arch/avr32/oprofile/op_model_avr32.c

   1 /*
   2  * AVR32 Performance Counter Driver
   3  *
   4  * Copyright (C) 2005-2007 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * Author: Ronny Pedersen
  11  */
  12 #include <linux/errno.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/irq.h>
  15 #include <linux/oprofile.h>
  16 #include <linux/sched.h>
  17 #include <linux/types.h>
  18
  19 #include <asm/sysreg.h>
  20 #include <asm/system.h>
  21
  22 #define AVR32_PERFCTR_IRQ_GROUP 0
  23 #define AVR32_PERFCTR_IRQ_LINE  1
  24
  25 void avr32_backtrace(struct pt_regs * const regs, unsigned int depth);
  26
  27 enum { PCCNT, PCNT0, PCNT1, NR_counter };
  28
  29 struct avr32_perf_counter {
  30         unsigned long   enabled;
  31         unsigned long   event;
  32         unsigned long   count;
  33         unsigned long   unit_mask;
  34         unsigned long   kernel;
  35         unsigned long   user;
  36
  37         u32             ie_mask;
  38         u32             flag_mask;
  39 };
  40
  41 static struct avr32_perf_counter counter[NR_counter] = {
  42         {
  43                 .ie_mask        = SYSREG_BIT(IEC),
  44                 .flag_mask      = SYSREG_BIT(FC),
  45         }, {
  46                 .ie_mask        = SYSREG_BIT(IE0),
  47                 .flag_mask      = SYSREG_BIT(F0),
  48         }, {
  49                 .ie_mask        = SYSREG_BIT(IE1),
  50                 .flag_mask      = SYSREG_BIT(F1),
  51         },
  52 };
  53
  54 static void avr32_perf_counter_reset(void)
  55 {
  56         /* Reset all counter and disable/clear all interrupts */
  57         sysreg_write(PCCR, (SYSREG_BIT(PCCR_R)
  58                                 | SYSREG_BIT(PCCR_C)
  59                                 | SYSREG_BIT(FC)
  60                                 | SYSREG_BIT(F0)
  61                                 | SYSREG_BIT(F1)));
  62 }
  63
  64 static irqreturn_t avr32_perf_counter_interrupt(int irq, void *dev_id)
  65 {
  66         struct avr32_perf_counter *ctr = dev_id;
  67         struct pt_regs *regs;
  68         u32 pccr;
  69
  70         if (likely(!(intc_get_pending(AVR32_PERFCTR_IRQ_GROUP)
  71                                         & (1 << AVR32_PERFCTR_IRQ_LINE))))
  72                 return IRQ_NONE;
  73
  74         regs = get_irq_regs();
  75         pccr = sysreg_read(PCCR);
  76
  77         /* Clear the interrupt flags we're about to handle */
  78         sysreg_write(PCCR, pccr);
  79
  80         /* PCCNT */
  81         if (ctr->enabled && (pccr & ctr->flag_mask)) {
  82                 sysreg_write(PCCNT, -ctr->count);
  83                 oprofile_add_sample(regs, PCCNT);
  84         }
  85         ctr++;
  86         /* PCNT0 */
  87         if (ctr->enabled && (pccr & ctr->flag_mask)) {
  88                 sysreg_write(PCNT0, -ctr->count);
  89                 oprofile_add_sample(regs, PCNT0);
  90         }
  91         ctr++;
  92         /* PCNT1 */
  93         if (ctr->enabled && (pccr & ctr->flag_mask)) {
  94                 sysreg_write(PCNT1, -ctr->count);
  95                 oprofile_add_sample(regs, PCNT1);
  96         }
  97
  98         return IRQ_HANDLED;
  99 }
 100
 101 static int avr32_perf_counter_create_files(struct super_block *sb,
 102                 struct dentry *root)
 103 {
 104         struct dentry *dir;
 105         unsigned int i;
 106         char filename[4];
 107
 108         for (i = 0; i < NR_counter; i++) {
 109                 snprintf(filename, sizeof(filename), "%u", i);
 110                 dir = oprofilefs_mkdir(sb, root, filename);
 111
 112                 oprofilefs_create_ulong(sb, dir, "enabled",
 113                                 &counter[i].enabled);
 114                 oprofilefs_create_ulong(sb, dir, "event",
 115                                 &counter[i].event);
 116                 oprofilefs_create_ulong(sb, dir, "count",
 117                                 &counter[i].count);
 118
 119                 /* Dummy entries */
 120                 oprofilefs_create_ulong(sb, dir, "kernel",
 121                                 &counter[i].kernel);
 122                 oprofilefs_create_ulong(sb, dir, "user",
 123                                 &counter[i].user);
 124                 oprofilefs_create_ulong(sb, dir, "unit_mask",
 125                                 &counter[i].unit_mask);
 126         }
 127
 128         return 0;
 129 }
 130
 131 static int avr32_perf_counter_setup(void)
 132 {
 133         struct avr32_perf_counter *ctr;
 134         u32 pccr;
 135         int ret;
 136         int i;
 137
 138         pr_debug("avr32_perf_counter_setup\n");
 139
 140         if (sysreg_read(PCCR) & SYSREG_BIT(PCCR_E)) {
 141                 printk(KERN_ERR
 142                         "oprofile: setup: perf counter already enabled\n");
 143                 return -EBUSY;
 144         }
 145
 146         ret = request_irq(AVR32_PERFCTR_IRQ_GROUP,
 147                         avr32_perf_counter_interrupt, IRQF_SHARED,
 148                         "oprofile", counter);
 149         if (ret)
 150                 return ret;
 151
 152         avr32_perf_counter_reset();
 153
 154         pccr = 0;
 155         for (i = PCCNT; i < NR_counter; i++) {
 156                 ctr = &counter[i];
 157                 if (!ctr->enabled)
 158                         continue;
 159
 160                 pr_debug("enabling counter %d...\n", i);
 161
 162                 pccr |= ctr->ie_mask;
 163
 164                 switch (i) {
 165                 case PCCNT:
 166                         /* PCCNT always counts cycles, so no events */
 167                         sysreg_write(PCCNT, -ctr->count);
 168                         break;
 169                 case PCNT0:
 170                         pccr |= SYSREG_BF(CONF0, ctr->event);
 171                         sysreg_write(PCNT0, -ctr->count);
 172                         break;
 173                 case PCNT1:
 174                         pccr |= SYSREG_BF(CONF1, ctr->event);
 175                         sysreg_write(PCNT1, -ctr->count);
 176                         break;
 177                 }
 178         }
 179
 180         pr_debug("oprofile: writing 0x%x to PCCR...\n", pccr);
 181
 182         sysreg_write(PCCR, pccr);
 183
 184         return 0;
 185 }
 186
 187 static void avr32_perf_counter_shutdown(void)
 188 {
 189         pr_debug("avr32_perf_counter_shutdown\n");
 190
 191         avr32_perf_counter_reset();
 192         free_irq(AVR32_PERFCTR_IRQ_GROUP, counter);
 193 }
 194
 195 static int avr32_perf_counter_start(void)
 196 {
 197         pr_debug("avr32_perf_counter_start\n");
 198
 199         sysreg_write(PCCR, sysreg_read(PCCR) | SYSREG_BIT(PCCR_E));
 200
 201         return 0;
 202 }
 203
 204 static void avr32_perf_counter_stop(void)
 205 {
 206         pr_debug("avr32_perf_counter_stop\n");
 207
 208         sysreg_write(PCCR, sysreg_read(PCCR) & ~SYSREG_BIT(PCCR_E));
 209 }
 210
 211 static struct oprofile_operations avr32_perf_counter_ops __initdata = {
 212         .create_files   = avr32_perf_counter_create_files,
 213         .setup          = avr32_perf_counter_setup,
 214         .shutdown       = avr32_perf_counter_shutdown,
 215         .start          = avr32_perf_counter_start,
 216         .stop           = avr32_perf_counter_stop,
 217         .cpu_type       = "avr32",
 218 };
 219
 220 int __init oprofile_arch_init(struct oprofile_operations *ops)
 221 {
 222         if (!(current_cpu_data.features & AVR32_FEATURE_PCTR))
 223                 return -ENODEV;
 224
 225         memcpy(ops, &avr32_perf_counter_ops,
 226                         sizeof(struct oprofile_operations));
 227
 228         ops->backtrace = avr32_backtrace;
 229
 230         printk(KERN_INFO "oprofile: using AVR32 performance monitoring.\n");
 231
 232         return 0;
 233 }
 234
 235 void oprofile_arch_exit(void)
 236 {
 237
 238 }