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new file for MIPS port by Craig Lebakken (lebakken@minn.net) and

Browse Source 
Derrick Ostertag (ostertag@transition.com).
This commit is contained in:
Joel Sherrill
1996-09-06 18:11:41 +00:00
parent f29032c587
commit f198c63d6a
71 changed files with 16850 additions and 0 deletions
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245
c/src/lib/libcpu/mips/clock/ckinit.c Normal file
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/* ckinit.c
*
* This file contains the clock driver initialization for the IDT 4650.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
* Derived from c/src/lib/libbsp/no_cpu/no_bsp/clock/ckinit.c:
*
* COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
* On-Line Applications Research Corporation (OAR).
* All rights assigned to U.S. Government, 1994.
*
* This material may be reproduced by or for the U.S. Government pursuant
* to the copyright license under the clause at DFARS 252.227-7013. This
* notice must appear in all copies of this file and its derivatives.
*
* ckinit.c,v 1.5 1995/10/30 21:53:23 joel Exp
*/
#ifndef lint
static char _sccsid[] = "@(#)ckinit.c 08/20/96 1.3\n";
#endif
#include <stdlib.h>
#include <rtems.h>
#include <rtems/libio.h>
#include <bsp.h>
#include <excepthdr.h>
#include "clock.h"
#define CLOCKS_PER_MICROSECOND ( CPU_CLOCK_RATE_MHZ ) /* equivalent to CPU clock speed in MHz */
void Clock_exit( void );
rtems_isr Clock_isr( rtems_vector_number vector );
/*
* The interrupt vector number associated with the clock tick device
* driver.
*/
#define CLOCK_VECTOR_MASK EXT_INT5
#define CLOCK_VECTOR 0x7
/*
* Clock_driver_ticks is a monotonically increasing counter of the
* number of clock ticks since the driver was initialized.
*/
volatile rtems_unsigned32 Clock_driver_ticks;
/*
* Clock_isrs is the number of clock ISRs until the next invocation of
* the RTEMS clock tick routine. The clock tick device driver
* gets an interrupt once a millisecond and counts down until the
* length of time between the user configured microseconds per tick
* has passed.
*/
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
/*
* The previous ISR on this clock tick interrupt vector.
*/
rtems_isr_entry Old_ticker;
void Clock_exit( void );
static unsigned32 mips_timer_rate = 0;
/*
* Isr Handler
*/
rtems_isr Clock_isr(
rtems_vector_number vector
)
{
/*
* bump the number of clock driver ticks since initialization
*
* determine if it is time to announce the passing of tick as configured
* to RTEMS through the rtems_clock_tick directive
*
* perform any timer dependent tasks
*/
/* refresh the internal CPU timer */
mips_set_timer( mips_timer_rate );
Clock_driver_ticks += 1;
rtems_clock_tick();
}
/* User callback shell (set from Clock_Control) */
static void (*user_callback)(void);
rtems_isr User_Clock_isr(
rtems_vector_number vector
)
{
/* refresh the internal CPU timer */
mips_set_timer( mips_timer_rate );
if (user_callback)
user_callback();
}
/*
* Install_clock
*
* Install a clock tick handleR and reprograms the chip. This
* is used to initially establish the clock tick.
*/
void Install_clock(
rtems_isr_entry clock_isr
)
{
/*
* Initialize the clock tick device driver variables
*/
Clock_driver_ticks = 0;
Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
/*
* If ticks_per_timeslice is configured as non-zero, then the user
* wants a clock tick.
*/
if ( BSP_Configuration.ticks_per_timeslice ) {
Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
/*
* Hardware specific initialize goes here
*/
mips_timer_rate = BSP_Configuration.microseconds_per_tick * CLOCKS_PER_MICROSECOND;
mips_set_timer( mips_timer_rate );
enable_int(CLOCK_VECTOR_MASK);
}
/*
* Schedule the clock cleanup routine to execute if the application exits.
*/
atexit( Clock_exit );
}
/*
* Clean up before the application exits
*/
void Clock_exit( void )
{
if ( BSP_Configuration.ticks_per_timeslice ) {
/* mips: turn off the timer interrupts */
disable_int(CLOCK_VECTOR_MASK);
}
}
/*
* Clock_initialize
*
* Device driver entry point for clock tick driver initialization.
*/
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
Install_clock( Clock_isr );
/*
* make major/minor avail to others such as shared memory driver
*/
rtems_clock_major = major;
rtems_clock_minor = minor;
return RTEMS_SUCCESSFUL;
}
rtems_device_driver Clock_control(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
rtems_unsigned32 isrlevel;
rtems_libio_ioctl_args_t *args = pargp;
if (args == 0)
goto done;
/*
* This is hokey, but until we get a defined interface
* to do this, it will just be this simple...
*/
if (args->command == rtems_build_name('I', 'S', 'R', ' '))
{
Clock_isr(CLOCK_VECTOR);
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
{
rtems_interrupt_disable( isrlevel );
user_callback = (void (*)(void))args->buffer;
(void) set_vector( User_Clock_isr, CLOCK_VECTOR, 1 );
rtems_interrupt_enable( isrlevel );
}
done:
return RTEMS_SUCCESSFUL;
}

44
c/src/lib/libcpu/mips/clock/clock.S Normal file
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/* clock.s
*
* This file contains the assembly code for the IDT 4650 clock driver.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
*/
/* @(#)clock.S 08/20/96 1.2 */
#include <rtems/score/iregdef.h>
#include <rtems/score/idtcpu.h>
#include <rtems/score/idtmon.h>
FRAME(mips_set_timer,sp,0,ra)
.set noreorder
mfc0 t0,C0_COUNT
nop
addu t0,a0,t0
mtc0 t0,C0_COMPARE
nop
j ra
.set reorder
ENDFRAME(mips_set_timer)
FRAME(mips_get_timer,sp,0,ra)
.set noreorder
mfc0 v0,C0_COUNT
nop
j ra
.set reorder
ENDFRAME(mips_get_timer)

24
c/src/lib/libcpu/mips/clock/clock.h Normal file
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/* clock.s
*
* This file contains the assembly code for the IDT 4650 clock driver.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
*/
/* @(#)clock.h 08/20/96 1.2 */
extern void mips_set_timer( unsigned32 timer_clock_interval );

34
c/src/lib/libcpu/mips/timer/gettime.S Normal file
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/* gettime.s
*
* This file contains the assembly code for the IDT 4650 timer driver.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
*/
/* @(#)gettime.S 08/20/96 1.2 */
#include <rtems/score/iregdef.h>
#include <rtems/score/idtcpu.h>
#include <rtems/score/idtmon.h>
FRAME(mips_read_timer,sp,0,ra)
.set noreorder
mfc0 v0,C0_COUNT
nop
j ra
.set reorder
ENDFRAME(mips_read_timer)

136
c/src/lib/libcpu/mips/timer/timer.c Normal file
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/* timer.c
*
* This file contains the initialization code for the IDT 4650 timer driver.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
* derived from src/lib/libbsp/no_cpu/no_bsp/timer/timer.c
*
* This file manages the benchmark timer used by the RTEMS Timing Test
* Suite. Each measured time period is demarcated by calls to
* Timer_initialize() and Read_timer(). Read_timer() usually returns
* the number of microseconds since Timer_initialize() exitted.
*
* NOTE: It is important that the timer start/stop overhead be
* determined when porting or modifying this code.
*
* COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
* On-Line Applications Research Corporation (OAR).
* All rights assigned to U.S. Government, 1994.
*
* This material may be reproduced by or for the U.S. Government pursuant
* to the copyright license under the clause at DFARS 252.227-7013. This
* notice must appear in all copies of this file and its derivatives.
*
* timer.c,v 1.2 1995/05/31 16:56:39 joel Exp
*/
#ifndef lint
static char _sccsid[] = "@(#)timer.c 08/20/96 1.5\n";
#endif
#include <rtems.h>
#include <bsp.h>
#define CLOCKS_PER_MICROSECOND ( CPU_CLOCK_RATE_MHZ )
#define TIMER_MAX_VALUE 0xffffffff
extern unsigned32 mips_read_timer( void );
static rtems_boolean Timer_driver_Find_average_overhead;
static unsigned32 Timer_initial_value = 0;
void Timer_initialize( void )
{
Timer_initial_value = mips_read_timer();
/*
* Somehow start the timer
*/
/* Timer on 4650 is always running */
}
/*
* The following controls the behavior of Read_timer().
*
* AVG_OVEREHAD is the overhead for starting and stopping the timer. It
* is usually deducted from the number returned.
*
* LEAST_VALID is the lowest number this routine should trust. Numbers
* below this are "noise" and zero is returned.
*/
#define AVG_OVERHEAD 8 /* It typically takes X.X microseconds */
/* (Y countdowns) to start/stop the timer. */
/* This value is in cycles. */
#define LEAST_VALID 1 /* Don't trust a clicks value lower than this */
int Read_timer( void )
{
unsigned64 clicks;
unsigned32 total;
/*
* Read the timer and see how many clicks it has been since we started.
*/
clicks = mips_read_timer(); /* XXX: read some HW here */
if (clicks < Timer_initial_value)
{
clicks += TIMER_MAX_VALUE;
}
clicks -= Timer_initial_value;
/*
* Total is calculated by taking into account the number of timer overflow
* interrupts since the timer was initialized and clicks since the last
* interrupts.
*/
#if 0 /* leave total in number of cycles */
total = clicks / CLOCKS_PER_MICROSECOND;
#else
total = clicks;
#endif
if ( Timer_driver_Find_average_overhead == 1 )
return total; /* in # cycles units */
else {
if ( total < LEAST_VALID )
return 0; /* below timer resolution */
/*
* leave total in cycles
*/
return (total - AVG_OVERHEAD);
}
}
/*
* Empty function call used in loops to measure basic cost of looping
* in Timing Test Suite.
*/
rtems_status_code Empty_function( void )
{
return RTEMS_SUCCESSFUL;
}
void Set_find_average_overhead(
rtems_boolean find_flag
)
{
Timer_driver_Find_average_overhead = find_flag;
}

245
c/src/lib/libcpu/mips64orion/clock/ckinit.c Normal file
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/* ckinit.c
*
* This file contains the clock driver initialization for the IDT 4650.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
* Derived from c/src/lib/libbsp/no_cpu/no_bsp/clock/ckinit.c:
*
* COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
* On-Line Applications Research Corporation (OAR).
* All rights assigned to U.S. Government, 1994.
*
* This material may be reproduced by or for the U.S. Government pursuant
* to the copyright license under the clause at DFARS 252.227-7013. This
* notice must appear in all copies of this file and its derivatives.
*
* ckinit.c,v 1.5 1995/10/30 21:53:23 joel Exp
*/
#ifndef lint
static char _sccsid[] = "@(#)ckinit.c 08/20/96 1.3\n";
#endif
#include <stdlib.h>
#include <rtems.h>
#include <rtems/libio.h>
#include <bsp.h>
#include <excepthdr.h>
#include "clock.h"
#define CLOCKS_PER_MICROSECOND ( CPU_CLOCK_RATE_MHZ ) /* equivalent to CPU clock speed in MHz */
void Clock_exit( void );
rtems_isr Clock_isr( rtems_vector_number vector );
/*
* The interrupt vector number associated with the clock tick device
* driver.
*/
#define CLOCK_VECTOR_MASK EXT_INT5
#define CLOCK_VECTOR 0x7
/*
* Clock_driver_ticks is a monotonically increasing counter of the
* number of clock ticks since the driver was initialized.
*/
volatile rtems_unsigned32 Clock_driver_ticks;
/*
* Clock_isrs is the number of clock ISRs until the next invocation of
* the RTEMS clock tick routine. The clock tick device driver
* gets an interrupt once a millisecond and counts down until the
* length of time between the user configured microseconds per tick
* has passed.
*/
rtems_unsigned32 Clock_isrs; /* ISRs until next tick */
/*
* These are set by clock driver during its init
*/
rtems_device_major_number rtems_clock_major = ~0;
rtems_device_minor_number rtems_clock_minor;
/*
* The previous ISR on this clock tick interrupt vector.
*/
rtems_isr_entry Old_ticker;
void Clock_exit( void );
static unsigned32 mips_timer_rate = 0;
/*
* Isr Handler
*/
rtems_isr Clock_isr(
rtems_vector_number vector
)
{
/*
* bump the number of clock driver ticks since initialization
*
* determine if it is time to announce the passing of tick as configured
* to RTEMS through the rtems_clock_tick directive
*
* perform any timer dependent tasks
*/
/* refresh the internal CPU timer */
mips_set_timer( mips_timer_rate );
Clock_driver_ticks += 1;
rtems_clock_tick();
}
/* User callback shell (set from Clock_Control) */
static void (*user_callback)(void);
rtems_isr User_Clock_isr(
rtems_vector_number vector
)
{
/* refresh the internal CPU timer */
mips_set_timer( mips_timer_rate );
if (user_callback)
user_callback();
}
/*
* Install_clock
*
* Install a clock tick handleR and reprograms the chip. This
* is used to initially establish the clock tick.
*/
void Install_clock(
rtems_isr_entry clock_isr
)
{
/*
* Initialize the clock tick device driver variables
*/
Clock_driver_ticks = 0;
Clock_isrs = BSP_Configuration.microseconds_per_tick / 1000;
/*
* If ticks_per_timeslice is configured as non-zero, then the user
* wants a clock tick.
*/
if ( BSP_Configuration.ticks_per_timeslice ) {
Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 );
/*
* Hardware specific initialize goes here
*/
mips_timer_rate = BSP_Configuration.microseconds_per_tick * CLOCKS_PER_MICROSECOND;
mips_set_timer( mips_timer_rate );
enable_int(CLOCK_VECTOR_MASK);
}
/*
* Schedule the clock cleanup routine to execute if the application exits.
*/
atexit( Clock_exit );
}
/*
* Clean up before the application exits
*/
void Clock_exit( void )
{
if ( BSP_Configuration.ticks_per_timeslice ) {
/* mips: turn off the timer interrupts */
disable_int(CLOCK_VECTOR_MASK);
}
}
/*
* Clock_initialize
*
* Device driver entry point for clock tick driver initialization.
*/
rtems_device_driver Clock_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
Install_clock( Clock_isr );
/*
* make major/minor avail to others such as shared memory driver
*/
rtems_clock_major = major;
rtems_clock_minor = minor;
return RTEMS_SUCCESSFUL;
}
rtems_device_driver Clock_control(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *pargp
)
{
rtems_unsigned32 isrlevel;
rtems_libio_ioctl_args_t *args = pargp;
if (args == 0)
goto done;
/*
* This is hokey, but until we get a defined interface
* to do this, it will just be this simple...
*/
if (args->command == rtems_build_name('I', 'S', 'R', ' '))
{
Clock_isr(CLOCK_VECTOR);
}
else if (args->command == rtems_build_name('N', 'E', 'W', ' '))
{
rtems_interrupt_disable( isrlevel );
user_callback = (void (*)(void))args->buffer;
(void) set_vector( User_Clock_isr, CLOCK_VECTOR, 1 );
rtems_interrupt_enable( isrlevel );
}
done:
return RTEMS_SUCCESSFUL;
}

44
c/src/lib/libcpu/mips64orion/clock/clock.S Normal file
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/* clock.s
*
* This file contains the assembly code for the IDT 4650 clock driver.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
*/
/* @(#)clock.S 08/20/96 1.2 */
#include <rtems/score/iregdef.h>
#include <rtems/score/idtcpu.h>
#include <rtems/score/idtmon.h>
FRAME(mips_set_timer,sp,0,ra)
.set noreorder
mfc0 t0,C0_COUNT
nop
addu t0,a0,t0
mtc0 t0,C0_COMPARE
nop
j ra
.set reorder
ENDFRAME(mips_set_timer)
FRAME(mips_get_timer,sp,0,ra)
.set noreorder
mfc0 v0,C0_COUNT
nop
j ra
.set reorder
ENDFRAME(mips_get_timer)

24
c/src/lib/libcpu/mips64orion/clock/clock.h Normal file
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/* clock.s
*
* This file contains the assembly code for the IDT 4650 clock driver.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
*/
/* @(#)clock.h 08/20/96 1.2 */
extern void mips_set_timer( unsigned32 timer_clock_interval );

34
c/src/lib/libcpu/mips64orion/timer/gettime.S Normal file
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/* gettime.s
*
* This file contains the assembly code for the IDT 4650 timer driver.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
*/
/* @(#)gettime.S 08/20/96 1.2 */
#include <rtems/score/iregdef.h>
#include <rtems/score/idtcpu.h>
#include <rtems/score/idtmon.h>
FRAME(mips_read_timer,sp,0,ra)
.set noreorder
mfc0 v0,C0_COUNT
nop
j ra
.set reorder
ENDFRAME(mips_read_timer)

136
c/src/lib/libcpu/mips64orion/timer/timer.c Normal file
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@@ -0,0 +1,136 @@
/* timer.c
*
* This file contains the initialization code for the IDT 4650 timer driver.
*
* Author: Craig Lebakken <craigl@transition.com>
*
* COPYRIGHT (c) 1996 by Transition Networks Inc.
*
* To anyone who acknowledges that this file is provided "AS IS"
* without any express or implied warranty:
* permission to use, copy, modify, and distribute this file
* for any purpose is hereby granted without fee, provided that
* the above copyright notice and this notice appears in all
* copies, and that the name of Transition Networks not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* Transition Networks makes no representations about the suitability
* of this software for any purpose.
*
* derived from src/lib/libbsp/no_cpu/no_bsp/timer/timer.c
*
* This file manages the benchmark timer used by the RTEMS Timing Test
* Suite. Each measured time period is demarcated by calls to
* Timer_initialize() and Read_timer(). Read_timer() usually returns
* the number of microseconds since Timer_initialize() exitted.
*
* NOTE: It is important that the timer start/stop overhead be
* determined when porting or modifying this code.
*
* COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
* On-Line Applications Research Corporation (OAR).
* All rights assigned to U.S. Government, 1994.
*
* This material may be reproduced by or for the U.S. Government pursuant
* to the copyright license under the clause at DFARS 252.227-7013. This
* notice must appear in all copies of this file and its derivatives.
*
* timer.c,v 1.2 1995/05/31 16:56:39 joel Exp
*/
#ifndef lint
static char _sccsid[] = "@(#)timer.c 08/20/96 1.5\n";
#endif
#include <rtems.h>
#include <bsp.h>
#define CLOCKS_PER_MICROSECOND ( CPU_CLOCK_RATE_MHZ )
#define TIMER_MAX_VALUE 0xffffffff
extern unsigned32 mips_read_timer( void );
static rtems_boolean Timer_driver_Find_average_overhead;
static unsigned32 Timer_initial_value = 0;
void Timer_initialize( void )
{
Timer_initial_value = mips_read_timer();
/*
* Somehow start the timer
*/
/* Timer on 4650 is always running */
}
/*
* The following controls the behavior of Read_timer().
*
* AVG_OVEREHAD is the overhead for starting and stopping the timer. It
* is usually deducted from the number returned.
*
* LEAST_VALID is the lowest number this routine should trust. Numbers
* below this are "noise" and zero is returned.
*/
#define AVG_OVERHEAD 8 /* It typically takes X.X microseconds */
/* (Y countdowns) to start/stop the timer. */
/* This value is in cycles. */
#define LEAST_VALID 1 /* Don't trust a clicks value lower than this */
int Read_timer( void )
{
unsigned64 clicks;
unsigned32 total;
/*
* Read the timer and see how many clicks it has been since we started.
*/
clicks = mips_read_timer(); /* XXX: read some HW here */
if (clicks < Timer_initial_value)
{
clicks += TIMER_MAX_VALUE;
}
clicks -= Timer_initial_value;
/*
* Total is calculated by taking into account the number of timer overflow
* interrupts since the timer was initialized and clicks since the last
* interrupts.
*/
#if 0 /* leave total in number of cycles */
total = clicks / CLOCKS_PER_MICROSECOND;
#else
total = clicks;
#endif
if ( Timer_driver_Find_average_overhead == 1 )
return total; /* in # cycles units */
else {
if ( total < LEAST_VALID )
return 0; /* below timer resolution */
/*
* leave total in cycles
*/
return (total - AVG_OVERHEAD);
}
}
/*
* Empty function call used in loops to measure basic cost of looping
* in Timing Test Suite.
*/
rtems_status_code Empty_function( void )
{
return RTEMS_SUCCESSFUL;
}
void Set_find_average_overhead(
rtems_boolean find_flag
)
{
Timer_driver_Find_average_overhead = find_flag;
}