arch/alpha/oprofile/op_model_ev67.c

   1 /**
   2  * @file arch/alpha/oprofile/op_model_ev67.c
   3  *
   4  * @remark Copyright 2002 OProfile authors
   5  * @remark Read the file COPYING
   6  *
   7  * @author Richard Henderson <rth@twiddle.net>
   8  * @author Falk Hueffner <falk@debian.org>
   9  */
  10
  11 #include <linux/oprofile.h>
  12 #include <linux/init.h>
  13 #include <linux/smp.h>
  14 #include <asm/ptrace.h>
  15 #include <asm/system.h>
  16
  17 #include "op_impl.h"
  18
  19
  20 /* Compute all of the registers in preparation for enabling profiling.  */
  21
  22 static void
  23 ev67_reg_setup(struct op_register_config *reg,
  24                struct op_counter_config *ctr,
  25                struct op_system_config *sys)
  26 {
  27         unsigned long ctl, reset, need_reset, i;
  28
  29         /* Select desired events.  */
  30         ctl = 1UL << 4;         /* Enable ProfileMe mode. */
  31
  32         /* The event numbers are chosen so we can use them directly if
  33            PCTR1 is enabled.  */
  34         if (ctr[1].enabled) {
  35                 ctl |= (ctr[1].event & 3) << 2;
  36         } else {
  37                 if (ctr[0].event == 0) /* cycles */
  38                         ctl |= 1UL << 2;
  39         }
  40         reg->mux_select = ctl;
  41
  42         /* Select logging options.  */
  43         /* ??? Need to come up with some mechanism to trace only
  44            selected processes.  EV67 does not have a mechanism to
  45            select kernel or user mode only.  For now, enable always.  */
  46         reg->proc_mode = 0;
  47
  48         /* EV67 cannot change the width of the counters as with the
  49            other implementations.  But fortunately, we can write to
  50            the counters and set the value such that it will overflow
  51            at the right time.  */
  52         reset = need_reset = 0;
  53         for (i = 0; i < 2; ++i) {
  54                 unsigned long count = ctr[i].count;
  55                 if (!ctr[i].enabled)
  56                         continue;
  57
  58                 if (count > 0x100000)
  59                         count = 0x100000;
  60                 ctr[i].count = count;
  61                 reset |= (0x100000 - count) << (i ? 6 : 28);
  62                 if (count != 0x100000)
  63                         need_reset |= 1 << i;
  64         }
  65         reg->reset_values = reset;
  66         reg->need_reset = need_reset;
  67 }
  68
  69 /* Program all of the registers in preparation for enabling profiling.  */
  70
  71 static void
  72 ev67_cpu_setup (void *x)
  73 {
  74         struct op_register_config *reg = x;
  75
  76         wrperfmon(2, reg->mux_select);
  77         wrperfmon(3, reg->proc_mode);
  78         wrperfmon(6, reg->reset_values | 3);
  79 }
  80
  81 /* CTR is a counter for which the user has requested an interrupt count
  82    in between one of the widths selectable in hardware.  Reset the count
  83    for CTR to the value stored in REG->RESET_VALUES.  */
  84
  85 static void
  86 ev67_reset_ctr(struct op_register_config *reg, unsigned long ctr)
  87 {
  88         wrperfmon(6, reg->reset_values | (1 << ctr));
  89 }
  90
  91 /* ProfileMe conditions which will show up as counters. We can also
  92    detect the following, but it seems unlikely that anybody is
  93    interested in counting them:
  94     * Reset
  95     * MT_FPCR (write to floating point control register)
  96     * Arithmetic trap
  97     * Dstream Fault
  98     * Machine Check (ECC fault, etc.)
  99     * OPCDEC (illegal opcode)
 100     * Floating point disabled
 101     * Differentiate between DTB single/double misses and 3 or 4 level
 102       page tables
 103     * Istream access violation
 104     * Interrupt
 105     * Icache Parity Error.
 106     * Instruction killed (nop, trapb)
 107
 108    Unfortunately, there seems to be no way to detect Dcache and Bcache
 109    misses; the latter could be approximated by making the counter
 110    count Bcache misses, but that is not precise.
 111
 112    We model this as 20 counters:
 113     * PCTR0
 114     * PCTR1
 115     * 9 ProfileMe events, induced by PCTR0
 116     * 9 ProfileMe events, induced by PCTR1
 117 */
 118
 119 enum profileme_counters {
 120         PM_STALLED,             /* Stalled for at least one cycle
 121                                    between the fetch and map stages  */
 122         PM_TAKEN,               /* Conditional branch taken */
 123         PM_MISPREDICT,          /* Branch caused mispredict trap */
 124         PM_ITB_MISS,            /* ITB miss */
 125         PM_DTB_MISS,            /* DTB miss */
 126         PM_REPLAY,              /* Replay trap */
 127         PM_LOAD_STORE,          /* Load-store order trap */
 128         PM_ICACHE_MISS,         /* Icache miss */
 129         PM_UNALIGNED,           /* Unaligned Load/Store */
 130         PM_NUM_COUNTERS
 131 };
 132
 133 static inline void
 134 op_add_pm(unsigned long pc, int kern, unsigned long counter,
 135           struct op_counter_config *ctr, unsigned long event)
 136 {
 137         unsigned long fake_counter = 2 + event;
 138         if (counter == 1)
 139                 fake_counter += PM_NUM_COUNTERS;
 140         if (ctr[fake_counter].enabled)
 141                 oprofile_add_pc(pc, kern, fake_counter);
 142 }
 143
 144 static void
 145 ev67_handle_interrupt(unsigned long which, struct pt_regs *regs,
 146                       struct op_counter_config *ctr)
 147 {
 148         unsigned long pmpc, pctr_ctl;
 149         int kern = !user_mode(regs);
 150         int mispredict = 0;
 151         union {
 152                 unsigned long v;
 153                 struct {
 154                         unsigned reserved:      30; /*  0-29 */
 155                         unsigned overcount:      3; /* 30-32 */
 156                         unsigned icache_miss:    1; /*    33 */
 157                         unsigned trap_type:      4; /* 34-37 */
 158                         unsigned load_store:     1; /*    38 */
 159                         unsigned trap:           1; /*    39 */
 160                         unsigned mispredict:     1; /*    40 */
 161                 } fields;
 162         } i_stat;
 163
 164         enum trap_types {
 165                 TRAP_REPLAY,
 166                 TRAP_INVALID0,
 167                 TRAP_DTB_DOUBLE_MISS_3,
 168                 TRAP_DTB_DOUBLE_MISS_4,
 169                 TRAP_FP_DISABLED,
 170                 TRAP_UNALIGNED,
 171                 TRAP_DTB_SINGLE_MISS,
 172                 TRAP_DSTREAM_FAULT,
 173                 TRAP_OPCDEC,
 174                 TRAP_INVALID1,
 175                 TRAP_MACHINE_CHECK,
 176                 TRAP_INVALID2,
 177                 TRAP_ARITHMETIC,
 178                 TRAP_INVALID3,
 179                 TRAP_MT_FPCR,
 180                 TRAP_RESET
 181         };
 182
 183         pmpc = wrperfmon(9, 0);
 184         /* ??? Don't know how to handle physical-mode PALcode address.  */
 185         if (pmpc & 1)
 186                 return;
 187         pmpc &= ~2;             /* clear reserved bit */
 188
 189         i_stat.v = wrperfmon(8, 0);
 190         if (i_stat.fields.trap) {
 191                 switch (i_stat.fields.trap_type) {
 192                 case TRAP_INVALID1:
 193                 case TRAP_INVALID2:
 194                 case TRAP_INVALID3:
 195                         /* Pipeline redirection ocurred. PMPC points
 196                            to PALcode. Recognize ITB miss by PALcode
 197                            offset address, and get actual PC from
 198                            EXC_ADDR.  */
 199                         oprofile_add_pc(regs->pc, kern, which);
 200                         if ((pmpc & ((1 << 15) - 1)) ==  581)
 201                                 op_add_pm(regs->pc, kern, which,
 202                                           ctr, PM_ITB_MISS);
 203                         /* Most other bit and counter values will be
 204                            those for the first instruction in the
 205                            fault handler, so we're done.  */
 206                         return;
 207                 case TRAP_REPLAY:
 208                         op_add_pm(pmpc, kern, which, ctr,
 209                                   (i_stat.fields.load_store
 210                                    ? PM_LOAD_STORE : PM_REPLAY));
 211                         break;
 212                 case TRAP_DTB_DOUBLE_MISS_3:
 213                 case TRAP_DTB_DOUBLE_MISS_4:
 214                 case TRAP_DTB_SINGLE_MISS:
 215                         op_add_pm(pmpc, kern, which, ctr, PM_DTB_MISS);
 216                         break;
 217                 case TRAP_UNALIGNED:
 218                         op_add_pm(pmpc, kern, which, ctr, PM_UNALIGNED);
 219                         break;
 220                 case TRAP_INVALID0:
 221                 case TRAP_FP_DISABLED:
 222                 case TRAP_DSTREAM_FAULT:
 223                 case TRAP_OPCDEC:
 224                 case TRAP_MACHINE_CHECK:
 225                 case TRAP_ARITHMETIC:
 226                 case TRAP_MT_FPCR:
 227                 case TRAP_RESET:
 228                         break;
 229                 }
 230
 231                 /* ??? JSR/JMP/RET/COR or HW_JSR/HW_JMP/HW_RET/HW_COR
 232                    mispredicts do not set this bit but can be
 233                    recognized by the presence of one of these
 234                    instructions at the PMPC location with bit 39
 235                    set.  */
 236                 if (i_stat.fields.mispredict) {
 237                         mispredict = 1;
 238                         op_add_pm(pmpc, kern, which, ctr, PM_MISPREDICT);
 239                 }
 240         }
 241
 242         oprofile_add_pc(pmpc, kern, which);
 243
 244         pctr_ctl = wrperfmon(5, 0);
 245         if (pctr_ctl & (1UL << 27))
 246                 op_add_pm(pmpc, kern, which, ctr, PM_STALLED);
 247
 248         /* Unfortunately, TAK is undefined on mispredicted branches.
 249            ??? It is also undefined for non-cbranch insns, should
 250            check that.  */
 251         if (!mispredict && pctr_ctl & (1UL << 0))
 252                 op_add_pm(pmpc, kern, which, ctr, PM_TAKEN);
 253 }
 254
 255 struct op_axp_model op_model_ev67 = {
 256         .reg_setup              = ev67_reg_setup,
 257         .cpu_setup              = ev67_cpu_setup,
 258         .reset_ctr              = ev67_reset_ctr,
 259         .handle_interrupt       = ev67_handle_interrupt,
 260         .cpu_type               = "alpha/ev67",
 261         .num_counters           = 20,
 262         .can_set_proc_mode      = 0,
 263 };