// SPDX-License-Identifier: GPL-2.0-only
#include <linux/perf_event.h>
#include <linux/jump_label.h>
#include <linux/export.h>
#include <linux/kvm_types.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <asm/apicdef.h>
#include <asm/apic.h>
#include <asm/msr.h>
#include <asm/nmi.h>

#include "../perf_event.h"

static DEFINE_PER_CPU(unsigned long, perf_nmi_tstamp);
static unsigned long perf_nmi_window;

/* AMD Event 0xFFF: Merge.  Used with Large Increment per Cycle events */
#define AMD_MERGE_EVENT ((0xFULL << 32) | 0xFFULL)
#define AMD_MERGE_EVENT_ENABLE (AMD_MERGE_EVENT | ARCH_PERFMON_EVENTSEL_ENABLE)

/* PMC Enable and Overflow bits for PerfCntrGlobal* registers */
static u64 amd_pmu_global_cntr_mask __read_mostly;

static __initconst const u64 amd_hw_cache_event_ids
                                [PERF_COUNT_HW_CACHE_MAX]
                                [PERF_COUNT_HW_CACHE_OP_MAX]
                                [PERF_COUNT_HW_CACHE_RESULT_MAX] =
{
 [ C(L1D) ] = {
        [ C(OP_READ) ] = {
                [ C(RESULT_ACCESS) ] = 0x0040, /* Data Cache Accesses        */
                [ C(RESULT_MISS)   ] = 0x0141, /* Data Cache Misses          */
        },
        [ C(OP_WRITE) ] = {
                [ C(RESULT_ACCESS) ] = 0,
                [ C(RESULT_MISS)   ] = 0,
        },
        [ C(OP_PREFETCH) ] = {
                [ C(RESULT_ACCESS) ] = 0x0267, /* Data Prefetcher :attempts  */
                [ C(RESULT_MISS)   ] = 0x0167, /* Data Prefetcher :cancelled */
        },
 },
 [ C(L1I ) ] = {
        [ C(OP_READ) ] = {
                [ C(RESULT_ACCESS) ] = 0x0080, /* Instruction cache fetches  */
                [ C(RESULT_MISS)   ] = 0x0081, /* Instruction cache misses   */
        },
        [ C(OP_WRITE) ] = {
                [ C(RESULT_ACCESS) ] = -1,
                [ C(RESULT_MISS)   ] = -1,
        },
        [ C(OP_PREFETCH) ] = {
                [ C(RESULT_ACCESS) ] = 0x014B, /* Prefetch Instructions :Load */
                [ C(RESULT_MISS)   ] = 0,
        },
 },
 [ C(LL  ) ] = {
        [ C(OP_READ) ] = {
                [ C(RESULT_ACCESS) ] = 0x037D, /* Requests to L2 Cache :IC+DC */
                [ C(RESULT_MISS)   ] = 0x037E, /* L2 Cache Misses : IC+DC     */
        },
        [ C(OP_WRITE) ] = {
                [ C(RESULT_ACCESS) ] = 0x017F, /* L2 Fill/Writeback           */
                [ C(RESULT_MISS)   ] = 0,
        },
        [ C(OP_PREFETCH) ] = {
                [ C(RESULT_ACCESS) ] = 0,
                [ C(RESULT_MISS)   ] = 0,
        },
 },
 [ C(DTLB) ] = {
        [ C(OP_READ) ] = {
                [ C(RESULT_ACCESS) ] = 0x0040, /* Data Cache Accesses        */
                [ C(RESULT_MISS)   ] = 0x0746, /* L1_DTLB_AND_L2_DLTB_MISS.ALL */
        },
        [ C(OP_WRITE) ] = {
                [ C(RESULT_ACCESS) ] = 0,
                [ C(RESULT_MISS)   ] = 0,
        },
        [ C(OP_PREFETCH) ] = {
                [ C(RESULT_ACCESS) ] = 0,
                [ C(RESULT_MISS)   ] = 0,
        },
 },
 [ C(ITLB) ] = {
        [ C(OP_READ) ] = {
                [ C(RESULT_ACCESS) ] = 0x0080, /* Instruction fecthes        */
                [ C(RESULT_MISS)   ] = 0x0385, /* L1_ITLB_AND_L2_ITLB_MISS.ALL */
        },
        [ C(OP_WRITE) ] = {
                [ C(RESULT_ACCESS) ] = -1,
                [ C(RESULT_MISS)   ] = -1,
        },
        [ C(OP_PREFETCH) ] = {
                [ C(RESULT_ACCESS) ] = -1,
                [ C(RESULT_MISS)   ] = -1,
        },
 },
 [ C(BPU ) ] = {
        [ C(OP_READ) ] = {
                [ C(RESULT_ACCESS) ] = 0x00c2, /* Retired Branch Instr.      */
                [ C(RESULT_MISS)   ] = 0x00c3, /* Retired Mispredicted BI    */
        },
        [ C(OP_WRITE) ] = {
                [ C(RESULT_ACCESS) ] = -1,
                [ C(RESULT_MISS)   ] = -1,
        },
        [ C(OP_PREFETCH) ] = {
                [ C(RESULT_ACCESS) ] = -1,
                [ C(RESULT_MISS)   ] = -1,
        },
 },
 [ C(NODE) ] = {
        [ C(OP_READ) ] = {
                [ C(RESULT_ACCESS) ] = 0xb8e9, /* CPU Request to Memory, l+r */
                [ C(RESULT_MISS)   ] = 0x98e9, /* CPU Request to Memory, r   */
        },
        [ C(OP_WRITE) ] = {
                [ C(RESULT_ACCESS) ] = -1,
                [ C(RESULT_MISS)   ] = -1,
        },
        [ C(OP_PREFETCH) ] = {
                [ C(RESULT_ACCESS) ] = -1,
                [ C(RESULT_MISS)   ] = -1,
        },
 },
};

static __initconst const u64 amd_hw_cache_event_ids_f17h
                                [PERF_COUNT_HW_CACHE_MAX]
                                [PERF_COUNT_HW_CACHE_OP_MAX]
                                [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
[C(L1D)] = {
        [C(OP_READ)] = {
                [C(RESULT_ACCESS)] = 0x0040, /* Data Cache Accesses */
                [C(RESULT_MISS)]   = 0xc860, /* L2$ access from DC Miss */
        },
        [C(OP_WRITE)] = {
                [C(RESULT_ACCESS)] = 0,
                [C(RESULT_MISS)]   = 0,
        },
        [C(OP_PREFETCH)] = {
                [C(RESULT_ACCESS)] = 0xff5a, /* h/w prefetch DC Fills */
                [C(RESULT_MISS)]   = 0,
        },
},
[C(L1I)] = {
        [C(OP_READ)] = {
                [C(RESULT_ACCESS)] = 0x0080, /* Instruction cache fetches  */
                [C(RESULT_MISS)]   = 0x0081, /* Instruction cache misses   */
        },
        [C(OP_WRITE)] = {
                [C(RESULT_ACCESS)] = -1,
                [C(RESULT_MISS)]   = -1,
        },
        [C(OP_PREFETCH)] = {
                [C(RESULT_ACCESS)] = 0,
                [C(RESULT_MISS)]   = 0,
        },
},
[C(LL)] = {
        [C(OP_READ)] = {
                [C(RESULT_ACCESS)] = 0,
                [C(RESULT_MISS)]   = 0,
        },
        [C(OP_WRITE)] = {
                [C(RESULT_ACCESS)] = 0,
                [C(RESULT_MISS)]   = 0,
        },
        [C(OP_PREFETCH)] = {
                [C(RESULT_ACCESS)] = 0,
                [C(RESULT_MISS)]   = 0,
        },
},
[C(DTLB)] = {
        [C(OP_READ)] = {
                [C(RESULT_ACCESS)] = 0xff45, /* All L2 DTLB accesses */
                [C(RESULT_MISS)]   = 0xf045, /* L2 DTLB misses (PT walks) */
        },
        [C(OP_WRITE)] = {
                [C(RESULT_ACCESS)] = 0,
                [C(RESULT_MISS)]   = 0,
        },
        [C(OP_PREFETCH)] = {
                [C(RESULT_ACCESS)] = 0,
                [C(RESULT_MISS)]   = 0,
        },
},
[C(ITLB)] = {
        [C(OP_READ)] = {
                [C(RESULT_ACCESS)] = 0x0084, /* L1 ITLB misses, L2 ITLB hits */
                [C(RESULT_MISS)]   = 0xff85, /* L1 ITLB misses, L2 misses */
        },
        [C(OP_WRITE)] = {
                [C(RESULT_ACCESS)] = -1,
                [C(RESULT_MISS)]   = -1,
        },
        [C(OP_PREFETCH)] = {
                [C(RESULT_ACCESS)] = -1,
                [C(RESULT_MISS)]   = -1,
        },
},
[C(BPU)] = {
        [C(OP_READ)] = {
                [C(RESULT_ACCESS)] = 0x00c2, /* Retired Branch Instr.      */
                [C(RESULT_MISS)]   = 0x00c3, /* Retired Mispredicted BI    */
        },
        [C(OP_WRITE)] = {
                [C(RESULT_ACCESS)] = -1,
                [C(RESULT_MISS)]   = -1,
        },
        [C(OP_PREFETCH)] = {
                [C(RESULT_ACCESS)] = -1,
                [C(RESULT_MISS)]   = -1,
        },
},
[C(NODE)] = {
        [C(OP_READ)] = {
                [C(RESULT_ACCESS)] = 0,
                [C(RESULT_MISS)]   = 0,
        },
        [C(OP_WRITE)] = {
                [C(RESULT_ACCESS)] = -1,
                [C(RESULT_MISS)]   = -1,
        },
        [C(OP_PREFETCH)] = {
                [C(RESULT_ACCESS)] = -1,
                [C(RESULT_MISS)]   = -1,
        },
},
};

/*
 * AMD Performance Monitor K7 and later, up to and including Family 16h:
 */
static const u64 amd_perfmon_event_map[PERF_COUNT_HW_MAX] =
{
        [PERF_COUNT_HW_CPU_CYCLES]              = 0x0076,
        [PERF_COUNT_HW_INSTRUCTIONS]            = 0x00c0,
        [PERF_COUNT_HW_CACHE_REFERENCES]        = 0x077d,
        [PERF_COUNT_HW_CACHE_MISSES]            = 0x077e,
        [PERF_COUNT_HW_BRANCH_INSTRUCTIONS]     = 0x00c2,
        [PERF_COUNT_HW_BRANCH_MISSES]           = 0x00c3,
        [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = 0x00d0, /* "Decoder empty" event */
        [PERF_COUNT_HW_STALLED_CYCLES_BACKEND]  = 0x00d1, /* "Dispatch stalls" event */
};

/*
 * AMD Performance Monitor Family 17h and later:
 */
static const u64 amd_zen1_perfmon_event_map[PERF_COUNT_HW_MAX] =
{
        [PERF_COUNT_HW_CPU_CYCLES]              = 0x0076,
        [PERF_COUNT_HW_INSTRUCTIONS]            = 0x00c0,
        [PERF_COUNT_HW_CACHE_REFERENCES]        = 0xff60,
        [PERF_COUNT_HW_CACHE_MISSES]            = 0x0964,
        [PERF_COUNT_HW_BRANCH_INSTRUCTIONS]     = 0x00c2,
        [PERF_COUNT_HW_BRANCH_MISSES]           = 0x00c3,
        [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = 0x0287,
        [PERF_COUNT_HW_STALLED_CYCLES_BACKEND]  = 0x0187,
};

static const u64 amd_zen2_perfmon_event_map[PERF_COUNT_HW_MAX] =
{
        [PERF_COUNT_HW_CPU_CYCLES]              = 0x0076,
        [PERF_COUNT_HW_INSTRUCTIONS]            = 0x00c0,
        [PERF_COUNT_HW_CACHE_REFERENCES]        = 0xff60,
        [PERF_COUNT_HW_CACHE_MISSES]            = 0x0964,
        [PERF_COUNT_HW_BRANCH_INSTRUCTIONS]     = 0x00c2,
        [PERF_COUNT_HW_BRANCH_MISSES]           = 0x00c3,
        [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = 0x00a9,
};

static const u64 amd_zen4_perfmon_event_map[PERF_COUNT_HW_MAX] =
{
        [PERF_COUNT_HW_CPU_CYCLES]              = 0x0076,
        [PERF_COUNT_HW_INSTRUCTIONS]            = 0x00c0,
        [PERF_COUNT_HW_CACHE_REFERENCES]        = 0xff60,
        [PERF_COUNT_HW_CACHE_MISSES]            = 0x0964,
        [PERF_COUNT_HW_BRANCH_INSTRUCTIONS]     = 0x00c2,
        [PERF_COUNT_HW_BRANCH_MISSES]           = 0x00c3,
        [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = 0x00a9,
        [PERF_COUNT_HW_REF_CPU_CYCLES]          = 0x100000120,
};

static u64 amd_pmu_event_map(int hw_event)
{
        if (cpu_feature_enabled(X86_FEATURE_ZEN4) || boot_cpu_data.x86 >= 0x1a)
                return amd_zen4_perfmon_event_map[hw_event];

        if (cpu_feature_enabled(X86_FEATURE_ZEN2) || boot_cpu_data.x86 >= 0x19)
                return amd_zen2_perfmon_event_map[hw_event];

        if (cpu_feature_enabled(X86_FEATURE_ZEN1))
                return amd_zen1_perfmon_event_map[hw_event];

        return amd_perfmon_event_map[hw_event];
}

/*
 * Previously calculated offsets
 */
static unsigned int event_offsets[X86_PMC_IDX_MAX] __read_mostly;
static unsigned int count_offsets[X86_PMC_IDX_MAX] __read_mostly;

/*
 * Legacy CPUs:
 *   4 counters starting at 0xc0010000 each offset by 1
 *
 * CPUs with core performance counter extensions:
 *   6 counters starting at 0xc0010200 each offset by 2
 */
static inline int amd_pmu_addr_offset(int index, bool eventsel)
{
        int offset;

        if (!index)
                return index;

        if (eventsel)
                offset = event_offsets[index];
        else
                offset = count_offsets[index];

        if (offset)
                return offset;

        if (!boot_cpu_has(X86_FEATURE_PERFCTR_CORE))
                offset = index;
        else
                offset = index << 1;

        if (eventsel)
                event_offsets[index] = offset;
        else
                count_offsets[index] = offset;

        return offset;
}

/*
 * AMD64 events are detected based on their event codes.
 */
static inline unsigned int amd_get_event_code(struct hw_perf_event *hwc)
{
        return ((hwc->config >> 24) & 0x0f00) | (hwc->config & 0x00ff);
}

static inline bool amd_is_pair_event_code(struct hw_perf_event *hwc)
{
        if (!(x86_pmu.flags & PMU_FL_PAIR))
                return false;

        switch (amd_get_event_code(hwc)) {
        case 0x003:     return true;    /* Retired SSE/AVX FLOPs */
        default:        return false;
        }
}

DEFINE_STATIC_CALL_RET0(amd_pmu_branch_hw_config, *x86_pmu.hw_config);

static int amd_core_hw_config(struct perf_event *event)
{
        if (event->attr.exclude_host && event->attr.exclude_guest)
                /*
                 * When HO == GO == 1 the hardware treats that as GO == HO == 0
                 * and will count in both modes. We don't want to count in that
                 * case so we emulate no-counting by setting US = OS = 0.
                 */
                event->hw.config &= ~(ARCH_PERFMON_EVENTSEL_USR |
                                      ARCH_PERFMON_EVENTSEL_OS);
        else if (event->attr.exclude_host)
                event->hw.config |= AMD64_EVENTSEL_GUESTONLY;
        else if (event->attr.exclude_guest)
                event->hw.config |= AMD64_EVENTSEL_HOSTONLY;

        if ((x86_pmu.flags & PMU_FL_PAIR) && amd_is_pair_event_code(&event->hw))
                event->hw.flags |= PERF_X86_EVENT_PAIR;

        if (has_branch_stack(event))
                return static_call(amd_pmu_branch_hw_config)(event);

        return 0;
}

static inline int amd_is_nb_event(struct hw_perf_event *hwc)
{
        return (hwc->config & 0xe0) == 0xe0;
}

static inline int amd_has_nb(struct cpu_hw_events *cpuc)
{
        struct amd_nb *nb = cpuc->amd_nb;

        return nb && nb->nb_id != -1;
}

static int amd_pmu_hw_config(struct perf_event *event)
{
        int ret;

        /* pass precise event sampling to ibs: */
        if (event->attr.precise_ip && get_ibs_caps())
                return forward_event_to_ibs(event);

        if (has_branch_stack(event) && !x86_pmu.lbr_nr)
                return -EOPNOTSUPP;

        ret = x86_pmu_hw_config(event);
        if (ret)
                return ret;

        if (event->attr.type == PERF_TYPE_RAW)
                event->hw.config |= event->attr.config & AMD64_RAW_EVENT_MASK;

        return amd_core_hw_config(event);
}

static void __amd_put_nb_event_constraints(struct cpu_hw_events *cpuc,
                                           struct perf_event *event)
{
        struct amd_nb *nb = cpuc->amd_nb;
        int i;

        /*
         * need to scan whole list because event may not have
         * been assigned during scheduling
         *
         * no race condition possible because event can only
         * be removed on one CPU at a time AND PMU is disabled
         * when we come here
         */
        for_each_set_bit(i, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
                struct perf_event *tmp = event;

                if (try_cmpxchg(nb->owners + i, &tmp, NULL))
                        break;
        }
}

 /*
  * AMD64 NorthBridge events need special treatment because
  * counter access needs to be synchronized across all cores
  * of a package. Refer to BKDG section 3.12
  *
  * NB events are events measuring L3 cache, Hypertransport
  * traffic. They are identified by an event code >= 0xe00.
  * They measure events on the NorthBride which is shared
  * by all cores on a package. NB events are counted on a
  * shared set of counters. When a NB event is programmed
  * in a counter, the data actually comes from a shared
  * counter. Thus, access to those counters needs to be
  * synchronized.
  *
  * We implement the synchronization such that no two cores
  * can be measuring NB events using the same counters. Thus,
  * we maintain a per-NB allocation table. The available slot
  * is propagated using the event_constraint structure.
  *
  * We provide only one choice for each NB event based on
  * the fact that only NB events have restrictions. Consequently,
  * if a counter is available, there is a guarantee the NB event
  * will be assigned to it. If no slot is available, an empty
  * constraint is returned and scheduling will eventually fail
  * for this event.
  *
  * Note that all cores attached the same NB compete for the same
  * counters to host NB events, this is why we use atomic ops. Some
  * multi-chip CPUs may have more than one NB.
  *
  * Given that resources are allocated (cmpxchg), they must be
  * eventually freed for others to use. This is accomplished by
  * calling __amd_put_nb_event_constraints()
  *
  * Non NB events are not impacted by this restriction.
  */
static struct event_constraint *
__amd_get_nb_event_constraints(struct cpu_hw_events *cpuc, struct perf_event *event,
                               struct event_constraint *c)
{
        struct hw_perf_event *hwc = &event->hw;
        struct amd_nb *nb = cpuc->amd_nb;
        struct perf_event *old;
        int idx, new = -1;

        if (!c)
                c = &unconstrained;

        if (cpuc->is_fake)
                return c;

        /*
         * detect if already present, if so reuse
         *
         * cannot merge with actual allocation
         * because of possible holes
         *
         * event can already be present yet not assigned (in hwc->idx)
         * because of successive calls to x86_schedule_events() from
         * hw_perf_group_sched_in() without hw_perf_enable()
         */
        for_each_set_bit(idx, c->idxmsk, x86_pmu_max_num_counters(NULL)) {
                if (new == -1 || hwc->idx == idx)
                        /* assign free slot, prefer hwc->idx */
                        old = cmpxchg(nb->owners + idx, NULL, event);
                else if (nb->owners[idx] == event)
                        /* event already present */
                        old = event;
                else
                        continue;

                if (old && old != event)
                        continue;

                /* reassign to this slot */
                if (new != -1)
                        cmpxchg(nb->owners + new, event, NULL);
                new = idx;

                /* already present, reuse */
                if (old == event)
                        break;
        }

        if (new == -1)
                return &emptyconstraint;

        return &nb->event_constraints[new];
}

static struct amd_nb *amd_alloc_nb(int cpu)
{
        struct amd_nb *nb;
        int i;

        nb = kzalloc_node(sizeof(struct amd_nb), GFP_KERNEL, cpu_to_node(cpu));
        if (!nb)
                return NULL;

        nb->nb_id = -1;

        /*
         * initialize all possible NB constraints
         */
        for_each_set_bit(i, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
                __set_bit(i, nb->event_constraints[i].idxmsk);
                nb->event_constraints[i].weight = 1;
        }
        return nb;
}

typedef void (amd_pmu_branch_reset_t)(void);
DEFINE_STATIC_CALL_NULL(amd_pmu_branch_reset, amd_pmu_branch_reset_t);

static void amd_pmu_cpu_reset(int cpu)
{
        if (x86_pmu.lbr_nr)
                static_call(amd_pmu_branch_reset)();

        if (x86_pmu.version < 2)
                return;

        /* Clear enable bits i.e. PerfCntrGlobalCtl.PerfCntrEn */
        wrmsrq(MSR_AMD64_PERF_CNTR_GLOBAL_CTL, 0);

        /*
         * Clear freeze and overflow bits i.e. PerfCntrGLobalStatus.LbrFreeze
         * and PerfCntrGLobalStatus.PerfCntrOvfl
         */
        wrmsrq(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR,
               GLOBAL_STATUS_LBRS_FROZEN | amd_pmu_global_cntr_mask);
}

static int amd_pmu_cpu_prepare(int cpu)
{
        struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);

        cpuc->lbr_sel = kzalloc_node(sizeof(struct er_account), GFP_KERNEL,
                                     cpu_to_node(cpu));
        if (!cpuc->lbr_sel)
                return -ENOMEM;

        WARN_ON_ONCE(cpuc->amd_nb);

        if (!x86_pmu.amd_nb_constraints)
                return 0;

        cpuc->amd_nb = amd_alloc_nb(cpu);
        if (cpuc->amd_nb)
                return 0;

        kfree(cpuc->lbr_sel);
        cpuc->lbr_sel = NULL;

        return -ENOMEM;
}

static void amd_pmu_cpu_starting(int cpu)
{
        struct cpu_hw_events *cpuc = &per_cpu(cpu_hw_events, cpu);
        void **onln = &cpuc->kfree_on_online[X86_PERF_KFREE_SHARED];
        struct amd_nb *nb;
        int i, nb_id;

        cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY;
        amd_pmu_cpu_reset(cpu);

        if (!x86_pmu.amd_nb_constraints)
                return;

        nb_id = topology_amd_node_id(cpu);
        WARN_ON_ONCE(nb_id == BAD_APICID);

        for_each_online_cpu(i) {
                nb = per_cpu(cpu_hw_events, i).amd_nb;
                if (WARN_ON_ONCE(!nb))
                        continue;

                if (nb->nb_id == nb_id) {
                        *onln = cpuc->amd_nb;
                        cpuc->amd_nb = nb;
                        break;
                }
        }

        cpuc->amd_nb->nb_id = nb_id;
        cpuc->amd_nb->refcnt++;
}

static void amd_pmu_cpu_dead(int cpu)
{
        struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);

        kfree(cpuhw->lbr_sel);
        cpuhw->lbr_sel = NULL;

        if (!x86_pmu.amd_nb_constraints)
                return;

        if (cpuhw->amd_nb) {
                struct amd_nb *nb = cpuhw->amd_nb;

                if (nb->nb_id == -1 || --nb->refcnt == 0)
                        kfree(nb);

                cpuhw->amd_nb = NULL;
        }
}

static __always_inline void amd_pmu_set_global_ctl(u64 ctl)
{
        wrmsrq(MSR_AMD64_PERF_CNTR_GLOBAL_CTL, ctl);
}

static inline u64 amd_pmu_get_global_status(void)
{
        u64 status;

        /* PerfCntrGlobalStatus is read-only */
        rdmsrq(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS, status);

        return status;
}

static inline void amd_pmu_ack_global_status(u64 status)
{
        /*
         * PerfCntrGlobalStatus is read-only but an overflow acknowledgment
         * mechanism exists; writing 1 to a bit in PerfCntrGlobalStatusClr
         * clears the same bit in PerfCntrGlobalStatus
         */

        wrmsrq(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR, status);
}

static bool amd_pmu_test_overflow_topbit(int idx)
{
        u64 counter;

        rdmsrq(x86_pmu_event_addr(idx), counter);

        return !(counter & BIT_ULL(x86_pmu.cntval_bits - 1));
}

static bool amd_pmu_test_overflow_status(int idx)
{
        return amd_pmu_get_global_status() & BIT_ULL(idx);
}

DEFINE_STATIC_CALL(amd_pmu_test_overflow, amd_pmu_test_overflow_topbit);

/*
 * When a PMC counter overflows, an NMI is used to process the event and
 * reset the counter. NMI latency can result in the counter being updated
 * before the NMI can run, which can result in what appear to be spurious
 * NMIs. This function is intended to wait for the NMI to run and reset
 * the counter to avoid possible unhandled NMI messages.
 */
#define OVERFLOW_WAIT_COUNT     50

static void amd_pmu_wait_on_overflow(int idx)
{
        unsigned int i;

        /*
         * Wait for the counter to be reset if it has overflowed. This loop
         * should exit very, very quickly, but just in case, don't wait
         * forever...
         */
        for (i = 0; i < OVERFLOW_WAIT_COUNT; i++) {
                if (!static_call(amd_pmu_test_overflow)(idx))
                        break;

                /* Might be in IRQ context, so can't sleep */
                udelay(1);
        }
}

static void amd_pmu_check_overflow(void)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        int idx;

        /*
         * This shouldn't be called from NMI context, but add a safeguard here
         * to return, since if we're in NMI context we can't wait for an NMI
         * to reset an overflowed counter value.
         */
        if (in_nmi())
                return;

        /*
         * Check each counter for overflow and wait for it to be reset by the
         * NMI if it has overflowed. This relies on the fact that all active
         * counters are always enabled when this function is called and
         * ARCH_PERFMON_EVENTSEL_INT is always set.
         */
        for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
                if (!test_bit(idx, cpuc->active_mask))
                        continue;

                amd_pmu_wait_on_overflow(idx);
        }
}

static void amd_pmu_enable_event(struct perf_event *event)
{
        x86_pmu_enable_event(event);
}

static void amd_pmu_enable_all(int added)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        int idx;

        amd_brs_enable_all();

        for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
                /* only activate events which are marked as active */
                if (!test_bit(idx, cpuc->active_mask))
                        continue;

                /*
                 * FIXME: cpuc->events[idx] can become NULL in a subtle race
                 * condition with NMI->throttle->x86_pmu_stop().
                 */
                if (cpuc->events[idx])
                        amd_pmu_enable_event(cpuc->events[idx]);
        }
}

static void amd_pmu_v2_enable_event(struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;

        /*
         * Testing cpu_hw_events.enabled should be skipped in this case unlike
         * in x86_pmu_enable_event().
         *
         * Since cpu_hw_events.enabled is set only after returning from
         * x86_pmu_start(), the PMCs must be programmed and kept ready.
         * Counting starts only after x86_pmu_enable_all() is called.
         */
        __x86_pmu_enable_event(hwc, ARCH_PERFMON_EVENTSEL_ENABLE);
}

static __always_inline void amd_pmu_core_enable_all(void)
{
        amd_pmu_set_global_ctl(amd_pmu_global_cntr_mask);
}

static void amd_pmu_v2_enable_all(int added)
{
        amd_pmu_lbr_enable_all();
        amd_pmu_core_enable_all();
}

static void amd_pmu_disable_event(struct perf_event *event)
{
        x86_pmu_disable_event(event);

        /*
         * This can be called from NMI context (via x86_pmu_stop). The counter
         * may have overflowed, but either way, we'll never see it get reset
         * by the NMI if we're already in the NMI. And the NMI latency support
         * below will take care of any pending NMI that might have been
         * generated by the overflow.
         */
        if (in_nmi())
                return;

        amd_pmu_wait_on_overflow(event->hw.idx);
}

static void amd_pmu_disable_all(void)
{
        amd_brs_disable_all();
        x86_pmu_disable_all();
        amd_pmu_check_overflow();
}

static __always_inline void amd_pmu_core_disable_all(void)
{
        amd_pmu_set_global_ctl(0);
}

static void amd_pmu_v2_disable_all(void)
{
        amd_pmu_core_disable_all();
        amd_pmu_lbr_disable_all();
        amd_pmu_check_overflow();
}

DEFINE_STATIC_CALL_NULL(amd_pmu_branch_add, *x86_pmu.add);

static void amd_pmu_add_event(struct perf_event *event)
{
        if (needs_branch_stack(event))
                static_call(amd_pmu_branch_add)(event);
}

DEFINE_STATIC_CALL_NULL(amd_pmu_branch_del, *x86_pmu.del);

static void amd_pmu_del_event(struct perf_event *event)
{
        if (needs_branch_stack(event))
                static_call(amd_pmu_branch_del)(event);
}

/*
 * Because of NMI latency, if multiple PMC counters are active or other sources
 * of NMIs are received, the perf NMI handler can handle one or more overflowed
 * PMC counters outside of the NMI associated with the PMC overflow. If the NMI
 * doesn't arrive at the LAPIC in time to become a pending NMI, then the kernel
 * back-to-back NMI support won't be active. This PMC handler needs to take into
 * account that this can occur, otherwise this could result in unknown NMI
 * messages being issued. Examples of this is PMC overflow while in the NMI
 * handler when multiple PMCs are active or PMC overflow while handling some
 * other source of an NMI.
 *
 * Attempt to mitigate this by creating an NMI window in which un-handled NMIs
 * received during this window will be claimed. This prevents extending the
 * window past when it is possible that latent NMIs should be received. The
 * per-CPU perf_nmi_tstamp will be set to the window end time whenever perf has
 * handled a counter. When an un-handled NMI is received, it will be claimed
 * only if arriving within that window.
 */
static inline int amd_pmu_adjust_nmi_window(int handled)
{
        /*
         * If a counter was handled, record a timestamp such that un-handled
         * NMIs will be claimed if arriving within that window.
         */
        if (handled) {
                this_cpu_write(perf_nmi_tstamp, jiffies + perf_nmi_window);

                return handled;
        }

        if (time_after(jiffies, this_cpu_read(perf_nmi_tstamp)))
                return NMI_DONE;

        return NMI_HANDLED;
}

static int amd_pmu_handle_irq(struct pt_regs *regs)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        int handled;
        int pmu_enabled;

        /*
         * Save the PMU state.
         * It needs to be restored when leaving the handler.
         */
        pmu_enabled = cpuc->enabled;
        cpuc->enabled = 0;

        amd_brs_disable_all();

        /* Drain BRS is in use (could be inactive) */
        if (cpuc->lbr_users)
                amd_brs_drain();

        /* Process any counter overflows */
        handled = x86_pmu_handle_irq(regs);

        cpuc->enabled = pmu_enabled;
        if (pmu_enabled)
                amd_brs_enable_all();

        return amd_pmu_adjust_nmi_window(handled);
}

/*
 * AMD-specific callback invoked through perf_snapshot_branch_stack static
 * call, defined in include/linux/perf_event.h. See its definition for API
 * details. It's up to caller to provide enough space in *entries* to fit all
 * LBR records, otherwise returned result will be truncated to *cnt* entries.
 */
static int amd_pmu_v2_snapshot_branch_stack(struct perf_branch_entry *entries, unsigned int cnt)
{
        struct cpu_hw_events *cpuc;
        unsigned long flags;

        /*
         * The sequence of steps to freeze LBR should be completely inlined
         * and contain no branches to minimize contamination of LBR snapshot
         */
        local_irq_save(flags);
        amd_pmu_core_disable_all();
        __amd_pmu_lbr_disable();

        cpuc = this_cpu_ptr(&cpu_hw_events);

        amd_pmu_lbr_read();
        cnt = min(cnt, x86_pmu.lbr_nr);
        memcpy(entries, cpuc->lbr_entries, sizeof(struct perf_branch_entry) * cnt);

        amd_pmu_v2_enable_all(0);
        local_irq_restore(flags);

        return cnt;
}

static int amd_pmu_v2_handle_irq(struct pt_regs *regs)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
        static atomic64_t status_warned = ATOMIC64_INIT(0);
        u64 reserved, status, mask, new_bits, prev_bits;
        struct perf_sample_data data;
        struct hw_perf_event *hwc;
        struct perf_event *event;
        int handled = 0, idx;
        bool pmu_enabled;

        /*
         * Save the PMU state as it needs to be restored when leaving the
         * handler
         */
        pmu_enabled = cpuc->enabled;
        cpuc->enabled = 0;

        /* Stop counting but do not disable LBR */
        amd_pmu_core_disable_all();

        status = amd_pmu_get_global_status();

        /* Check if any overflows are pending */
        if (!status)
                goto done;

        /* Read branch records */
        if (x86_pmu.lbr_nr) {
                amd_pmu_lbr_read();
                status &= ~GLOBAL_STATUS_LBRS_FROZEN;
        }

        reserved = status & ~amd_pmu_global_cntr_mask;
        if (reserved)
                pr_warn_once("Reserved PerfCntrGlobalStatus bits are set (0x%llx), please consider updating microcode\n",
                             reserved);

        /* Clear any reserved bits set by buggy microcode */
        status &= amd_pmu_global_cntr_mask;

        for_each_set_bit(idx, x86_pmu.cntr_mask, X86_PMC_IDX_MAX) {
                if (!test_bit(idx, cpuc->active_mask))
                        continue;

                event = cpuc->events[idx];
                hwc = &event->hw;
                x86_perf_event_update(event);
                mask = BIT_ULL(idx);

                if (!(status & mask))
                        continue;

                /* Event overflow */
                handled++;
                status &= ~mask;
                perf_sample_data_init(&data, 0, hwc->last_period);

                if (!x86_perf_event_set_period(event))
                        continue;

                perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL);

                perf_event_overflow(event, &data, regs);
        }

        /*
         * It should never be the case that some overflows are not handled as
         * the corresponding PMCs are expected to be inactive according to the
         * active_mask
         */
        if (status > 0) {
                prev_bits = atomic64_fetch_or(status, &status_warned);
                // A new bit was set for the very first time.
                new_bits = status & ~prev_bits;
                WARN(new_bits, "New overflows for inactive PMCs: %llx\n", new_bits);
        }

        /* Clear overflow and freeze bits */
        amd_pmu_ack_global_status(~status);

        /*
         * Unmasking the LVTPC is not required as the Mask (M) bit of the LVT
         * PMI entry is not set by the local APIC when a PMC overflow occurs
         */
        inc_irq_stat(apic_perf_irqs);

done:
        cpuc->enabled = pmu_enabled;

        /* Resume counting only if PMU is active */
        if (pmu_enabled)
                amd_pmu_core_enable_all();

        return amd_pmu_adjust_nmi_window(handled);
}

static struct event_constraint *
amd_get_event_constraints(struct cpu_hw_events *cpuc, int idx,
                          struct perf_event *event)
{
        /*
         * if not NB event or no NB, then no constraints
         */
        if (!(amd_has_nb(cpuc) && amd_is_nb_event(&event->hw)))
                return &unconstrained;

        return __amd_get_nb_event_constraints(cpuc, event, NULL);
}

static void amd_put_event_constraints(struct cpu_hw_events *cpuc,
                                      struct perf_event *event)
{
        if (amd_has_nb(cpuc) && amd_is_nb_event(&event->hw))
                __amd_put_nb_event_constraints(cpuc, event);
}

PMU_FORMAT_ATTR(event,  "config:0-7,32-35");
PMU_FORMAT_ATTR(umask,  "config:8-15"   );
PMU_FORMAT_ATTR(edge,   "config:18"     );
PMU_FORMAT_ATTR(inv,    "config:23"     );
PMU_FORMAT_ATTR(cmask,  "config:24-31"  );

static struct attribute *amd_format_attr[] = {
        &format_attr_event.attr,
        &format_attr_umask.attr,
        &format_attr_edge.attr,
        &format_attr_inv.attr,
        &format_attr_cmask.attr,
        NULL,
};

/* AMD Family 15h */

#define AMD_EVENT_TYPE_MASK     0x000000F0ULL

#define AMD_EVENT_FP            0x00000000ULL ... 0x00000010ULL
#define AMD_EVENT_LS            0x00000020ULL ... 0x00000030ULL
#define AMD_EVENT_DC            0x00000040ULL ... 0x00000050ULL
#define AMD_EVENT_CU            0x00000060ULL ... 0x00000070ULL
#define AMD_EVENT_IC_DE         0x00000080ULL ... 0x00000090ULL
#define AMD_EVENT_EX_LS         0x000000C0ULL
#define AMD_EVENT_DE            0x000000D0ULL
#define AMD_EVENT_NB            0x000000E0ULL ... 0x000000F0ULL

/*
 * AMD family 15h event code/PMC mappings:
 *
 * type = event_code & 0x0F0:
 *
 * 0x000        FP      PERF_CTL[5:3]
 * 0x010        FP      PERF_CTL[5:3]
 * 0x020        LS      PERF_CTL[5:0]
 * 0x030        LS      PERF_CTL[5:0]
 * 0x040        DC      PERF_CTL[5:0]
 * 0x050        DC      PERF_CTL[5:0]
 * 0x060        CU      PERF_CTL[2:0]
 * 0x070        CU      PERF_CTL[2:0]
 * 0x080        IC/DE   PERF_CTL[2:0]
 * 0x090        IC/DE   PERF_CTL[2:0]
 * 0x0A0        ---
 * 0x0B0        ---
 * 0x0C0        EX/LS   PERF_CTL[5:0]
 * 0x0D0        DE      PERF_CTL[2:0]
 * 0x0E0        NB      NB_PERF_CTL[3:0]
 * 0x0F0        NB      NB_PERF_CTL[3:0]
 *
 * Exceptions:
 *
 * 0x000        FP      PERF_CTL[3], PERF_CTL[5:3] (*)
 * 0x003        FP      PERF_CTL[3]
 * 0x004        FP      PERF_CTL[3], PERF_CTL[5:3] (*)
 * 0x00B        FP      PERF_CTL[3]
 * 0x00D        FP      PERF_CTL[3]
 * 0x023        DE      PERF_CTL[2:0]
 * 0x02D        LS      PERF_CTL[3]
 * 0x02E        LS      PERF_CTL[3,0]
 * 0x031        LS      PERF_CTL[2:0] (**)
 * 0x043        CU      PERF_CTL[2:0]
 * 0x045        CU      PERF_CTL[2:0]
 * 0x046        CU      PERF_CTL[2:0]
 * 0x054        CU      PERF_CTL[2:0]
 * 0x055        CU      PERF_CTL[2:0]
 * 0x08F        IC      PERF_CTL[0]
 * 0x187        DE      PERF_CTL[0]
 * 0x188        DE      PERF_CTL[0]
 * 0x0DB        EX      PERF_CTL[5:0]
 * 0x0DC        LS      PERF_CTL[5:0]
 * 0x0DD        LS      PERF_CTL[5:0]
 * 0x0DE        LS      PERF_CTL[5:0]
 * 0x0DF        LS      PERF_CTL[5:0]
 * 0x1C0        EX      PERF_CTL[5:3]
 * 0x1D6        EX      PERF_CTL[5:0]
 * 0x1D8        EX      PERF_CTL[5:0]
 *
 * (*)  depending on the umask all FPU counters may be used
 * (**) only one unitmask enabled at a time
 */

static struct event_constraint amd_f15_PMC0  = EVENT_CONSTRAINT(0, 0x01, 0);
static struct event_constraint amd_f15_PMC20 = EVENT_CONSTRAINT(0, 0x07, 0);
static struct event_constraint amd_f15_PMC3  = EVENT_CONSTRAINT(0, 0x08, 0);
static struct event_constraint amd_f15_PMC30 = EVENT_CONSTRAINT_OVERLAP(0, 0x09, 0);
static struct event_constraint amd_f15_PMC50 = EVENT_CONSTRAINT(0, 0x3F, 0);
static struct event_constraint amd_f15_PMC53 = EVENT_CONSTRAINT(0, 0x38, 0);

static struct event_constraint *
amd_get_event_constraints_f15h(struct cpu_hw_events *cpuc, int idx,
                               struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;
        unsigned int event_code = amd_get_event_code(hwc);

        switch (event_code & AMD_EVENT_TYPE_MASK) {
        case AMD_EVENT_FP:
                switch (event_code) {
                case 0x000:
                        if (!(hwc->config & 0x0000F000ULL))
                                break;
                        if (!(hwc->config & 0x00000F00ULL))
                                break;
                        return &amd_f15_PMC3;
                case 0x004:
                        if (hweight_long(hwc->config & ARCH_PERFMON_EVENTSEL_UMASK) <= 1)
                                break;
                        return &amd_f15_PMC3;
                case 0x003:
                case 0x00B:
                case 0x00D:
                        return &amd_f15_PMC3;
                }
                return &amd_f15_PMC53;
        case AMD_EVENT_LS:
        case AMD_EVENT_DC:
        case AMD_EVENT_EX_LS:
                switch (event_code) {
                case 0x023:
                case 0x043:
                case 0x045:
                case 0x046:
                case 0x054:
                case 0x055:
                        return &amd_f15_PMC20;
                case 0x02D:
                        return &amd_f15_PMC3;
                case 0x02E:
                        return &amd_f15_PMC30;
                case 0x031:
                        if (hweight_long(hwc->config & ARCH_PERFMON_EVENTSEL_UMASK) <= 1)
                                return &amd_f15_PMC20;
                        return &emptyconstraint;
                case 0x1C0:
                        return &amd_f15_PMC53;
                default:
                        return &amd_f15_PMC50;
                }
        case AMD_EVENT_CU:
        case AMD_EVENT_IC_DE:
        case AMD_EVENT_DE:
                switch (event_code) {
                case 0x08F:
                case 0x187:
                case 0x188:
                        return &amd_f15_PMC0;
                case 0x0DB ... 0x0DF:
                case 0x1D6:
                case 0x1D8:
                        return &amd_f15_PMC50;
                default:
                        return &amd_f15_PMC20;
                }
        case AMD_EVENT_NB:
                /* moved to uncore.c */
                return &emptyconstraint;
        default:
                return &emptyconstraint;
        }
}

static struct event_constraint pair_constraint;

static struct event_constraint *
amd_get_event_constraints_f17h(struct cpu_hw_events *cpuc, int idx,
                               struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;

        if (amd_is_pair_event_code(hwc))
                return &pair_constraint;

        return &unconstrained;
}

static void amd_put_event_constraints_f17h(struct cpu_hw_events *cpuc,
                                           struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;

        if (is_counter_pair(hwc))
                --cpuc->n_pair;
}

/*
 * Because of the way BRS operates with an inactive and active phases, and
 * the link to one counter, it is not possible to have two events using BRS
 * scheduled at the same time. There would be an issue with enforcing the
 * period of each one and given that the BRS saturates, it would not be possible
 * to guarantee correlated content for all events. Therefore, in situations
 * where multiple events want to use BRS, the kernel enforces mutual exclusion.
 * Exclusion is enforced by choosing only one counter for events using BRS.
 * The event scheduling logic will then automatically multiplex the
 * events and ensure that at most one event is actively using BRS.
 *
 * The BRS counter could be any counter, but there is no constraint on Fam19h,
 * therefore all counters are equal and thus we pick the first one: PMC0
 */
static struct event_constraint amd_fam19h_brs_cntr0_constraint =
        EVENT_CONSTRAINT(0, 0x1, AMD64_RAW_EVENT_MASK);

static struct event_constraint amd_fam19h_brs_pair_cntr0_constraint =
        __EVENT_CONSTRAINT(0, 0x1, AMD64_RAW_EVENT_MASK, 1, 0, PERF_X86_EVENT_PAIR);

static struct event_constraint *
amd_get_event_constraints_f19h(struct cpu_hw_events *cpuc, int idx,
                          struct perf_event *event)
{
        struct hw_perf_event *hwc = &event->hw;
        bool has_brs = has_amd_brs(hwc);

        /*
         * In case BRS is used with an event requiring a counter pair,
         * the kernel allows it but only on counter 0 & 1 to enforce
         * multiplexing requiring to protect BRS in case of multiple
         * BRS users
         */
        if (amd_is_pair_event_code(hwc)) {
                return has_brs ? &amd_fam19h_brs_pair_cntr0_constraint
                               : &pair_constraint;
        }

        if (has_brs)
                return &amd_fam19h_brs_cntr0_constraint;

        return &unconstrained;
}


static ssize_t amd_event_sysfs_show(char *page, u64 config)
{
        u64 event = (config & ARCH_PERFMON_EVENTSEL_EVENT) |
                    (config & AMD64_EVENTSEL_EVENT) >> 24;

        return x86_event_sysfs_show(page, config, event);
}

static void amd_pmu_limit_period(struct perf_event *event, s64 *left)
{
        /*
         * Decrease period by the depth of the BRS feature to get the last N
         * taken branches and approximate the desired period
         */
        if (has_branch_stack(event) && *left > x86_pmu.lbr_nr)
                *left -= x86_pmu.lbr_nr;
}

static __initconst const struct x86_pmu amd_pmu = {
        .name                   = "AMD",
        .handle_irq             = amd_pmu_handle_irq,
        .disable_all            = amd_pmu_disable_all,
        .enable_all             = amd_pmu_enable_all,
        .enable                 = amd_pmu_enable_event,
        .disable                = amd_pmu_disable_event,
        .hw_config              = amd_pmu_hw_config,
        .schedule_events        = x86_schedule_events,
        .eventsel               = MSR_K7_EVNTSEL0,
        .perfctr                = MSR_K7_PERFCTR0,
        .addr_offset            = amd_pmu_addr_offset,
        .event_map              = amd_pmu_event_map,
        .max_events             = ARRAY_SIZE(amd_perfmon_event_map),
        .cntr_mask64            = GENMASK_ULL(AMD64_NUM_COUNTERS - 1, 0),
        .add                    = amd_pmu_add_event,
        .del                    = amd_pmu_del_event,
        .cntval_bits            = 48,
        .cntval_mask            = (1ULL << 48) - 1,
        .apic                   = 1,
        /* use highest bit to detect overflow */
        .max_period             = (1ULL << 47) - 1,
        .get_event_constraints  = amd_get_event_constraints,
        .put_event_constraints  = amd_put_event_constraints,

        .format_attrs           = amd_format_attr,
        .events_sysfs_show      = amd_event_sysfs_show,

        .cpu_prepare            = amd_pmu_cpu_prepare,
        .cpu_starting           = amd_pmu_cpu_starting,
        .cpu_dead               = amd_pmu_cpu_dead,

        .amd_nb_constraints     = 1,
};

static ssize_t branches_show(struct device *cdev,
                              struct device_attribute *attr,
                              char *buf)
{
        return snprintf(buf, PAGE_SIZE, "%d\n", x86_pmu.lbr_nr);
}

static DEVICE_ATTR_RO(branches);

static struct attribute *amd_pmu_branches_attrs[] = {
        &dev_attr_branches.attr,
        NULL,
};

static umode_t
amd_branches_is_visible(struct kobject *kobj, struct attribute *attr, int i)
{
        return x86_pmu.lbr_nr ? attr->mode : 0;
}

static struct attribute_group group_caps_amd_branches = {
        .name  = "caps",
        .attrs = amd_pmu_branches_attrs,
        .is_visible = amd_branches_is_visible,
};

#ifdef CONFIG_PERF_EVENTS_AMD_BRS

EVENT_ATTR_STR(branch-brs, amd_branch_brs,
               "event=" __stringify(AMD_FAM19H_BRS_EVENT)"\n");

static struct attribute *amd_brs_events_attrs[] = {
        EVENT_PTR(amd_branch_brs),
        NULL,
};

static umode_t
amd_brs_is_visible(struct kobject *kobj, struct attribute *attr, int i)
{
        return static_cpu_has(X86_FEATURE_BRS) && x86_pmu.lbr_nr ?
               attr->mode : 0;
}

static struct attribute_group group_events_amd_brs = {
        .name       = "events",
        .attrs      = amd_brs_events_attrs,
        .is_visible = amd_brs_is_visible,
};

#endif  /* CONFIG_PERF_EVENTS_AMD_BRS */

static const struct attribute_group *amd_attr_update[] = {
        &group_caps_amd_branches,
#ifdef CONFIG_PERF_EVENTS_AMD_BRS
        &group_events_amd_brs,
#endif
        NULL,
};

static int __init amd_core_pmu_init(void)
{
        union cpuid_0x80000022_ebx ebx;
        u64 even_ctr_mask = 0ULL;
        int i;

        if (!boot_cpu_has(X86_FEATURE_PERFCTR_CORE))
                return 0;

        /* Avoid calculating the value each time in the NMI handler */
        perf_nmi_window = msecs_to_jiffies(100);

        /*
         * If core performance counter extensions exists, we must use
         * MSR_F15H_PERF_CTL/MSR_F15H_PERF_CTR msrs. See also
         * amd_pmu_addr_offset().
         */
        x86_pmu.eventsel        = MSR_F15H_PERF_CTL;
        x86_pmu.perfctr         = MSR_F15H_PERF_CTR;
        x86_pmu.cntr_mask64     = GENMASK_ULL(AMD64_NUM_COUNTERS_CORE - 1, 0);

        /* Check for Performance Monitoring v2 support */
        if (boot_cpu_has(X86_FEATURE_PERFMON_V2)) {
                ebx.full = cpuid_ebx(EXT_PERFMON_DEBUG_FEATURES);

                /* Update PMU version for later usage */
                x86_pmu.version = 2;

                /* Find the number of available Core PMCs */
                x86_pmu.cntr_mask64 = GENMASK_ULL(ebx.split.num_core_pmc - 1, 0);

                amd_pmu_global_cntr_mask = x86_pmu.cntr_mask64;

                x86_get_pmu(smp_processor_id())->capabilities |= PERF_PMU_CAP_MEDIATED_VPMU;

                /* Update PMC handling functions */
                x86_pmu.enable_all = amd_pmu_v2_enable_all;
                x86_pmu.disable_all = amd_pmu_v2_disable_all;
                x86_pmu.enable = amd_pmu_v2_enable_event;
                x86_pmu.handle_irq = amd_pmu_v2_handle_irq;
                static_call_update(amd_pmu_test_overflow, amd_pmu_test_overflow_status);
        }

        /*
         * AMD Core perfctr has separate MSRs for the NB events, see
         * the amd/uncore.c driver.
         */
        x86_pmu.amd_nb_constraints = 0;

        if (boot_cpu_data.x86 == 0x15) {
                pr_cont("Fam15h ");
                x86_pmu.get_event_constraints = amd_get_event_constraints_f15h;
        }
        if (boot_cpu_data.x86 >= 0x17) {
                pr_cont("Fam17h+ ");
                /*
                 * Family 17h and compatibles have constraints for Large
                 * Increment per Cycle events: they may only be assigned an
                 * even numbered counter that has a consecutive adjacent odd
                 * numbered counter following it.
                 */
                for (i = 0; i < x86_pmu_max_num_counters(NULL) - 1; i += 2)
                        even_ctr_mask |= BIT_ULL(i);

                pair_constraint = (struct event_constraint)
                                    __EVENT_CONSTRAINT(0, even_ctr_mask, 0,
                                    x86_pmu_max_num_counters(NULL) / 2, 0,
                                    PERF_X86_EVENT_PAIR);

                x86_pmu.get_event_constraints = amd_get_event_constraints_f17h;
                x86_pmu.put_event_constraints = amd_put_event_constraints_f17h;
                x86_pmu.perf_ctr_pair_en = AMD_MERGE_EVENT_ENABLE;
                x86_pmu.flags |= PMU_FL_PAIR;
        }

        /* LBR and BRS are mutually exclusive features */
        if (!amd_pmu_lbr_init()) {
                /* LBR requires flushing on context switch */
                x86_pmu.sched_task = amd_pmu_lbr_sched_task;
                static_call_update(amd_pmu_branch_hw_config, amd_pmu_lbr_hw_config);
                static_call_update(amd_pmu_branch_reset, amd_pmu_lbr_reset);
                static_call_update(amd_pmu_branch_add, amd_pmu_lbr_add);
                static_call_update(amd_pmu_branch_del, amd_pmu_lbr_del);

                /* Only support branch_stack snapshot on perfmon v2 */
                if (x86_pmu.handle_irq == amd_pmu_v2_handle_irq)
                        static_call_update(perf_snapshot_branch_stack, amd_pmu_v2_snapshot_branch_stack);
        } else if (!amd_brs_init()) {
                /*
                 * BRS requires special event constraints and flushing on ctxsw.
                 */
                x86_pmu.get_event_constraints = amd_get_event_constraints_f19h;
                x86_pmu.sched_task = amd_pmu_brs_sched_task;
                x86_pmu.limit_period = amd_pmu_limit_period;

                static_call_update(amd_pmu_branch_hw_config, amd_brs_hw_config);
                static_call_update(amd_pmu_branch_reset, amd_brs_reset);
                static_call_update(amd_pmu_branch_add, amd_pmu_brs_add);
                static_call_update(amd_pmu_branch_del, amd_pmu_brs_del);

                /*
                 * put_event_constraints callback same as Fam17h, set above
                 */

                /* branch sampling must be stopped when entering low power */
                amd_brs_lopwr_init();
        }

        x86_pmu.attr_update = amd_attr_update;

        pr_cont("core perfctr, ");
        return 0;
}

__init int amd_pmu_init(void)
{
        int ret;

        /* Performance-monitoring supported from K7 and later: */
        if (boot_cpu_data.x86 < 6)
                return -ENODEV;

        x86_pmu = amd_pmu;

        ret = amd_core_pmu_init();
        if (ret)
                return ret;

        if (num_possible_cpus() == 1) {
                /*
                 * No point in allocating data structures to serialize
                 * against other CPUs, when there is only the one CPU.
                 */
                x86_pmu.amd_nb_constraints = 0;
        }

        if (boot_cpu_data.x86 >= 0x17)
                memcpy(hw_cache_event_ids, amd_hw_cache_event_ids_f17h, sizeof(hw_cache_event_ids));
        else
                memcpy(hw_cache_event_ids, amd_hw_cache_event_ids, sizeof(hw_cache_event_ids));

        return 0;
}

static inline void amd_pmu_reload_virt(void)
{
        if (x86_pmu.version >= 2) {
                /*
                 * Clear global enable bits, reprogram the PERF_CTL
                 * registers with updated perf_ctr_virt_mask and then
                 * set global enable bits once again
                 */
                amd_pmu_v2_disable_all();
                amd_pmu_enable_all(0);
                amd_pmu_v2_enable_all(0);
                return;
        }

        amd_pmu_disable_all();
        amd_pmu_enable_all(0);
}

void amd_pmu_enable_virt(void)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);

        cpuc->perf_ctr_virt_mask = 0;

        /* Reload all events */
        amd_pmu_reload_virt();
}
EXPORT_SYMBOL_FOR_KVM(amd_pmu_enable_virt);

void amd_pmu_disable_virt(void)
{
        struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);

        /*
         * We only mask out the Host-only bit so that host-only counting works
         * when SVM is disabled. If someone sets up a guest-only counter when
         * SVM is disabled the Guest-only bits still gets set and the counter
         * will not count anything.
         */
        cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY;

        /* Reload all events */
        amd_pmu_reload_virt();
}
EXPORT_SYMBOL_FOR_KVM(amd_pmu_disable_virt);