arch/mips/oprofile/op_model_rm9000.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2004 by Ralf Baechle
   7  */
   8 #include <linux/init.h>
   9 #include <linux/oprofile.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/smp.h>
  12
  13 #include "op_impl.h"
  14
  15 #define RM9K_COUNTER1_EVENT(event)      ((event) << 0)
  16 #define RM9K_COUNTER1_SUPERVISOR        (1ULL    <<  7)
  17 #define RM9K_COUNTER1_KERNEL            (1ULL    <<  8)
  18 #define RM9K_COUNTER1_USER              (1ULL    <<  9)
  19 #define RM9K_COUNTER1_ENABLE            (1ULL    << 10)
  20 #define RM9K_COUNTER1_OVERFLOW          (1ULL    << 15)
  21
  22 #define RM9K_COUNTER2_EVENT(event)      ((event) << 16)
  23 #define RM9K_COUNTER2_SUPERVISOR        (1ULL    << 23)
  24 #define RM9K_COUNTER2_KERNEL            (1ULL    << 24)
  25 #define RM9K_COUNTER2_USER              (1ULL    << 25)
  26 #define RM9K_COUNTER2_ENABLE            (1ULL    << 26)
  27 #define RM9K_COUNTER2_OVERFLOW          (1ULL    << 31)
  28
  29 extern unsigned int rm9000_perfcount_irq;
  30
  31 static struct rm9k_register_config {
  32         unsigned int control;
  33         unsigned int reset_counter1;
  34         unsigned int reset_counter2;
  35 } reg;
  36
  37 /* Compute all of the registers in preparation for enabling profiling.  */
  38
  39 static void rm9000_reg_setup(struct op_counter_config *ctr)
  40 {
  41         unsigned int control = 0;
  42
  43         /* Compute the performance counter control word.  */
  44         /* For now count kernel and user mode */
  45         if (ctr[0].enabled)
  46                 control |= RM9K_COUNTER1_EVENT(ctr[0].event) |
  47                            RM9K_COUNTER1_KERNEL |
  48                            RM9K_COUNTER1_USER |
  49                            RM9K_COUNTER1_ENABLE;
  50         if (ctr[1].enabled)
  51                 control |= RM9K_COUNTER2_EVENT(ctr[1].event) |
  52                            RM9K_COUNTER2_KERNEL |
  53                            RM9K_COUNTER2_USER |
  54                            RM9K_COUNTER2_ENABLE;
  55         reg.control = control;
  56
  57         reg.reset_counter1 = 0x80000000 - ctr[0].count;
  58         reg.reset_counter2 = 0x80000000 - ctr[1].count;
  59 }
  60
  61 /* Program all of the registers in preparation for enabling profiling.  */
  62
  63 static void rm9000_cpu_setup(void *args)
  64 {
  65         uint64_t perfcount;
  66
  67         perfcount = ((uint64_t) reg.reset_counter2 << 32) | reg.reset_counter1;
  68         write_c0_perfcount(perfcount);
  69 }
  70
  71 static void rm9000_cpu_start(void *args)
  72 {
  73         /* Start all counters on current CPU */
  74         write_c0_perfcontrol(reg.control);
  75 }
  76
  77 static void rm9000_cpu_stop(void *args)
  78 {
  79         /* Stop all counters on current CPU */
  80         write_c0_perfcontrol(0);
  81 }
  82
  83 static irqreturn_t rm9000_perfcount_handler(int irq, void *dev_id)
  84 {
  85         unsigned int control = read_c0_perfcontrol();
  86         struct pt_regs *regs = get_irq_regs();
  87         uint32_t counter1, counter2;
  88         uint64_t counters;
  89
  90         /*
  91          * RM9000 combines two 32-bit performance counters into a single
  92          * 64-bit coprocessor zero register.  To avoid a race updating the
  93          * registers we need to stop the counters while we're messing with
  94          * them ...
  95          */
  96         write_c0_perfcontrol(0);
  97
  98         counters = read_c0_perfcount();
  99         counter1 = counters;
 100         counter2 = counters >> 32;
 101
 102         if (control & RM9K_COUNTER1_OVERFLOW) {
 103                 oprofile_add_sample(regs, 0);
 104                 counter1 = reg.reset_counter1;
 105         }
 106         if (control & RM9K_COUNTER2_OVERFLOW) {
 107                 oprofile_add_sample(regs, 1);
 108                 counter2 = reg.reset_counter2;
 109         }
 110
 111         counters = ((uint64_t)counter2 << 32) | counter1;
 112         write_c0_perfcount(counters);
 113         write_c0_perfcontrol(reg.control);
 114
 115         return IRQ_HANDLED;
 116 }
 117
 118 static int __init rm9000_init(void)
 119 {
 120         return request_irq(rm9000_perfcount_irq, rm9000_perfcount_handler,
 121                            0, "Perfcounter", NULL);
 122 }
 123
 124 static void rm9000_exit(void)
 125 {
 126         free_irq(rm9000_perfcount_irq, NULL);
 127 }
 128
 129 struct op_mips_model op_model_rm9000_ops = {
 130         .reg_setup      = rm9000_reg_setup,
 131         .cpu_setup      = rm9000_cpu_setup,
 132         .init           = rm9000_init,
 133         .exit           = rm9000_exit,
 134         .cpu_start      = rm9000_cpu_start,
 135         .cpu_stop       = rm9000_cpu_stop,
 136         .cpu_type       = "mips/rm9000",
 137         .num_counters   = 2
 138 };