forked from luck/tmp_suning_uos_patched
[IA64] Add hotplug cpu to salinfo.c, replace semaphore with mutex
Add hotplug cpu support to salinfo.c. The cpu_event field is a cpumask so use the cpu_* macros consistently, replacing the existing mixture of cpu_* and *_bit macros. Instead of counting the number of outstanding events in a semaphore and trying to track that count over user space context, interrupt context, non-maskable interrupt context and cpu hotplug, replace the semaphore with a test for "any bits set" combined with a mutex. Modify the locking to make the test for "work to do" an atomic operation. Signed-off-by: Keith Owens <kaos@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Keith Owens
Tony Luck
parent
15029285dc
commit
e026cca0f2
|
|
@ -3,7 +3,7 @@
|
|||
*
|
||||
* Creates entries in /proc/sal for various system features.
|
||||
*
|
||||
* Copyright (c) 2003 Silicon Graphics, Inc. All rights reserved.
|
||||
* Copyright (c) 2003, 2006 Silicon Graphics, Inc. All rights reserved.
|
||||
* Copyright (c) 2003 Hewlett-Packard Co
|
||||
* Bjorn Helgaas <bjorn.helgaas@hp.com>
|
||||
*
|
||||
|
|
@ -27,9 +27,17 @@
|
|||
* mca.c may not pass a buffer, a NULL buffer just indicates that a new
|
||||
* record is available in SAL.
|
||||
* Replace some NR_CPUS by cpus_online, for hotplug cpu.
|
||||
*
|
||||
* Jan 5 2006 kaos@sgi.com
|
||||
* Handle hotplug cpus coming online.
|
||||
* Handle hotplug cpus going offline while they still have outstanding records.
|
||||
* Use the cpu_* macros consistently.
|
||||
* Replace the counting semaphore with a mutex and a test if the cpumask is non-empty.
|
||||
* Modify the locking to make the test for "work to do" an atomic operation.
|
||||
*/
|
||||
|
||||
#include <linux/capability.h>
|
||||
#include <linux/cpu.h>
|
||||
#include <linux/types.h>
|
||||
#include <linux/proc_fs.h>
|
||||
#include <linux/module.h>
|
||||
|
|
@ -132,8 +140,8 @@ enum salinfo_state {
|
|||
};
|
||||
|
||||
struct salinfo_data {
|
||||
volatile cpumask_t cpu_event; /* which cpus have outstanding events */
|
||||
struct semaphore sem; /* count of cpus with outstanding events (bits set in cpu_event) */
|
||||
cpumask_t cpu_event; /* which cpus have outstanding events */
|
||||
struct semaphore mutex;
|
||||
u8 *log_buffer;
|
||||
u64 log_size;
|
||||
u8 *oemdata; /* decoded oem data */
|
||||
|
|
@ -174,6 +182,21 @@ struct salinfo_platform_oemdata_parms {
|
|||
int ret;
|
||||
};
|
||||
|
||||
/* Kick the mutex that tells user space that there is work to do. Instead of
|
||||
* trying to track the state of the mutex across multiple cpus, in user
|
||||
* context, interrupt context, non-maskable interrupt context and hotplug cpu,
|
||||
* it is far easier just to grab the mutex if it is free then release it.
|
||||
*
|
||||
* This routine must be called with data_saved_lock held, to make the down/up
|
||||
* operation atomic.
|
||||
*/
|
||||
static void
|
||||
salinfo_work_to_do(struct salinfo_data *data)
|
||||
{
|
||||
down_trylock(&data->mutex);
|
||||
up(&data->mutex);
|
||||
}
|
||||
|
||||
static void
|
||||
salinfo_platform_oemdata_cpu(void *context)
|
||||
{
|
||||
|
|
@ -212,9 +235,9 @@ salinfo_log_wakeup(int type, u8 *buffer, u64 size, int irqsafe)
|
|||
|
||||
BUG_ON(type >= ARRAY_SIZE(salinfo_log_name));
|
||||
|
||||
if (irqsafe)
|
||||
spin_lock_irqsave(&data_saved_lock, flags);
|
||||
if (buffer) {
|
||||
if (irqsafe)
|
||||
spin_lock_irqsave(&data_saved_lock, flags);
|
||||
for (i = 0, data_saved = data->data_saved; i < saved_size; ++i, ++data_saved) {
|
||||
if (!data_saved->buffer)
|
||||
break;
|
||||
|
|
@ -232,13 +255,11 @@ salinfo_log_wakeup(int type, u8 *buffer, u64 size, int irqsafe)
|
|||
data_saved->size = size;
|
||||
data_saved->buffer = buffer;
|
||||
}
|
||||
if (irqsafe)
|
||||
spin_unlock_irqrestore(&data_saved_lock, flags);
|
||||
}
|
||||
|
||||
if (!test_and_set_bit(smp_processor_id(), &data->cpu_event)) {
|
||||
if (irqsafe)
|
||||
up(&data->sem);
|
||||
cpu_set(smp_processor_id(), data->cpu_event);
|
||||
if (irqsafe) {
|
||||
salinfo_work_to_do(data);
|
||||
spin_unlock_irqrestore(&data_saved_lock, flags);
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -249,20 +270,17 @@ static struct timer_list salinfo_timer;
|
|||
static void
|
||||
salinfo_timeout_check(struct salinfo_data *data)
|
||||
{
|
||||
int i;
|
||||
unsigned long flags;
|
||||
if (!data->open)
|
||||
return;
|
||||
for_each_online_cpu(i) {
|
||||
if (test_bit(i, &data->cpu_event)) {
|
||||
/* double up() is not a problem, user space will see no
|
||||
* records for the additional "events".
|
||||
*/
|
||||
up(&data->sem);
|
||||
}
|
||||
if (!cpus_empty(data->cpu_event)) {
|
||||
spin_lock_irqsave(&data_saved_lock, flags);
|
||||
salinfo_work_to_do(data);
|
||||
spin_unlock_irqrestore(&data_saved_lock, flags);
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
static void
|
||||
salinfo_timeout (unsigned long arg)
|
||||
{
|
||||
salinfo_timeout_check(salinfo_data + SAL_INFO_TYPE_MCA);
|
||||
|
|
@ -290,16 +308,20 @@ salinfo_event_read(struct file *file, char __user *buffer, size_t count, loff_t
|
|||
int i, n, cpu = -1;
|
||||
|
||||
retry:
|
||||
if (down_trylock(&data->sem)) {
|
||||
if (cpus_empty(data->cpu_event) && down_trylock(&data->mutex)) {
|
||||
if (file->f_flags & O_NONBLOCK)
|
||||
return -EAGAIN;
|
||||
if (down_interruptible(&data->sem))
|
||||
if (down_interruptible(&data->mutex))
|
||||
return -EINTR;
|
||||
}
|
||||
|
||||
n = data->cpu_check;
|
||||
for (i = 0; i < NR_CPUS; i++) {
|
||||
if (test_bit(n, &data->cpu_event) && cpu_online(n)) {
|
||||
if (cpu_isset(n, data->cpu_event)) {
|
||||
if (!cpu_online(n)) {
|
||||
cpu_clear(n, data->cpu_event);
|
||||
continue;
|
||||
}
|
||||
cpu = n;
|
||||
break;
|
||||
}
|
||||
|
|
@ -310,9 +332,6 @@ salinfo_event_read(struct file *file, char __user *buffer, size_t count, loff_t
|
|||
if (cpu == -1)
|
||||
goto retry;
|
||||
|
||||
/* events are sticky until the user says "clear" */
|
||||
up(&data->sem);
|
||||
|
||||
/* for next read, start checking at next CPU */
|
||||
data->cpu_check = cpu;
|
||||
if (++data->cpu_check == NR_CPUS)
|
||||
|
|
@ -381,10 +400,8 @@ salinfo_log_release(struct inode *inode, struct file *file)
|
|||
static void
|
||||
call_on_cpu(int cpu, void (*fn)(void *), void *arg)
|
||||
{
|
||||
cpumask_t save_cpus_allowed, new_cpus_allowed;
|
||||
memcpy(&save_cpus_allowed, ¤t->cpus_allowed, sizeof(save_cpus_allowed));
|
||||
memset(&new_cpus_allowed, 0, sizeof(new_cpus_allowed));
|
||||
set_bit(cpu, &new_cpus_allowed);
|
||||
cpumask_t save_cpus_allowed = current->cpus_allowed;
|
||||
cpumask_t new_cpus_allowed = cpumask_of_cpu(cpu);
|
||||
set_cpus_allowed(current, new_cpus_allowed);
|
||||
(*fn)(arg);
|
||||
set_cpus_allowed(current, save_cpus_allowed);
|
||||
|
|
@ -433,10 +450,10 @@ salinfo_log_new_read(int cpu, struct salinfo_data *data)
|
|||
if (!data->saved_num)
|
||||
call_on_cpu(cpu, salinfo_log_read_cpu, data);
|
||||
if (!data->log_size) {
|
||||
data->state = STATE_NO_DATA;
|
||||
clear_bit(cpu, &data->cpu_event);
|
||||
data->state = STATE_NO_DATA;
|
||||
cpu_clear(cpu, data->cpu_event);
|
||||
} else {
|
||||
data->state = STATE_LOG_RECORD;
|
||||
data->state = STATE_LOG_RECORD;
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -473,27 +490,31 @@ static int
|
|||
salinfo_log_clear(struct salinfo_data *data, int cpu)
|
||||
{
|
||||
sal_log_record_header_t *rh;
|
||||
unsigned long flags;
|
||||
spin_lock_irqsave(&data_saved_lock, flags);
|
||||
data->state = STATE_NO_DATA;
|
||||
if (!test_bit(cpu, &data->cpu_event))
|
||||
return 0;
|
||||
down(&data->sem);
|
||||
clear_bit(cpu, &data->cpu_event);
|
||||
if (data->saved_num) {
|
||||
unsigned long flags;
|
||||
spin_lock_irqsave(&data_saved_lock, flags);
|
||||
shift1_data_saved(data, data->saved_num - 1 );
|
||||
data->saved_num = 0;
|
||||
if (!cpu_isset(cpu, data->cpu_event)) {
|
||||
spin_unlock_irqrestore(&data_saved_lock, flags);
|
||||
return 0;
|
||||
}
|
||||
cpu_clear(cpu, data->cpu_event);
|
||||
if (data->saved_num) {
|
||||
shift1_data_saved(data, data->saved_num - 1);
|
||||
data->saved_num = 0;
|
||||
}
|
||||
spin_unlock_irqrestore(&data_saved_lock, flags);
|
||||
rh = (sal_log_record_header_t *)(data->log_buffer);
|
||||
/* Corrected errors have already been cleared from SAL */
|
||||
if (rh->severity != sal_log_severity_corrected)
|
||||
call_on_cpu(cpu, salinfo_log_clear_cpu, data);
|
||||
/* clearing a record may make a new record visible */
|
||||
salinfo_log_new_read(cpu, data);
|
||||
if (data->state == STATE_LOG_RECORD &&
|
||||
!test_and_set_bit(cpu, &data->cpu_event))
|
||||
up(&data->sem);
|
||||
if (data->state == STATE_LOG_RECORD) {
|
||||
spin_lock_irqsave(&data_saved_lock, flags);
|
||||
cpu_set(cpu, data->cpu_event);
|
||||
salinfo_work_to_do(data);
|
||||
spin_unlock_irqrestore(&data_saved_lock, flags);
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
@ -550,6 +571,53 @@ static struct file_operations salinfo_data_fops = {
|
|||
.write = salinfo_log_write,
|
||||
};
|
||||
|
||||
#ifdef CONFIG_HOTPLUG_CPU
|
||||
static int __devinit
|
||||
salinfo_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
|
||||
{
|
||||
unsigned int i, cpu = (unsigned long)hcpu;
|
||||
unsigned long flags;
|
||||
struct salinfo_data *data;
|
||||
switch (action) {
|
||||
case CPU_ONLINE:
|
||||
spin_lock_irqsave(&data_saved_lock, flags);
|
||||
for (i = 0, data = salinfo_data;
|
||||
i < ARRAY_SIZE(salinfo_data);
|
||||
++i, ++data) {
|
||||
cpu_set(cpu, data->cpu_event);
|
||||
salinfo_work_to_do(data);
|
||||
}
|
||||
spin_unlock_irqrestore(&data_saved_lock, flags);
|
||||
break;
|
||||
case CPU_DEAD:
|
||||
spin_lock_irqsave(&data_saved_lock, flags);
|
||||
for (i = 0, data = salinfo_data;
|
||||
i < ARRAY_SIZE(salinfo_data);
|
||||
++i, ++data) {
|
||||
struct salinfo_data_saved *data_saved;
|
||||
int j;
|
||||
for (j = ARRAY_SIZE(data->data_saved) - 1, data_saved = data->data_saved + j;
|
||||
j >= 0;
|
||||
--j, --data_saved) {
|
||||
if (data_saved->buffer && data_saved->cpu == cpu) {
|
||||
shift1_data_saved(data, j);
|
||||
}
|
||||
}
|
||||
cpu_clear(cpu, data->cpu_event);
|
||||
}
|
||||
spin_unlock_irqrestore(&data_saved_lock, flags);
|
||||
break;
|
||||
}
|
||||
return NOTIFY_OK;
|
||||
}
|
||||
|
||||
static struct notifier_block salinfo_cpu_notifier =
|
||||
{
|
||||
.notifier_call = salinfo_cpu_callback,
|
||||
.priority = 0,
|
||||
};
|
||||
#endif /* CONFIG_HOTPLUG_CPU */
|
||||
|
||||
static int __init
|
||||
salinfo_init(void)
|
||||
{
|
||||
|
|
@ -557,7 +625,7 @@ salinfo_init(void)
|
|||
struct proc_dir_entry **sdir = salinfo_proc_entries; /* keeps track of every entry */
|
||||
struct proc_dir_entry *dir, *entry;
|
||||
struct salinfo_data *data;
|
||||
int i, j, online;
|
||||
int i, j;
|
||||
|
||||
salinfo_dir = proc_mkdir("sal", NULL);
|
||||
if (!salinfo_dir)
|
||||
|
|
@ -572,7 +640,7 @@ salinfo_init(void)
|
|||
for (i = 0; i < ARRAY_SIZE(salinfo_log_name); i++) {
|
||||
data = salinfo_data + i;
|
||||
data->type = i;
|
||||
sema_init(&data->sem, 0);
|
||||
init_MUTEX(&data->mutex);
|
||||
dir = proc_mkdir(salinfo_log_name[i], salinfo_dir);
|
||||
if (!dir)
|
||||
continue;
|
||||
|
|
@ -592,12 +660,8 @@ salinfo_init(void)
|
|||
*sdir++ = entry;
|
||||
|
||||
/* we missed any events before now */
|
||||
online = 0;
|
||||
for_each_online_cpu(j) {
|
||||
set_bit(j, &data->cpu_event);
|
||||
++online;
|
||||
}
|
||||
sema_init(&data->sem, online);
|
||||
for_each_online_cpu(j)
|
||||
cpu_set(j, data->cpu_event);
|
||||
|
||||
*sdir++ = dir;
|
||||
}
|
||||
|
|
@ -609,6 +673,10 @@ salinfo_init(void)
|
|||
salinfo_timer.function = &salinfo_timeout;
|
||||
add_timer(&salinfo_timer);
|
||||
|
||||
#ifdef CONFIG_HOTPLUG_CPU
|
||||
register_cpu_notifier(&salinfo_cpu_notifier);
|
||||
#endif
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user