scheduler timer

abstraction of a timer that is local to each cpu and is used for scheduling

src/arch/x86_64/apic.c

@@ -9,7 +9,10 @@
 #define APIC_REGISTER_ID 0x20
 #define APIC_REGISTER_EOI 0xB0
 #define APIC_REGISTER_SPURIOUS 0xF0
-
+#define APIC_TIMER_LVT 0x320
+#define APIC_TIMER_INITIALCOUNT 0x380
+#define APIC_TIMER_COUNT 0x390
+#define APIC_TIMER_DIVIDE 0x3E0
 
 #define TYPE_LAPIC 0
 #define TYPE_IOAPIC 1
@@ -148,11 +151,38 @@ static void ioapic_writeiored(ioapic_descriptor* ioapic, uint8_t irq, uint8_t ve
 }
 
 static inline uint32_t lapic_readreg(size_t reg){
-	return *(uint32_t* volatile)(lapicaddr + reg);
+	return *(uint32_t volatile*)(lapicaddr + reg);
 }
 
 static inline void lapic_writereg(size_t reg, uint32_t data){
-	*(uint32_t* volatile)(lapicaddr + reg) = data;
+	*(uint32_t volatile*)(lapicaddr + reg) = data;
+}
+
+void apic_timerstart(size_t ticks){
+	lapic_writereg(APIC_TIMER_INITIALCOUNT, ticks);
+}
+
+void apic_timerinterruptset(uint8_t vector){
+	lapic_writereg(APIC_TIMER_LVT, vector);
+}
+
+void apic_timerstop(){
+	lapic_writereg(APIC_TIMER_INITIALCOUNT, 0);
+}
+
+size_t apic_timercalibrate(size_t ms){
+	
+	lapic_writereg(APIC_TIMER_INITIALCOUNT, 0xFFFFFFFF);
+	lapic_writereg(APIC_TIMER_DIVIDE, 0b111); // no divider
+
+	hpet_wait_ms(ms);
+
+	size_t ticks = 0xFFFFFFFF - lapic_readreg(APIC_TIMER_COUNT);
+
+	apic_timerstop();
+
+	return ticks;
+
 }
 
 void apic_lapicinit(){
@@ -161,6 +191,9 @@ void apic_lapicinit(){
 	arch_getcls()->lapicid >>= 24;
 	
 	lapic_writereg(APIC_REGISTER_SPURIOUS, 0x1FF);
+	lapic_writereg(APIC_TIMER_LVT, 1 << 16); // mask timer interrupt off
+	
+
 
 }
 

src/arch/x86_64/idt.c

@@ -2,6 +2,7 @@
 #include <arch/isr.h>
 #include <stdint.h>
 #include <stddef.h>
+#include <arch/schedtimer.h>
 
 idtentry_t idt[256];
 
@@ -36,6 +37,8 @@ void idt_bspinit(){
 	
 	idt_setentry(&idt[VECTOR_PF], asmisr_pagefault, 0x28, FLAGS_PRESENT | FLAGS_TYPE_TRAP, 0);
 	
+	idt_setentry(&idt[SCHEDTIMER_VECTOR], asmisr_schedtimer, 0x28, FLAGS_PRESENT | FLAGS_TYPE_INTERRUPT, 0);
+
 	idt_reload();
 
 }

src/arch/x86_64/include/arch/apic.h

@@ -1,7 +1,13 @@
 #ifndef _APIC_H_INCLUDE
 #define _APIC_H_INCLUDE
 
+#include <stddef.h>
+#include <stdint.h>
 
+void apic_timerstop();
+void apic_timerstart(size_t ticks);
+void apic_timerinterruptset(uint8_t vector);
+size_t apic_timercalibrate(size_t ms);
 void apic_lapicinit();
 void apic_init();
 

src/arch/x86_64/include/arch/cls.h

@@ -16,6 +16,7 @@ typedef struct{
 	int lapicid;
 	arch_regs *laststate;
 	vmm_context *context;
+	size_t schedtimerticksperms;
 } cls_t;
 
 void bsp_setcls();

src/arch/x86_64/include/arch/cpuid.h

@@ -0,0 +1,13 @@
+#ifndef _CPUID_H_INCLUDE
+#define _CPUID_H_INCLUDE
+
+#include <stdint.h>
+#include <cpuid.h>
+
+static inline uint64_t cpuid(){
+    uint32_t eax, unused, edx;
+    __get_cpuid(1, &eax, &unused, &unused, &edx);
+    return ((uint64_t)edx << 32) + eax;
+}
+
+#endif

src/arch/x86_64/include/arch/isr.h

@@ -3,6 +3,7 @@
 
 #include <arch/regs.h>
 
+extern void asmisr_schedtimer(arch_regs*);
 extern void asmisr_general(arch_regs*);
 extern void asmisr_except(arch_regs*);
 extern void asmisr_pagefault(arch_regs*);

src/arch/x86_64/include/arch/schedtimer.h

@@ -0,0 +1,12 @@
+#ifndef _SCHEDTIMER_H_INCLUDE
+#define _SCHEDTIMER_H_INCLUDE
+
+#include <stddef.h>
+
+#define SCHEDTIMER_VECTOR 0x50
+
+void arch_schedtimer_run(size_t ms);
+void arch_schedtimer_stop();
+void arch_schedtimer_calibrate();
+
+#endif

src/arch/x86_64/isr.asm

@@ -126,6 +126,7 @@ section .text
 	iretq
 %endmacro
 
-except asmisr_pagefault, isr_pagefault
+except	asmisr_pagefault, isr_pagefault
-isr    asmisr_general, isr_general
+isr	asmisr_general, isr_general
-except asmisr_except, isr_except
+except	asmisr_except, isr_except
+isr	asmisr_schedtimer, isr_schedtimer

src/arch/x86_64/isr.c

@@ -2,6 +2,10 @@
 #include <arch/panic.h>
 #include <kernel/vmm.h>
 
+void isr_schedtimer(arch_regs *reg){
+	printf("schedtimer irq\n");
+}
+
 void isr_general(arch_regs *reg){
 	_panic("Unhandled interrupt", reg);
 	asm("hlt");

src/arch/x86_64/main.c

@@ -73,6 +73,8 @@ void kmain(){
 	
 	hpet_init();
 	
+	arch_schedtimer_calibrate();
+
 	smp_init();
 
 	_panic("End of kmain()", 0);

src/arch/x86_64/schedtimer.c

@@ -0,0 +1,23 @@
+#include <arch/schedtimer.h>
+#include <arch/cls.h>
+#include <arch/apic.h>
+
+void arch_schedtimer_waitms(size_t ms){
+	
+	apic_timerstart(cls->schedtimerticksperms * ms);
+	
+}
+
+void arch_schedtimer_stop(){
+
+	apic_timerstop();
+
+}
+
+void arch_schedtimer_calibrate(){
+	
+	cls->schedtimerticksperms = apic_timercalibrate(1);
+	
+	apic_timerinterruptset(SCHEDTIMER_VECTOR);
+
+}

src/arch/x86_64/smp.c

@@ -18,8 +18,6 @@ static size_t cpucount = 1;
 
 static void apstartup(struct limine_smp_info *info){
 	
-	spinlock_acquire(&lock);
-	
 	arch_setcls(&apcls[info->processor_id]);
 	
 	gdt_init();
@@ -30,11 +28,10 @@ static void apstartup(struct limine_smp_info *info){
 	
 	apic_lapicinit();
 	
+	arch_schedtimer_calibrate();
+
 	printf("CPU %lu ready!\n", info->lapic_id);
 
-	spinlock_release(&lock);
-	
-
 
 	asm("cli;hlt");