arch/powerpc/kernel/mpc7450-pmu.c

   1 /*
   2  * Performance counter support for MPC7450-family processors.
   3  *
   4  * Copyright 2008-2009 Paul Mackerras, IBM Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11 #include <linux/string.h>
  12 #include <linux/perf_event.h>
  13 #include <asm/reg.h>
  14 #include <asm/cputable.h>
  15
  16 #define N_COUNTER       6       /* Number of hardware counters */
  17 #define MAX_ALT         3       /* Maximum number of event alternative codes */
  18
  19 /*
  20  * Bits in event code for MPC7450 family
  21  */
  22 #define PM_THRMULT_MSKS 0x40000
  23 #define PM_THRESH_SH    12
  24 #define PM_THRESH_MSK   0x3f
  25 #define PM_PMC_SH       8
  26 #define PM_PMC_MSK      7
  27 #define PM_PMCSEL_MSK   0x7f
  28
  29 /*
  30  * Classify events according to how specific their PMC requirements are.
  31  * Result is:
  32  *      0: can go on any PMC
  33  *      1: can go on PMCs 1-4
  34  *      2: can go on PMCs 1,2,4
  35  *      3: can go on PMCs 1 or 2
  36  *      4: can only go on one PMC
  37  *      -1: event code is invalid
  38  */
  39 #define N_CLASSES       5
  40
  41 static int mpc7450_classify_event(u32 event)
  42 {
  43         int pmc;
  44
  45         pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
  46         if (pmc) {
  47                 if (pmc > N_COUNTER)
  48                         return -1;
  49                 return 4;
  50         }
  51         event &= PM_PMCSEL_MSK;
  52         if (event <= 1)
  53                 return 0;
  54         if (event <= 7)
  55                 return 1;
  56         if (event <= 13)
  57                 return 2;
  58         if (event <= 22)
  59                 return 3;
  60         return -1;
  61 }
  62
  63 /*
  64  * Events using threshold and possible threshold scale:
  65  *      code    scale?  name
  66  *      11e     N       PM_INSTQ_EXCEED_CYC
  67  *      11f     N       PM_ALTV_IQ_EXCEED_CYC
  68  *      128     Y       PM_DTLB_SEARCH_EXCEED_CYC
  69  *      12b     Y       PM_LD_MISS_EXCEED_L1_CYC
  70  *      220     N       PM_CQ_EXCEED_CYC
  71  *      30c     N       PM_GPR_RB_EXCEED_CYC
  72  *      30d     ?       PM_FPR_IQ_EXCEED_CYC ?
  73  *      311     Y       PM_ITLB_SEARCH_EXCEED
  74  *      410     N       PM_GPR_IQ_EXCEED_CYC
  75  */
  76
  77 /*
  78  * Return use of threshold and threshold scale bits:
  79  * 0 = uses neither, 1 = uses threshold, 2 = uses both
  80  */
  81 static int mpc7450_threshold_use(u32 event)
  82 {
  83         int pmc, sel;
  84
  85         pmc = (event >> PM_PMC_SH) & PM_PMC_MSK;
  86         sel = event & PM_PMCSEL_MSK;
  87         switch (pmc) {
  88         case 1:
  89                 if (sel == 0x1e || sel == 0x1f)
  90                         return 1;
  91                 if (sel == 0x28 || sel == 0x2b)
  92                         return 2;
  93                 break;
  94         case 2:
  95                 if (sel == 0x20)
  96                         return 1;
  97                 break;
  98         case 3:
  99                 if (sel == 0xc || sel == 0xd)
 100                         return 1;
 101                 if (sel == 0x11)
 102                         return 2;
 103                 break;
 104         case 4:
 105                 if (sel == 0x10)
 106                         return 1;
 107                 break;
 108         }
 109         return 0;
 110 }
 111
 112 /*
 113  * Layout of constraint bits:
 114  * 33222222222211111111110000000000
 115  * 10987654321098765432109876543210
 116  *  |<    ><  > < > < ><><><><><><>
 117  *  TS TV   G4   G3  G2P6P5P4P3P2P1
 118  *
 119  * P1 - P6
 120  *      0 - 11: Count of events needing PMC1 .. PMC6
 121  *
 122  * G2
 123  *      12 - 14: Count of events needing PMC1 or PMC2
 124  *
 125  * G3
 126  *      16 - 18: Count of events needing PMC1, PMC2 or PMC4
 127  *
 128  * G4
 129  *      20 - 23: Count of events needing PMC1, PMC2, PMC3 or PMC4
 130  *
 131  * TV
 132  *      24 - 29: Threshold value requested
 133  *
 134  * TS
 135  *      30: Threshold scale value requested
 136  */
 137
 138 static u32 pmcbits[N_COUNTER][2] = {
 139         { 0x00844002, 0x00111001 },     /* PMC1 mask, value: P1,G2,G3,G4 */
 140         { 0x00844008, 0x00111004 },     /* PMC2: P2,G2,G3,G4 */
 141         { 0x00800020, 0x00100010 },     /* PMC3: P3,G4 */
 142         { 0x00840080, 0x00110040 },     /* PMC4: P4,G3,G4 */
 143         { 0x00000200, 0x00000100 },     /* PMC5: P5 */
 144         { 0x00000800, 0x00000400 }      /* PMC6: P6 */
 145 };
 146
 147 static u32 classbits[N_CLASSES - 1][2] = {
 148         { 0x00000000, 0x00000000 },     /* class 0: no constraint */
 149         { 0x00800000, 0x00100000 },     /* class 1: G4 */
 150         { 0x00040000, 0x00010000 },     /* class 2: G3 */
 151         { 0x00004000, 0x00001000 },     /* class 3: G2 */
 152 };
 153
 154 static int mpc7450_get_constraint(u64 event, unsigned long *maskp,
 155                                   unsigned long *valp)
 156 {
 157         int pmc, class;
 158         u32 mask, value;
 159         int thresh, tuse;
 160
 161         class = mpc7450_classify_event(event);
 162         if (class < 0)
 163                 return -1;
 164         if (class == 4) {
 165                 pmc = ((unsigned int)event >> PM_PMC_SH) & PM_PMC_MSK;
 166                 mask  = pmcbits[pmc - 1][0];
 167                 value = pmcbits[pmc - 1][1];
 168         } else {
 169                 mask  = classbits[class][0];
 170                 value = classbits[class][1];
 171         }
 172
 173         tuse = mpc7450_threshold_use(event);
 174         if (tuse) {
 175                 thresh = ((unsigned int)event >> PM_THRESH_SH) & PM_THRESH_MSK;
 176                 mask  |= 0x3f << 24;
 177                 value |= thresh << 24;
 178                 if (tuse == 2) {
 179                         mask |= 0x40000000;
 180                         if ((unsigned int)event & PM_THRMULT_MSKS)
 181                                 value |= 0x40000000;
 182                 }
 183         }
 184
 185         *maskp = mask;
 186         *valp = value;
 187         return 0;
 188 }
 189
 190 static const unsigned int event_alternatives[][MAX_ALT] = {
 191         { 0x217, 0x317 },               /* PM_L1_DCACHE_MISS */
 192         { 0x418, 0x50f, 0x60f },        /* PM_SNOOP_RETRY */
 193         { 0x502, 0x602 },               /* PM_L2_HIT */
 194         { 0x503, 0x603 },               /* PM_L3_HIT */
 195         { 0x504, 0x604 },               /* PM_L2_ICACHE_MISS */
 196         { 0x505, 0x605 },               /* PM_L3_ICACHE_MISS */
 197         { 0x506, 0x606 },               /* PM_L2_DCACHE_MISS */
 198         { 0x507, 0x607 },               /* PM_L3_DCACHE_MISS */
 199         { 0x50a, 0x623 },               /* PM_LD_HIT_L3 */
 200         { 0x50b, 0x624 },               /* PM_ST_HIT_L3 */
 201         { 0x50d, 0x60d },               /* PM_L2_TOUCH_HIT */
 202         { 0x50e, 0x60e },               /* PM_L3_TOUCH_HIT */
 203         { 0x512, 0x612 },               /* PM_INT_LOCAL */
 204         { 0x513, 0x61d },               /* PM_L2_MISS */
 205         { 0x514, 0x61e },               /* PM_L3_MISS */
 206 };
 207
 208 /*
 209  * Scan the alternatives table for a match and return the
 210  * index into the alternatives table if found, else -1.
 211  */
 212 static int find_alternative(u32 event)
 213 {
 214         int i, j;
 215
 216         for (i = 0; i < ARRAY_SIZE(event_alternatives); ++i) {
 217                 if (event < event_alternatives[i][0])
 218                         break;
 219                 for (j = 0; j < MAX_ALT && event_alternatives[i][j]; ++j)
 220                         if (event == event_alternatives[i][j])
 221                                 return i;
 222         }
 223         return -1;
 224 }
 225
 226 static int mpc7450_get_alternatives(u64 event, unsigned int flags, u64 alt[])
 227 {
 228         int i, j, nalt = 1;
 229         u32 ae;
 230
 231         alt[0] = event;
 232         nalt = 1;
 233         i = find_alternative((u32)event);
 234         if (i >= 0) {
 235                 for (j = 0; j < MAX_ALT; ++j) {
 236                         ae = event_alternatives[i][j];
 237                         if (ae && ae != (u32)event)
 238                                 alt[nalt++] = ae;
 239                 }
 240         }
 241         return nalt;
 242 }
 243
 244 /*
 245  * Bitmaps of which PMCs each class can use for classes 0 - 3.
 246  * Bit i is set if PMC i+1 is usable.
 247  */
 248 static const u8 classmap[N_CLASSES] = {
 249         0x3f, 0x0f, 0x0b, 0x03, 0
 250 };
 251
 252 /* Bit position and width of each PMCSEL field */
 253 static const int pmcsel_shift[N_COUNTER] = {
 254         6,      0,      27,     22,     17,     11
 255 };
 256 static const u32 pmcsel_mask[N_COUNTER] = {
 257         0x7f,   0x3f,   0x1f,   0x1f,   0x1f,   0x3f
 258 };
 259
 260 /*
 261  * Compute MMCR0/1/2 values for a set of events.
 262  */
 263 static int mpc7450_compute_mmcr(u64 event[], int n_ev,
 264                                 unsigned int hwc[], unsigned long mmcr[])
 265 {
 266         u8 event_index[N_CLASSES][N_COUNTER];
 267         int n_classevent[N_CLASSES];
 268         int i, j, class, tuse;
 269         u32 pmc_inuse = 0, pmc_avail;
 270         u32 mmcr0 = 0, mmcr1 = 0, mmcr2 = 0;
 271         u32 ev, pmc, thresh;
 272
 273         if (n_ev > N_COUNTER)
 274                 return -1;
 275
 276         /* First pass: count usage in each class */
 277         for (i = 0; i < N_CLASSES; ++i)
 278                 n_classevent[i] = 0;
 279         for (i = 0; i < n_ev; ++i) {
 280                 class = mpc7450_classify_event(event[i]);
 281                 if (class < 0)
 282                         return -1;
 283                 j = n_classevent[class]++;
 284                 event_index[class][j] = i;
 285         }
 286
 287         /* Second pass: allocate PMCs from most specific event to least */
 288         for (class = N_CLASSES - 1; class >= 0; --class) {
 289                 for (i = 0; i < n_classevent[class]; ++i) {
 290                         ev = event[event_index[class][i]];
 291                         if (class == 4) {
 292                                 pmc = (ev >> PM_PMC_SH) & PM_PMC_MSK;
 293                                 if (pmc_inuse & (1 << (pmc - 1)))
 294                                         return -1;
 295                         } else {
 296                                 /* Find a suitable PMC */
 297                                 pmc_avail = classmap[class] & ~pmc_inuse;
 298                                 if (!pmc_avail)
 299                                         return -1;
 300                                 pmc = ffs(pmc_avail);
 301                         }
 302                         pmc_inuse |= 1 << (pmc - 1);
 303
 304                         tuse = mpc7450_threshold_use(ev);
 305                         if (tuse) {
 306                                 thresh = (ev >> PM_THRESH_SH) & PM_THRESH_MSK;
 307                                 mmcr0 |= thresh << 16;
 308                                 if (tuse == 2 && (ev & PM_THRMULT_MSKS))
 309                                         mmcr2 = 0x80000000;
 310                         }
 311                         ev &= pmcsel_mask[pmc - 1];
 312                         ev <<= pmcsel_shift[pmc - 1];
 313                         if (pmc <= 2)
 314                                 mmcr0 |= ev;
 315                         else
 316                                 mmcr1 |= ev;
 317                         hwc[event_index[class][i]] = pmc - 1;
 318                 }
 319         }
 320
 321         if (pmc_inuse & 1)
 322                 mmcr0 |= MMCR0_PMC1CE;
 323         if (pmc_inuse & 0x3e)
 324                 mmcr0 |= MMCR0_PMCnCE;
 325
 326         /* Return MMCRx values */
 327         mmcr[0] = mmcr0;
 328         mmcr[1] = mmcr1;
 329         mmcr[2] = mmcr2;
 330         return 0;
 331 }
 332
 333 /*
 334  * Disable counting by a PMC.
 335  * Note that the pmc argument is 0-based here, not 1-based.
 336  */
 337 static void mpc7450_disable_pmc(unsigned int pmc, unsigned long mmcr[])
 338 {
 339         if (pmc <= 1)
 340                 mmcr[0] &= ~(pmcsel_mask[pmc] << pmcsel_shift[pmc]);
 341         else
 342                 mmcr[1] &= ~(pmcsel_mask[pmc] << pmcsel_shift[pmc]);
 343 }
 344
 345 static int mpc7450_generic_events[] = {
 346         [PERF_COUNT_HW_CPU_CYCLES]              = 1,
 347         [PERF_COUNT_HW_INSTRUCTIONS]            = 2,
 348         [PERF_COUNT_HW_CACHE_MISSES]            = 0x217, /* PM_L1_DCACHE_MISS */
 349         [PERF_COUNT_HW_BRANCH_INSTRUCTIONS]     = 0x122, /* PM_BR_CMPL */
 350         [PERF_COUNT_HW_BRANCH_MISSES]           = 0x41c, /* PM_BR_MPRED */
 351 };
 352
 353 #define C(x)    PERF_COUNT_HW_CACHE_##x
 354
 355 /*
 356  * Table of generalized cache-related events.
 357  * 0 means not supported, -1 means nonsensical, other values
 358  * are event codes.
 359  */
 360 static int mpc7450_cache_events[C(MAX)][C(OP_MAX)][C(RESULT_MAX)] = {
 361         [C(L1D)] = {            /*      RESULT_ACCESS   RESULT_MISS */
 362                 [C(OP_READ)] = {        0,              0x225   },
 363                 [C(OP_WRITE)] = {       0,              0x227   },
 364                 [C(OP_PREFETCH)] = {    0,              0       },
 365         },
 366         [C(L1I)] = {            /*      RESULT_ACCESS   RESULT_MISS */
 367                 [C(OP_READ)] = {        0x129,          0x115   },
 368                 [C(OP_WRITE)] = {       -1,             -1      },
 369                 [C(OP_PREFETCH)] = {    0x634,          0       },
 370         },
 371         [C(LL)] = {             /*      RESULT_ACCESS   RESULT_MISS */
 372                 [C(OP_READ)] = {        0,              0       },
 373                 [C(OP_WRITE)] = {       0,              0       },
 374                 [C(OP_PREFETCH)] = {    0,              0       },
 375         },
 376         [C(DTLB)] = {           /*      RESULT_ACCESS   RESULT_MISS */
 377                 [C(OP_READ)] = {        0,              0x312   },
 378                 [C(OP_WRITE)] = {       -1,             -1      },
 379                 [C(OP_PREFETCH)] = {    -1,             -1      },
 380         },
 381         [C(ITLB)] = {           /*      RESULT_ACCESS   RESULT_MISS */
 382                 [C(OP_READ)] = {        0,              0x223   },
 383                 [C(OP_WRITE)] = {       -1,             -1      },
 384                 [C(OP_PREFETCH)] = {    -1,             -1      },
 385         },
 386         [C(BPU)] = {            /*      RESULT_ACCESS   RESULT_MISS */
 387                 [C(OP_READ)] = {        0x122,          0x41c   },
 388                 [C(OP_WRITE)] = {       -1,             -1      },
 389                 [C(OP_PREFETCH)] = {    -1,             -1      },
 390         },
 391 };
 392
 393 struct power_pmu mpc7450_pmu = {
 394         .name                   = "MPC7450 family",
 395         .n_counter              = N_COUNTER,
 396         .max_alternatives       = MAX_ALT,
 397         .add_fields             = 0x00111555ul,
 398         .test_adder             = 0x00301000ul,
 399         .compute_mmcr           = mpc7450_compute_mmcr,
 400         .get_constraint         = mpc7450_get_constraint,
 401         .get_alternatives       = mpc7450_get_alternatives,
 402         .disable_pmc            = mpc7450_disable_pmc,
 403         .n_generic              = ARRAY_SIZE(mpc7450_generic_events),
 404         .generic_events         = mpc7450_generic_events,
 405         .cache_events           = &mpc7450_cache_events,
 406 };
 407
 408 static int init_mpc7450_pmu(void)
 409 {
 410         if (!cur_cpu_spec->oprofile_cpu_type ||
 411             strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc/7450"))
 412                 return -ENODEV;
 413
 414         return register_power_pmu(&mpc7450_pmu);
 415 }
 416
 417 early_initcall(init_mpc7450_pmu);