diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index f7735a125f4b21cd1bb1758ba575dd4df531323e..60b98cea06fcd92215fdfb2975fcb73485d336a9 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1851,6 +1851,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. timer: [X86] Force use of architectural NMI timer mode (see also oprofile.timer for generic hr timer mode) + [s390] Force legacy basic mode sampling + (report cpu_type "timer") oops=panic Always panic on oopses. Default is to just kill the process, but there is a small probability of diff --git a/arch/s390/oprofile/hwsampler.c b/arch/s390/oprofile/hwsampler.c index 4552ce40c81a5086ad550e21092c78b36ad3b7c3..cab0fe932c08ea7b121b7ee13423b1ff2ac22495 100644 --- a/arch/s390/oprofile/hwsampler.c +++ b/arch/s390/oprofile/hwsampler.c @@ -22,6 +22,7 @@ #include #include "hwsampler.h" +#include "op_counter.h" #define MAX_NUM_SDB 511 #define MIN_NUM_SDB 1 @@ -896,6 +897,8 @@ static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt, if (sample_data_ptr->P == 1) { /* userspace sample */ unsigned int pid = sample_data_ptr->prim_asn; + if (!counter_config.user) + goto skip_sample; rcu_read_lock(); tsk = pid_task(find_vpid(pid), PIDTYPE_PID); if (tsk) @@ -903,6 +906,8 @@ static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt, rcu_read_unlock(); } else { /* kernelspace sample */ + if (!counter_config.kernel) + goto skip_sample; regs = task_pt_regs(current); } @@ -910,7 +915,7 @@ static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt, oprofile_add_ext_hw_sample(sample_data_ptr->ia, regs, 0, !sample_data_ptr->P, tsk); mutex_unlock(&hws_sem); - + skip_sample: sample_data_ptr++; } } diff --git a/arch/s390/oprofile/init.c b/arch/s390/oprofile/init.c index 113d7cbbc06571f9198f7b58044cca0530ac435f..6cf2286d0405c0b111d5a41a35d0f3c912c88d0d 100644 --- a/arch/s390/oprofile/init.c +++ b/arch/s390/oprofile/init.c @@ -2,10 +2,11 @@ * 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 */ @@ -14,6 +15,8 @@ #include #include #include +#include +#include #include "../../../drivers/oprofile/oprof.h" @@ -22,6 +25,7 @@ extern void s390_backtrace(struct pt_regs * const regs, unsigned int depth); #ifdef CONFIG_64BIT #include "hwsampler.h" +#include "op_counter.h" #define DEFAULT_INTERVAL 4127518 @@ -35,16 +39,41 @@ 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_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(); @@ -72,10 +101,16 @@ static void oprofile_hwsampler_stop(void) 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, @@ -91,6 +126,9 @@ 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 @@ -99,7 +137,7 @@ static ssize_t hwsampler_write(struct file *file, char const __user *buf, */ return -EBUSY; - hwsampler_file = val; + hwsampler_enabled = val; return count; } @@ -109,38 +147,311 @@ static const struct file_operations hwsampler_fops = { .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) @@ -155,16 +466,11 @@ static int oprofile_hwsampler_init(struct oprofile_operations *ops) 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; } @@ -181,7 +487,15 @@ int __init oprofile_arch_init(struct oprofile_operations *ops) 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 diff --git a/arch/s390/oprofile/op_counter.h b/arch/s390/oprofile/op_counter.h new file mode 100644 index 0000000000000000000000000000000000000000..1a8d3ca09014c36fdf967ee981f258e3012b9949 --- /dev/null +++ b/arch/s390/oprofile/op_counter.h @@ -0,0 +1,23 @@ +/** + * arch/s390/oprofile/op_counter.h + * + * Copyright (C) 2011 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Author(s): Andreas Krebbel (krebbel@linux.vnet.ibm.com) + * + * @remark Copyright 2011 OProfile authors + */ + +#ifndef OP_COUNTER_H +#define OP_COUNTER_H + +struct op_counter_config { + /* `enabled' maps to the hwsampler_file variable. */ + /* `count' maps to the oprofile_hw_interval variable. */ + /* `event' and `unit_mask' are unused. */ + unsigned long kernel; + unsigned long user; +}; + +extern struct op_counter_config counter_config; + +#endif /* OP_COUNTER_H */