diff options
Diffstat (limited to 'kernel/arch/s390/oprofile/init.c')
| -rw-r--r-- | kernel/arch/s390/oprofile/init.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/kernel/arch/s390/oprofile/init.c b/kernel/arch/s390/oprofile/init.c new file mode 100644 index 000000000..bc927a09a --- /dev/null +++ b/kernel/arch/s390/oprofile/init.c @@ -0,0 +1,513 @@ +/* + * S390 Version + * Copyright IBM Corp. 2002, 2011 + * 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/oprofile.h> +#include <linux/perf_event.h> +#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" + +extern void s390_backtrace(struct pt_regs * const regs, unsigned int depth); + +#include "hwsampler.h" +#include "op_counter.h" + +#define DEFAULT_INTERVAL 4127518 + +#define DEFAULT_SDBT_BLOCKS 1 +#define DEFAULT_SDB_BLOCKS 511 + +static unsigned long oprofile_hw_interval = DEFAULT_INTERVAL; +static unsigned long oprofile_min_interval; +static unsigned long oprofile_max_interval; + +static unsigned long oprofile_sdbt_blocks = DEFAULT_SDBT_BLOCKS; +static unsigned long oprofile_sdb_blocks = DEFAULT_SDB_BLOCKS; + +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; + + retval = hwsampler_allocate(oprofile_sdbt_blocks, oprofile_sdb_blocks); + if (retval) + return retval; + + retval = hwsampler_start_all(oprofile_hw_interval); + if (retval) + hwsampler_deallocate(); + + return retval; +} + +static int oprofile_hwsampler_start(void) +{ + int retval; + + hwsampler_running = hwsampler_enabled; + + if (!hwsampler_running) + return timer_ops.start(); + + retval = perf_reserve_sampling(); + if (retval) + return retval; + + retval = __oprofile_hwsampler_start(); + if (retval) + perf_release_sampling(); + + return retval; +} + +static void oprofile_hwsampler_stop(void) +{ + if (!hwsampler_running) { + timer_ops.stop(); + return; + } + + hwsampler_stop_all(); + hwsampler_deallocate(); + perf_release_sampling(); + 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_enabled, buf, count, offset); +} + +static ssize_t hwsampler_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 <= 0) + return retval; + + if (val != 0 && val != 1) + 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 hwsampler_fops = { + .read = hwsampler_read, + .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 <= 0) + 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 <= 0) + 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 <= 0) + 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 <= 0) + 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 <= 0) + 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 dentry *root) +{ + struct dentry *dir; + + dir = oprofilefs_mkdir(root, "timer"); + if (!dir) + return -EINVAL; + + oprofilefs_create_file(dir, "enabled", &timer_enabled_fops); + + if (!hwsampler_available) + return 0; + + /* reinitialize default values */ + hwsampler_enabled = 1; + counter_config.kernel = 1; + counter_config.user = 1; + + 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(root, "0"); + if (!dir) + return -EINVAL; + + oprofilefs_create_file(dir, "enabled", &hwsampler_fops); + oprofilefs_create_file(dir, "event", &zero_fops); + oprofilefs_create_file(dir, "count", &hw_interval_fops); + oprofilefs_create_file(dir, "unit_mask", &zero_fops); + oprofilefs_create_file(dir, "kernel", &kernel_fops); + oprofilefs_create_file(dir, "user", &user_fops); + oprofilefs_create_ulong(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(root, "hwsampling"); + if (!dir) + return -EINVAL; + + oprofilefs_create_file(dir, "hwsampler", + &hwsampler_fops); + oprofilefs_create_file(dir, "hw_interval", + &hw_interval_fops); + oprofilefs_create_ro_ulong(dir, "hw_min_interval", + &oprofile_min_interval); + oprofilefs_create_ro_ulong(dir, "hw_max_interval", + &oprofile_max_interval); + oprofilefs_create_ulong(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; + case 0x2827: case 0x2828: ops->cpu_type = "s390/zEC12"; break; + default: return -ENODEV; + } + } + + if (hwsampler_setup()) + return -ENODEV; + + /* + * Query the range for the sampling interval from the + * hardware. + */ + oprofile_min_interval = hwsampler_query_min_interval(); + if (oprofile_min_interval == 0) + return -ENODEV; + oprofile_max_interval = hwsampler_query_max_interval(); + if (oprofile_max_interval == 0) + return -ENODEV; + + /* The initial value should be sane */ + if (oprofile_hw_interval < oprofile_min_interval) + oprofile_hw_interval = oprofile_min_interval; + if (oprofile_hw_interval > oprofile_max_interval) + oprofile_hw_interval = oprofile_max_interval; + + printk(KERN_INFO "oprofile: System z hardware sampling " + "facility found.\n"); + + ops->start = oprofile_hwsampler_start; + ops->stop = oprofile_hwsampler_stop; + + return 0; +} + +static void oprofile_hwsampler_exit(void) +{ + hwsampler_shutdown(); +} + +int __init oprofile_arch_init(struct oprofile_operations *ops) +{ + ops->backtrace = s390_backtrace; + + /* + * -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; +} + +void oprofile_arch_exit(void) +{ + oprofile_hwsampler_exit(); +} |