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linux/arch/s390/oprofile/hwsampler.c
Christoph Lameter eb7e7d7663 s390: Replace __get_cpu_var uses 
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x).  This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.

Other use cases are for storing and retrieving data from the current
processors percpu area.  __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.

__get_cpu_var() is defined as :

#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))

__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.

this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.

This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset.  Thereby address calculations are avoided and less registers
are used when code is generated.

At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.

The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e.  using a global
register that may be set to the per cpu base.

Transformations done to __get_cpu_var()

1. Determine the address of the percpu instance of the current processor.

	DEFINE_PER_CPU(int, y);
	int *x = &__get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(&y);

2. Same as #1 but this time an array structure is involved.

	DEFINE_PER_CPU(int, y[20]);
	int *x = __get_cpu_var(y);

    Converts to

	int *x = this_cpu_ptr(y);

3. Retrieve the content of the current processors instance of a per cpu
variable.

	DEFINE_PER_CPU(int, y);
	int x = __get_cpu_var(y)

   Converts to

	int x = __this_cpu_read(y);

4. Retrieve the content of a percpu struct

	DEFINE_PER_CPU(struct mystruct, y);
	struct mystruct x = __get_cpu_var(y);

   Converts to

	memcpy(&x, this_cpu_ptr(&y), sizeof(x));

5. Assignment to a per cpu variable

	DEFINE_PER_CPU(int, y)
	__get_cpu_var(y) = x;

   Converts to

	this_cpu_write(y, x);

6. Increment/Decrement etc of a per cpu variable

	DEFINE_PER_CPU(int, y);
	__get_cpu_var(y)++

   Converts to

	this_cpu_inc(y)

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
CC: linux390@de.ibm.com
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-26 13:45:52 -04:00

1179 lines
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/*
* Copyright IBM Corp. 2010
* Author: Heinz Graalfs <graalfs@de.ibm.com>
*/
#include <linux/kernel_stat.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/semaphore.h>
#include <linux/oom.h>
#include <linux/oprofile.h>
#include <asm/facility.h>
#include <asm/cpu_mf.h>
#include <asm/irq.h>
#include "hwsampler.h"
#include "op_counter.h"
#define MAX_NUM_SDB 511
#define MIN_NUM_SDB 1
DECLARE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
struct hws_execute_parms {
void *buffer;
signed int rc;
};
DEFINE_PER_CPU(struct hws_cpu_buffer, sampler_cpu_buffer);
EXPORT_PER_CPU_SYMBOL(sampler_cpu_buffer);
static DEFINE_MUTEX(hws_sem);
static DEFINE_MUTEX(hws_sem_oom);
static unsigned char hws_flush_all;
static unsigned int hws_oom;
static unsigned int hws_alert;
static struct workqueue_struct *hws_wq;
static unsigned int hws_state;
enum {
HWS_INIT = 1,
HWS_DEALLOCATED,
HWS_STOPPED,
HWS_STARTED,
HWS_STOPPING };
/* set to 1 if called by kernel during memory allocation */
static unsigned char oom_killer_was_active;
/* size of SDBT and SDB as of allocate API */
static unsigned long num_sdbt = 100;
static unsigned long num_sdb = 511;
/* sampling interval (machine cycles) */
static unsigned long interval;
static unsigned long min_sampler_rate;
static unsigned long max_sampler_rate;
static void execute_qsi(void *parms)
{
struct hws_execute_parms *ep = parms;
ep->rc = qsi(ep->buffer);
}
static void execute_ssctl(void *parms)
{
struct hws_execute_parms *ep = parms;
ep->rc = lsctl(ep->buffer);
}
static int smp_ctl_ssctl_stop(int cpu)
{
int rc;
struct hws_execute_parms ep;
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
cb->ssctl.es = 0;
cb->ssctl.cs = 0;
ep.buffer = &cb->ssctl;
smp_call_function_single(cpu, execute_ssctl, &ep, 1);
rc = ep.rc;
if (rc) {
printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
dump_stack();
}
ep.buffer = &cb->qsi;
smp_call_function_single(cpu, execute_qsi, &ep, 1);
if (cb->qsi.es || cb->qsi.cs) {
printk(KERN_EMERG "CPUMF sampling did not stop properly.\n");
dump_stack();
}
return rc;
}
static int smp_ctl_ssctl_deactivate(int cpu)
{
int rc;
struct hws_execute_parms ep;
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
cb->ssctl.es = 1;
cb->ssctl.cs = 0;
ep.buffer = &cb->ssctl;
smp_call_function_single(cpu, execute_ssctl, &ep, 1);
rc = ep.rc;
if (rc)
printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
ep.buffer = &cb->qsi;
smp_call_function_single(cpu, execute_qsi, &ep, 1);
if (cb->qsi.cs)
printk(KERN_EMERG "CPUMF sampling was not set inactive.\n");
return rc;
}
static int smp_ctl_ssctl_enable_activate(int cpu, unsigned long interval)
{
int rc;
struct hws_execute_parms ep;
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
cb->ssctl.h = 1;
cb->ssctl.tear = cb->first_sdbt;
cb->ssctl.dear = *(unsigned long *) cb->first_sdbt;
cb->ssctl.interval = interval;
cb->ssctl.es = 1;
cb->ssctl.cs = 1;
ep.buffer = &cb->ssctl;
smp_call_function_single(cpu, execute_ssctl, &ep, 1);
rc = ep.rc;
if (rc)
printk(KERN_ERR "hwsampler: CPU %d CPUMF SSCTL failed.\n", cpu);
ep.buffer = &cb->qsi;
smp_call_function_single(cpu, execute_qsi, &ep, 1);
if (ep.rc)
printk(KERN_ERR "hwsampler: CPU %d CPUMF QSI failed.\n", cpu);
return rc;
}
static int smp_ctl_qsi(int cpu)
{
struct hws_execute_parms ep;
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
ep.buffer = &cb->qsi;
smp_call_function_single(cpu, execute_qsi, &ep, 1);
return ep.rc;
}
static void hws_ext_handler(struct ext_code ext_code,
unsigned int param32, unsigned long param64)
{
struct hws_cpu_buffer *cb = this_cpu_ptr(&sampler_cpu_buffer);
if (!(param32 & CPU_MF_INT_SF_MASK))
return;
if (!hws_alert)
return;
inc_irq_stat(IRQEXT_CMS);
atomic_xchg(&cb->ext_params, atomic_read(&cb->ext_params) | param32);
if (hws_wq)
queue_work(hws_wq, &cb->worker);
}
static void worker(struct work_struct *work);
static void add_samples_to_oprofile(unsigned cpu, unsigned long *,
unsigned long *dear);
static void init_all_cpu_buffers(void)
{
int cpu;
struct hws_cpu_buffer *cb;
for_each_online_cpu(cpu) {
cb = &per_cpu(sampler_cpu_buffer, cpu);
memset(cb, 0, sizeof(struct hws_cpu_buffer));
}
}
static void prepare_cpu_buffers(void)
{
struct hws_cpu_buffer *cb;
int cpu;
for_each_online_cpu(cpu) {
cb = &per_cpu(sampler_cpu_buffer, cpu);
atomic_set(&cb->ext_params, 0);
cb->worker_entry = 0;
cb->sample_overflow = 0;
cb->req_alert = 0;
cb->incorrect_sdbt_entry = 0;
cb->invalid_entry_address = 0;
cb->loss_of_sample_data = 0;
cb->sample_auth_change_alert = 0;
cb->finish = 0;
cb->oom = 0;
cb->stop_mode = 0;
}
}
/*
* allocate_sdbt() - allocate sampler memory
* @cpu: the cpu for which sampler memory is allocated
*
* A 4K page is allocated for each requested SDBT.
* A maximum of 511 4K pages are allocated for the SDBs in each of the SDBTs.
* Set ALERT_REQ mask in each SDBs trailer.
* Returns zero if successful, <0 otherwise.
*/
static int allocate_sdbt(int cpu)
{
int j, k, rc;
unsigned long *sdbt;
unsigned long sdb;
unsigned long *tail;
unsigned long *trailer;
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
if (cb->first_sdbt)
return -EINVAL;
sdbt = NULL;
tail = sdbt;
for (j = 0; j < num_sdbt; j++) {
sdbt = (unsigned long *)get_zeroed_page(GFP_KERNEL);
mutex_lock(&hws_sem_oom);
/* OOM killer might have been activated */
barrier();
if (oom_killer_was_active || !sdbt) {
if (sdbt)
free_page((unsigned long)sdbt);
goto allocate_sdbt_error;
}
if (cb->first_sdbt == 0)
cb->first_sdbt = (unsigned long)sdbt;
/* link current page to tail of chain */
if (tail)
*tail = (unsigned long)(void *)sdbt + 1;
mutex_unlock(&hws_sem_oom);
for (k = 0; k < num_sdb; k++) {
/* get and set SDB page */
sdb = get_zeroed_page(GFP_KERNEL);
mutex_lock(&hws_sem_oom);
/* OOM killer might have been activated */
barrier();
if (oom_killer_was_active || !sdb) {
if (sdb)
free_page(sdb);
goto allocate_sdbt_error;
}
*sdbt = sdb;
trailer = trailer_entry_ptr(*sdbt);
*trailer = SDB_TE_ALERT_REQ_MASK;
sdbt++;
mutex_unlock(&hws_sem_oom);
}
tail = sdbt;
}
mutex_lock(&hws_sem_oom);
if (oom_killer_was_active)
goto allocate_sdbt_error;
rc = 0;
if (tail)
*tail = (unsigned long)
((void *)cb->first_sdbt) + 1;
allocate_sdbt_exit:
mutex_unlock(&hws_sem_oom);
return rc;
allocate_sdbt_error:
rc = -ENOMEM;
goto allocate_sdbt_exit;
}
/*
* deallocate_sdbt() - deallocate all sampler memory
*
* For each online CPU all SDBT trees are deallocated.
* Returns the number of freed pages.
*/
static int deallocate_sdbt(void)
{
int cpu;
int counter;
counter = 0;
for_each_online_cpu(cpu) {
unsigned long start;
unsigned long sdbt;
unsigned long *curr;
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
if (!cb->first_sdbt)
continue;
sdbt = cb->first_sdbt;
curr = (unsigned long *) sdbt;
start = sdbt;
/* we'll free the SDBT after all SDBs are processed... */
while (1) {
if (!*curr || !sdbt)
break;
/* watch for link entry reset if found */
if (is_link_entry(curr)) {
curr = get_next_sdbt(curr);
if (sdbt)
free_page(sdbt);
/* we are done if we reach the start */
if ((unsigned long) curr == start)
break;
else
sdbt = (unsigned long) curr;
} else {
/* process SDB pointer */
if (*curr) {
free_page(*curr);
curr++;
}
}
counter++;
}
cb->first_sdbt = 0;
}
return counter;
}
static int start_sampling(int cpu)
{
int rc;
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
rc = smp_ctl_ssctl_enable_activate(cpu, interval);
if (rc) {
printk(KERN_INFO "hwsampler: CPU %d ssctl failed.\n", cpu);
goto start_exit;
}
rc = -EINVAL;
if (!cb->qsi.es) {
printk(KERN_INFO "hwsampler: CPU %d ssctl not enabled.\n", cpu);
goto start_exit;
}
if (!cb->qsi.cs) {
printk(KERN_INFO "hwsampler: CPU %d ssctl not active.\n", cpu);
goto start_exit;
}
printk(KERN_INFO
"hwsampler: CPU %d, CPUMF Sampling started, interval %lu.\n",
cpu, interval);
rc = 0;
start_exit:
return rc;
}
static int stop_sampling(int cpu)
{
unsigned long v;
int rc;
struct hws_cpu_buffer *cb;
rc = smp_ctl_qsi(cpu);
WARN_ON(rc);
cb = &per_cpu(sampler_cpu_buffer, cpu);
if (!rc && !cb->qsi.es)
printk(KERN_INFO "hwsampler: CPU %d, already stopped.\n", cpu);
rc = smp_ctl_ssctl_stop(cpu);
if (rc) {
printk(KERN_INFO "hwsampler: CPU %d, ssctl stop error %d.\n",
cpu, rc);
goto stop_exit;
}
printk(KERN_INFO "hwsampler: CPU %d, CPUMF Sampling stopped.\n", cpu);
stop_exit:
v = cb->req_alert;
if (v)
printk(KERN_ERR "hwsampler: CPU %d CPUMF Request alert,"
" count=%lu.\n", cpu, v);
v = cb->loss_of_sample_data;
if (v)
printk(KERN_ERR "hwsampler: CPU %d CPUMF Loss of sample data,"
" count=%lu.\n", cpu, v);
v = cb->invalid_entry_address;
if (v)
printk(KERN_ERR "hwsampler: CPU %d CPUMF Invalid entry address,"
" count=%lu.\n", cpu, v);
v = cb->incorrect_sdbt_entry;
if (v)
printk(KERN_ERR
"hwsampler: CPU %d CPUMF Incorrect SDBT address,"
" count=%lu.\n", cpu, v);
v = cb->sample_auth_change_alert;
if (v)
printk(KERN_ERR
"hwsampler: CPU %d CPUMF Sample authorization change,"
" count=%lu.\n", cpu, v);
return rc;
}
static int check_hardware_prerequisites(void)
{
if (!test_facility(68))
return -EOPNOTSUPP;
return 0;
}
/*
* hws_oom_callback() - the OOM callback function
*
* In case the callback is invoked during memory allocation for the
* hw sampler, all obtained memory is deallocated and a flag is set
* so main sampler memory allocation can exit with a failure code.
* In case the callback is invoked during sampling the hw sampler
* is deactivated for all CPUs.
*/
static int hws_oom_callback(struct notifier_block *nfb,
unsigned long dummy, void *parm)
{
unsigned long *freed;
int cpu;
struct hws_cpu_buffer *cb;
freed = parm;
mutex_lock(&hws_sem_oom);
if (hws_state == HWS_DEALLOCATED) {
/* during memory allocation */
if (oom_killer_was_active == 0) {
oom_killer_was_active = 1;
*freed += deallocate_sdbt();
}
} else {
int i;
cpu = get_cpu();
cb = &per_cpu(sampler_cpu_buffer, cpu);
if (!cb->oom) {
for_each_online_cpu(i) {
smp_ctl_ssctl_deactivate(i);
cb->oom = 1;
}
cb->finish = 1;
printk(KERN_INFO
"hwsampler: CPU %d, OOM notify during CPUMF Sampling.\n",
cpu);
}
}
mutex_unlock(&hws_sem_oom);
return NOTIFY_OK;
}
static struct notifier_block hws_oom_notifier = {
.notifier_call = hws_oom_callback
};
static int hws_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
/* We do not have sampler space available for all possible CPUs.
All CPUs should be online when hw sampling is activated. */
return (hws_state <= HWS_DEALLOCATED) ? NOTIFY_OK : NOTIFY_BAD;
}
static struct notifier_block hws_cpu_notifier = {
.notifier_call = hws_cpu_callback
};
/**
* hwsampler_deactivate() - set hardware sampling temporarily inactive
* @cpu: specifies the CPU to be set inactive.
*
* Returns 0 on success, !0 on failure.
*/
int hwsampler_deactivate(unsigned int cpu)
{
/*
* Deactivate hw sampling temporarily and flush the buffer
* by pushing all the pending samples to oprofile buffer.
*
* This function can be called under one of the following conditions:
* Memory unmap, task is exiting.
*/
int rc;
struct hws_cpu_buffer *cb;
rc = 0;
mutex_lock(&hws_sem);
cb = &per_cpu(sampler_cpu_buffer, cpu);
if (hws_state == HWS_STARTED) {
rc = smp_ctl_qsi(cpu);
WARN_ON(rc);
if (cb->qsi.cs) {
rc = smp_ctl_ssctl_deactivate(cpu);
if (rc) {
printk(KERN_INFO
"hwsampler: CPU %d, CPUMF Deactivation failed.\n", cpu);
cb->finish = 1;
hws_state = HWS_STOPPING;
} else {
hws_flush_all = 1;
/* Add work to queue to read pending samples.*/
queue_work_on(cpu, hws_wq, &cb->worker);
}
}
}
mutex_unlock(&hws_sem);
if (hws_wq)
flush_workqueue(hws_wq);
return rc;
}
/**
* hwsampler_activate() - activate/resume hardware sampling which was deactivated
* @cpu: specifies the CPU to be set active.
*
* Returns 0 on success, !0 on failure.
*/
int hwsampler_activate(unsigned int cpu)
{
/*
* Re-activate hw sampling. This should be called in pair with
* hwsampler_deactivate().
*/
int rc;
struct hws_cpu_buffer *cb;
rc = 0;
mutex_lock(&hws_sem);
cb = &per_cpu(sampler_cpu_buffer, cpu);
if (hws_state == HWS_STARTED) {
rc = smp_ctl_qsi(cpu);
WARN_ON(rc);
if (!cb->qsi.cs) {
hws_flush_all = 0;
rc = smp_ctl_ssctl_enable_activate(cpu, interval);
if (rc) {
printk(KERN_ERR
"CPU %d, CPUMF activate sampling failed.\n",
cpu);
}
}
}
mutex_unlock(&hws_sem);
return rc;
}
static int check_qsi_on_setup(void)
{
int rc;
unsigned int cpu;
struct hws_cpu_buffer *cb;
for_each_online_cpu(cpu) {
cb = &per_cpu(sampler_cpu_buffer, cpu);
rc = smp_ctl_qsi(cpu);
WARN_ON(rc);
if (rc)
return -EOPNOTSUPP;
if (!cb->qsi.as) {
printk(KERN_INFO "hwsampler: CPUMF sampling is not authorized.\n");
return -EINVAL;
}
if (cb->qsi.es) {
printk(KERN_WARNING "hwsampler: CPUMF is still enabled.\n");
rc = smp_ctl_ssctl_stop(cpu);
if (rc)
return -EINVAL;
printk(KERN_INFO
"CPU %d, CPUMF Sampling stopped now.\n", cpu);
}
}
return 0;
}
static int check_qsi_on_start(void)
{
unsigned int cpu;
int rc;
struct hws_cpu_buffer *cb;
for_each_online_cpu(cpu) {
cb = &per_cpu(sampler_cpu_buffer, cpu);
rc = smp_ctl_qsi(cpu);
WARN_ON(rc);
if (!cb->qsi.as)
return -EINVAL;
if (cb->qsi.es)
return -EINVAL;
if (cb->qsi.cs)
return -EINVAL;
}
return 0;
}
static void worker_on_start(unsigned int cpu)
{
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
cb->worker_entry = cb->first_sdbt;
}
static int worker_check_error(unsigned int cpu, int ext_params)
{
int rc;
unsigned long *sdbt;
struct hws_cpu_buffer *cb;
rc = 0;
cb = &per_cpu(sampler_cpu_buffer, cpu);
sdbt = (unsigned long *) cb->worker_entry;
if (!sdbt || !*sdbt)
return -EINVAL;
if (ext_params & CPU_MF_INT_SF_PRA)
cb->req_alert++;
if (ext_params & CPU_MF_INT_SF_LSDA)
cb->loss_of_sample_data++;
if (ext_params & CPU_MF_INT_SF_IAE) {
cb->invalid_entry_address++;
rc = -EINVAL;
}
if (ext_params & CPU_MF_INT_SF_ISE) {
cb->incorrect_sdbt_entry++;
rc = -EINVAL;
}
if (ext_params & CPU_MF_INT_SF_SACA) {
cb->sample_auth_change_alert++;
rc = -EINVAL;
}
return rc;
}
static void worker_on_finish(unsigned int cpu)
{
int rc, i;
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
if (cb->finish) {
rc = smp_ctl_qsi(cpu);
WARN_ON(rc);
if (cb->qsi.es) {
printk(KERN_INFO
"hwsampler: CPU %d, CPUMF Stop/Deactivate sampling.\n",
cpu);
rc = smp_ctl_ssctl_stop(cpu);
if (rc)
printk(KERN_INFO
"hwsampler: CPU %d, CPUMF Deactivation failed.\n",
cpu);
for_each_online_cpu(i) {
if (i == cpu)
continue;
if (!cb->finish) {
cb->finish = 1;
queue_work_on(i, hws_wq,
&cb->worker);
}
}
}
}
}
static void worker_on_interrupt(unsigned int cpu)
{
unsigned long *sdbt;
unsigned char done;
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
sdbt = (unsigned long *) cb->worker_entry;
done = 0;
/* do not proceed if stop was entered,
* forget the buffers not yet processed */
while (!done && !cb->stop_mode) {
unsigned long *trailer;
struct hws_trailer_entry *te;
unsigned long *dear = 0;
trailer = trailer_entry_ptr(*sdbt);
/* leave loop if no more work to do */
if (!(*trailer & SDB_TE_BUFFER_FULL_MASK)) {
done = 1;
if (!hws_flush_all)
continue;
}
te = (struct hws_trailer_entry *)trailer;
cb->sample_overflow += te->overflow;
add_samples_to_oprofile(cpu, sdbt, dear);
/* reset trailer */
xchg((unsigned char *) te, 0x40);
/* advance to next sdb slot in current sdbt */
sdbt++;
/* in case link bit is set use address w/o link bit */
if (is_link_entry(sdbt))
sdbt = get_next_sdbt(sdbt);
cb->worker_entry = (unsigned long)sdbt;
}
}
static void add_samples_to_oprofile(unsigned int cpu, unsigned long *sdbt,
unsigned long *dear)
{
struct hws_basic_entry *sample_data_ptr;
unsigned long *trailer;
trailer = trailer_entry_ptr(*sdbt);
if (dear) {
if (dear > trailer)
return;
trailer = dear;
}
sample_data_ptr = (struct hws_basic_entry *)(*sdbt);
while ((unsigned long *)sample_data_ptr < trailer) {
struct pt_regs *regs = NULL;
struct task_struct *tsk = NULL;
/*
* Check sampling mode, 1 indicates basic (=customer) sampling
* mode.
*/
if (sample_data_ptr->def != 1) {
/* sample slot is not yet written */
break;
} else {
/* make sure we don't use it twice,
* the next time the sampler will set it again */
sample_data_ptr->def = 0;
}
/* Get pt_regs. */
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)
regs = task_pt_regs(tsk);
rcu_read_unlock();
} else {
/* kernelspace sample */
if (!counter_config.kernel)
goto skip_sample;
regs = task_pt_regs(current);
}
mutex_lock(&hws_sem);
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++;
}
}
static void worker(struct work_struct *work)
{
unsigned int cpu;
int ext_params;
struct hws_cpu_buffer *cb;
cb = container_of(work, struct hws_cpu_buffer, worker);
cpu = smp_processor_id();
ext_params = atomic_xchg(&cb->ext_params, 0);
if (!cb->worker_entry)
worker_on_start(cpu);
if (worker_check_error(cpu, ext_params))
return;
if (!cb->finish)
worker_on_interrupt(cpu);
if (cb->finish)
worker_on_finish(cpu);
}
/**
* hwsampler_allocate() - allocate memory for the hardware sampler
* @sdbt: number of SDBTs per online CPU (must be > 0)
* @sdb: number of SDBs per SDBT (minimum 1, maximum 511)
*
* Returns 0 on success, !0 on failure.
*/
int hwsampler_allocate(unsigned long sdbt, unsigned long sdb)
{
int cpu, rc;
mutex_lock(&hws_sem);
rc = -EINVAL;
if (hws_state != HWS_DEALLOCATED)
goto allocate_exit;
if (sdbt < 1)
goto allocate_exit;
if (sdb > MAX_NUM_SDB || sdb < MIN_NUM_SDB)
goto allocate_exit;
num_sdbt = sdbt;
num_sdb = sdb;
oom_killer_was_active = 0;
register_oom_notifier(&hws_oom_notifier);
for_each_online_cpu(cpu) {
if (allocate_sdbt(cpu)) {
unregister_oom_notifier(&hws_oom_notifier);
goto allocate_error;
}
}
unregister_oom_notifier(&hws_oom_notifier);
if (oom_killer_was_active)
goto allocate_error;
hws_state = HWS_STOPPED;
rc = 0;
allocate_exit:
mutex_unlock(&hws_sem);
return rc;
allocate_error:
rc = -ENOMEM;
printk(KERN_ERR "hwsampler: CPUMF Memory allocation failed.\n");
goto allocate_exit;
}
/**
* hwsampler_deallocate() - deallocate hardware sampler memory
*
* Returns 0 on success, !0 on failure.
*/
int hwsampler_deallocate(void)
{
int rc;
mutex_lock(&hws_sem);
rc = -EINVAL;
if (hws_state != HWS_STOPPED)
goto deallocate_exit;
irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
hws_alert = 0;
deallocate_sdbt();
hws_state = HWS_DEALLOCATED;
rc = 0;
deallocate_exit:
mutex_unlock(&hws_sem);
return rc;
}
unsigned long hwsampler_query_min_interval(void)
{
return min_sampler_rate;
}
unsigned long hwsampler_query_max_interval(void)
{
return max_sampler_rate;
}
unsigned long hwsampler_get_sample_overflow_count(unsigned int cpu)
{
struct hws_cpu_buffer *cb;
cb = &per_cpu(sampler_cpu_buffer, cpu);
return cb->sample_overflow;
}
int hwsampler_setup(void)
{
int rc;
int cpu;
struct hws_cpu_buffer *cb;
mutex_lock(&hws_sem);
rc = -EINVAL;
if (hws_state)
goto setup_exit;
hws_state = HWS_INIT;
init_all_cpu_buffers();
rc = check_hardware_prerequisites();
if (rc)
goto setup_exit;
rc = check_qsi_on_setup();
if (rc)
goto setup_exit;
rc = -EINVAL;
hws_wq = create_workqueue("hwsampler");
if (!hws_wq)
goto setup_exit;
register_cpu_notifier(&hws_cpu_notifier);
for_each_online_cpu(cpu) {
cb = &per_cpu(sampler_cpu_buffer, cpu);
INIT_WORK(&cb->worker, worker);
rc = smp_ctl_qsi(cpu);
WARN_ON(rc);
if (min_sampler_rate != cb->qsi.min_sampl_rate) {
if (min_sampler_rate) {
printk(KERN_WARNING
"hwsampler: different min sampler rate values.\n");
if (min_sampler_rate < cb->qsi.min_sampl_rate)
min_sampler_rate =
cb->qsi.min_sampl_rate;
} else
min_sampler_rate = cb->qsi.min_sampl_rate;
}
if (max_sampler_rate != cb->qsi.max_sampl_rate) {
if (max_sampler_rate) {
printk(KERN_WARNING
"hwsampler: different max sampler rate values.\n");
if (max_sampler_rate > cb->qsi.max_sampl_rate)
max_sampler_rate =
cb->qsi.max_sampl_rate;
} else
max_sampler_rate = cb->qsi.max_sampl_rate;
}
}
register_external_irq(EXT_IRQ_MEASURE_ALERT, hws_ext_handler);
hws_state = HWS_DEALLOCATED;
rc = 0;
setup_exit:
mutex_unlock(&hws_sem);
return rc;
}
int hwsampler_shutdown(void)
{
int rc;
mutex_lock(&hws_sem);
rc = -EINVAL;
if (hws_state == HWS_DEALLOCATED || hws_state == HWS_STOPPED) {
mutex_unlock(&hws_sem);
if (hws_wq)
flush_workqueue(hws_wq);
mutex_lock(&hws_sem);
if (hws_state == HWS_STOPPED) {
irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
hws_alert = 0;
deallocate_sdbt();
}
if (hws_wq) {
destroy_workqueue(hws_wq);
hws_wq = NULL;
}
unregister_external_irq(EXT_IRQ_MEASURE_ALERT, hws_ext_handler);
hws_state = HWS_INIT;
rc = 0;
}
mutex_unlock(&hws_sem);
unregister_cpu_notifier(&hws_cpu_notifier);
return rc;
}
/**
* hwsampler_start_all() - start hardware sampling on all online CPUs
* @rate: specifies the used interval when samples are taken
*
* Returns 0 on success, !0 on failure.
*/
int hwsampler_start_all(unsigned long rate)
{
int rc, cpu;
mutex_lock(&hws_sem);
hws_oom = 0;
rc = -EINVAL;
if (hws_state != HWS_STOPPED)
goto start_all_exit;
interval = rate;
/* fail if rate is not valid */
if (interval < min_sampler_rate || interval > max_sampler_rate)
goto start_all_exit;
rc = check_qsi_on_start();
if (rc)
goto start_all_exit;
prepare_cpu_buffers();
for_each_online_cpu(cpu) {
rc = start_sampling(cpu);
if (rc)
break;
}
if (rc) {
for_each_online_cpu(cpu) {
stop_sampling(cpu);
}
goto start_all_exit;
}
hws_state = HWS_STARTED;
rc = 0;
start_all_exit:
mutex_unlock(&hws_sem);
if (rc)
return rc;
register_oom_notifier(&hws_oom_notifier);
hws_oom = 1;
hws_flush_all = 0;
/* now let them in, 1407 CPUMF external interrupts */
hws_alert = 1;
irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT);
return 0;
}
/**
* hwsampler_stop_all() - stop hardware sampling on all online CPUs
*
* Returns 0 on success, !0 on failure.
*/
int hwsampler_stop_all(void)
{
int tmp_rc, rc, cpu;
struct hws_cpu_buffer *cb;
mutex_lock(&hws_sem);
rc = 0;
if (hws_state == HWS_INIT) {
mutex_unlock(&hws_sem);
return 0;
}
hws_state = HWS_STOPPING;
mutex_unlock(&hws_sem);
for_each_online_cpu(cpu) {
cb = &per_cpu(sampler_cpu_buffer, cpu);
cb->stop_mode = 1;
tmp_rc = stop_sampling(cpu);
if (tmp_rc)
rc = tmp_rc;
}
if (hws_wq)
flush_workqueue(hws_wq);
mutex_lock(&hws_sem);
if (hws_oom) {
unregister_oom_notifier(&hws_oom_notifier);
hws_oom = 0;
}
hws_state = HWS_STOPPED;
mutex_unlock(&hws_sem);
return rc;
}
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