drivers/perf/arm_pmuv3.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ARMv8 PMUv3 Performance Events handling code.
   4  *
   5  * Copyright (C) 2012 ARM Limited
   6  * Author: Will Deacon <will.deacon@arm.com>
   7  *
   8  * This code is based heavily on the ARMv7 perf event code.
   9  */
  10
  11 #include <asm/irq_regs.h>
  12 #include <asm/perf_event.h>
  13 #include <asm/virt.h>
  14
  15 #include <clocksource/arm_arch_timer.h>
  16
  17 #include <linux/acpi.h>
  18 #include <linux/clocksource.h>
  19 #include <linux/of.h>
  20 #include <linux/perf/arm_pmu.h>
  21 #include <linux/perf/arm_pmuv3.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/sched_clock.h>
  24 #include <linux/smp.h>
  25 #include <linux/nmi.h>
  26
  27 #include <asm/arm_pmuv3.h>
  28
  29 /* ARMv8 Cortex-A53 specific event types. */
  30 #define ARMV8_A53_PERFCTR_PREF_LINEFILL                         0xC2
  31
  32 /* ARMv8 Cavium ThunderX specific event types. */
  33 #define ARMV8_THUNDER_PERFCTR_L1D_CACHE_MISS_ST                 0xE9
  34 #define ARMV8_THUNDER_PERFCTR_L1D_CACHE_PREF_ACCESS             0xEA
  35 #define ARMV8_THUNDER_PERFCTR_L1D_CACHE_PREF_MISS               0xEB
  36 #define ARMV8_THUNDER_PERFCTR_L1I_CACHE_PREF_ACCESS             0xEC
  37 #define ARMV8_THUNDER_PERFCTR_L1I_CACHE_PREF_MISS               0xED
  38
  39 /*
  40  * ARMv8 Architectural defined events, not all of these may
  41  * be supported on any given implementation. Unsupported events will
  42  * be disabled at run-time based on the PMCEID registers.
  43  */
  44 static const unsigned armv8_pmuv3_perf_map[PERF_COUNT_HW_MAX] = {
  45         PERF_MAP_ALL_UNSUPPORTED,
  46         [PERF_COUNT_HW_CPU_CYCLES]              = ARMV8_PMUV3_PERFCTR_CPU_CYCLES,
  47         [PERF_COUNT_HW_INSTRUCTIONS]            = ARMV8_PMUV3_PERFCTR_INST_RETIRED,
  48         [PERF_COUNT_HW_CACHE_REFERENCES]        = ARMV8_PMUV3_PERFCTR_L1D_CACHE,
  49         [PERF_COUNT_HW_CACHE_MISSES]            = ARMV8_PMUV3_PERFCTR_L1D_CACHE_REFILL,
  50         [PERF_COUNT_HW_BRANCH_MISSES]           = ARMV8_PMUV3_PERFCTR_BR_MIS_PRED,
  51         [PERF_COUNT_HW_BUS_CYCLES]              = ARMV8_PMUV3_PERFCTR_BUS_CYCLES,
  52         [PERF_COUNT_HW_STALLED_CYCLES_FRONTEND] = ARMV8_PMUV3_PERFCTR_STALL_FRONTEND,
  53         [PERF_COUNT_HW_STALLED_CYCLES_BACKEND]  = ARMV8_PMUV3_PERFCTR_STALL_BACKEND,
  54 };
  55
  56 static const unsigned armv8_pmuv3_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
  57                                                 [PERF_COUNT_HW_CACHE_OP_MAX]
  58                                                 [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
  59         PERF_CACHE_MAP_ALL_UNSUPPORTED,
  60
  61         [C(L1D)][C(OP_READ)][C(RESULT_ACCESS)]  = ARMV8_PMUV3_PERFCTR_L1D_CACHE,
  62         [C(L1D)][C(OP_READ)][C(RESULT_MISS)]    = ARMV8_PMUV3_PERFCTR_L1D_CACHE_REFILL,
  63
  64         [C(L1I)][C(OP_READ)][C(RESULT_ACCESS)]  = ARMV8_PMUV3_PERFCTR_L1I_CACHE,
  65         [C(L1I)][C(OP_READ)][C(RESULT_MISS)]    = ARMV8_PMUV3_PERFCTR_L1I_CACHE_REFILL,
  66
  67         [C(DTLB)][C(OP_READ)][C(RESULT_MISS)]   = ARMV8_PMUV3_PERFCTR_L1D_TLB_REFILL,
  68         [C(DTLB)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1D_TLB,
  69
  70         [C(ITLB)][C(OP_READ)][C(RESULT_MISS)]   = ARMV8_PMUV3_PERFCTR_L1I_TLB_REFILL,
  71         [C(ITLB)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_PMUV3_PERFCTR_L1I_TLB,
  72
  73         [C(LL)][C(OP_READ)][C(RESULT_MISS)]     = ARMV8_PMUV3_PERFCTR_LL_CACHE_MISS_RD,
  74         [C(LL)][C(OP_READ)][C(RESULT_ACCESS)]   = ARMV8_PMUV3_PERFCTR_LL_CACHE_RD,
  75
  76         [C(BPU)][C(OP_READ)][C(RESULT_ACCESS)]  = ARMV8_PMUV3_PERFCTR_BR_PRED,
  77         [C(BPU)][C(OP_READ)][C(RESULT_MISS)]    = ARMV8_PMUV3_PERFCTR_BR_MIS_PRED,
  78 };
  79
  80 static const unsigned armv8_a53_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
  81                                               [PERF_COUNT_HW_CACHE_OP_MAX]
  82                                               [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
  83         PERF_CACHE_MAP_ALL_UNSUPPORTED,
  84
  85         [C(L1D)][C(OP_PREFETCH)][C(RESULT_MISS)] = ARMV8_A53_PERFCTR_PREF_LINEFILL,
  86
  87         [C(NODE)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_RD,
  88         [C(NODE)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_WR,
  89 };
  90
  91 static const unsigned armv8_a57_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
  92                                               [PERF_COUNT_HW_CACHE_OP_MAX]
  93                                               [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
  94         PERF_CACHE_MAP_ALL_UNSUPPORTED,
  95
  96         [C(L1D)][C(OP_READ)][C(RESULT_ACCESS)]  = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_RD,
  97         [C(L1D)][C(OP_READ)][C(RESULT_MISS)]    = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_RD,
  98         [C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_WR,
  99         [C(L1D)][C(OP_WRITE)][C(RESULT_MISS)]   = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_WR,
 100
 101         [C(DTLB)][C(OP_READ)][C(RESULT_MISS)]   = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_RD,
 102         [C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)]  = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_WR,
 103
 104         [C(NODE)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_RD,
 105         [C(NODE)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_WR,
 106 };
 107
 108 static const unsigned armv8_a73_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
 109                                               [PERF_COUNT_HW_CACHE_OP_MAX]
 110                                               [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
 111         PERF_CACHE_MAP_ALL_UNSUPPORTED,
 112
 113         [C(L1D)][C(OP_READ)][C(RESULT_ACCESS)]  = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_RD,
 114         [C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_WR,
 115 };
 116
 117 static const unsigned armv8_thunder_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
 118                                                    [PERF_COUNT_HW_CACHE_OP_MAX]
 119                                                    [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
 120         PERF_CACHE_MAP_ALL_UNSUPPORTED,
 121
 122         [C(L1D)][C(OP_READ)][C(RESULT_ACCESS)]  = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_RD,
 123         [C(L1D)][C(OP_READ)][C(RESULT_MISS)]    = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_RD,
 124         [C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_WR,
 125         [C(L1D)][C(OP_WRITE)][C(RESULT_MISS)]   = ARMV8_THUNDER_PERFCTR_L1D_CACHE_MISS_ST,
 126         [C(L1D)][C(OP_PREFETCH)][C(RESULT_ACCESS)] = ARMV8_THUNDER_PERFCTR_L1D_CACHE_PREF_ACCESS,
 127         [C(L1D)][C(OP_PREFETCH)][C(RESULT_MISS)] = ARMV8_THUNDER_PERFCTR_L1D_CACHE_PREF_MISS,
 128
 129         [C(L1I)][C(OP_PREFETCH)][C(RESULT_ACCESS)] = ARMV8_THUNDER_PERFCTR_L1I_CACHE_PREF_ACCESS,
 130         [C(L1I)][C(OP_PREFETCH)][C(RESULT_MISS)] = ARMV8_THUNDER_PERFCTR_L1I_CACHE_PREF_MISS,
 131
 132         [C(DTLB)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_RD,
 133         [C(DTLB)][C(OP_READ)][C(RESULT_MISS)]   = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_RD,
 134         [C(DTLB)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_WR,
 135         [C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)]  = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_WR,
 136 };
 137
 138 static const unsigned armv8_vulcan_perf_cache_map[PERF_COUNT_HW_CACHE_MAX]
 139                                               [PERF_COUNT_HW_CACHE_OP_MAX]
 140                                               [PERF_COUNT_HW_CACHE_RESULT_MAX] = {
 141         PERF_CACHE_MAP_ALL_UNSUPPORTED,
 142
 143         [C(L1D)][C(OP_READ)][C(RESULT_ACCESS)]  = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_RD,
 144         [C(L1D)][C(OP_READ)][C(RESULT_MISS)]    = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_RD,
 145         [C(L1D)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_WR,
 146         [C(L1D)][C(OP_WRITE)][C(RESULT_MISS)]   = ARMV8_IMPDEF_PERFCTR_L1D_CACHE_REFILL_WR,
 147
 148         [C(DTLB)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_RD,
 149         [C(DTLB)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_L1D_TLB_WR,
 150         [C(DTLB)][C(OP_READ)][C(RESULT_MISS)]   = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_RD,
 151         [C(DTLB)][C(OP_WRITE)][C(RESULT_MISS)]  = ARMV8_IMPDEF_PERFCTR_L1D_TLB_REFILL_WR,
 152
 153         [C(NODE)][C(OP_READ)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_RD,
 154         [C(NODE)][C(OP_WRITE)][C(RESULT_ACCESS)] = ARMV8_IMPDEF_PERFCTR_BUS_ACCESS_WR,
 155 };
 156
 157 static ssize_t
 158 armv8pmu_events_sysfs_show(struct device *dev,
 159                            struct device_attribute *attr, char *page)
 160 {
 161         struct perf_pmu_events_attr *pmu_attr;
 162
 163         pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr);
 164
 165         return sprintf(page, "event=0x%04llx\n", pmu_attr->id);
 166 }
 167
 168 #define ARMV8_EVENT_ATTR(name, config)                                          \
 169         PMU_EVENT_ATTR_ID(name, armv8pmu_events_sysfs_show, config)
 170
 171 static struct attribute *armv8_pmuv3_event_attrs[] = {
 172         ARMV8_EVENT_ATTR(sw_incr, ARMV8_PMUV3_PERFCTR_SW_INCR),
 173         ARMV8_EVENT_ATTR(l1i_cache_refill, ARMV8_PMUV3_PERFCTR_L1I_CACHE_REFILL),
 174         ARMV8_EVENT_ATTR(l1i_tlb_refill, ARMV8_PMUV3_PERFCTR_L1I_TLB_REFILL),
 175         ARMV8_EVENT_ATTR(l1d_cache_refill, ARMV8_PMUV3_PERFCTR_L1D_CACHE_REFILL),
 176         ARMV8_EVENT_ATTR(l1d_cache, ARMV8_PMUV3_PERFCTR_L1D_CACHE),
 177         ARMV8_EVENT_ATTR(l1d_tlb_refill, ARMV8_PMUV3_PERFCTR_L1D_TLB_REFILL),
 178         ARMV8_EVENT_ATTR(ld_retired, ARMV8_PMUV3_PERFCTR_LD_RETIRED),
 179         ARMV8_EVENT_ATTR(st_retired, ARMV8_PMUV3_PERFCTR_ST_RETIRED),
 180         ARMV8_EVENT_ATTR(inst_retired, ARMV8_PMUV3_PERFCTR_INST_RETIRED),
 181         ARMV8_EVENT_ATTR(exc_taken, ARMV8_PMUV3_PERFCTR_EXC_TAKEN),
 182         ARMV8_EVENT_ATTR(exc_return, ARMV8_PMUV3_PERFCTR_EXC_RETURN),
 183         ARMV8_EVENT_ATTR(cid_write_retired, ARMV8_PMUV3_PERFCTR_CID_WRITE_RETIRED),
 184         ARMV8_EVENT_ATTR(pc_write_retired, ARMV8_PMUV3_PERFCTR_PC_WRITE_RETIRED),
 185         ARMV8_EVENT_ATTR(br_immed_retired, ARMV8_PMUV3_PERFCTR_BR_IMMED_RETIRED),
 186         ARMV8_EVENT_ATTR(br_return_retired, ARMV8_PMUV3_PERFCTR_BR_RETURN_RETIRED),
 187         ARMV8_EVENT_ATTR(unaligned_ldst_retired, ARMV8_PMUV3_PERFCTR_UNALIGNED_LDST_RETIRED),
 188         ARMV8_EVENT_ATTR(br_mis_pred, ARMV8_PMUV3_PERFCTR_BR_MIS_PRED),
 189         ARMV8_EVENT_ATTR(cpu_cycles, ARMV8_PMUV3_PERFCTR_CPU_CYCLES),
 190         ARMV8_EVENT_ATTR(br_pred, ARMV8_PMUV3_PERFCTR_BR_PRED),
 191         ARMV8_EVENT_ATTR(mem_access, ARMV8_PMUV3_PERFCTR_MEM_ACCESS),
 192         ARMV8_EVENT_ATTR(l1i_cache, ARMV8_PMUV3_PERFCTR_L1I_CACHE),
 193         ARMV8_EVENT_ATTR(l1d_cache_wb, ARMV8_PMUV3_PERFCTR_L1D_CACHE_WB),
 194         ARMV8_EVENT_ATTR(l2d_cache, ARMV8_PMUV3_PERFCTR_L2D_CACHE),
 195         ARMV8_EVENT_ATTR(l2d_cache_refill, ARMV8_PMUV3_PERFCTR_L2D_CACHE_REFILL),
 196         ARMV8_EVENT_ATTR(l2d_cache_wb, ARMV8_PMUV3_PERFCTR_L2D_CACHE_WB),
 197         ARMV8_EVENT_ATTR(bus_access, ARMV8_PMUV3_PERFCTR_BUS_ACCESS),
 198         ARMV8_EVENT_ATTR(memory_error, ARMV8_PMUV3_PERFCTR_MEMORY_ERROR),
 199         ARMV8_EVENT_ATTR(inst_spec, ARMV8_PMUV3_PERFCTR_INST_SPEC),
 200         ARMV8_EVENT_ATTR(ttbr_write_retired, ARMV8_PMUV3_PERFCTR_TTBR_WRITE_RETIRED),
 201         ARMV8_EVENT_ATTR(bus_cycles, ARMV8_PMUV3_PERFCTR_BUS_CYCLES),
 202         /* Don't expose the chain event in /sys, since it's useless in isolation */
 203         ARMV8_EVENT_ATTR(l1d_cache_allocate, ARMV8_PMUV3_PERFCTR_L1D_CACHE_ALLOCATE),
 204         ARMV8_EVENT_ATTR(l2d_cache_allocate, ARMV8_PMUV3_PERFCTR_L2D_CACHE_ALLOCATE),
 205         ARMV8_EVENT_ATTR(br_retired, ARMV8_PMUV3_PERFCTR_BR_RETIRED),
 206         ARMV8_EVENT_ATTR(br_mis_pred_retired, ARMV8_PMUV3_PERFCTR_BR_MIS_PRED_RETIRED),
 207         ARMV8_EVENT_ATTR(stall_frontend, ARMV8_PMUV3_PERFCTR_STALL_FRONTEND),
 208         ARMV8_EVENT_ATTR(stall_backend, ARMV8_PMUV3_PERFCTR_STALL_BACKEND),
 209         ARMV8_EVENT_ATTR(l1d_tlb, ARMV8_PMUV3_PERFCTR_L1D_TLB),
 210         ARMV8_EVENT_ATTR(l1i_tlb, ARMV8_PMUV3_PERFCTR_L1I_TLB),
 211         ARMV8_EVENT_ATTR(l2i_cache, ARMV8_PMUV3_PERFCTR_L2I_CACHE),
 212         ARMV8_EVENT_ATTR(l2i_cache_refill, ARMV8_PMUV3_PERFCTR_L2I_CACHE_REFILL),
 213         ARMV8_EVENT_ATTR(l3d_cache_allocate, ARMV8_PMUV3_PERFCTR_L3D_CACHE_ALLOCATE),
 214         ARMV8_EVENT_ATTR(l3d_cache_refill, ARMV8_PMUV3_PERFCTR_L3D_CACHE_REFILL),
 215         ARMV8_EVENT_ATTR(l3d_cache, ARMV8_PMUV3_PERFCTR_L3D_CACHE),
 216         ARMV8_EVENT_ATTR(l3d_cache_wb, ARMV8_PMUV3_PERFCTR_L3D_CACHE_WB),
 217         ARMV8_EVENT_ATTR(l2d_tlb_refill, ARMV8_PMUV3_PERFCTR_L2D_TLB_REFILL),
 218         ARMV8_EVENT_ATTR(l2i_tlb_refill, ARMV8_PMUV3_PERFCTR_L2I_TLB_REFILL),
 219         ARMV8_EVENT_ATTR(l2d_tlb, ARMV8_PMUV3_PERFCTR_L2D_TLB),
 220         ARMV8_EVENT_ATTR(l2i_tlb, ARMV8_PMUV3_PERFCTR_L2I_TLB),
 221         ARMV8_EVENT_ATTR(remote_access, ARMV8_PMUV3_PERFCTR_REMOTE_ACCESS),
 222         ARMV8_EVENT_ATTR(ll_cache, ARMV8_PMUV3_PERFCTR_LL_CACHE),
 223         ARMV8_EVENT_ATTR(ll_cache_miss, ARMV8_PMUV3_PERFCTR_LL_CACHE_MISS),
 224         ARMV8_EVENT_ATTR(dtlb_walk, ARMV8_PMUV3_PERFCTR_DTLB_WALK),
 225         ARMV8_EVENT_ATTR(itlb_walk, ARMV8_PMUV3_PERFCTR_ITLB_WALK),
 226         ARMV8_EVENT_ATTR(ll_cache_rd, ARMV8_PMUV3_PERFCTR_LL_CACHE_RD),
 227         ARMV8_EVENT_ATTR(ll_cache_miss_rd, ARMV8_PMUV3_PERFCTR_LL_CACHE_MISS_RD),
 228         ARMV8_EVENT_ATTR(remote_access_rd, ARMV8_PMUV3_PERFCTR_REMOTE_ACCESS_RD),
 229         ARMV8_EVENT_ATTR(l1d_cache_lmiss_rd, ARMV8_PMUV3_PERFCTR_L1D_CACHE_LMISS_RD),
 230         ARMV8_EVENT_ATTR(op_retired, ARMV8_PMUV3_PERFCTR_OP_RETIRED),
 231         ARMV8_EVENT_ATTR(op_spec, ARMV8_PMUV3_PERFCTR_OP_SPEC),
 232         ARMV8_EVENT_ATTR(stall, ARMV8_PMUV3_PERFCTR_STALL),
 233         ARMV8_EVENT_ATTR(stall_slot_backend, ARMV8_PMUV3_PERFCTR_STALL_SLOT_BACKEND),
 234         ARMV8_EVENT_ATTR(stall_slot_frontend, ARMV8_PMUV3_PERFCTR_STALL_SLOT_FRONTEND),
 235         ARMV8_EVENT_ATTR(stall_slot, ARMV8_PMUV3_PERFCTR_STALL_SLOT),
 236         ARMV8_EVENT_ATTR(sample_pop, ARMV8_SPE_PERFCTR_SAMPLE_POP),
 237         ARMV8_EVENT_ATTR(sample_feed, ARMV8_SPE_PERFCTR_SAMPLE_FEED),
 238         ARMV8_EVENT_ATTR(sample_filtrate, ARMV8_SPE_PERFCTR_SAMPLE_FILTRATE),
 239         ARMV8_EVENT_ATTR(sample_collision, ARMV8_SPE_PERFCTR_SAMPLE_COLLISION),
 240         ARMV8_EVENT_ATTR(cnt_cycles, ARMV8_AMU_PERFCTR_CNT_CYCLES),
 241         ARMV8_EVENT_ATTR(stall_backend_mem, ARMV8_AMU_PERFCTR_STALL_BACKEND_MEM),
 242         ARMV8_EVENT_ATTR(l1i_cache_lmiss, ARMV8_PMUV3_PERFCTR_L1I_CACHE_LMISS),
 243         ARMV8_EVENT_ATTR(l2d_cache_lmiss_rd, ARMV8_PMUV3_PERFCTR_L2D_CACHE_LMISS_RD),
 244         ARMV8_EVENT_ATTR(l2i_cache_lmiss, ARMV8_PMUV3_PERFCTR_L2I_CACHE_LMISS),
 245         ARMV8_EVENT_ATTR(l3d_cache_lmiss_rd, ARMV8_PMUV3_PERFCTR_L3D_CACHE_LMISS_RD),
 246         ARMV8_EVENT_ATTR(trb_wrap, ARMV8_PMUV3_PERFCTR_TRB_WRAP),
 247         ARMV8_EVENT_ATTR(trb_trig, ARMV8_PMUV3_PERFCTR_TRB_TRIG),
 248         ARMV8_EVENT_ATTR(trcextout0, ARMV8_PMUV3_PERFCTR_TRCEXTOUT0),
 249         ARMV8_EVENT_ATTR(trcextout1, ARMV8_PMUV3_PERFCTR_TRCEXTOUT1),
 250         ARMV8_EVENT_ATTR(trcextout2, ARMV8_PMUV3_PERFCTR_TRCEXTOUT2),
 251         ARMV8_EVENT_ATTR(trcextout3, ARMV8_PMUV3_PERFCTR_TRCEXTOUT3),
 252         ARMV8_EVENT_ATTR(cti_trigout4, ARMV8_PMUV3_PERFCTR_CTI_TRIGOUT4),
 253         ARMV8_EVENT_ATTR(cti_trigout5, ARMV8_PMUV3_PERFCTR_CTI_TRIGOUT5),
 254         ARMV8_EVENT_ATTR(cti_trigout6, ARMV8_PMUV3_PERFCTR_CTI_TRIGOUT6),
 255         ARMV8_EVENT_ATTR(cti_trigout7, ARMV8_PMUV3_PERFCTR_CTI_TRIGOUT7),
 256         ARMV8_EVENT_ATTR(ldst_align_lat, ARMV8_PMUV3_PERFCTR_LDST_ALIGN_LAT),
 257         ARMV8_EVENT_ATTR(ld_align_lat, ARMV8_PMUV3_PERFCTR_LD_ALIGN_LAT),
 258         ARMV8_EVENT_ATTR(st_align_lat, ARMV8_PMUV3_PERFCTR_ST_ALIGN_LAT),
 259         ARMV8_EVENT_ATTR(mem_access_checked, ARMV8_MTE_PERFCTR_MEM_ACCESS_CHECKED),
 260         ARMV8_EVENT_ATTR(mem_access_checked_rd, ARMV8_MTE_PERFCTR_MEM_ACCESS_CHECKED_RD),
 261         ARMV8_EVENT_ATTR(mem_access_checked_wr, ARMV8_MTE_PERFCTR_MEM_ACCESS_CHECKED_WR),
 262         NULL,
 263 };
 264
 265 static umode_t
 266 armv8pmu_event_attr_is_visible(struct kobject *kobj,
 267                                struct attribute *attr, int unused)
 268 {
 269         struct device *dev = kobj_to_dev(kobj);
 270         struct pmu *pmu = dev_get_drvdata(dev);
 271         struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
 272         struct perf_pmu_events_attr *pmu_attr;
 273
 274         pmu_attr = container_of(attr, struct perf_pmu_events_attr, attr.attr);
 275
 276         if (pmu_attr->id < ARMV8_PMUV3_MAX_COMMON_EVENTS &&
 277             test_bit(pmu_attr->id, cpu_pmu->pmceid_bitmap))
 278                 return attr->mode;
 279
 280         if (pmu_attr->id >= ARMV8_PMUV3_EXT_COMMON_EVENT_BASE) {
 281                 u64 id = pmu_attr->id - ARMV8_PMUV3_EXT_COMMON_EVENT_BASE;
 282
 283                 if (id < ARMV8_PMUV3_MAX_COMMON_EVENTS &&
 284                     test_bit(id, cpu_pmu->pmceid_ext_bitmap))
 285                         return attr->mode;
 286         }
 287
 288         return 0;
 289 }
 290
 291 static const struct attribute_group armv8_pmuv3_events_attr_group = {
 292         .name = "events",
 293         .attrs = armv8_pmuv3_event_attrs,
 294         .is_visible = armv8pmu_event_attr_is_visible,
 295 };
 296
 297 PMU_FORMAT_ATTR(event, "config:0-15");
 298 PMU_FORMAT_ATTR(long, "config1:0");
 299 PMU_FORMAT_ATTR(rdpmc, "config1:1");
 300
 301 static int sysctl_perf_user_access __read_mostly;
 302
 303 static inline bool armv8pmu_event_is_64bit(struct perf_event *event)
 304 {
 305         return event->attr.config1 & 0x1;
 306 }
 307
 308 static inline bool armv8pmu_event_want_user_access(struct perf_event *event)
 309 {
 310         return event->attr.config1 & 0x2;
 311 }
 312
 313 static struct attribute *armv8_pmuv3_format_attrs[] = {
 314         &format_attr_event.attr,
 315         &format_attr_long.attr,
 316         &format_attr_rdpmc.attr,
 317         NULL,
 318 };
 319
 320 static const struct attribute_group armv8_pmuv3_format_attr_group = {
 321         .name = "format",
 322         .attrs = armv8_pmuv3_format_attrs,
 323 };
 324
 325 static ssize_t slots_show(struct device *dev, struct device_attribute *attr,
 326                           char *page)
 327 {
 328         struct pmu *pmu = dev_get_drvdata(dev);
 329         struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
 330         u32 slots = cpu_pmu->reg_pmmir & ARMV8_PMU_SLOTS_MASK;
 331
 332         return sysfs_emit(page, "0x%08x\n", slots);
 333 }
 334
 335 static DEVICE_ATTR_RO(slots);
 336
 337 static ssize_t bus_slots_show(struct device *dev, struct device_attribute *attr,
 338                               char *page)
 339 {
 340         struct pmu *pmu = dev_get_drvdata(dev);
 341         struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
 342         u32 bus_slots = (cpu_pmu->reg_pmmir >> ARMV8_PMU_BUS_SLOTS_SHIFT)
 343                         & ARMV8_PMU_BUS_SLOTS_MASK;
 344
 345         return sysfs_emit(page, "0x%08x\n", bus_slots);
 346 }
 347
 348 static DEVICE_ATTR_RO(bus_slots);
 349
 350 static ssize_t bus_width_show(struct device *dev, struct device_attribute *attr,
 351                               char *page)
 352 {
 353         struct pmu *pmu = dev_get_drvdata(dev);
 354         struct arm_pmu *cpu_pmu = container_of(pmu, struct arm_pmu, pmu);
 355         u32 bus_width = (cpu_pmu->reg_pmmir >> ARMV8_PMU_BUS_WIDTH_SHIFT)
 356                         & ARMV8_PMU_BUS_WIDTH_MASK;
 357         u32 val = 0;
 358
 359         /* Encoded as Log2(number of bytes), plus one */
 360         if (bus_width > 2 && bus_width < 13)
 361                 val = 1 << (bus_width - 1);
 362
 363         return sysfs_emit(page, "0x%08x\n", val);
 364 }
 365
 366 static DEVICE_ATTR_RO(bus_width);
 367
 368 static struct attribute *armv8_pmuv3_caps_attrs[] = {
 369         &dev_attr_slots.attr,
 370         &dev_attr_bus_slots.attr,
 371         &dev_attr_bus_width.attr,
 372         NULL,
 373 };
 374
 375 static const struct attribute_group armv8_pmuv3_caps_attr_group = {
 376         .name = "caps",
 377         .attrs = armv8_pmuv3_caps_attrs,
 378 };
 379
 380 /*
 381  * Perf Events' indices
 382  */
 383 #define ARMV8_IDX_CYCLE_COUNTER 0
 384 #define ARMV8_IDX_COUNTER0      1
 385 #define ARMV8_IDX_CYCLE_COUNTER_USER    32
 386
 387 /*
 388  * We unconditionally enable ARMv8.5-PMU long event counter support
 389  * (64-bit events) where supported. Indicate if this arm_pmu has long
 390  * event counter support.
 391  *
 392  * On AArch32, long counters make no sense (you can't access the top
 393  * bits), so we only enable this on AArch64.
 394  */
 395 static bool armv8pmu_has_long_event(struct arm_pmu *cpu_pmu)
 396 {
 397         return (IS_ENABLED(CONFIG_ARM64) && is_pmuv3p5(cpu_pmu->pmuver));
 398 }
 399
 400 static inline bool armv8pmu_event_has_user_read(struct perf_event *event)
 401 {
 402         return event->hw.flags & PERF_EVENT_FLAG_USER_READ_CNT;
 403 }
 404
 405 /*
 406  * We must chain two programmable counters for 64 bit events,
 407  * except when we have allocated the 64bit cycle counter (for CPU
 408  * cycles event) or when user space counter access is enabled.
 409  */
 410 static inline bool armv8pmu_event_is_chained(struct perf_event *event)
 411 {
 412         int idx = event->hw.idx;
 413         struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
 414
 415         return !armv8pmu_event_has_user_read(event) &&
 416                armv8pmu_event_is_64bit(event) &&
 417                !armv8pmu_has_long_event(cpu_pmu) &&
 418                (idx != ARMV8_IDX_CYCLE_COUNTER);
 419 }
 420
 421 /*
 422  * ARMv8 low level PMU access
 423  */
 424
 425 /*
 426  * Perf Event to low level counters mapping
 427  */
 428 #define ARMV8_IDX_TO_COUNTER(x) \
 429         (((x) - ARMV8_IDX_COUNTER0) & ARMV8_PMU_COUNTER_MASK)
 430
 431 static inline u32 armv8pmu_pmcr_read(void)
 432 {
 433         return read_pmcr();
 434 }
 435
 436 static inline void armv8pmu_pmcr_write(u32 val)
 437 {
 438         val &= ARMV8_PMU_PMCR_MASK;
 439         isb();
 440         write_pmcr(val);
 441 }
 442
 443 static inline int armv8pmu_has_overflowed(u32 pmovsr)
 444 {
 445         return pmovsr & ARMV8_PMU_OVERFLOWED_MASK;
 446 }
 447
 448 static inline int armv8pmu_counter_has_overflowed(u32 pmnc, int idx)
 449 {
 450         return pmnc & BIT(ARMV8_IDX_TO_COUNTER(idx));
 451 }
 452
 453 static inline u64 armv8pmu_read_evcntr(int idx)
 454 {
 455         u32 counter = ARMV8_IDX_TO_COUNTER(idx);
 456
 457         return read_pmevcntrn(counter);
 458 }
 459
 460 static inline u64 armv8pmu_read_hw_counter(struct perf_event *event)
 461 {
 462         int idx = event->hw.idx;
 463         u64 val = armv8pmu_read_evcntr(idx);
 464
 465         if (armv8pmu_event_is_chained(event))
 466                 val = (val << 32) | armv8pmu_read_evcntr(idx - 1);
 467         return val;
 468 }
 469
 470 /*
 471  * The cycle counter is always a 64-bit counter. When ARMV8_PMU_PMCR_LP
 472  * is set the event counters also become 64-bit counters. Unless the
 473  * user has requested a long counter (attr.config1) then we want to
 474  * interrupt upon 32-bit overflow - we achieve this by applying a bias.
 475  */
 476 static bool armv8pmu_event_needs_bias(struct perf_event *event)
 477 {
 478         struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
 479         struct hw_perf_event *hwc = &event->hw;
 480         int idx = hwc->idx;
 481
 482         if (armv8pmu_event_is_64bit(event))
 483                 return false;
 484
 485         if (armv8pmu_has_long_event(cpu_pmu) ||
 486             idx == ARMV8_IDX_CYCLE_COUNTER)
 487                 return true;
 488
 489         return false;
 490 }
 491
 492 static u64 armv8pmu_bias_long_counter(struct perf_event *event, u64 value)
 493 {
 494         if (armv8pmu_event_needs_bias(event))
 495                 value |= GENMASK_ULL(63, 32);
 496
 497         return value;
 498 }
 499
 500 static u64 armv8pmu_unbias_long_counter(struct perf_event *event, u64 value)
 501 {
 502         if (armv8pmu_event_needs_bias(event))
 503                 value &= ~GENMASK_ULL(63, 32);
 504
 505         return value;
 506 }
 507
 508 static u64 armv8pmu_read_counter(struct perf_event *event)
 509 {
 510         struct hw_perf_event *hwc = &event->hw;
 511         int idx = hwc->idx;
 512         u64 value;
 513
 514         if (idx == ARMV8_IDX_CYCLE_COUNTER)
 515                 value = read_pmccntr();
 516         else
 517                 value = armv8pmu_read_hw_counter(event);
 518
 519         return  armv8pmu_unbias_long_counter(event, value);
 520 }
 521
 522 static inline void armv8pmu_write_evcntr(int idx, u64 value)
 523 {
 524         u32 counter = ARMV8_IDX_TO_COUNTER(idx);
 525
 526         write_pmevcntrn(counter, value);
 527 }
 528
 529 static inline void armv8pmu_write_hw_counter(struct perf_event *event,
 530                                              u64 value)
 531 {
 532         int idx = event->hw.idx;
 533
 534         if (armv8pmu_event_is_chained(event)) {
 535                 armv8pmu_write_evcntr(idx, upper_32_bits(value));
 536                 armv8pmu_write_evcntr(idx - 1, lower_32_bits(value));
 537         } else {
 538                 armv8pmu_write_evcntr(idx, value);
 539         }
 540 }
 541
 542 static void armv8pmu_write_counter(struct perf_event *event, u64 value)
 543 {
 544         struct hw_perf_event *hwc = &event->hw;
 545         int idx = hwc->idx;
 546
 547         value = armv8pmu_bias_long_counter(event, value);
 548
 549         if (idx == ARMV8_IDX_CYCLE_COUNTER)
 550                 write_pmccntr(value);
 551         else
 552                 armv8pmu_write_hw_counter(event, value);
 553 }
 554
 555 static inline void armv8pmu_write_evtype(int idx, u32 val)
 556 {
 557         u32 counter = ARMV8_IDX_TO_COUNTER(idx);
 558
 559         val &= ARMV8_PMU_EVTYPE_MASK;
 560         write_pmevtypern(counter, val);
 561 }
 562
 563 static inline void armv8pmu_write_event_type(struct perf_event *event)
 564 {
 565         struct hw_perf_event *hwc = &event->hw;
 566         int idx = hwc->idx;
 567
 568         /*
 569          * For chained events, the low counter is programmed to count
 570          * the event of interest and the high counter is programmed
 571          * with CHAIN event code with filters set to count at all ELs.
 572          */
 573         if (armv8pmu_event_is_chained(event)) {
 574                 u32 chain_evt = ARMV8_PMUV3_PERFCTR_CHAIN |
 575                                 ARMV8_PMU_INCLUDE_EL2;
 576
 577                 armv8pmu_write_evtype(idx - 1, hwc->config_base);
 578                 armv8pmu_write_evtype(idx, chain_evt);
 579         } else {
 580                 if (idx == ARMV8_IDX_CYCLE_COUNTER)
 581                         write_pmccfiltr(hwc->config_base);
 582                 else
 583                         armv8pmu_write_evtype(idx, hwc->config_base);
 584         }
 585 }
 586
 587 static u32 armv8pmu_event_cnten_mask(struct perf_event *event)
 588 {
 589         int counter = ARMV8_IDX_TO_COUNTER(event->hw.idx);
 590         u32 mask = BIT(counter);
 591
 592         if (armv8pmu_event_is_chained(event))
 593                 mask |= BIT(counter - 1);
 594         return mask;
 595 }
 596
 597 static inline void armv8pmu_enable_counter(u32 mask)
 598 {
 599         /*
 600          * Make sure event configuration register writes are visible before we
 601          * enable the counter.
 602          * */
 603         isb();
 604         write_pmcntenset(mask);
 605 }
 606
 607 static inline void armv8pmu_enable_event_counter(struct perf_event *event)
 608 {
 609         struct perf_event_attr *attr = &event->attr;
 610         u32 mask = armv8pmu_event_cnten_mask(event);
 611
 612         kvm_set_pmu_events(mask, attr);
 613
 614         /* We rely on the hypervisor switch code to enable guest counters */
 615         if (!kvm_pmu_counter_deferred(attr))
 616                 armv8pmu_enable_counter(mask);
 617 }
 618
 619 static inline void armv8pmu_disable_counter(u32 mask)
 620 {
 621         write_pmcntenclr(mask);
 622         /*
 623          * Make sure the effects of disabling the counter are visible before we
 624          * start configuring the event.
 625          */
 626         isb();
 627 }
 628
 629 static inline void armv8pmu_disable_event_counter(struct perf_event *event)
 630 {
 631         struct perf_event_attr *attr = &event->attr;
 632         u32 mask = armv8pmu_event_cnten_mask(event);
 633
 634         kvm_clr_pmu_events(mask);
 635
 636         /* We rely on the hypervisor switch code to disable guest counters */
 637         if (!kvm_pmu_counter_deferred(attr))
 638                 armv8pmu_disable_counter(mask);
 639 }
 640
 641 static inline void armv8pmu_enable_intens(u32 mask)
 642 {
 643         write_pmintenset(mask);
 644 }
 645
 646 static inline void armv8pmu_enable_event_irq(struct perf_event *event)
 647 {
 648         u32 counter = ARMV8_IDX_TO_COUNTER(event->hw.idx);
 649         armv8pmu_enable_intens(BIT(counter));
 650 }
 651
 652 static inline void armv8pmu_disable_intens(u32 mask)
 653 {
 654         write_pmintenclr(mask);
 655         isb();
 656         /* Clear the overflow flag in case an interrupt is pending. */
 657         write_pmovsclr(mask);
 658         isb();
 659 }
 660
 661 static inline void armv8pmu_disable_event_irq(struct perf_event *event)
 662 {
 663         u32 counter = ARMV8_IDX_TO_COUNTER(event->hw.idx);
 664         armv8pmu_disable_intens(BIT(counter));
 665 }
 666
 667 static inline u32 armv8pmu_getreset_flags(void)
 668 {
 669         u32 value;
 670
 671         /* Read */
 672         value = read_pmovsclr();
 673
 674         /* Write to clear flags */
 675         value &= ARMV8_PMU_OVSR_MASK;
 676         write_pmovsclr(value);
 677
 678         return value;
 679 }
 680
 681 static void update_pmuserenr(u64 val)
 682 {
 683         lockdep_assert_irqs_disabled();
 684
 685         /*
 686          * The current PMUSERENR_EL0 value might be the value for the guest.
 687          * If that's the case, have KVM keep tracking of the register value
 688          * for the host EL0 so that KVM can restore it before returning to
 689          * the host EL0. Otherwise, update the register now.
 690          */
 691         if (kvm_set_pmuserenr(val))
 692                 return;
 693
 694         write_pmuserenr(val);
 695 }
 696
 697 static void armv8pmu_disable_user_access(void)
 698 {
 699         update_pmuserenr(0);
 700 }
 701
 702 static void armv8pmu_enable_user_access(struct arm_pmu *cpu_pmu)
 703 {
 704         int i;
 705         struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
 706
 707         /* Clear any unused counters to avoid leaking their contents */
 708         for_each_clear_bit(i, cpuc->used_mask, cpu_pmu->num_events) {
 709                 if (i == ARMV8_IDX_CYCLE_COUNTER)
 710                         write_pmccntr(0);
 711                 else
 712                         armv8pmu_write_evcntr(i, 0);
 713         }
 714
 715         update_pmuserenr(ARMV8_PMU_USERENR_ER | ARMV8_PMU_USERENR_CR);
 716 }
 717
 718 static void armv8pmu_enable_event(struct perf_event *event)
 719 {
 720         /*
 721          * Enable counter and interrupt, and set the counter to count
 722          * the event that we're interested in.
 723          */
 724
 725         /*
 726          * Disable counter
 727          */
 728         armv8pmu_disable_event_counter(event);
 729
 730         /*
 731          * Set event.
 732          */
 733         armv8pmu_write_event_type(event);
 734
 735         /*
 736          * Enable interrupt for this counter
 737          */
 738         armv8pmu_enable_event_irq(event);
 739
 740         /*
 741          * Enable counter
 742          */
 743         armv8pmu_enable_event_counter(event);
 744 }
 745
 746 static void armv8pmu_disable_event(struct perf_event *event)
 747 {
 748         /*
 749          * Disable counter
 750          */
 751         armv8pmu_disable_event_counter(event);
 752
 753         /*
 754          * Disable interrupt for this counter
 755          */
 756         armv8pmu_disable_event_irq(event);
 757 }
 758
 759 static void armv8pmu_start(struct arm_pmu *cpu_pmu)
 760 {
 761         struct perf_event_context *ctx;
 762         int nr_user = 0;
 763
 764         ctx = perf_cpu_task_ctx();
 765         if (ctx)
 766                 nr_user = ctx->nr_user;
 767
 768         if (sysctl_perf_user_access && nr_user)
 769                 armv8pmu_enable_user_access(cpu_pmu);
 770         else
 771                 armv8pmu_disable_user_access();
 772
 773         /* Enable all counters */
 774         armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMU_PMCR_E);
 775 }
 776
 777 static void armv8pmu_stop(struct arm_pmu *cpu_pmu)
 778 {
 779         /* Disable all counters */
 780         armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMU_PMCR_E);
 781 }
 782
 783 static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu)
 784 {
 785         u32 pmovsr;
 786         struct perf_sample_data data;
 787         struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
 788         struct pt_regs *regs;
 789         int idx;
 790
 791         /*
 792          * Get and reset the IRQ flags
 793          */
 794         pmovsr = armv8pmu_getreset_flags();
 795
 796         /*
 797          * Did an overflow occur?
 798          */
 799         if (!armv8pmu_has_overflowed(pmovsr))
 800                 return IRQ_NONE;
 801
 802         /*
 803          * Handle the counter(s) overflow(s)
 804          */
 805         regs = get_irq_regs();
 806
 807         /*
 808          * Stop the PMU while processing the counter overflows
 809          * to prevent skews in group events.
 810          */
 811         armv8pmu_stop(cpu_pmu);
 812         for (idx = 0; idx < cpu_pmu->num_events; ++idx) {
 813                 struct perf_event *event = cpuc->events[idx];
 814                 struct hw_perf_event *hwc;
 815
 816                 /* Ignore if we don't have an event. */
 817                 if (!event)
 818                         continue;
 819
 820                 /*
 821                  * We have a single interrupt for all counters. Check that
 822                  * each counter has overflowed before we process it.
 823                  */
 824                 if (!armv8pmu_counter_has_overflowed(pmovsr, idx))
 825                         continue;
 826
 827                 hwc = &event->hw;
 828                 armpmu_event_update(event);
 829                 perf_sample_data_init(&data, 0, hwc->last_period);
 830                 if (!armpmu_event_set_period(event))
 831                         continue;
 832
 833                 /*
 834                  * Perf event overflow will queue the processing of the event as
 835                  * an irq_work which will be taken care of in the handling of
 836                  * IPI_IRQ_WORK.
 837                  */
 838                 if (perf_event_overflow(event, &data, regs))
 839                         cpu_pmu->disable(event);
 840         }
 841         armv8pmu_start(cpu_pmu);
 842
 843         return IRQ_HANDLED;
 844 }
 845
 846 static int armv8pmu_get_single_idx(struct pmu_hw_events *cpuc,
 847                                     struct arm_pmu *cpu_pmu)
 848 {
 849         int idx;
 850
 851         for (idx = ARMV8_IDX_COUNTER0; idx < cpu_pmu->num_events; idx++) {
 852                 if (!test_and_set_bit(idx, cpuc->used_mask))
 853                         return idx;
 854         }
 855         return -EAGAIN;
 856 }
 857
 858 static int armv8pmu_get_chain_idx(struct pmu_hw_events *cpuc,
 859                                    struct arm_pmu *cpu_pmu)
 860 {
 861         int idx;
 862
 863         /*
 864          * Chaining requires two consecutive event counters, where
 865          * the lower idx must be even.
 866          */
 867         for (idx = ARMV8_IDX_COUNTER0 + 1; idx < cpu_pmu->num_events; idx += 2) {
 868                 if (!test_and_set_bit(idx, cpuc->used_mask)) {
 869                         /* Check if the preceding even counter is available */
 870                         if (!test_and_set_bit(idx - 1, cpuc->used_mask))
 871                                 return idx;
 872                         /* Release the Odd counter */
 873                         clear_bit(idx, cpuc->used_mask);
 874                 }
 875         }
 876         return -EAGAIN;
 877 }
 878
 879 static int armv8pmu_get_event_idx(struct pmu_hw_events *cpuc,
 880                                   struct perf_event *event)
 881 {
 882         struct arm_pmu *cpu_pmu = to_arm_pmu(event->pmu);
 883         struct hw_perf_event *hwc = &event->hw;
 884         unsigned long evtype = hwc->config_base & ARMV8_PMU_EVTYPE_EVENT;
 885
 886         /* Always prefer to place a cycle counter into the cycle counter. */
 887         if (evtype == ARMV8_PMUV3_PERFCTR_CPU_CYCLES) {
 888                 if (!test_and_set_bit(ARMV8_IDX_CYCLE_COUNTER, cpuc->used_mask))
 889                         return ARMV8_IDX_CYCLE_COUNTER;
 890                 else if (armv8pmu_event_is_64bit(event) &&
 891                            armv8pmu_event_want_user_access(event) &&
 892                            !armv8pmu_has_long_event(cpu_pmu))
 893                                 return -EAGAIN;
 894         }
 895
 896         /*
 897          * Otherwise use events counters
 898          */
 899         if (armv8pmu_event_is_chained(event))
 900                 return  armv8pmu_get_chain_idx(cpuc, cpu_pmu);
 901         else
 902                 return armv8pmu_get_single_idx(cpuc, cpu_pmu);
 903 }
 904
 905 static void armv8pmu_clear_event_idx(struct pmu_hw_events *cpuc,
 906                                      struct perf_event *event)
 907 {
 908         int idx = event->hw.idx;
 909
 910         clear_bit(idx, cpuc->used_mask);
 911         if (armv8pmu_event_is_chained(event))
 912                 clear_bit(idx - 1, cpuc->used_mask);
 913 }
 914
 915 static int armv8pmu_user_event_idx(struct perf_event *event)
 916 {
 917         if (!sysctl_perf_user_access || !armv8pmu_event_has_user_read(event))
 918                 return 0;
 919
 920         /*
 921          * We remap the cycle counter index to 32 to
 922          * match the offset applied to the rest of
 923          * the counter indices.
 924          */
 925         if (event->hw.idx == ARMV8_IDX_CYCLE_COUNTER)
 926                 return ARMV8_IDX_CYCLE_COUNTER_USER;
 927
 928         return event->hw.idx;
 929 }
 930
 931 /*
 932  * Add an event filter to a given event.
 933  */
 934 static int armv8pmu_set_event_filter(struct hw_perf_event *event,
 935                                      struct perf_event_attr *attr)
 936 {
 937         unsigned long config_base = 0;
 938
 939         if (attr->exclude_idle)
 940                 return -EPERM;
 941
 942         /*
 943          * If we're running in hyp mode, then we *are* the hypervisor.
 944          * Therefore we ignore exclude_hv in this configuration, since
 945          * there's no hypervisor to sample anyway. This is consistent
 946          * with other architectures (x86 and Power).
 947          */
 948         if (is_kernel_in_hyp_mode()) {
 949                 if (!attr->exclude_kernel && !attr->exclude_host)
 950                         config_base |= ARMV8_PMU_INCLUDE_EL2;
 951                 if (attr->exclude_guest)
 952                         config_base |= ARMV8_PMU_EXCLUDE_EL1;
 953                 if (attr->exclude_host)
 954                         config_base |= ARMV8_PMU_EXCLUDE_EL0;
 955         } else {
 956                 if (!attr->exclude_hv && !attr->exclude_host)
 957                         config_base |= ARMV8_PMU_INCLUDE_EL2;
 958         }
 959
 960         /*
 961          * Filter out !VHE kernels and guest kernels
 962          */
 963         if (attr->exclude_kernel)
 964                 config_base |= ARMV8_PMU_EXCLUDE_EL1;
 965
 966         if (attr->exclude_user)
 967                 config_base |= ARMV8_PMU_EXCLUDE_EL0;
 968
 969         /*
 970          * Install the filter into config_base as this is used to
 971          * construct the event type.
 972          */
 973         event->config_base = config_base;
 974
 975         return 0;
 976 }
 977
 978 static void armv8pmu_reset(void *info)
 979 {
 980         struct arm_pmu *cpu_pmu = (struct arm_pmu *)info;
 981         u32 pmcr;
 982
 983         /* The counter and interrupt enable registers are unknown at reset. */
 984         armv8pmu_disable_counter(U32_MAX);
 985         armv8pmu_disable_intens(U32_MAX);
 986
 987         /* Clear the counters we flip at guest entry/exit */
 988         kvm_clr_pmu_events(U32_MAX);
 989
 990         /*
 991          * Initialize & Reset PMNC. Request overflow interrupt for
 992          * 64 bit cycle counter but cheat in armv8pmu_write_counter().
 993          */
 994         pmcr = ARMV8_PMU_PMCR_P | ARMV8_PMU_PMCR_C | ARMV8_PMU_PMCR_LC;
 995
 996         /* Enable long event counter support where available */
 997         if (armv8pmu_has_long_event(cpu_pmu))
 998                 pmcr |= ARMV8_PMU_PMCR_LP;
 999
1000         armv8pmu_pmcr_write(pmcr);
1001 }
1002
1003 static int __armv8_pmuv3_map_event_id(struct arm_pmu *armpmu,
1004                                       struct perf_event *event)
1005 {
1006         if (event->attr.type == PERF_TYPE_HARDWARE &&
1007             event->attr.config == PERF_COUNT_HW_BRANCH_INSTRUCTIONS) {
1008
1009                 if (test_bit(ARMV8_PMUV3_PERFCTR_PC_WRITE_RETIRED,
1010                              armpmu->pmceid_bitmap))
1011                         return ARMV8_PMUV3_PERFCTR_PC_WRITE_RETIRED;
1012
1013                 if (test_bit(ARMV8_PMUV3_PERFCTR_BR_RETIRED,
1014                              armpmu->pmceid_bitmap))
1015                         return ARMV8_PMUV3_PERFCTR_BR_RETIRED;
1016
1017                 return HW_OP_UNSUPPORTED;
1018         }
1019
1020         return armpmu_map_event(event, &armv8_pmuv3_perf_map,
1021                                 &armv8_pmuv3_perf_cache_map,
1022                                 ARMV8_PMU_EVTYPE_EVENT);
1023 }
1024
1025 static int __armv8_pmuv3_map_event(struct perf_event *event,
1026                                    const unsigned (*extra_event_map)
1027                                                   [PERF_COUNT_HW_MAX],
1028                                    const unsigned (*extra_cache_map)
1029                                                   [PERF_COUNT_HW_CACHE_MAX]
1030                                                   [PERF_COUNT_HW_CACHE_OP_MAX]
1031                                                   [PERF_COUNT_HW_CACHE_RESULT_MAX])
1032 {
1033         int hw_event_id;
1034         struct arm_pmu *armpmu = to_arm_pmu(event->pmu);
1035
1036         hw_event_id = __armv8_pmuv3_map_event_id(armpmu, event);
1037
1038         /*
1039          * CHAIN events only work when paired with an adjacent counter, and it
1040          * never makes sense for a user to open one in isolation, as they'll be
1041          * rotated arbitrarily.
1042          */
1043         if (hw_event_id == ARMV8_PMUV3_PERFCTR_CHAIN)
1044                 return -EINVAL;
1045
1046         if (armv8pmu_event_is_64bit(event))
1047                 event->hw.flags |= ARMPMU_EVT_64BIT;
1048
1049         /*
1050          * User events must be allocated into a single counter, and so
1051          * must not be chained.
1052          *
1053          * Most 64-bit events require long counter support, but 64-bit
1054          * CPU_CYCLES events can be placed into the dedicated cycle
1055          * counter when this is free.
1056          */
1057         if (armv8pmu_event_want_user_access(event)) {
1058                 if (!(event->attach_state & PERF_ATTACH_TASK))
1059                         return -EINVAL;
1060                 if (armv8pmu_event_is_64bit(event) &&
1061                     (hw_event_id != ARMV8_PMUV3_PERFCTR_CPU_CYCLES) &&
1062                     !armv8pmu_has_long_event(armpmu))
1063                         return -EOPNOTSUPP;
1064
1065                 event->hw.flags |= PERF_EVENT_FLAG_USER_READ_CNT;
1066         }
1067
1068         /* Only expose micro/arch events supported by this PMU */
1069         if ((hw_event_id > 0) && (hw_event_id < ARMV8_PMUV3_MAX_COMMON_EVENTS)
1070             && test_bit(hw_event_id, armpmu->pmceid_bitmap)) {
1071                 return hw_event_id;
1072         }
1073
1074         return armpmu_map_event(event, extra_event_map, extra_cache_map,
1075                                 ARMV8_PMU_EVTYPE_EVENT);
1076 }
1077
1078 static int armv8_pmuv3_map_event(struct perf_event *event)
1079 {
1080         return __armv8_pmuv3_map_event(event, NULL, NULL);
1081 }
1082
1083 static int armv8_a53_map_event(struct perf_event *event)
1084 {
1085         return __armv8_pmuv3_map_event(event, NULL, &armv8_a53_perf_cache_map);
1086 }
1087
1088 static int armv8_a57_map_event(struct perf_event *event)
1089 {
1090         return __armv8_pmuv3_map_event(event, NULL, &armv8_a57_perf_cache_map);
1091 }
1092
1093 static int armv8_a73_map_event(struct perf_event *event)
1094 {
1095         return __armv8_pmuv3_map_event(event, NULL, &armv8_a73_perf_cache_map);
1096 }
1097
1098 static int armv8_thunder_map_event(struct perf_event *event)
1099 {
1100         return __armv8_pmuv3_map_event(event, NULL,
1101                                        &armv8_thunder_perf_cache_map);
1102 }
1103
1104 static int armv8_vulcan_map_event(struct perf_event *event)
1105 {
1106         return __armv8_pmuv3_map_event(event, NULL,
1107                                        &armv8_vulcan_perf_cache_map);
1108 }
1109
1110 struct armv8pmu_probe_info {
1111         struct arm_pmu *pmu;
1112         bool present;
1113 };
1114
1115 static void __armv8pmu_probe_pmu(void *info)
1116 {
1117         struct armv8pmu_probe_info *probe = info;
1118         struct arm_pmu *cpu_pmu = probe->pmu;
1119         u64 pmceid_raw[2];
1120         u32 pmceid[2];
1121         int pmuver;
1122
1123         pmuver = read_pmuver();
1124         if (!pmuv3_implemented(pmuver))
1125                 return;
1126
1127         cpu_pmu->pmuver = pmuver;
1128         probe->present = true;
1129
1130         /* Read the nb of CNTx counters supported from PMNC */
1131         cpu_pmu->num_events = (armv8pmu_pmcr_read() >> ARMV8_PMU_PMCR_N_SHIFT)
1132                 & ARMV8_PMU_PMCR_N_MASK;
1133
1134         /* Add the CPU cycles counter */
1135         cpu_pmu->num_events += 1;
1136
1137         pmceid[0] = pmceid_raw[0] = read_pmceid0();
1138         pmceid[1] = pmceid_raw[1] = read_pmceid1();
1139
1140         bitmap_from_arr32(cpu_pmu->pmceid_bitmap,
1141                              pmceid, ARMV8_PMUV3_MAX_COMMON_EVENTS);
1142
1143         pmceid[0] = pmceid_raw[0] >> 32;
1144         pmceid[1] = pmceid_raw[1] >> 32;
1145
1146         bitmap_from_arr32(cpu_pmu->pmceid_ext_bitmap,
1147                              pmceid, ARMV8_PMUV3_MAX_COMMON_EVENTS);
1148
1149         /* store PMMIR register for sysfs */
1150         if (is_pmuv3p4(pmuver) && (pmceid_raw[1] & BIT(31)))
1151                 cpu_pmu->reg_pmmir = read_pmmir();
1152         else
1153                 cpu_pmu->reg_pmmir = 0;
1154 }
1155
1156 static int armv8pmu_probe_pmu(struct arm_pmu *cpu_pmu)
1157 {
1158         struct armv8pmu_probe_info probe = {
1159                 .pmu = cpu_pmu,
1160                 .present = false,
1161         };
1162         int ret;
1163
1164         ret = smp_call_function_any(&cpu_pmu->supported_cpus,
1165                                     __armv8pmu_probe_pmu,
1166                                     &probe, 1);
1167         if (ret)
1168                 return ret;
1169
1170         return probe.present ? 0 : -ENODEV;
1171 }
1172
1173 static void armv8pmu_disable_user_access_ipi(void *unused)
1174 {
1175         armv8pmu_disable_user_access();
1176 }
1177
1178 static int armv8pmu_proc_user_access_handler(struct ctl_table *table, int write,
1179                 void *buffer, size_t *lenp, loff_t *ppos)
1180 {
1181         int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
1182         if (ret || !write || sysctl_perf_user_access)
1183                 return ret;
1184
1185         on_each_cpu(armv8pmu_disable_user_access_ipi, NULL, 1);
1186         return 0;
1187 }
1188
1189 static struct ctl_table armv8_pmu_sysctl_table[] = {
1190         {
1191                 .procname       = "perf_user_access",
1192                 .data           = &sysctl_perf_user_access,
1193                 .maxlen         = sizeof(unsigned int),
1194                 .mode           = 0644,
1195                 .proc_handler   = armv8pmu_proc_user_access_handler,
1196                 .extra1         = SYSCTL_ZERO,
1197                 .extra2         = SYSCTL_ONE,
1198         },
1199         { }
1200 };
1201
1202 static void armv8_pmu_register_sysctl_table(void)
1203 {
1204         static u32 tbl_registered = 0;
1205
1206         if (!cmpxchg_relaxed(&tbl_registered, 0, 1))
1207                 register_sysctl("kernel", armv8_pmu_sysctl_table);
1208 }
1209
1210 static int armv8_pmu_init(struct arm_pmu *cpu_pmu, char *name,
1211                           int (*map_event)(struct perf_event *event),
1212                           const struct attribute_group *events,
1213                           const struct attribute_group *format,
1214                           const struct attribute_group *caps)
1215 {
1216         int ret = armv8pmu_probe_pmu(cpu_pmu);
1217         if (ret)
1218                 return ret;
1219
1220         cpu_pmu->handle_irq             = armv8pmu_handle_irq;
1221         cpu_pmu->enable                 = armv8pmu_enable_event;
1222         cpu_pmu->disable                = armv8pmu_disable_event;
1223         cpu_pmu->read_counter           = armv8pmu_read_counter;
1224         cpu_pmu->write_counter          = armv8pmu_write_counter;
1225         cpu_pmu->get_event_idx          = armv8pmu_get_event_idx;
1226         cpu_pmu->clear_event_idx        = armv8pmu_clear_event_idx;
1227         cpu_pmu->start                  = armv8pmu_start;
1228         cpu_pmu->stop                   = armv8pmu_stop;
1229         cpu_pmu->reset                  = armv8pmu_reset;
1230         cpu_pmu->set_event_filter       = armv8pmu_set_event_filter;
1231
1232         cpu_pmu->pmu.event_idx          = armv8pmu_user_event_idx;
1233
1234         cpu_pmu->name                   = name;
1235         cpu_pmu->map_event              = map_event;
1236         cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_EVENTS] = events ?
1237                         events : &armv8_pmuv3_events_attr_group;
1238         cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_FORMATS] = format ?
1239                         format : &armv8_pmuv3_format_attr_group;
1240         cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_CAPS] = caps ?
1241                         caps : &armv8_pmuv3_caps_attr_group;
1242
1243         armv8_pmu_register_sysctl_table();
1244         return 0;
1245 }
1246
1247 static int armv8_pmu_init_nogroups(struct arm_pmu *cpu_pmu, char *name,
1248                                    int (*map_event)(struct perf_event *event))
1249 {
1250         return armv8_pmu_init(cpu_pmu, name, map_event, NULL, NULL, NULL);
1251 }
1252
1253 #define PMUV3_INIT_SIMPLE(name)                                         \
1254 static int name##_pmu_init(struct arm_pmu *cpu_pmu)                     \
1255 {                                                                       \
1256         return armv8_pmu_init_nogroups(cpu_pmu, #name, armv8_pmuv3_map_event);\
1257 }
1258
1259 PMUV3_INIT_SIMPLE(armv8_pmuv3)
1260
1261 PMUV3_INIT_SIMPLE(armv8_cortex_a34)
1262 PMUV3_INIT_SIMPLE(armv8_cortex_a55)
1263 PMUV3_INIT_SIMPLE(armv8_cortex_a65)
1264 PMUV3_INIT_SIMPLE(armv8_cortex_a75)
1265 PMUV3_INIT_SIMPLE(armv8_cortex_a76)
1266 PMUV3_INIT_SIMPLE(armv8_cortex_a77)
1267 PMUV3_INIT_SIMPLE(armv8_cortex_a78)
1268 PMUV3_INIT_SIMPLE(armv9_cortex_a510)
1269 PMUV3_INIT_SIMPLE(armv9_cortex_a710)
1270 PMUV3_INIT_SIMPLE(armv8_cortex_x1)
1271 PMUV3_INIT_SIMPLE(armv9_cortex_x2)
1272 PMUV3_INIT_SIMPLE(armv8_neoverse_e1)
1273 PMUV3_INIT_SIMPLE(armv8_neoverse_n1)
1274 PMUV3_INIT_SIMPLE(armv9_neoverse_n2)
1275 PMUV3_INIT_SIMPLE(armv8_neoverse_v1)
1276
1277 PMUV3_INIT_SIMPLE(armv8_nvidia_carmel)
1278 PMUV3_INIT_SIMPLE(armv8_nvidia_denver)
1279
1280 static int armv8_a35_pmu_init(struct arm_pmu *cpu_pmu)
1281 {
1282         return armv8_pmu_init_nogroups(cpu_pmu, "armv8_cortex_a35",
1283                                        armv8_a53_map_event);
1284 }
1285
1286 static int armv8_a53_pmu_init(struct arm_pmu *cpu_pmu)
1287 {
1288         return armv8_pmu_init_nogroups(cpu_pmu, "armv8_cortex_a53",
1289                                        armv8_a53_map_event);
1290 }
1291
1292 static int armv8_a57_pmu_init(struct arm_pmu *cpu_pmu)
1293 {
1294         return armv8_pmu_init_nogroups(cpu_pmu, "armv8_cortex_a57",
1295                                        armv8_a57_map_event);
1296 }
1297
1298 static int armv8_a72_pmu_init(struct arm_pmu *cpu_pmu)
1299 {
1300         return armv8_pmu_init_nogroups(cpu_pmu, "armv8_cortex_a72",
1301                                        armv8_a57_map_event);
1302 }
1303
1304 static int armv8_a73_pmu_init(struct arm_pmu *cpu_pmu)
1305 {
1306         return armv8_pmu_init_nogroups(cpu_pmu, "armv8_cortex_a73",
1307                                        armv8_a73_map_event);
1308 }
1309
1310 static int armv8_thunder_pmu_init(struct arm_pmu *cpu_pmu)
1311 {
1312         return armv8_pmu_init_nogroups(cpu_pmu, "armv8_cavium_thunder",
1313                                        armv8_thunder_map_event);
1314 }
1315
1316 static int armv8_vulcan_pmu_init(struct arm_pmu *cpu_pmu)
1317 {
1318         return armv8_pmu_init_nogroups(cpu_pmu, "armv8_brcm_vulcan",
1319                                        armv8_vulcan_map_event);
1320 }
1321
1322 static const struct of_device_id armv8_pmu_of_device_ids[] = {
1323         {.compatible = "arm,armv8-pmuv3",       .data = armv8_pmuv3_pmu_init},
1324         {.compatible = "arm,cortex-a34-pmu",    .data = armv8_cortex_a34_pmu_init},
1325         {.compatible = "arm,cortex-a35-pmu",    .data = armv8_a35_pmu_init},
1326         {.compatible = "arm,cortex-a53-pmu",    .data = armv8_a53_pmu_init},
1327         {.compatible = "arm,cortex-a55-pmu",    .data = armv8_cortex_a55_pmu_init},
1328         {.compatible = "arm,cortex-a57-pmu",    .data = armv8_a57_pmu_init},
1329         {.compatible = "arm,cortex-a65-pmu",    .data = armv8_cortex_a65_pmu_init},
1330         {.compatible = "arm,cortex-a72-pmu",    .data = armv8_a72_pmu_init},
1331         {.compatible = "arm,cortex-a73-pmu",    .data = armv8_a73_pmu_init},
1332         {.compatible = "arm,cortex-a75-pmu",    .data = armv8_cortex_a75_pmu_init},
1333         {.compatible = "arm,cortex-a76-pmu",    .data = armv8_cortex_a76_pmu_init},
1334         {.compatible = "arm,cortex-a77-pmu",    .data = armv8_cortex_a77_pmu_init},
1335         {.compatible = "arm,cortex-a78-pmu",    .data = armv8_cortex_a78_pmu_init},
1336         {.compatible = "arm,cortex-a510-pmu",   .data = armv9_cortex_a510_pmu_init},
1337         {.compatible = "arm,cortex-a710-pmu",   .data = armv9_cortex_a710_pmu_init},
1338         {.compatible = "arm,cortex-x1-pmu",     .data = armv8_cortex_x1_pmu_init},
1339         {.compatible = "arm,cortex-x2-pmu",     .data = armv9_cortex_x2_pmu_init},
1340         {.compatible = "arm,neoverse-e1-pmu",   .data = armv8_neoverse_e1_pmu_init},
1341         {.compatible = "arm,neoverse-n1-pmu",   .data = armv8_neoverse_n1_pmu_init},
1342         {.compatible = "arm,neoverse-n2-pmu",   .data = armv9_neoverse_n2_pmu_init},
1343         {.compatible = "arm,neoverse-v1-pmu",   .data = armv8_neoverse_v1_pmu_init},
1344         {.compatible = "cavium,thunder-pmu",    .data = armv8_thunder_pmu_init},
1345         {.compatible = "brcm,vulcan-pmu",       .data = armv8_vulcan_pmu_init},
1346         {.compatible = "nvidia,carmel-pmu",     .data = armv8_nvidia_carmel_pmu_init},
1347         {.compatible = "nvidia,denver-pmu",     .data = armv8_nvidia_denver_pmu_init},
1348         {},
1349 };
1350
1351 static int armv8_pmu_device_probe(struct platform_device *pdev)
1352 {
1353         return arm_pmu_device_probe(pdev, armv8_pmu_of_device_ids, NULL);
1354 }
1355
1356 static struct platform_driver armv8_pmu_driver = {
1357         .driver         = {
1358                 .name   = ARMV8_PMU_PDEV_NAME,
1359                 .of_match_table = armv8_pmu_of_device_ids,
1360                 .suppress_bind_attrs = true,
1361         },
1362         .probe          = armv8_pmu_device_probe,
1363 };
1364
1365 static int __init armv8_pmu_driver_init(void)
1366 {
1367         int ret;
1368
1369         if (acpi_disabled)
1370                 ret = platform_driver_register(&armv8_pmu_driver);
1371         else
1372                 ret = arm_pmu_acpi_probe(armv8_pmuv3_pmu_init);
1373
1374         if (!ret)
1375                 lockup_detector_retry_init();
1376
1377         return ret;
1378 }
1379 device_initcall(armv8_pmu_driver_init)
1380
1381 void arch_perf_update_userpage(struct perf_event *event,
1382                                struct perf_event_mmap_page *userpg, u64 now)
1383 {
1384         struct clock_read_data *rd;
1385         unsigned int seq;
1386         u64 ns;
1387
1388         userpg->cap_user_time = 0;
1389         userpg->cap_user_time_zero = 0;
1390         userpg->cap_user_time_short = 0;
1391         userpg->cap_user_rdpmc = armv8pmu_event_has_user_read(event);
1392
1393         if (userpg->cap_user_rdpmc) {
1394                 if (event->hw.flags & ARMPMU_EVT_64BIT)
1395                         userpg->pmc_width = 64;
1396                 else
1397                         userpg->pmc_width = 32;
1398         }
1399
1400         do {
1401                 rd = sched_clock_read_begin(&seq);
1402
1403                 if (rd->read_sched_clock != arch_timer_read_counter)
1404                         return;
1405
1406                 userpg->time_mult = rd->mult;
1407                 userpg->time_shift = rd->shift;
1408                 userpg->time_zero = rd->epoch_ns;
1409                 userpg->time_cycles = rd->epoch_cyc;
1410                 userpg->time_mask = rd->sched_clock_mask;
1411
1412                 /*
1413                  * Subtract the cycle base, such that software that
1414                  * doesn't know about cap_user_time_short still 'works'
1415                  * assuming no wraps.
1416                  */
1417                 ns = mul_u64_u32_shr(rd->epoch_cyc, rd->mult, rd->shift);
1418                 userpg->time_zero -= ns;
1419
1420         } while (sched_clock_read_retry(seq));
1421
1422         userpg->time_offset = userpg->time_zero - now;
1423
1424         /*
1425          * time_shift is not expected to be greater than 31 due to
1426          * the original published conversion algorithm shifting a
1427          * 32-bit value (now specifies a 64-bit value) - refer
1428          * perf_event_mmap_page documentation in perf_event.h.
1429          */
1430         if (userpg->time_shift == 32) {
1431                 userpg->time_shift = 31;
1432                 userpg->time_mult >>= 1;
1433         }
1434
1435         /*
1436          * Internal timekeeping for enabled/running/stopped times
1437          * is always computed with the sched_clock.
1438          */
1439         userpg->cap_user_time = 1;
1440         userpg->cap_user_time_zero = 1;
1441         userpg->cap_user_time_short = 1;
1442 }