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   1 /*
   2  * arch/sh/oprofile/op_model_sh7750.c
   3  *
   4  * OProfile support for SH7750/SH7750S Performance Counters
   5  *
   6  * Copyright (C) 2003, 2004  Paul Mundt
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12 #include <linux/kernel.h>
  13 #include <linux/oprofile.h>
  14 #include <linux/profile.h>
  15 #include <linux/init.h>
  16 #include <linux/errno.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/fs.h>
  19 #include <asm/uaccess.h>
  20 #include <asm/io.h>
  21
  22 #define PM_CR_BASE      0xff000084      /* 16-bit */
  23 #define PM_CTR_BASE     0xff100004      /* 32-bit */
  24
  25 #define PMCR1           (PM_CR_BASE  + 0x00)
  26 #define PMCR2           (PM_CR_BASE  + 0x04)
  27 #define PMCTR1H         (PM_CTR_BASE + 0x00)
  28 #define PMCTR1L         (PM_CTR_BASE + 0x04)
  29 #define PMCTR2H         (PM_CTR_BASE + 0x08)
  30 #define PMCTR2L         (PM_CTR_BASE + 0x0c)
  31
  32 #define PMCR_PMM_MASK   0x0000003f
  33
  34 #define PMCR_CLKF       0x00000100
  35 #define PMCR_PMCLR      0x00002000
  36 #define PMCR_PMST       0x00004000
  37 #define PMCR_PMEN       0x00008000
  38
  39 #define PMCR_ENABLE     (PMCR_PMST | PMCR_PMEN)
  40
  41 /*
  42  * SH7750/SH7750S have 2 perf counters
  43  */
  44 #define NR_CNTRS        2
  45
  46 struct op_counter_config {
  47         unsigned long enabled;
  48         unsigned long event;
  49         unsigned long count;
  50
  51         /* Dummy values for userspace tool compliance */
  52         unsigned long kernel;
  53         unsigned long user;
  54         unsigned long unit_mask;
  55 };
  56
  57 static struct op_counter_config ctr[NR_CNTRS];
  58
  59 /*
  60  * There are a number of events supported by each counter (33 in total).
  61  * Since we have 2 counters, each counter will take the event code as it
  62  * corresponds to the PMCR PMM setting. Each counter can be configured
  63  * independently.
  64  *
  65  *      Event Code      Description
  66  *      ----------      -----------
  67  *
  68  *      0x01            Operand read access
  69  *      0x02            Operand write access
  70  *      0x03            UTLB miss
  71  *      0x04            Operand cache read miss
  72  *      0x05            Operand cache write miss
  73  *      0x06            Instruction fetch (w/ cache)
  74  *      0x07            Instruction TLB miss
  75  *      0x08            Instruction cache miss
  76  *      0x09            All operand accesses
  77  *      0x0a            All instruction accesses
  78  *      0x0b            OC RAM operand access
  79  *      0x0d            On-chip I/O space access
  80  *      0x0e            Operand access (r/w)
  81  *      0x0f            Operand cache miss (r/w)
  82  *      0x10            Branch instruction
  83  *      0x11            Branch taken
  84  *      0x12            BSR/BSRF/JSR
  85  *      0x13            Instruction execution
  86  *      0x14            Instruction execution in parallel
  87  *      0x15            FPU Instruction execution
  88  *      0x16            Interrupt
  89  *      0x17            NMI
  90  *      0x18            trapa instruction execution
  91  *      0x19            UBCA match
  92  *      0x1a            UBCB match
  93  *      0x21            Instruction cache fill
  94  *      0x22            Operand cache fill
  95  *      0x23            Elapsed time
  96  *      0x24            Pipeline freeze by I-cache miss
  97  *      0x25            Pipeline freeze by D-cache miss
  98  *      0x27            Pipeline freeze by branch instruction
  99  *      0x28            Pipeline freeze by CPU register
 100  *      0x29            Pipeline freeze by FPU
 101  *
 102  * Unfortunately we don't have a native exception or interrupt for counter
 103  * overflow (although since these counters can run for 16.3 days without
 104  * overflowing, it's not really necessary).
 105  *
 106  * OProfile on the other hand likes to have samples taken periodically, so
 107  * for now we just piggyback the timer interrupt to get the expected
 108  * behavior.
 109  */
 110
 111 static int sh7750_timer_notify(struct pt_regs *regs)
 112 {
 113         oprofile_add_sample(regs, 0);
 114         return 0;
 115 }
 116
 117 static u64 sh7750_read_counter(int counter)
 118 {
 119         u32 hi, lo;
 120
 121         hi = (counter == 0) ? ctrl_inl(PMCTR1H) : ctrl_inl(PMCTR2H);
 122         lo = (counter == 0) ? ctrl_inl(PMCTR1L) : ctrl_inl(PMCTR2L);
 123
 124         return (u64)((u64)(hi & 0xffff) << 32) | lo;
 125 }
 126
 127 /*
 128  * Files will be in a path like:
 129  *
 130  *  /<oprofilefs mount point>/<counter number>/<file>
 131  *
 132  * So when dealing with <file>, we look to the parent dentry for the counter
 133  * number.
 134  */
 135 static inline int to_counter(struct file *file)
 136 {
 137         const unsigned char *name = file->f_path.dentry->d_parent->d_name.name;
 138
 139         return (int)simple_strtol(name, NULL, 10);
 140 }
 141
 142 /*
 143  * XXX: We have 48-bit counters, so we're probably going to want something
 144  * more along the lines of oprofilefs_ullong_to_user().. Truncating to
 145  * unsigned long works fine for now though, as long as we don't attempt to
 146  * profile for too horribly long.
 147  */
 148 static ssize_t sh7750_read_count(struct file *file, char __user *buf,
 149                                  size_t count, loff_t *ppos)
 150 {
 151         int counter = to_counter(file);
 152         u64 val = sh7750_read_counter(counter);
 153
 154         return oprofilefs_ulong_to_user((unsigned long)val, buf, count, ppos);
 155 }
 156
 157 static ssize_t sh7750_write_count(struct file *file, const char __user *buf,
 158                                   size_t count, loff_t *ppos)
 159 {
 160         int counter = to_counter(file);
 161         unsigned long val;
 162
 163         if (oprofilefs_ulong_from_user(&val, buf, count))
 164                 return -EFAULT;
 165
 166         /*
 167          * Any write will clear the counter, although only 0 should be
 168          * written for this purpose, as we do not support setting the
 169          * counter to an arbitrary value.
 170          */
 171         WARN_ON(val != 0);
 172
 173         if (counter == 0) {
 174                 ctrl_outw(ctrl_inw(PMCR1) | PMCR_PMCLR, PMCR1);
 175         } else {
 176                 ctrl_outw(ctrl_inw(PMCR2) | PMCR_PMCLR, PMCR2);
 177         }
 178
 179         return count;
 180 }
 181
 182 static const struct file_operations count_fops = {
 183         .read           = sh7750_read_count,
 184         .write          = sh7750_write_count,
 185 };
 186
 187 static int sh7750_perf_counter_create_files(struct super_block *sb, struct dentry *root)
 188 {
 189         int i;
 190
 191         for (i = 0; i < NR_CNTRS; i++) {
 192                 struct dentry *dir;
 193                 char buf[4];
 194
 195                 snprintf(buf, sizeof(buf), "%d", i);
 196                 dir = oprofilefs_mkdir(sb, root, buf);
 197
 198                 oprofilefs_create_ulong(sb, dir, "enabled", &ctr[i].enabled);
 199                 oprofilefs_create_ulong(sb, dir, "event", &ctr[i].event);
 200                 oprofilefs_create_file(sb, dir, "count", &count_fops);
 201
 202                 /* Dummy entries */
 203                 oprofilefs_create_ulong(sb, dir, "kernel", &ctr[i].kernel);
 204                 oprofilefs_create_ulong(sb, dir, "user", &ctr[i].user);
 205                 oprofilefs_create_ulong(sb, dir, "unit_mask", &ctr[i].unit_mask);
 206         }
 207
 208         return 0;
 209 }
 210
 211 static int sh7750_perf_counter_start(void)
 212 {
 213         u16 pmcr;
 214
 215         /* Enable counter 1 */
 216         if (ctr[0].enabled) {
 217                 pmcr = ctrl_inw(PMCR1);
 218                 WARN_ON(pmcr & PMCR_PMEN);
 219
 220                 pmcr &= ~PMCR_PMM_MASK;
 221                 pmcr |= ctr[0].event;
 222                 ctrl_outw(pmcr | PMCR_ENABLE, PMCR1);
 223         }
 224
 225         /* Enable counter 2 */
 226         if (ctr[1].enabled) {
 227                 pmcr = ctrl_inw(PMCR2);
 228                 WARN_ON(pmcr & PMCR_PMEN);
 229
 230                 pmcr &= ~PMCR_PMM_MASK;
 231                 pmcr |= ctr[1].event;
 232                 ctrl_outw(pmcr | PMCR_ENABLE, PMCR2);
 233         }
 234
 235         return register_timer_hook(sh7750_timer_notify);
 236 }
 237
 238 static void sh7750_perf_counter_stop(void)
 239 {
 240         ctrl_outw(ctrl_inw(PMCR1) & ~PMCR_PMEN, PMCR1);
 241         ctrl_outw(ctrl_inw(PMCR2) & ~PMCR_PMEN, PMCR2);
 242
 243         unregister_timer_hook(sh7750_timer_notify);
 244 }
 245
 246 static struct oprofile_operations sh7750_perf_counter_ops = {
 247         .create_files   = sh7750_perf_counter_create_files,
 248         .start          = sh7750_perf_counter_start,
 249         .stop           = sh7750_perf_counter_stop,
 250 };
 251
 252 int __init oprofile_arch_init(struct oprofile_operations *ops)
 253 {
 254         if (!(current_cpu_data.flags & CPU_HAS_PERF_COUNTER))
 255                 return -ENODEV;
 256
 257         ops = &sh7750_perf_counter_ops;
 258         ops->cpu_type = (char *)get_cpu_subtype(&current_cpu_data);
 259
 260         printk(KERN_INFO "oprofile: using SH-4 (%s) performance monitoring.\n",
 261                sh7750_perf_counter_ops.cpu_type);
 262
 263         /* Clear the counters */
 264         ctrl_outw(ctrl_inw(PMCR1) | PMCR_PMCLR, PMCR1);
 265         ctrl_outw(ctrl_inw(PMCR2) | PMCR_PMCLR, PMCR2);
 266
 267         return 0;
 268 }
 269
 270 void oprofile_arch_exit(void)
 271 {
 272 }
 273