timer: get_timer_ticks and some more changes

kernel-src/arch/x86-64/apic.c

@@ -194,7 +194,7 @@ void arch_apic_eoi() {
 	writelapic(APIC_REG_EOI, 0);
 }
 
-static time_t stoptimer() {
+static time_t stoptimer(timer_t *) {
 	time_t remaining = readlapic(APIC_TIMER_COUNT);
 	time_t initial = readlapic(APIC_TIMER_INITIALCOUNT);
 
@@ -203,11 +203,18 @@ static time_t stoptimer() {
 	return initial - remaining;
 }
 
+static time_t time_passed(timer_t *) {
+	time_t remaining = readlapic(APIC_TIMER_COUNT);
+	time_t initial = readlapic(APIC_TIMER_INITIALCOUNT);
+
+	return initial - remaining;
+}
+
 static void timerisr(isr_t *isr, context_t *context) {
 	timer_isr(current_cpu()->timer, context);
 }
 
-static void armtimer(time_t ticks) {
+static void armtimer(timer_t *, time_t ticks) {
 	writelapic(APIC_TIMER_INITIALCOUNT, ticks);
 }
 
@@ -237,7 +244,7 @@ void arch_apic_timerinit() {
 
 	writelapic(APIC_LVT_TIMER, vec);
 
-	current_cpu()->timer = timer_new(ticksperus, armtimer, stoptimer, 0xffffffff);
+	current_cpu()->timer = timer_new(ticksperus, armtimer, stoptimer, time_passed, 0xffffffff);
 	__assert(current_cpu()->timer);
 }
 

kernel-src/include/kernel/timer.h

@@ -17,23 +17,25 @@ typedef struct timerentry_t {
 	bool fired;
 } timerentry_t;
 
-typedef struct {
+typedef struct timer_t {
 	spinlock_t lock;
 	time_t tick_limit;
 	time_t ticksperus;
 	time_t tickcurrent;
 	time_t current_target;
 	bool running;
-	void (*arm)(time_t);
-	time_t (*stop)();
+	void (*arm)(struct timer_t *, time_t);
+	time_t (*stop)(struct timer_t *);
+	time_t (*time_passed)(struct timer_t *);
 	timerentry_t *queue;
 } timer_t;
 
+time_t timer_get_ticks(timer_t *timer);
 void timer_resume(timer_t *timer);
 void timer_stop(timer_t *timer);
 void timer_isr(timer_t *timer, context_t *context);
 void timer_insert(timer_t *timer, timerentry_t *entry, dpcfn_t fn, dpcarg_t arg, time_t us, bool repeating);
-uintmax_t timer_remove(timer_t *timer, timerentry_t *entry);
-timer_t *timer_new(time_t ticksperus, void (*arm)(time_t), time_t (*stop)(), time_t tick_limit);
+time_t timer_remove(timer_t *timer, timerentry_t *entry);
+timer_t *timer_new(time_t ticksperus, void (*arm)(timer_t *, time_t), time_t (*stop)(timer_t *), time_t (*time_passed)(timer_t *), time_t tick_limit);
 
 #endif

kernel-src/sys/timer.c

@@ -45,7 +45,7 @@ static inline void arm_for_next_target(timer_t *timer) {
 		target = timer->tick_limit;
 
 	timer->current_target = timer->tickcurrent + target;
-	timer->arm(target);
+	timer->arm(timer, target);
 }
 
 // expects IPL to be at least IPL_TIMER
@@ -96,6 +96,16 @@ void timer_isr(timer_t *timer, context_t *context) {
 	spinlock_release(&timer->lock);
 }
 
+time_t timer_get_ticks(timer_t *timer) {
+	long ipl = spinlock_acquireraiseipl(&timer->lock, IPL_TIMER);
+
+	time_t ticks = timer->tickcurrent + timer->time_passed(timer);
+
+	spinlock_releaseloweripl(&timer->lock, ipl);
+
+	return ticks;
+}
+
 void timer_resume(timer_t *timer) {
 	long oldipl = interrupt_raiseipl(IPL_TIMER);
 	spinlock_acquire(&timer->lock);
@@ -147,7 +157,7 @@ void timer_insert(timer_t *timer, timerentry_t *entry, dpcfn_t fn, dpcarg_t arg,
 	interrupt_loweripl(oldipl);
 }
 
-uintmax_t timer_remove(timer_t *timer, timerentry_t *entry) {
+time_t timer_remove(timer_t *timer, timerentry_t *entry) {
 	long oldipl = interrupt_raiseipl(IPL_TIMER);
 	spinlock_acquire(&timer->lock);
 
@@ -191,7 +201,7 @@ uintmax_t timer_remove(timer_t *timer, timerentry_t *entry) {
 	return timeremaining;
 }
 
-timer_t *timer_new(time_t ticksperus, void (*arm)(time_t), time_t (*stop)(), time_t tick_limit) {
+timer_t *timer_new(time_t ticksperus, void (*arm)(timer_t *, time_t), time_t (*stop)(timer_t *), time_t (*time_passed)(timer_t *), time_t tick_limit) {
 	timer_t *timer = alloc(sizeof(timer_t));
 	if (timer == NULL)
 		return NULL;
@@ -201,6 +211,7 @@ timer_t *timer_new(time_t ticksperus, void (*arm)(time_t), time_t (*stop)(), tim
 	timer->tick_limit = tick_limit;
 	timer->arm = arm;
 	timer->stop = stop;
+	timer->time_passed = time_passed;
 	SPINLOCK_INIT(timer->lock);
 
 	return timer;