* arch/s390/oprofile/init.c
*
* S390 Version
- * Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Copyright (C) 2002-2011 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Thomas Spatzier (tspat@de.ibm.com)
* Author(s): Mahesh Salgaonkar (mahesh@linux.vnet.ibm.com)
* Author(s): Heinz Graalfs (graalfs@linux.vnet.ibm.com)
+ * Author(s): Andreas Krebbel (krebbel@linux.vnet.ibm.com)
*
* @remark Copyright 2002-2011 OProfile authors
*/
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/fs.h>
+#include <linux/module.h>
+#include <asm/processor.h>
#include "../../../drivers/oprofile/oprof.h"
#ifdef CONFIG_64BIT
#include "hwsampler.h"
+#include "op_counter.h"
#define DEFAULT_INTERVAL 4127518
static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS;
static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS;
-static int hwsampler_file;
+static int hwsampler_enabled;
static int hwsampler_running; /* start_mutex must be held to change */
+static int hwsampler_available;
static struct oprofile_operations timer_ops;
+struct op_counter_config counter_config;
+
+enum __force_cpu_type {
+ reserved = 0, /* do not force */
+ timer,
+};
+static int force_cpu_type;
+
+static int set_cpu_type(const char *str, struct kernel_param *kp)
+{
+ if (!strcmp(str, "timer")) {
+ force_cpu_type = timer;
+ printk(KERN_INFO "oprofile: forcing timer to be returned "
+ "as cpu type\n");
+ } else {
+ force_cpu_type = 0;
+ }
+
+ return 0;
+}
+module_param_call(cpu_type, set_cpu_type, NULL, NULL, 0);
+MODULE_PARM_DESC(cpu_type, "Force legacy basic mode sampling"
+ "(report cpu_type \"timer\"");
+
static int oprofile_hwsampler_start(void)
{
int retval;
- hwsampler_running = hwsampler_file;
+ hwsampler_running = hwsampler_enabled;
if (!hwsampler_running)
return timer_ops.start();
return;
}
+/*
+ * File ops used for:
+ * /dev/oprofile/0/enabled
+ * /dev/oprofile/hwsampling/hwsampler (cpu_type = timer)
+ */
+
static ssize_t hwsampler_read(struct file *file, char __user *buf,
size_t count, loff_t *offset)
{
- return oprofilefs_ulong_to_user(hwsampler_file, buf, count, offset);
+ return oprofilefs_ulong_to_user(hwsampler_enabled, buf, count, offset);
}
static ssize_t hwsampler_write(struct file *file, char const __user *buf,
if (retval)
return retval;
+ if (val != 0 && val != 1)
+ return -EINVAL;
+
if (oprofile_started)
/*
* save to do without locking as we set
*/
return -EBUSY;
- hwsampler_file = val;
+ hwsampler_enabled = val;
return count;
}
.write = hwsampler_write,
};
+/*
+ * File ops used for:
+ * /dev/oprofile/0/count
+ * /dev/oprofile/hwsampling/hw_interval (cpu_type = timer)
+ *
+ * Make sure that the value is within the hardware range.
+ */
+
+static ssize_t hw_interval_read(struct file *file, char __user *buf,
+ size_t count, loff_t *offset)
+{
+ return oprofilefs_ulong_to_user(oprofile_hw_interval, buf,
+ count, offset);
+}
+
+static ssize_t hw_interval_write(struct file *file, char const __user *buf,
+ size_t count, loff_t *offset)
+{
+ unsigned long val;
+ int retval;
+
+ if (*offset)
+ return -EINVAL;
+ retval = oprofilefs_ulong_from_user(&val, buf, count);
+ if (retval)
+ return retval;
+ if (val < oprofile_min_interval)
+ oprofile_hw_interval = oprofile_min_interval;
+ else if (val > oprofile_max_interval)
+ oprofile_hw_interval = oprofile_max_interval;
+ else
+ oprofile_hw_interval = val;
+
+ return count;
+}
+
+static const struct file_operations hw_interval_fops = {
+ .read = hw_interval_read,
+ .write = hw_interval_write,
+};
+
+/*
+ * File ops used for:
+ * /dev/oprofile/0/event
+ * Only a single event with number 0 is supported with this counter.
+ *
+ * /dev/oprofile/0/unit_mask
+ * This is a dummy file needed by the user space tools.
+ * No value other than 0 is accepted or returned.
+ */
+
+static ssize_t hwsampler_zero_read(struct file *file, char __user *buf,
+ size_t count, loff_t *offset)
+{
+ return oprofilefs_ulong_to_user(0, buf, count, offset);
+}
+
+static ssize_t hwsampler_zero_write(struct file *file, char const __user *buf,
+ size_t count, loff_t *offset)
+{
+ unsigned long val;
+ int retval;
+
+ if (*offset)
+ return -EINVAL;
+
+ retval = oprofilefs_ulong_from_user(&val, buf, count);
+ if (retval)
+ return retval;
+ if (val != 0)
+ return -EINVAL;
+ return count;
+}
+
+static const struct file_operations zero_fops = {
+ .read = hwsampler_zero_read,
+ .write = hwsampler_zero_write,
+};
+
+/* /dev/oprofile/0/kernel file ops. */
+
+static ssize_t hwsampler_kernel_read(struct file *file, char __user *buf,
+ size_t count, loff_t *offset)
+{
+ return oprofilefs_ulong_to_user(counter_config.kernel,
+ buf, count, offset);
+}
+
+static ssize_t hwsampler_kernel_write(struct file *file, char const __user *buf,
+ size_t count, loff_t *offset)
+{
+ unsigned long val;
+ int retval;
+
+ if (*offset)
+ return -EINVAL;
+
+ retval = oprofilefs_ulong_from_user(&val, buf, count);
+ if (retval)
+ return retval;
+
+ if (val != 0 && val != 1)
+ return -EINVAL;
+
+ counter_config.kernel = val;
+
+ return count;
+}
+
+static const struct file_operations kernel_fops = {
+ .read = hwsampler_kernel_read,
+ .write = hwsampler_kernel_write,
+};
+
+/* /dev/oprofile/0/user file ops. */
+
+static ssize_t hwsampler_user_read(struct file *file, char __user *buf,
+ size_t count, loff_t *offset)
+{
+ return oprofilefs_ulong_to_user(counter_config.user,
+ buf, count, offset);
+}
+
+static ssize_t hwsampler_user_write(struct file *file, char const __user *buf,
+ size_t count, loff_t *offset)
+{
+ unsigned long val;
+ int retval;
+
+ if (*offset)
+ return -EINVAL;
+
+ retval = oprofilefs_ulong_from_user(&val, buf, count);
+ if (retval)
+ return retval;
+
+ if (val != 0 && val != 1)
+ return -EINVAL;
+
+ counter_config.user = val;
+
+ return count;
+}
+
+static const struct file_operations user_fops = {
+ .read = hwsampler_user_read,
+ .write = hwsampler_user_write,
+};
+
+
+/*
+ * File ops used for: /dev/oprofile/timer/enabled
+ * The value always has to be the inverted value of hwsampler_enabled. So
+ * no separate variable is created. That way we do not need locking.
+ */
+
+static ssize_t timer_enabled_read(struct file *file, char __user *buf,
+ size_t count, loff_t *offset)
+{
+ return oprofilefs_ulong_to_user(!hwsampler_enabled, buf, count, offset);
+}
+
+static ssize_t timer_enabled_write(struct file *file, char const __user *buf,
+ size_t count, loff_t *offset)
+{
+ unsigned long val;
+ int retval;
+
+ if (*offset)
+ return -EINVAL;
+
+ retval = oprofilefs_ulong_from_user(&val, buf, count);
+ if (retval)
+ return retval;
+
+ if (val != 0 && val != 1)
+ return -EINVAL;
+
+ /* Timer cannot be disabled without having hardware sampling. */
+ if (val == 0 && !hwsampler_available)
+ return -EINVAL;
+
+ if (oprofile_started)
+ /*
+ * save to do without locking as we set
+ * hwsampler_running in start() when start_mutex is
+ * held
+ */
+ return -EBUSY;
+
+ hwsampler_enabled = !val;
+
+ return count;
+}
+
+static const struct file_operations timer_enabled_fops = {
+ .read = timer_enabled_read,
+ .write = timer_enabled_write,
+};
+
+
static int oprofile_create_hwsampling_files(struct super_block *sb,
- struct dentry *root)
+ struct dentry *root)
{
- struct dentry *hw_dir;
+ struct dentry *dir;
+
+ dir = oprofilefs_mkdir(sb, root, "timer");
+ if (!dir)
+ return -EINVAL;
+
+ oprofilefs_create_file(sb, dir, "enabled", &timer_enabled_fops);
+
+ if (!hwsampler_available)
+ return 0;
/* reinitialize default values */
- hwsampler_file = 1;
+ hwsampler_enabled = 1;
+ counter_config.kernel = 1;
+ counter_config.user = 1;
- hw_dir = oprofilefs_mkdir(sb, root, "hwsampling");
- if (!hw_dir)
- return -EINVAL;
+ if (!force_cpu_type) {
+ /*
+ * Create the counter file system. A single virtual
+ * counter is created which can be used to
+ * enable/disable hardware sampling dynamically from
+ * user space. The user space will configure a single
+ * counter with a single event. The value of 'event'
+ * and 'unit_mask' are not evaluated by the kernel code
+ * and can only be set to 0.
+ */
+
+ dir = oprofilefs_mkdir(sb, root, "0");
+ if (!dir)
+ return -EINVAL;
- oprofilefs_create_file(sb, hw_dir, "hwsampler", &hwsampler_fops);
- oprofilefs_create_ulong(sb, hw_dir, "hw_interval",
- &oprofile_hw_interval);
- oprofilefs_create_ro_ulong(sb, hw_dir, "hw_min_interval",
- &oprofile_min_interval);
- oprofilefs_create_ro_ulong(sb, hw_dir, "hw_max_interval",
- &oprofile_max_interval);
- oprofilefs_create_ulong(sb, hw_dir, "hw_sdbt_blocks",
- &oprofile_sdbt_blocks);
+ oprofilefs_create_file(sb, dir, "enabled", &hwsampler_fops);
+ oprofilefs_create_file(sb, dir, "event", &zero_fops);
+ oprofilefs_create_file(sb, dir, "count", &hw_interval_fops);
+ oprofilefs_create_file(sb, dir, "unit_mask", &zero_fops);
+ oprofilefs_create_file(sb, dir, "kernel", &kernel_fops);
+ oprofilefs_create_file(sb, dir, "user", &user_fops);
+ oprofilefs_create_ulong(sb, dir, "hw_sdbt_blocks",
+ &oprofile_sdbt_blocks);
+ } else {
+ /*
+ * Hardware sampling can be used but the cpu_type is
+ * forced to timer in order to deal with legacy user
+ * space tools. The /dev/oprofile/hwsampling fs is
+ * provided in that case.
+ */
+ dir = oprofilefs_mkdir(sb, root, "hwsampling");
+ if (!dir)
+ return -EINVAL;
+
+ oprofilefs_create_file(sb, dir, "hwsampler",
+ &hwsampler_fops);
+ oprofilefs_create_file(sb, dir, "hw_interval",
+ &hw_interval_fops);
+ oprofilefs_create_ro_ulong(sb, dir, "hw_min_interval",
+ &oprofile_min_interval);
+ oprofilefs_create_ro_ulong(sb, dir, "hw_max_interval",
+ &oprofile_max_interval);
+ oprofilefs_create_ulong(sb, dir, "hw_sdbt_blocks",
+ &oprofile_sdbt_blocks);
+ }
return 0;
}
static int oprofile_hwsampler_init(struct oprofile_operations *ops)
{
+ /*
+ * Initialize the timer mode infrastructure as well in order
+ * to be able to switch back dynamically. oprofile_timer_init
+ * is not supposed to fail.
+ */
+ if (oprofile_timer_init(ops))
+ BUG();
+
+ memcpy(&timer_ops, ops, sizeof(timer_ops));
+ ops->create_files = oprofile_create_hwsampling_files;
+
+ /*
+ * If the user space tools do not support newer cpu types,
+ * the force_cpu_type module parameter
+ * can be used to always return \"timer\" as cpu type.
+ */
+ if (force_cpu_type != timer) {
+ struct cpuid id;
+
+ get_cpu_id (&id);
+
+ switch (id.machine) {
+ case 0x2097: case 0x2098: ops->cpu_type = "s390/z10"; break;
+ case 0x2817: case 0x2818: ops->cpu_type = "s390/z196"; break;
+ default: return -ENODEV;
+ }
+ }
+
if (hwsampler_setup())
return -ENODEV;
/*
- * create hwsampler files only if hwsampler_setup() succeeds.
+ * Query the range for the sampling interval from the
+ * hardware.
*/
oprofile_min_interval = hwsampler_query_min_interval();
if (oprofile_min_interval == 0)
if (oprofile_hw_interval > oprofile_max_interval)
oprofile_hw_interval = oprofile_max_interval;
- if (oprofile_timer_init(ops))
- return -ENODEV;
-
- printk(KERN_INFO "oprofile: using hardware sampling\n");
-
- memcpy(&timer_ops, ops, sizeof(timer_ops));
+ printk(KERN_INFO "oprofile: System z hardware sampling "
+ "facility found.\n");
ops->start = oprofile_hwsampler_start;
ops->stop = oprofile_hwsampler_stop;
- ops->create_files = oprofile_create_hwsampling_files;
return 0;
}
ops->backtrace = s390_backtrace;
#ifdef CONFIG_64BIT
- return oprofile_hwsampler_init(ops);
+
+ /*
+ * -ENODEV is not reported to the caller. The module itself
+ * will use the timer mode sampling as fallback and this is
+ * always available.
+ */
+ hwsampler_available = oprofile_hwsampler_init(ops) == 0;
+
+ return 0;
#else
return -ENODEV;
#endif
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