event_map)(int);
	int		max_events;
	int		num_counters;
	int		num_counters_fixed;
	int		cntval_bits;
	u64		cntval_mask;
	union {
			unsigned long events_maskl;
			unsigned long events_mask[BITS_TO_LONGS(ARCH_PERFMON_EVENTS_COUNT)];
	};
	int		events_mask_len;
	int		apic;
	u64		max_period;
	struct event_constraint *
			(*get_event_constraints)(struct cpu_hw_events *cpuc,
						 struct perf_event *event);

	void		(*put_event_constraints)(struct cpu_hw_events *cpuc,
						 struct perf_event *event);
	struct event_constraint *event_constraints;
	struct x86_pmu_quirk *quirks;
	int		perfctr_second_write;

	int		(*cpu_prepare)(int cpu);
	void		(*cpu_starting)(int cpu);
	void		(*cpu_dying)(int cpu);
	void		(*cpu_dead)(int cpu);

	/*
	 * Intel Arch Perfmon v2+
	 */
	u64			intel_ctrl;
	union perf_capabilities intel_cap;

	/*
	 * Intel DebugStore bits
	 */
	int		bts, pebs;
	int		bts_active, pebs_active;
	int		pebs_record_size;
	void		(*drain_pebs)(struct pt_regs *regs);
	struct event_constraint *pebs_constraints;

	/*
	 * Intel LBR
	 */
	unsigned long	lbr_tos, lbr_from, lbr_to; /* MSR base regs       */
	int		lbr_nr;			   /* hardware stack size */

	/*
	 * Extra registers for events
	 */
	struct extra_reg *extra_regs;
	unsigned int er_flags;

	/*
	 * Intel host/guest support (KVM)
	 */
	struct perf_guest_switch_msr *(*guest_get_msrs)(int *nr);
};

#define x86_add_quirk(func_)						\
do {									\
	static struct x86_pmu_quirk __quirk __initdata = {		\
		.func = func_,						\
	};								\
	__quirk.next = x86_pmu.quirks;					\
	x86_pmu.quirks = &__quirk;					\
} while (0)

#define ERF_NO_HT_SHARING	1
#define ERF_HAS_RSP_1		2

extern struct x86_pmu x86_pmu __read_mostly;

DECLARE_PER_CPU(struct cpu_hw_events, cpu_hw_events);

int x86_perf_event_set_period(struct perf_event *event);

/*
 * Generalized hw caching related hw_event table, filled
 * in on a per model basis. A value of 0 means
 * 'not supported', -1 means 'hw_event makes no sense on
 * this CPU', any other value means the raw hw_event
 * ID.
 */

#define C(x) PERF_COUNT_HW_CACHE_##x

extern u64 __read_mostly hw_cache_event_ids
				[PERF_COUNT_HW_CACHE_MAX]
				[PERF_COUNT_HW_CACHE_OP_MAX]
				[PERF_COUNT_HW_CACHE_RESULT_MAX];
extern u64 __read_mostly hw_cache_extra_regs
				[PERF_COUNT_HW_CACHE_MAX]
				[PERF_COUNT_HW_CACHE_OP_MAX]
				[PERF_COUNT_HW_CACHE_RESULT_MAX];

u64 x86_perf_event_update(struct perf_event *event);

static inline int x86_pmu_addr_offset(int index)
{
	int offset;

	/* offset = X86_FEATURE_PERFCTR_CORE ? index << 1 : index */
	alternative_io(ASM_NOP2,
		       "shll $1, %%eax",
		       X86_FEATURE_PERFCTR_CORE,
		       "=a" (offset),
		       "a"  (index));

	return offset;
}

static inline unsigned int x86_pmu_config_addr(int index)
{
	return x86_pmu.eventsel + x86_pmu_addr_offset(index);
}

static inline unsigned int x86_pmu_event_addr(int index)
{
	return x86_pmu.perfctr + x86_pmu_addr_offset(index);
}

int x86_setup_perfctr(struct perf_event *event);

int x86_pmu_hw_config(struct perf_event *event);

void x86_pmu_disable_all(void);

static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc,
					  u64 enable_mask)
{
	if (hwc->extra_reg.reg)
		wrmsrl(hwc->extra_reg.reg, hwc->extra_reg.config);
	wrmsrl(hwc->config_base, hwc->config | enable_mask);
}

void x86_pmu_enable_all(int added);

int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign);

void x86_pmu_stop(struct perf_event *event, int flags);

static inline void x86_pmu_disable_event(struct perf_event *event)
{
	struct hw_perf_event *hwc = &event->hw;

	wrmsrl(hwc->config_base, hwc->config);
}

void x86_pmu_enable_event(struct perf_event *event);

int x86_pmu_handle_irq(struct pt_regs *regs);

extern struct event_constraint emptyconstraint;

extern struct event_constraint unconstrained;

#ifdef CONFIG_CPU_SUP_AMD

int amd_pmu_init(void);

#else /* CONFIG_CPU_SUP_AMD */

static inline int amd_pmu_init(void)
{
	return 0;
}

#endif /* CONFIG_CPU_SUP_AMD */

#ifdef CONFIG_CPU_SUP_INTEL

int intel_pmu_save_and_restart(struct perf_event *event);

struct event_constraint *
x86_get_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event);

struct intel_shared_regs *allocate_shared_regs(int cpu);

int intel_pmu_init(void);

void init_debug_store_on_cpu(int cpu);

void fini_debug_store_on_cpu(int cpu);

void release_ds_buffers(void);

void reserve_ds_buffers(void);

extern struct event_constraint bts_constraint;

void intel_pmu_enable_bts(u64 config);

void intel_pmu_disable_bts(void);

int intel_pmu_drain_bts_buffer(void);

extern struct event_constraint intel_core2_pebs_event_constraints[];

extern struct event_constraint intel_atom_pebs_event_constraints[];

extern struct event_constraint intel_nehalem_pebs_event_constraints[];

extern struct event_constraint intel_westmere_pebs_event_constraints[];

extern struct event_constraint intel_snb_pebs_event_constraints[];

struct event_constraint *intel_pebs_constraints(struct perf_event *event);

void intel_pmu_pebs_enable(struct perf_event *event);

void intel_pmu_pebs_disable(struct perf_event *event);

void intel_pmu_pebs_enable_all(void);

void intel_pmu_pebs_disable_all(void);

void intel_ds_init(void);

void intel_pmu_lbr_reset(void);

void intel_pmu_lbr_enable(struct perf_event *event);

void intel_pmu_lbr_disable(struct perf_event *event);

void intel_pmu_lbr_enable_all(void);

void intel_pmu_lbr_disable_all(void);

void intel_pmu_lbr_read(void);

void intel_pmu_lbr_init_core(void);

void intel_pmu_lbr_init_nhm(void);

void intel_pmu_lbr_init_atom(void);

int p4_pmu_init(void);

int p6_pmu_init(void);

#else /* CONFIG_CPU_SUP_INTEL */

static inline void reserve_ds_buffers(void)
{
}

static inline void release_ds_buffers(void)
{
}

static inline int intel_pmu_init(void)
{
	return 0;
}

static inline struct intel_shared_regs *allocate_shared_regs(int cpu)
{
	return NULL;
}

#endif /* CONFIG_CPU_SUP_INTEL */