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Commit d8e5219f authored by Jesper Nilsson's avatar Jesper Nilsson Committed by Linus Torvalds
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CRISv10 improve and bugfix fasttimer 

Improve and bugfix CRIS v10 fast timers.

- irq_handler_t now only takes two arguments.
- Keep interrupts disabled as long as we have a reference to the
  fasttimer list and only enable them while doing the callback.
  del_fast_timer may be called from other interrupt context.
- Fix bug where debug code could return without calling local_irq_restore.
- Use jiffies instead of usec (change from struct timeval to fasttime_t).
- Don't initialize static variables to zero.
- Remove obsolete #ifndef DECLARE_WAITQUEUE code.
- fast_timer_init should be __initcall.
- Change status/debug variables to unsigned.
- Remove CVS log and CVS id.
Signed-off-by: default avatarJesper Nilsson <jesper.nilsson@axis.com>
Cc: Mikael Starvik <mikael.starvik@axis.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3244c77b
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Showing with 124 additions and 207 deletions
arch/cris/arch-v10/kernel/fasttimer.c
View file @ d8e5219f
/* $Id: fasttimer.c,v 1.9 2005/03/04 08:16:16 starvik Exp $
/*
* linux/arch/cris/kernel/fasttimer.c
*
* Fast timers for ETRAX100/ETRAX100LX
* This may be useful in other OS than Linux so use 2 space indentation...
*
* $Log: fasttimer.c,v $
* Revision 1.9 2005/03/04 08:16:16 starvik
* Merge of Linux 2.6.11.
*
* Revision 1.8 2005/01/05 06:09:29 starvik
* cli()/sti() will be obsolete in 2.6.11.
*
* Revision 1.7 2005/01/03 13:35:46 starvik
* Removed obsolete stuff.
* Mark fast timer IRQ as not shared.
*
* Revision 1.6 2004/05/14 10:18:39 starvik
* Export fast_timer_list
*
* Revision 1.5 2004/05/14 07:58:01 starvik
* Merge of changes from 2.4
*
* Revision 1.4 2003/07/04 08:27:41 starvik
* Merge of Linux 2.5.74
*
* Revision 1.3 2002/12/12 08:26:32 starvik
* Don't use C-comments inside CVS comments
*
* Revision 1.2 2002/12/11 15:42:02 starvik
* Extracted v10 (ETRAX 100LX) specific stuff from arch/cris/kernel/
*
* Revision 1.1 2002/11/18 07:58:06 starvik
* Fast timers (from Linux 2.4)
*
* Revision 1.5 2002/10/15 06:21:39 starvik
* Added call to init_waitqueue_head
*
* Revision 1.4 2002/05/28 17:47:59 johana
* Added del_fast_timer()
*
* Revision 1.3 2002/05/28 16:16:07 johana
* Handle empty fast_timer_list
*
* Revision 1.2 2002/05/27 15:38:42 johana
* Made it compile without warnings on Linux 2.4.
* (includes, wait_queue, PROC_FS and snprintf)
*
* Revision 1.1 2002/05/27 15:32:25 johana
* arch/etrax100/kernel/fasttimer.c v1.8 from the elinux tree.
*
* Revision 1.8 2001/11/27 13:50:40 pkj
* Disable interrupts while stopping the timer and while modifying the
* list of active timers in timer1_handler() as it may be interrupted
* by other interrupts (e.g., the serial interrupt) which may add fast
* timers.
*
* Revision 1.7 2001/11/22 11:50:32 pkj
* * Only store information about the last 16 timers.
* * proc_fasttimer_read() now uses an allocated buffer, since it
* requires more space than just a page even for only writing the
* last 16 timers. The buffer is only allocated on request, so
* unless /proc/fasttimer is read, it is never allocated.
* * Renamed fast_timer_started to fast_timers_started to match
* fast_timers_added and fast_timers_expired.
* * Some clean-up.
*
* Revision 1.6 2000/12/13 14:02:08 johana
* Removed volatile for fast_timer_list
*
* Revision 1.5 2000/12/13 13:55:35 johana
* Added DEBUG_LOG, added som cli() and cleanup
*
* Revision 1.4 2000/12/05 13:48:50 johana
* Added range check when writing proc file, modified timer int handling
*
* Revision 1.3 2000/11/23 10:10:20 johana
* More debug/logging possibilities.
* Moved GET_JIFFIES_USEC() to timex.h and time.c
*
* Revision 1.2 2000/11/01 13:41:04 johana
* Clean up and bugfixes.
* Created new do_gettimeofday_fast() that gets a timeval struct
* with time based on jiffies and *R_TIMER0_DATA, uses a table
* for fast conversion of timer value to microseconds.
* (Much faster the standard do_gettimeofday() and we don't really
* want to use the true time - we want the "uptime" so timers don't screw up
* when we change the time.
* TODO: Add efficient support for continuous timers as well.
*
* Revision 1.1 2000/10/26 15:49:16 johana
* Added fasttimer, highresolution timers.
*
* Copyright (C) 2000,2001 2002 Axis Communications AB, Lund, Sweden
* Copyright (C) 2000-2007 Axis Communications AB, Lund, Sweden
*/
#include <linux/errno.h>
......@@ -125,7 +37,7 @@
#ifdef FAST_TIMER_SANITY_CHECKS
#define SANITYCHECK(x) x
static int sanity_failed = 0;
static int sanity_failed;
#else
#define SANITYCHECK(x)
#endif
......@@ -136,13 +48,13 @@ static int sanity_failed = 0;
#define __INLINE__ inline
static int fast_timer_running = 0;
static int fast_timers_added = 0;
static int fast_timers_started = 0;
static int fast_timers_expired = 0;
static int fast_timers_deleted = 0;
static int fast_timer_is_init = 0;
static int fast_timer_ints = 0;
static unsigned int fast_timer_running;
static unsigned int fast_timers_added;
static unsigned int fast_timers_started;
static unsigned int fast_timers_expired;
static unsigned int fast_timers_deleted;
static unsigned int fast_timer_is_init;
static unsigned int fast_timer_ints;
struct fast_timer *fast_timer_list = NULL;
......@@ -150,8 +62,8 @@ struct fast_timer *fast_timer_list = NULL;
#define DEBUG_LOG_MAX 128
static const char * debug_log_string[DEBUG_LOG_MAX];
static unsigned long debug_log_value[DEBUG_LOG_MAX];
static int debug_log_cnt = 0;
static int debug_log_cnt_wrapped = 0;
static unsigned int debug_log_cnt;
static unsigned int debug_log_cnt_wrapped;
#define DEBUG_LOG(string, value) \
{ \
......@@ -206,42 +118,26 @@ int timer_freq_settings[NUM_TIMER_STATS];
int timer_delay_settings[NUM_TIMER_STATS];
/* Not true gettimeofday, only checks the jiffies (uptime) + useconds */
void __INLINE__ do_gettimeofday_fast(struct timeval *tv)
void __INLINE__ do_gettimeofday_fast(struct fasttime_t *tv)
{
unsigned long sec = jiffies;
unsigned long usec = GET_JIFFIES_USEC();
usec += (sec % HZ) * (1000000 / HZ);
sec = sec / HZ;
if (usec > 1000000)
{
usec -= 1000000;
sec++;
}
tv->tv_sec = sec;
tv->tv_usec = usec;
tv->tv_jiff = jiffies;
tv->tv_usec = GET_JIFFIES_USEC();
}
int __INLINE__ timeval_cmp(struct timeval *t0, struct timeval *t1)
int __INLINE__ timeval_cmp(struct fasttime_t *t0, struct fasttime_t *t1)
{
if (t0->tv_sec < t1->tv_sec)
{
return -1;
}
else if (t0->tv_sec > t1->tv_sec)
{
return 1;
}
if (t0->tv_usec < t1->tv_usec)
{
return -1;
}
else if (t0->tv_usec > t1->tv_usec)
{
return 1;
}
return 0;
/* Compare jiffies. Takes care of wrapping */
if (time_before(t0->tv_jiff, t1->tv_jiff))
return -1;
else if (time_after(t0->tv_jiff, t1->tv_jiff))
return 1;
/* Compare us */
if (t0->tv_usec < t1->tv_usec)
return -1;
else if (t0->tv_usec > t1->tv_usec)
return 1;
return 0;
}
void __INLINE__ start_timer1(unsigned long delay_us)
......@@ -285,7 +181,7 @@ void __INLINE__ start_timer1(unsigned long delay_us)
timer_freq_settings[fast_timers_started % NUM_TIMER_STATS] = freq_index;
timer_delay_settings[fast_timers_started % NUM_TIMER_STATS] = delay_us;
D1(printk("start_timer1 : %d us freq: %i div: %i\n",
D1(printk(KERN_DEBUG "start_timer1 : %d us freq: %i div: %i\n",
delay_us, freq_index, div));
/* Clear timer1 irq */
*R_IRQ_MASK0_CLR = IO_STATE(R_IRQ_MASK0_CLR, timer1, clr);
......@@ -340,7 +236,7 @@ void start_one_shot_timer(struct fast_timer *t,
printk(KERN_WARNING
"timer name: %s data: 0x%08lX already in list!\n", name, data);
sanity_failed++;
return;
goto done;
}
else
{
......@@ -356,11 +252,11 @@ void start_one_shot_timer(struct fast_timer *t,
t->name = name;
t->tv_expires.tv_usec = t->tv_set.tv_usec + delay_us % 1000000;
t->tv_expires.tv_sec = t->tv_set.tv_sec + delay_us / 1000000;
t->tv_expires.tv_jiff = t->tv_set.tv_jiff + delay_us / 1000000 / HZ;
if (t->tv_expires.tv_usec > 1000000)
{
t->tv_expires.tv_usec -= 1000000;
t->tv_expires.tv_sec++;
t->tv_expires.tv_jiff += HZ;
}
#ifdef FAST_TIMER_LOG
timer_added_log[fast_timers_added % NUM_TIMER_STATS] = *t;
......@@ -401,6 +297,7 @@ void start_one_shot_timer(struct fast_timer *t,
D2(printk("start_one_shot_timer: %d us done\n", delay_us));
done:
local_irq_restore(flags);
} /* start_one_shot_timer */
......@@ -444,11 +341,18 @@ int del_fast_timer(struct fast_timer * t)
/* Timer 1 interrupt handler */
static irqreturn_t
timer1_handler(int irq, void *dev_id, struct pt_regs *regs)
timer1_handler(int irq, void *dev_id)
{
struct fast_timer *t;
unsigned long flags;
/* We keep interrupts disabled not only when we modify the
* fast timer list, but any time we hold a reference to a
* timer in the list, since del_fast_timer may be called
* from (another) interrupt context. Thus, the only time
* when interrupts are enabled is when calling the timer
* callback function.
*/
local_irq_save(flags);
/* Clear timer1 irq */
......@@ -466,16 +370,17 @@ timer1_handler(int irq, void *dev_id, struct pt_regs *regs)
fast_timer_running = 0;
fast_timer_ints++;
local_irq_restore(flags);
t = fast_timer_list;
while (t)
{
struct timeval tv;
struct fasttime_t tv;
fast_timer_function_type *f;
unsigned long d;
/* Has it really expired? */
do_gettimeofday_fast(&tv);
D1(printk("t: %is %06ius\n", tv.tv_sec, tv.tv_usec));
D1(printk(KERN_DEBUG "t: %is %06ius\n",
tv.tv_jiff, tv.tv_usec));
if (timeval_cmp(&t->tv_expires, &tv) <= 0)
{
......@@ -486,7 +391,6 @@ timer1_handler(int irq, void *dev_id, struct pt_regs *regs)
fast_timers_expired++;
/* Remove this timer before call, since it may reuse the timer */
local_irq_save(flags);
if (t->prev)
{
t->prev->next = t->next;
......@@ -501,16 +405,23 @@ timer1_handler(int irq, void *dev_id, struct pt_regs *regs)
}
t->prev = NULL;
t->next = NULL;
local_irq_restore(flags);
if (t->function != NULL)
{
t->function(t->data);
}
else
{
/* Save function callback data before enabling
* interrupts, since the timer may be removed and
* we don't know how it was allocated
* (e.g. ->function and ->data may become overwritten
* after deletion if the timer was stack-allocated).
*/
f = t->function;
d = t->data;
if (f != NULL) {
/* Run callback with interrupts enabled. */
local_irq_restore(flags);
f(d);
local_irq_save(flags);
} else
DEBUG_LOG("!timer1 %i function==NULL!\n", fast_timer_ints);
}
}
else
{
......@@ -518,16 +429,20 @@ timer1_handler(int irq, void *dev_id, struct pt_regs *regs)
D1(printk(".\n"));
}
local_irq_save(flags);
if ((t = fast_timer_list) != NULL)
{
/* Start next timer.. */
long us;
struct timeval tv;
long us = 0;
struct fasttime_t tv;
do_gettimeofday_fast(&tv);
us = ((t->tv_expires.tv_sec - tv.tv_sec) * 1000000 +
t->tv_expires.tv_usec - tv.tv_usec);
/* time_after_eq takes care of wrapping */
if (time_after_eq(t->tv_expires.tv_jiff, tv.tv_jiff))
us = ((t->tv_expires.tv_jiff - tv.tv_jiff) *
1000000 / HZ + t->tv_expires.tv_usec -
tv.tv_usec);
if (us > 0)
{
if (!fast_timer_running)
......@@ -537,7 +452,6 @@ timer1_handler(int irq, void *dev_id, struct pt_regs *regs)
#endif
start_timer1(us);
}
local_irq_restore(flags);
break;
}
else
......@@ -548,9 +462,10 @@ timer1_handler(int irq, void *dev_id, struct pt_regs *regs)
D1(printk("e! %d\n", us));
}
}
local_irq_restore(flags);
}
local_irq_restore(flags);
if (!t)
{
D1(printk("t1 stop!\n"));
......@@ -575,28 +490,17 @@ static void wake_up_func(unsigned long data)
void schedule_usleep(unsigned long us)
{
struct fast_timer t;
#ifdef DECLARE_WAITQUEUE
wait_queue_head_t sleep_wait;
init_waitqueue_head(&sleep_wait);
{
DECLARE_WAITQUEUE(wait, current);
#else
struct wait_queue *sleep_wait = NULL;
struct wait_queue wait = { current, NULL };
#endif
D1(printk("schedule_usleep(%d)\n", us));
add_wait_queue(&sleep_wait, &wait);
set_current_state(TASK_INTERRUPTIBLE);
start_one_shot_timer(&t, wake_up_func, (unsigned long)&sleep_wait, us,
"usleep");
schedule();
set_current_state(TASK_RUNNING);
remove_wait_queue(&sleep_wait, &wait);
/* Uninterruptible sleep on the fast timer. (The condition is somewhat
* redundant since the timer is what wakes us up.) */
wait_event(sleep_wait, !fast_timer_pending(&t));
D1(printk("done schedule_usleep(%d)\n", us));
#ifdef DECLARE_WAITQUEUE
}
#endif
}
#ifdef CONFIG_PROC_FS
......@@ -616,7 +520,7 @@ static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
unsigned long flags;
int i = 0;
int num_to_show;
struct timeval tv;
struct fasttime_t tv;
struct fast_timer *t, *nextt;
static char *bigbuf = NULL;
static unsigned long used;
......@@ -624,7 +528,8 @@ static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
if (!bigbuf && !(bigbuf = vmalloc(BIG_BUF_SIZE)))
{
used = 0;
bigbuf[0] = '\0';
if (buf)
buf[0] = '\0';
return 0;
}
......@@ -646,7 +551,7 @@ static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
used += sprintf(bigbuf + used, "Fast timer running: %s\n",
fast_timer_running ? "yes" : "no");
used += sprintf(bigbuf + used, "Current time: %lu.%06lu\n",
(unsigned long)tv.tv_sec,
(unsigned long)tv.tv_jiff,
(unsigned long)tv.tv_usec);
#ifdef FAST_TIMER_SANITY_CHECKS
used += sprintf(bigbuf + used, "Sanity failed: %i\n",
......@@ -696,9 +601,9 @@ static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
"d: %6li us data: 0x%08lX"
"\n",
t->name,
(unsigned long)t->tv_set.tv_sec,
(unsigned long)t->tv_set.tv_jiff,
(unsigned long)t->tv_set.tv_usec,
(unsigned long)t->tv_expires.tv_sec,
(unsigned long)t->tv_expires.tv_jiff,
(unsigned long)t->tv_expires.tv_usec,
t->delay_us,
t->data
......@@ -718,9 +623,9 @@ static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
"d: %6li us data: 0x%08lX"
"\n",
t->name,
(unsigned long)t->tv_set.tv_sec,
(unsigned long)t->tv_set.tv_jiff,
(unsigned long)t->tv_set.tv_usec,
(unsigned long)t->tv_expires.tv_sec,
(unsigned long)t->tv_expires.tv_jiff,
(unsigned long)t->tv_expires.tv_usec,
t->delay_us,
t->data
......@@ -738,9 +643,9 @@ static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
"d: %6li us data: 0x%08lX"
"\n",
t->name,
(unsigned long)t->tv_set.tv_sec,
(unsigned long)t->tv_set.tv_jiff,
(unsigned long)t->tv_set.tv_usec,
(unsigned long)t->tv_expires.tv_sec,
(unsigned long)t->tv_expires.tv_jiff,
(unsigned long)t->tv_expires.tv_usec,
t->delay_us,
t->data
......@@ -761,15 +666,15 @@ static int proc_fasttimer_read(char *buf, char **start, off_t offset, int len
/* " func: 0x%08lX" */
"\n",
t->name,
(unsigned long)t->tv_set.tv_sec,
(unsigned long)t->tv_set.tv_jiff,
(unsigned long)t->tv_set.tv_usec,
(unsigned long)t->tv_expires.tv_sec,
(unsigned long)t->tv_expires.tv_jiff,
(unsigned long)t->tv_expires.tv_usec,
t->delay_us,
t->data
/* , t->function */
);
local_irq_disable();
local_irq_save(flags);
if (t->next != nextt)
{
printk(KERN_WARNING "timer removed!\n");
......@@ -798,7 +703,7 @@ static volatile int num_test_timeout = 0;
static struct fast_timer tr[10];
static int exp_num[10];
static struct timeval tv_exp[100];
static struct fasttime_t tv_exp[100];
static void test_timeout(unsigned long data)
{
......@@ -836,7 +741,7 @@ static void fast_timer_test(void)
int prev_num;
int j;
struct timeval tv, tv0, tv1, tv2;
struct fasttime_t tv, tv0, tv1, tv2;
printk("fast_timer_test() start\n");
do_gettimeofday_fast(&tv);
......@@ -849,7 +754,8 @@ static void fast_timer_test(void)
{
do_gettimeofday_fast(&tv_exp[j]);
}
printk("fast_timer_test() %is %06i\n", tv.tv_sec, tv.tv_usec);
printk(KERN_DEBUG "fast_timer_test() %is %06i\n",
tv.tv_jiff, tv.tv_usec);
for (j = 0; j < 1000; j++)
{
......@@ -858,12 +764,12 @@ static void fast_timer_test(void)
}
for (j = 0; j < 100; j++)
{
printk("%i.%i %i.%i %i.%i %i.%i %i.%i\n",
tv_exp[j].tv_sec,tv_exp[j].tv_usec,
tv_exp[j+1].tv_sec,tv_exp[j+1].tv_usec,
tv_exp[j+2].tv_sec,tv_exp[j+2].tv_usec,
tv_exp[j+3].tv_sec,tv_exp[j+3].tv_usec,
tv_exp[j+4].tv_sec,tv_exp[j+4].tv_usec);
printk(KERN_DEBUG "%i.%i %i.%i %i.%i %i.%i %i.%i\n",
tv_exp[j].tv_jiff, tv_exp[j].tv_usec,
tv_exp[j+1].tv_jiff, tv_exp[j+1].tv_usec,
tv_exp[j+2].tv_jiff, tv_exp[j+2].tv_usec,
tv_exp[j+3].tv_jiff, tv_exp[j+3].tv_usec,
tv_exp[j+4].tv_jiff, tv_exp[j+4].tv_usec);
j += 4;
}
do_gettimeofday_fast(&tv0);
......@@ -895,9 +801,12 @@ static void fast_timer_test(void)
}
}
do_gettimeofday_fast(&tv2);
printk("Timers started %is %06i\n", tv0.tv_sec, tv0.tv_usec);
printk("Timers started at %is %06i\n", tv1.tv_sec, tv1.tv_usec);
printk("Timers done %is %06i\n", tv2.tv_sec, tv2.tv_usec);
printk(KERN_DEBUG "Timers started %is %06i\n",
tv0.tv_jiff, tv0.tv_usec);
printk(KERN_DEBUG "Timers started at %is %06i\n",
tv1.tv_jiff, tv1.tv_usec);
printk(KERN_DEBUG "Timers done %is %06i\n",
tv2.tv_jiff, tv2.tv_usec);
DP(printk("buf0:\n");
printk(buf0);
printk("buf1:\n");
......@@ -919,9 +828,9 @@ static void fast_timer_test(void)
printk("%-10s set: %6is %06ius exp: %6is %06ius "
"data: 0x%08X func: 0x%08X\n",
t->name,
t->tv_set.tv_sec,
t->tv_set.tv_jiff,
t->tv_set.tv_usec,
t->tv_expires.tv_sec,
t->tv_expires.tv_jiff,
t->tv_expires.tv_usec,
t->data,
t->function
......@@ -929,10 +838,12 @@ static void fast_timer_test(void)
printk(" del: %6ius did exp: %6is %06ius as #%i error: %6li\n",
t->delay_us,
tv_exp[j].tv_sec,
tv_exp[j].tv_jiff,
tv_exp[j].tv_usec,
exp_num[j],
(tv_exp[j].tv_sec - t->tv_expires.tv_sec)*1000000 + tv_exp[j].tv_usec - t->tv_expires.tv_usec);
(tv_exp[j].tv_jiff - t->tv_expires.tv_jiff) *
1000000 + tv_exp[j].tv_usec -
t->tv_expires.tv_usec);
}
proc_fasttimer_read(buf5, NULL, 0, 0, 0);
printk("buf5 after all done:\n");
......@@ -942,7 +853,7 @@ static void fast_timer_test(void)
#endif
void fast_timer_init(void)
int fast_timer_init(void)
{
/* For some reason, request_irq() hangs when called froom time_init() */
if (!fast_timer_is_init)
......@@ -975,4 +886,6 @@ void fast_timer_init(void)
fast_timer_test();
#endif
}
return 0;
}
__initcall(fast_timer_init);
include/asm-cris/fasttimer.h
View file @ d8e5219f
/* $Id: fasttimer.h,v 1.3 2004/05/14 10:19:19 starvik Exp $
/*
* linux/include/asm-cris/fasttimer.h
*
* Fast timers for ETRAX100LX
* This may be useful in other OS than Linux so use 2 space indentation...
* Copyright (C) 2000, 2002 Axis Communications AB
* Copyright (C) 2000-2007 Axis Communications AB
*/
#include <linux/time.h> /* struct timeval */
#include <linux/timex.h>
......@@ -12,11 +11,16 @@
typedef void fast_timer_function_type(unsigned long);
struct fasttime_t {
unsigned long tv_jiff; /* jiffies */
unsigned long tv_usec; /* microseconds */
};
struct fast_timer{ /* Close to timer_list */
struct fast_timer *next;
struct fast_timer *prev;
struct timeval tv_set;
struct timeval tv_expires;
struct fasttime_t tv_set;
struct fasttime_t tv_expires;
unsigned long delay_us;
fast_timer_function_type *function;
unsigned long data;
......@@ -38,6 +42,6 @@ int del_fast_timer(struct fast_timer * t);
void schedule_usleep(unsigned long us);
void fast_timer_init(void);
int fast_timer_init(void);
#endif
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