Imagelibrary/rtems
1
0
Fork 1
mirror of https://gitlab.rtems.org/rtems/rtos/rtems.git synced 2025-12-05 15:15:44 +00:00
Code Issues Packages Projects Releases Wiki Activity

2010-05-09 Joel Sherrill <joel.sherrill@oarcorp.com>

Browse Source 
* timer/timer.c: Now runs on 486 and below again. Reformatted.
This commit is contained in:
Joel Sherrill
2010-05-10 00:29:30 +00:00
parent faeb54323b
commit 171f8346c6
2 changed files with 224 additions and 278 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
c/src/lib/libbsp/i386/pc386/ChangeLog
View File

@@ -1,3 +1,7 @@
2010-05-09 Joel Sherrill <joel.sherrill@oarcorp.com>
* timer/timer.c: Now runs on 486 and below again. Reformatted.
2010-04-30 Sebastian Huber <sebastian.huber@embedded-brains.de>
* Makefile.am, preinstall.am: Update for generic interrupt support

498
c/src/lib/libbsp/i386/pc386/timer/timer.c
View File

@@ -1,42 +1,31 @@
/*-------------------------------------------------------------------------+
| timer.c v1.1 - PC386 BSP - 1997/08/07
+--------------------------------------------------------------------------+
| This file contains the PC386 timer package.
+--------------------------------------------------------------------------+
| NOTE: It is important that the timer start/stop overhead be determined
| when porting or modifying this code.
+--------------------------------------------------------------------------+
| (C) Copyright 1997 -
| - NavIST Group - Real-Time Distributed Systems and Industrial Automation
|
| http://pandora.ist.utl.pt
|
| Instituto Superior Tecnico * Lisboa * PORTUGAL
+--------------------------------------------------------------------------+
| Disclaimer:
|
| This file is provided "AS IS" without warranty of any kind, either
| expressed or implied.
+--------------------------------------------------------------------------+
| This code is base on:
| timer.c,v 1.7 1995/12/19 20:07:43 joel Exp - go32 BSP
|
| Rosimildo daSilva -ConnectTel, Inc - Fixed infinite loop in the Calibration
| routine. I've seen this problems with faster machines ( pentiums ). Sometimes
| RTEMS just hangs at startup.
|
| With the following copyright notice:
| **************************************************************************
| * COPYRIGHT (c) 1989-1999.
| * On-Line Applications Research Corporation (OAR).
| *
| * The license and distribution terms for this file may be
| * found in found in the file LICENSE in this distribution or at
| * http://www.rtems.com/license/LICENSE.
| **************************************************************************
|
| $Id$
+--------------------------------------------------------------------------*/
/*
* This file contains the PC386 timer package.
*
* Rosimildo daSilva -ConnectTel, Inc - Fixed infinite loop in the Calibration
* routine. I've seen this problems with faster machines ( pentiums ). Sometimes
* RTEMS just hangs at startup.
*
* Joel 9 May 2010: This is now seen sometimes on qemu.
*
* Modifications by:
* (C) Copyright 1997 -
* NavIST Group - Real-Time Distributed Systems and Industrial Automation
* http://pandora.ist.utl.pt
* Instituto Superior Tecnico * Lisboa * PORTUGAL
*
* This file is provided "AS IS" without warranty of any kind, either
* expressed or implied.
*
* Based upon code by
* COPYRIGHT (c) 1989-1999.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*/
#include <stdlib.h>
@@ -44,144 +33,115 @@
#include <bsp/irq.h>
#include <libcpu/cpuModel.h>
/*-------------------------------------------------------------------------+
| Constants
+--------------------------------------------------------------------------*/
#define AVG_OVERHEAD 0 /* 0.1 microseconds to start/stop timer. */
#define LEAST_VALID 1 /* Don't trust a value lower than this. */
#define SLOW_DOWN_IO 0x80 /* io which does nothing */
/*
* Constants
*/
#define AVG_OVERHEAD 0 /* 0.1 microseconds to start/stop timer. */
#define LEAST_VALID 1 /* Don't trust a value lower than this. */
#define SLOW_DOWN_IO 0x80 /* io which does nothing */
#define TWO_MS (uint32_t)(2000) /* TWO_MS = 2000us (sic!) */
#define TWO_MS (uint32_t)(2000) /* TWO_MS = 2000us (sic!) */
#define MSK_NULL_COUNT 0x40 /* bit counter available for reading */
#define MSK_NULL_COUNT 0x40 /* bit counter available for reading */
#define CMD_READ_BACK_STATUS 0xE2 /* command read back status */
/*-------------------------------------------------------------------------+
| Global Variables
+--------------------------------------------------------------------------*/
/*
* Global Variables
*/
volatile uint32_t Ttimer_val;
bool benchmark_timer_find_average_overhead = true;
bool benchmark_timer_find_average_overhead = true;
volatile unsigned int fastLoop1ms, slowLoop1ms;
void (*benchmark_timer_initialize_function)(void) = 0;
uint32_t (*benchmark_timer_read_function)(void) = 0;
void (*Timer_exit_function)(void) = 0;
/*-------------------------------------------------------------------------+
| External Prototypes
+--------------------------------------------------------------------------*/
/* timer (int 08h) Interrupt Service Routine (defined in 'timerisr.s') */
extern void timerisr(void);
/* timer (int 08h) Interrupt Service Routine (defined in 'timerisr.s') */
/*
* forward declarations
*/
void Timer_exit(void);
/*-------------------------------------------------------------------------+
| Pentium optimized timer handling.
+--------------------------------------------------------------------------*/
/*
* Pentium optimized timer handling.
*/
/*-------------------------------------------------------------------------+
| Function: Timer_exit
| Description: Timer cleanup routine at RTEMS exit. NOTE: This routine is
| not really necessary, since there will be a reset at exit.
| Global Variables: None.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
void
tsc_timer_exit(void)
/*
* Timer cleanup routine at RTEMS exit. NOTE: This routine is
* not really necessary, since there will be a reset at exit.
*/
void tsc_timer_exit(void)
{
} /* tsc_timer_exit */
}
/*-------------------------------------------------------------------------+
| Function: benchmark_timer_initialize
| Description: Timer initialization routine.
| Global Variables: Ttimer_val.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
void
tsc_timer_initialize(void)
void tsc_timer_initialize(void)
{
static bool First = true;
if (First)
{
if (First) {
First = false;
atexit(Timer_exit); /* Try not to hose the system at exit. */
}
Ttimer_val = rdtsc(); /* read starting time */
} /* tsc_timer_initialize */
}
/*-------------------------------------------------------------------------+
| Function: benchmark_timer_read
| Description: Read hardware timer value.
| Global Variables: Ttimer_val, benchmark_timer_find_average_overhead.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
uint32_t
tsc_read_timer(void)
/*
*
*/
uint32_t tsc_read_timer(void)
{
register uint32_t total;
register uint32_t total;
total = (uint32_t)(rdtsc() - Ttimer_val);
if (benchmark_timer_find_average_overhead)
return total;
else if (total < LEAST_VALID)
return 0; /* below timer resolution */
else
return (total - AVG_OVERHEAD);
} /* tsc_read_timer */
/*-------------------------------------------------------------------------+
| Non-Pentium timer handling.
+--------------------------------------------------------------------------*/
#define US_PER_ISR 250 /* Number of micro-seconds per timer interruption */
if (total < LEAST_VALID)
return 0; /* below timer resolution */
/*-------------------------------------------------------------------------+
| Function: Timer_exit
| Description: Timer cleanup routine at RTEMS exit. NOTE: This routine is
| not really necessary, since there will be a reset at exit.
| Global Variables: None.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
static void
timerOff(const rtems_raw_irq_connect_data* used)
{
/*
* disable interrrupt at i8259 level
*/
BSP_irq_disable_at_i8259s(used->idtIndex - BSP_IRQ_VECTOR_BASE);
/* reset timer mode to standard (DOS) value */
outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN);
outport_byte(TIMER_CNTR0, 0);
outport_byte(TIMER_CNTR0, 0);
} /* Timer_exit */
static void
timerOn(const rtems_raw_irq_connect_data* used)
{
/* load timer for US_PER_ISR microsecond period */
outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN);
outport_byte(TIMER_CNTR0, US_TO_TICK(US_PER_ISR) >> 0 & 0xff);
outport_byte(TIMER_CNTR0, US_TO_TICK(US_PER_ISR) >> 8 & 0xff);
/*
* enable interrrupt at i8259 level
*/
BSP_irq_enable_at_i8259s(used->idtIndex - BSP_IRQ_VECTOR_BASE);
return (total - AVG_OVERHEAD);
}
static int
timerIsOn(const rtems_raw_irq_connect_data *used)
/*
* Non-Pentium timer handling.
*/
#define US_PER_ISR 250 /* Number of micro-seconds per timer interruption */
/*
* Timer cleanup routine at RTEMS exit. NOTE: This routine is
* not really necessary, since there will be a reset at exit.
*/
static void timerOff(const rtems_raw_irq_connect_data* used)
{
return BSP_irq_enabled_at_i8259s(used->idtIndex - BSP_IRQ_VECTOR_BASE);
/*
* disable interrrupt at i8259 level
*/
BSP_irq_disable_at_i8259s(used->idtIndex - BSP_IRQ_VECTOR_BASE);
/* reset timer mode to standard (DOS) value */
outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN);
outport_byte(TIMER_CNTR0, 0);
outport_byte(TIMER_CNTR0, 0);
}
static void timerOn(const rtems_raw_irq_connect_data* used)
{
/* load timer for US_PER_ISR microsecond period */
outport_byte(TIMER_MODE, TIMER_SEL0|TIMER_16BIT|TIMER_RATEGEN);
outport_byte(TIMER_CNTR0, US_TO_TICK(US_PER_ISR) >> 0 & 0xff);
outport_byte(TIMER_CNTR0, US_TO_TICK(US_PER_ISR) >> 8 & 0xff);
/*
* enable interrrupt at i8259 level
*/
BSP_irq_enable_at_i8259s(used->idtIndex - BSP_IRQ_VECTOR_BASE);
}
static int timerIsOn(const rtems_raw_irq_connect_data *used)
{
return BSP_irq_enabled_at_i8259s(used->idtIndex - BSP_IRQ_VECTOR_BASE);
}
static rtems_raw_irq_connect_data timer_raw_irq_data = {
@@ -192,39 +152,35 @@ static rtems_raw_irq_connect_data timer_raw_irq_data = {
timerIsOn
};
/*-------------------------------------------------------------------------+
| Function: Timer_exit
| Description: Timer cleanup routine at RTEMS exit. NOTE: This routine is
| not really necessary, since there will be a reset at exit.
| Global Variables: None.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
void
/*
* Timer cleanup routine at RTEMS exit. NOTE: This routine is
* not really necessary, since there will be a reset at exit.
*/ void
i386_timer_exit(void)
{
i386_delete_idt_entry (&timer_raw_irq_data);
} /* Timer_exit */
}
/*-------------------------------------------------------------------------+
| Function: benchmark_timer_initialize
| Description: Timer initialization routine.
| Global Variables: Ttimer_val.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
void
i386_timer_initialize(void)
extern void rtems_irq_prologue_0(void);
void i386_timer_initialize(void)
{
static bool First = true;
if (First)
{
First = false;
if (First) {
rtems_raw_irq_connect_data raw_irq_data = {
BSP_PERIODIC_TIMER + BSP_IRQ_VECTOR_BASE,
rtems_irq_prologue_0,
NULL,
NULL,
NULL
};
atexit(Timer_exit); /* Try not to hose the system at exit. */
First = false;
i386_delete_idt_entry (&raw_irq_data);
atexit(Timer_exit); /* Try not to hose the system at exit. */
if (!i386_set_idt_entry (&timer_raw_irq_data)) {
printk("raw handler connexion failed\n");
printk("raw handler connection failed\n");
rtems_fatal_error_occurred(1);
}
}
@@ -233,17 +189,12 @@ i386_timer_initialize(void)
while (Ttimer_val == 0)
continue;
Ttimer_val = 0;
} /* benchmark_timer_initialize */
}
/*-------------------------------------------------------------------------+
| Function: benchmark_timer_read
| Description: Read hardware timer value.
| Global Variables: Ttimer_val, benchmark_timer_find_average_overhead.
| Arguments: None.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
uint32_t
i386_read_timer(void)
/*
* Read hardware timer value.
*/
uint32_t i386_read_timer(void)
{
register uint32_t total, clicks;
register uint8_t lsb, msb;
@@ -256,10 +207,11 @@ i386_read_timer(void)
if (benchmark_timer_find_average_overhead)
return total;
else if (total < LEAST_VALID)
return 0; /* below timer resolution */
else
return (total - AVG_OVERHEAD);
if (total < LEAST_VALID)
return 0; /* below timer resolution */
return (total - AVG_OVERHEAD);
}
/*
@@ -267,64 +219,56 @@ i386_read_timer(void)
* or interrupt-based implementation
*/
void
benchmark_timer_initialize(void)
void benchmark_timer_initialize(void)
{
static bool First = true;
static bool First = true;
if (First) {
if (x86_has_tsc()) {
if (First) {
if (x86_has_tsc()) {
#if defined(DEBUG)
printk("TSC: timer initialization\n");
printk("TSC: timer initialization\n");
#endif /* DEBUG */
benchmark_timer_initialize_function = &tsc_timer_initialize;
benchmark_timer_read_function = &tsc_read_timer;
Timer_exit_function = &tsc_timer_exit;
}
else {
benchmark_timer_initialize_function = &tsc_timer_initialize;
benchmark_timer_read_function = &tsc_read_timer;
Timer_exit_function = &tsc_timer_exit;
} else {
#if defined(DEBUG)
printk("ISR: timer initialization\n");
printk("ISR: timer initialization\n");
#endif /* DEBUG */
benchmark_timer_initialize_function = &i386_timer_initialize;
benchmark_timer_read_function = &i386_read_timer;
Timer_exit_function = &i386_timer_exit;
}
First = false;
benchmark_timer_initialize_function = &i386_timer_initialize;
benchmark_timer_read_function = &i386_read_timer;
Timer_exit_function = &i386_timer_exit;
}
(*benchmark_timer_initialize_function)();
First = false;
}
(*benchmark_timer_initialize_function)();
}
uint32_t
benchmark_timer_read(void)
uint32_t benchmark_timer_read(void)
{
return (*benchmark_timer_read_function)();
return (*benchmark_timer_read_function)();
}
void
Timer_exit(void)
void Timer_exit(void)
{
return (*Timer_exit_function)();
return (*Timer_exit_function)();
}
/*-------------------------------------------------------------------------+
| Function: benchmark_timer_disable_subtracting_average_overhead
| Description: Set internal benchmark_timer_find_average_overhead flag value.
| Global Variables: benchmark_timer_find_average_overhead.
| Arguments: find_flag - new value of the flag.
| Returns: Nothing.
+--------------------------------------------------------------------------*/
void
benchmark_timer_disable_subtracting_average_overhead(bool find_flag)
/*
* Set internal benchmark_timer_find_average_overhead flag value.
*/
void benchmark_timer_disable_subtracting_average_overhead(bool find_flag)
{
benchmark_timer_find_average_overhead = find_flag;
} /* benchmark_timer_disable_subtracting_average_overhead */
}
static unsigned short lastLoadedValue;
/*-------------------------------------------------------------------------+
| Description: Loads timer 0 with value passed as arguemnt.
| Returns: Nothing. Loaded value must be a number of clock bits...
+--------------------------------------------------------------------------*/
/*
* Loads timer 0 with value passed as arguemnt.
*
* Returns: Nothing. Loaded value must be a number of clock bits...
*/
void loadTimerValue( unsigned short loadedValue )
{
lastLoadedValue = loadedValue;
@@ -333,24 +277,28 @@ void loadTimerValue( unsigned short loadedValue )
outport_byte(TIMER_CNTR0, (loadedValue >> 8) & 0xff);
}
/*-------------------------------------------------------------------------+
| Description: Reads the current value of the timer, and converts the
| number of ticks to micro-seconds.
| Returns: number of clock bits elapsed since last load.
+--------------------------------------------------------------------------*/
/*
* Reads the current value of the timer, and converts the
* number of ticks to micro-seconds.
*
* Returns: number of clock bits elapsed since last load.
*/
unsigned int readTimer0(void)
{
unsigned short lsb, msb;
unsigned char status;
unsigned int count;
unsigned int count;
outport_byte(TIMER_MODE, (TIMER_RD_BACK | (RB_COUNT_0 & ~(RB_NOT_STATUS | RB_NOT_COUNT))));
outport_byte(
TIMER_MODE,
(TIMER_RD_BACK | (RB_COUNT_0 & ~(RB_NOT_STATUS | RB_NOT_COUNT)))
);
inport_byte(TIMER_CNTR0, status);
inport_byte(TIMER_CNTR0, lsb);
inport_byte(TIMER_CNTR0, msb);
count = ( msb << 8 ) | lsb ;
if (status & RB_OUTPUT )
count += lastLoadedValue;
count += lastLoadedValue;
return (2*lastLoadedValue - count);
}
@@ -387,7 +335,7 @@ Calibrate_loop_1ms(void)
rtems_interrupt_level level;
#ifdef DEBUG_CALIBRATE
printk( "Calibrate_loop_1ms is starting, please wait ( but not too loooong. )\n" );
printk("Calibrate_loop_1ms is starting, please wait (but not too long.)\n");
#endif
targetClockBits = US_TO_TICK(1000);
@@ -459,9 +407,9 @@ Calibrate_loop_1ms(void)
targetClockBits += offset;
#ifdef DEBUG_CALIBRATE
printk("offset = %u, emptyCall = %u, targetClockBits = %u\n",
offset, emptyCall, targetClockBits);
offset, emptyCall, targetClockBits);
printk("slowLoopGranularity = %u fastLoopGranularity = %u\n",
slowLoopGranularity, fastLoopGranularity);
slowLoopGranularity, fastLoopGranularity);
#endif
slowLoop1ms = (targetClockBits - emptyCall) / slowLoopGranularity;
if (slowLoop1ms != 0) {
@@ -478,33 +426,33 @@ Calibrate_loop_1ms(void)
while(1)
{
int previousSign = 0; /* 0 = unset, 1 = incrementing, 2 = decrementing */
Timer0Reset();
slowLoop(slowLoop1ms);
currentClockBits = readTimer0();
if (currentClockBits > targetClockBits) {
if ((currentClockBits - targetClockBits) < slowLoopGranularity) {
/* decrement loop counter anyway to be sure slowLoop(slowLoop1ms) < targetClockBits */
--slowLoop1ms;
break;
}
else {
--slowLoop1ms;
if (slowLoop1ms == 0) break;
if (previousSign == 0) previousSign = 2;
if (previousSign == 1) break;
}
}
else {
if ((targetClockBits - currentClockBits) < slowLoopGranularity) {
break;
}
else {
++slowLoop1ms;
if (previousSign == 0) previousSign = 1;
if (previousSign == 2) break;
}
}
int previousSign = 0; /* 0 = unset, 1 = incrementing, 2 = decrementing */
Timer0Reset();
slowLoop(slowLoop1ms);
currentClockBits = readTimer0();
if (currentClockBits > targetClockBits) {
if ((currentClockBits - targetClockBits) < slowLoopGranularity) {
/* decrement loop counter anyway to be sure slowLoop(slowLoop1ms) < targetClockBits */
--slowLoop1ms;
break;
}
else {
--slowLoop1ms;
if (slowLoop1ms == 0) break;
if (previousSign == 0) previousSign = 2;
if (previousSign == 1) break;
}
}
else {
if ((targetClockBits - currentClockBits) < slowLoopGranularity) {
break;
}
else {
++slowLoop1ms;
if (previousSign == 0) previousSign = 1;
if (previousSign == 2) break;
}
}
}
}
/*
@@ -519,22 +467,22 @@ Calibrate_loop_1ms(void)
fastLoop(fastLoop1ms);
currentClockBits = readTimer0();
if (currentClockBits > targetClockBits) {
if ((currentClockBits - targetClockBits) < fastLoopGranularity)
break;
else {
--fastLoop1ms;
if (previousSign == 0) previousSign = 2;
if (previousSign == 1) break;
}
if ((currentClockBits - targetClockBits) < fastLoopGranularity)
break;
else {
--fastLoop1ms;
if (previousSign == 0) previousSign = 2;
if (previousSign == 1) break;
}
}
else {
if ((targetClockBits - currentClockBits) < fastLoopGranularity)
break;
else {
++fastLoop1ms;
if (previousSign == 0) previousSign = 1;
if (previousSign == 2) break;
}
if ((targetClockBits - currentClockBits) < fastLoopGranularity)
break;
else {
++fastLoop1ms;
if (previousSign == 0) previousSign = 1;
if (previousSign == 2) break;
}
}
}
}
@@ -545,21 +493,15 @@ Calibrate_loop_1ms(void)
}
/*-------------------------------------------------------------------------+
| Function: Wait_X_1ms
| Description: loop which waits at least timeToWait ms
| Global Variables: loop1ms
| Arguments: timeToWait
| Returns: Nothing.
+--------------------------------------------------------------------------*/
void
Wait_X_ms( unsigned int timeToWait){
/*
* loop which waits at least timeToWait ms
*/
void Wait_X_ms( unsigned int timeToWait)
{
unsigned int j;
for (j=0; j<timeToWait ; j++) {
if (slowLoop1ms != 0) slowLoop(slowLoop1ms);
fastLoop(fastLoop1ms);
}
}