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Introduce the new timer subsystem.

Browse Source 
Timer subsystem initialization code in core/timer.c

	Split the BIOS and RTDSC timer drivers from i386_timer.c

	Split arch/i386/firmware/pcbios/bios.c into the RTSDC
	timer driver and arch/i386/core/nap.c

	Split the headers properly:
		include/unistd.h - delay functions to be used by the
					gPXE core and drivers.

		include/gpxe/timer.h - the fimer subsystem interface
					to be used by the timer drivers
					and currticks() to be used by
					the code gPXE subsystems.

		include/latch.h	- removed
		include/timer.h - scheduled for removal. Some driver
					are using currticks, which is
					only for core subsystems.

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
This commit is contained in:
Alexey Zaytsev 2007-12-01 07:07:01 +03:00
parent 844828cb15
commit 4006d229e5
13 changed files with 384 additions and 296 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

213
src/arch/i386/core/i386_timer.c
View File

@ -1,18 +1,58 @@
/* A couple of routines to implement a low-overhead timer for drivers */
/*
/*
* arch/i386/core/i386_timer.c
*
* Use the "System Timer 2" to implement the udelay callback in
* the BIOS timer driver. Also used to calibrate the clock rate
* in the RTDSC timer driver.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2, or (at
* your option) any later version.
*/
#include "timer.h"
#include "latch.h"
#include <io.h>
#include <gpxe/init.h>
#include <stddef.h>
#include <bits/timer2.h>
#include <gpxe/timer.h>
#include <io.h>
void __load_timer2(unsigned int ticks)
/* Timers tick over at this rate */
#define TIMER2_TICK_RATE 1193180U
/* Parallel Peripheral Controller Port B */
#define PPC_PORTB 0x61
/* Meaning of the port bits */
#define PPCB_T2OUT 0x20 /* Bit 5 */
#define PPCB_SPKR 0x02 /* Bit 1 */
#define PPCB_T2GATE 0x01 /* Bit 0 */
/* Ports for the 8254 timer chip */
#define TIMER2_PORT 0x42
#define TIMER_MODE_PORT 0x43
/* Meaning of the mode bits */
#define TIMER0_SEL 0x00
#define TIMER1_SEL 0x40
#define TIMER2_SEL 0x80
#define READBACK_SEL 0xC0
#define LATCH_COUNT 0x00
#define LOBYTE_ACCESS 0x10
#define HIBYTE_ACCESS 0x20
#define WORD_ACCESS 0x30
#define MODE0 0x00
#define MODE1 0x02
#define MODE2 0x04
#define MODE3 0x06
#define MODE4 0x08
#define MODE5 0x0A
#define BINARY_COUNT 0x00
#define BCD_COUNT 0x01
static void load_timer2(unsigned int ticks)
{
/*
* Now let's take care of PPC channel 2
@ -35,162 +75,15 @@ void __load_timer2(unsigned int ticks)
outb(ticks >> 8, TIMER2_PORT);
}
static int __timer2_running(void)
static int timer2_running(void)
{
return ((inb(PPC_PORTB) & PPCB_T2OUT) == 0);
}
#if !defined(CONFIG_TSC_CURRTICKS)
static void setup_timers(void)
void i386_timer2_udelay(unsigned int usecs)
{
return;
load_timer2((usecs * TIMER2_TICK_RATE)/USECS_IN_SEC);
while (timer2_running())
;
}
void load_timer2(unsigned int ticks)
{
return __load_timer2(ticks);
}
int timer2_running(void)
{
return __timer2_running();
}
void ndelay(unsigned int nsecs)
{
waiton_timer2((nsecs * CLOCK_TICK_RATE)/1000000000);
}
void udelay(unsigned int usecs)
{
waiton_timer2((usecs * TICKS_PER_MS)/1000);
}
#endif /* !defined(CONFIG_TSC_CURRTICKS) */
#if defined(CONFIG_TSC_CURRTICKS)
#define rdtsc(low,high) \
__asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high))
#define rdtscll(val) \
__asm__ __volatile__ ("rdtsc" : "=A" (val))
/* Number of clock ticks to time with the rtc */
#define LATCH 0xFF
#define LATCHES_PER_SEC ((CLOCK_TICK_RATE + (LATCH/2))/LATCH)
#define TICKS_PER_LATCH ((LATCHES_PER_SEC + (TICKS_PER_SEC/2))/TICKS_PER_SEC)
static void sleep_latch(void)
{
__load_timer2(LATCH);
while(__timer2_running());
}
/* ------ Calibrate the TSC -------
* Time how long it takes to excute a loop that runs in known time.
* And find the convertion needed to get to CLOCK_TICK_RATE
*/
static unsigned long long calibrate_tsc(void)
{
unsigned long startlow, starthigh;
unsigned long endlow, endhigh;
rdtsc(startlow,starthigh);
sleep_latch();
rdtsc(endlow,endhigh);
/* 64-bit subtract - gcc just messes up with long longs */
__asm__("subl %2,%0\n\t"
"sbbl %3,%1"
:"=a" (endlow), "=d" (endhigh)
:"g" (startlow), "g" (starthigh),
"0" (endlow), "1" (endhigh));
/* Error: ECPUTOOFAST */
if (endhigh)
goto bad_ctc;
endlow *= TICKS_PER_LATCH;
return endlow;
/*
* The CTC wasn't reliable: we got a hit on the very first read,
* or the CPU was so fast/slow that the quotient wouldn't fit in
* 32 bits..
*/
bad_ctc:
printf("bad_ctc\n");
return 0;
}
static unsigned long clocks_per_tick;
static void setup_timers(void)
{
if (!clocks_per_tick) {
clocks_per_tick = calibrate_tsc();
/* Display the CPU Mhz to easily test if the calibration was bad */
printf("CPU %ld Mhz\n", (clocks_per_tick/1000 * TICKS_PER_SEC)/1000);
}
}
unsigned long currticks(void)
{
unsigned long clocks_high, clocks_low;
unsigned long currticks;
/* Read the Time Stamp Counter */
rdtsc(clocks_low, clocks_high);
/* currticks = clocks / clocks_per_tick; */
__asm__("divl %1"
:"=a" (currticks)
:"r" (clocks_per_tick), "0" (clocks_low), "d" (clocks_high));
return currticks;
}
static unsigned long long timer_timeout;
static int __timer_running(void)
{
unsigned long long now;
rdtscll(now);
return now < timer_timeout;
}
void udelay(unsigned int usecs)
{
unsigned long long now;
rdtscll(now);
timer_timeout = now + usecs * ((clocks_per_tick * TICKS_PER_SEC)/(1000*1000));
while(__timer_running());
}
void ndelay(unsigned int nsecs)
{
unsigned long long now;
rdtscll(now);
timer_timeout = now + nsecs * ((clocks_per_tick * TICKS_PER_SEC)/(1000*1000*1000));
while(__timer_running());
}
void load_timer2(unsigned int timer2_ticks)
{
unsigned long long now;
unsigned long clocks;
rdtscll(now);
clocks = timer2_ticks * ((clocks_per_tick * TICKS_PER_SEC)/CLOCK_TICK_RATE);
timer_timeout = now + clocks;
}
int timer2_running(void)
{
return __timer_running();
}
#endif /* RTC_CURRTICKS */
struct init_fn timer_init_fn __init_fn ( INIT_NORMAL ) = {
.initialise = setup_timers,
};

12
src/arch/i386/core/nap.c Normal file
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@ -0,0 +1,12 @@
#include <realmode.h>
#include <bios.h>
/**************************************************************************
* Save power by halting the CPU until the next interrupt
**************************************************************************/
void cpu_nap ( void ) {
__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
"hlt\n\t"
"cli\n\t" ) : : );
}

57
src/arch/i386/drivers/timer_bios.c Normal file
View File

@ -0,0 +1,57 @@
/*
* Etherboot routines for PCBIOS firmware.
*
* Body of routines taken from old pcbios.S
*/
#include <gpxe/init.h>
#include <gpxe/timer.h>
#include <stdio.h>
#include <realmode.h>
#include <bios.h>
#include <bits/timer2.h>
/* A bit faster actually, but we don't care. */
#define TIMER2_TICKS_PER_SEC 18
/*
* Use direct memory access to BIOS variables, longword 0040:006C (ticks
* today) and byte 0040:0070 (midnight crossover flag) instead of calling
* timeofday BIOS interrupt.
*/
static tick_t bios_currticks ( void ) {
static int days = 0;
uint32_t ticks;
uint8_t midnight;
/* Re-enable interrupts so that the timer interrupt can occur */
__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
"nop\n\t"
"nop\n\t"
"cli\n\t" ) : : );
get_real ( ticks, BDA_SEG, 0x006c );
get_real ( midnight, BDA_SEG, 0x0070 );
if ( midnight ) {
midnight = 0;
put_real ( midnight, BDA_SEG, 0x0070 );
days += 0x1800b0;
}
return ( (days + ticks) * (USECS_IN_SEC / TIMER2_TICKS_PER_SEC) );
}
static int bios_ts_init(void)
{
DBG("BIOS timer installed\n");
return 0;
}
struct timer bios_ts __timer ( 02 ) = {
.init = bios_ts_init,
.udelay = i386_timer2_udelay,
.currticks = bios_currticks,
};

90
src/arch/i386/drivers/timer_rtdsc.c Normal file
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@ -0,0 +1,90 @@
#include <gpxe/init.h>
#include <gpxe/timer.h>
#include <stdio.h>
#include <bits/cpu.h>
#include <bits/timer2.h>
#include <io.h>
#define rdtsc(low,high) \
__asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high))
#define rdtscll(val) \
__asm__ __volatile__ ("rdtsc" : "=A" (val))
static unsigned long long calibrate_tsc(void)
{
uint32_t startlow, starthigh;
uint32_t endlow, endhigh;
rdtsc(startlow,starthigh);
i386_timer2_udelay(USECS_IN_MSEC/2);
rdtsc(endlow,endhigh);
/* 64-bit subtract - gcc just messes up with long longs */
/* XXX ORLY? Check it. */
__asm__("subl %2,%0\n\t"
"sbbl %3,%1"
:"=a" (endlow), "=d" (endhigh)
:"g" (startlow), "g" (starthigh),
"0" (endlow), "1" (endhigh));
/* Error: ECPUTOOFAST */
if (endhigh)
goto bad_ctc;
endlow *= MSECS_IN_SEC*2;
return endlow;
/*
* The CTC wasn't reliable: we got a hit on the very first read,
* or the CPU was so fast/slow that the quotient wouldn't fit in
* 32 bits..
*/
bad_ctc:
return 0;
}
static uint32_t clocks_per_second = 0;
static tick_t rtdsc_currticks(void)
{
uint32_t clocks_high, clocks_low;
uint32_t currticks;
/* Read the Time Stamp Counter */
rdtsc(clocks_low, clocks_high);
/* currticks = clocks / clocks_per_tick; */
__asm__("divl %1"
:"=a" (currticks)
:"r" (clocks_per_second/USECS_IN_SEC), "0" (clocks_low), "d" (clocks_high));
return currticks;
}
static int rtdsc_ts_init(void)
{
struct cpuinfo_x86 cpu_info;
get_cpuinfo(&cpu_info);
if (cpu_info.features & X86_FEATURE_TSC) {
clocks_per_second = calibrate_tsc();
if (clocks_per_second) {
DBG("RTDSC Ticksource installed. CPU running at %ld Mhz\n",
clocks_per_second/(1000*1000));
return 0;
}
}
printf("RTDSC timer not available on this machine.\n");
return 1;
}
struct timer rtdsc_ts __timer (01) = {
.init = rtdsc_ts_init,
.udelay = generic_currticks_udelay,
.currticks = rtdsc_currticks,
};

55
src/arch/i386/firmware/pcbios/bios.c
View File

@ -1,55 +0,0 @@
/* Etherboot routines for PCBIOS firmware.
*
* Body of routines taken from old pcbios.S
*/
#include <stdint.h>
#include <realmode.h>
#include <bios.h>
#define CF ( 1 << 0 )
/**************************************************************************
CURRTICKS - Get Time
Use direct memory access to BIOS variables, longword 0040:006C (ticks
today) and byte 0040:0070 (midnight crossover flag) instead of calling
timeofday BIOS interrupt.
**************************************************************************/
#if defined(CONFIG_TSC_CURRTICKS)
#undef CONFIG_BIOS_CURRTICKS
#else
#define CONFIG_BIOS_CURRTICKS 1
#endif
#if defined(CONFIG_BIOS_CURRTICKS)
unsigned long currticks ( void ) {
static uint32_t days = 0;
uint32_t ticks;
uint8_t midnight;
/* Re-enable interrupts so that the timer interrupt can occur
*/
__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
"nop\n\t"
"nop\n\t"
"cli\n\t" ) : : );
get_real ( ticks, BDA_SEG, 0x006c );
get_real ( midnight, BDA_SEG, 0x0070 );
if ( midnight ) {
midnight = 0;
put_real ( midnight, BDA_SEG, 0x0070 );
days += 0x1800b0;
}
return ( days + ticks );
}
#endif /* CONFIG_BIOS_CURRTICKS */
/**************************************************************************
CPU_NAP - Save power by halting the CPU until the next interrupt
**************************************************************************/
void cpu_nap ( void ) {
__asm__ __volatile__ ( REAL_CODE ( "sti\n\t"
"hlt\n\t"
"cli\n\t" ) : : );
}

8
src/arch/i386/include/bits/timer2.h Normal file
View File

@ -0,0 +1,8 @@
#ifndef BITS_TIMER2_H
#define BITS_TIMER2_H
#include <stddef.h>
void i386_timer2_udelay(unsigned int usecs);
#endif

5
src/config.h
View File

@ -18,11 +18,14 @@
*/
#define CONSOLE_FIRMWARE /* Default BIOS console */
#undef CONSOLE_SERIAL /* Serial port */
#define CONSOLE_SERIAL /* Serial port */
#undef CONSOLE_DIRECT_VGA /* Direct access to VGA card */
#undef CONSOLE_BTEXT /* Who knows what this does? */
#undef CONSOLE_PC_KBD /* Direct access to PC keyboard */
#define TIMER_BIOS
#define TIMER_RTDSC
/* @END general.h */
/* @BEGIN serial.h

11
src/core/config.c
View File

@ -74,6 +74,17 @@ REQUIRE_OBJECT ( pc_kbd );
REQUIRE_OBJECT ( syslog );
#endif
/*
* Timers
*/
#ifdef TIMER_BIOS
REQUIRE_OBJECT ( timer_bios );
#endif
#ifdef TIMER_RTDSC
REQUIRE_OBJECT ( timer_rtdsc );
#endif
/*
* Drag in all requested protocols
*

12
src/core/misc.c
View File

@ -7,18 +7,6 @@ MISC Support Routines
#include <latch.h>
#include <gpxe/in.h>
/**************************************************************************
SLEEP
**************************************************************************/
unsigned int sleep(unsigned int secs)
{
unsigned long tmo;
for (tmo = currticks()+secs*TICKS_PER_SEC; currticks() < tmo; ) {
}
return 0;
}
/**************************************************************************
INET_ATON - Convert an ascii x.x.x.x to binary form
**************************************************************************/

107
src/core/timer.c
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@ -1,27 +1,104 @@
/* A couple of routines to implement a low-overhead timer for drivers */
/*
/*
* core/timer.c
*
* Copyright (C) 2007 Alexey Zaytsev <alexey.zaytsev@gmail.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2, or (at
* your option) any later version.
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "timer.h"
#include <stddef.h>
#include <assert.h>
#include <gpxe/init.h>
#include <gpxe/timer.h>
#include <stdio.h>
/* Machine Independant timer helper functions */
static struct timer ts_table[0]
__table_start ( struct timer, timers );
static struct timer ts_table_end[0]
__table_end ( struct timer, timers );
static struct timer *used_ts = NULL;
/*
* This function may be used in custom timer driver.
*
* This udelay implementation works well if you've got a
* fast currticks().
*/
void generic_currticks_udelay(unsigned int usecs)
{
tick_t t;
t = currticks();
while (t + usecs > currticks())
; /* xxx: Relax the cpu some way. */
}
static void timer_init(void)
{
struct timer *ts;
for (ts = ts_table; ts < ts_table_end; ts++) {
if (ts->init && !ts->init()) {
used_ts = ts;
break;
}
}
if (!used_ts) {
printf("No timer available. This should never happen. Expect gPXE to die soon.\n");
/* Panic */
}
}
struct init_fn ts_init_fn __init_fn ( INIT_NORMAL ) = {
.initialise = timer_init,
};
/* Functions for public use. */
tick_t currticks(void)
{
tick_t ct;
assert(used_ts);
ct = used_ts->currticks();
DBG("currticks: %ld seconds and %06ld microseconds\n", ct/USECS_IN_SEC, ct%USECS_IN_SEC);
return ct;
}
void udelay(unsigned int usecs)
{
used_ts->udelay(usecs);
}
void mdelay(unsigned int msecs)
{
unsigned int i;
for(i = 0; i < msecs; i++) {
udelay(1000);
}
while(msecs--)
used_ts->udelay(USECS_IN_MSEC);
}
void waiton_timer2(unsigned int ticks)
unsigned int sleep(unsigned int secs)
{
load_timer2(ticks);
while(timer2_running()) {
}
while (secs--)
mdelay(MSECS_IN_SEC);
return 0;
}

32
src/include/gpxe/timer.h Normal file
View File

@ -0,0 +1,32 @@
#ifndef GPXE_TIMER_H
#define GPXE_TIMER_H
#include <stddef.h>
typedef uint32_t tick_t;
#define MSECS_IN_SEC (1000)
#define USECS_IN_SEC (1000*1000)
#define USECS_IN_MSEC (1000)
#define TICKS_PER_SEC USECS_IN_SEC
tick_t currticks(void);
void generic_currticks_udelay(unsigned int usecs);
struct timer {
/* Returns zero on successful initialisation. */
int (*init) (void);
/* Return the current time, int mictoseconds since the beginning. */
tick_t (*currticks) (void);
/* Sleep for a few useconds. */
void (*udelay) (unsigned int useconds);
};
#define __timer(order) __table (struct timer, timers, order)
#endif /* GPXE_TIMER_H */

70
src/include/timer.h
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@ -1,61 +1,27 @@
/* Defines for routines to implement a low-overhead timer for drivers */
/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2, or (at
* your option) any later version.
*/
#ifndef TIMER_H
#ifndef TIMER_H
#define TIMER_H
/* Ports for the 8254 timer chip */
#define TIMER2_PORT 0x42
#define TIMER_MODE_PORT 0x43
/*
* This file should be removed as soon as there are no
* currticks() abusers.
*/
/* Meaning of the mode bits */
#define TIMER0_SEL 0x00
#define TIMER1_SEL 0x40
#define TIMER2_SEL 0x80
#define READBACK_SEL 0xC0
#include <stddef.h>
/*
#warning Please fix me. I'm abusing the deprecated include/timer.h
*/
#include <unistd.h>
#define LATCH_COUNT 0x00
#define LOBYTE_ACCESS 0x10
#define HIBYTE_ACCESS 0x20
#define WORD_ACCESS 0x30
/* Duplicates include/gpxe/timer.h */
typedef uint32_t tick_t;
#define MODE0 0x00
#define MODE1 0x02
#define MODE2 0x04
#define MODE3 0x06
#define MODE4 0x08
#define MODE5 0x0A
#define MSECS_IN_SEC (1000)
#define USECS_IN_SEC (1000*1000)
#define USECS_IN_MSEC (1000)
#define BINARY_COUNT 0x00
#define BCD_COUNT 0x01
#define TICKS_PER_SEC USECS_IN_SEC
/* Timers tick over at this rate */
#define CLOCK_TICK_RATE 1193180U
#define TICKS_PER_MS (CLOCK_TICK_RATE/1000)
tick_t currticks(void);
/* Parallel Peripheral Controller Port B */
#define PPC_PORTB 0x61
#endif
/* Meaning of the port bits */
#define PPCB_T2OUT 0x20 /* Bit 5 */
#define PPCB_SPKR 0x02 /* Bit 1 */
#define PPCB_T2GATE 0x01 /* Bit 0 */
/* Ticks must be between 0 and 65535 (0 == 65536)
because it is a 16 bit counter */
extern void load_timer2(unsigned int ticks);
extern inline int timer2_running(void);
extern void waiton_timer2(unsigned int ticks);
extern void ndelay(unsigned int nsecs);
extern void udelay(unsigned int usecs);
extern void mdelay(unsigned int msecs);
#endif /* TIMER_H */

8
src/include/unistd.h
View File

@ -4,7 +4,7 @@
#include <stddef.h>
#include <stdarg.h>
extern unsigned int sleep ( unsigned int seconds );
unsigned int sleep ( unsigned int seconds );
extern int execv ( const char *command, char * const argv[] );
/**
@ -22,4 +22,10 @@ extern int execv ( const char *command, char * const argv[] );
rc; \
} )
void udelay(unsigned int usecs);
void mdelay(unsigned int msecs);
#define usleep(x) udelay(x)
#endif /* _UNISTD_H */