kernel: spinlocks

kernel-src/include/kernel/slab.h

@@ -3,6 +3,7 @@
 
 #include <stddef.h>
 #include <stdint.h>
+#include <spinlock.h>
 
 typedef struct slab_t {
 	struct slab_t *next;
@@ -13,7 +14,7 @@ typedef struct slab_t {
 } slab_t;
 
 typedef struct scache_t {
-	// TODO lock
+	spinlock_t lock;
 	void (*ctor)(struct scache_t *cache, void *obj);
 	void (*dtor)(struct scache_t *cache, void *obj);
 	slab_t *full;

kernel-src/include/kernel/timer.h

@@ -3,6 +3,7 @@
 
 #include <time.h>
 #include <arch/context.h>
+#include <spinlock.h>
 
 typedef struct timerentry_t {
 	struct timerentry_t *next;
@@ -12,6 +13,7 @@ typedef struct timerentry_t {
 } timerentry_t;
 
 typedef struct {
+	spinlock_t lock;
 	time_t ticksperus;
 	time_t tickcurrent;
 	void (*arm)(time_t);

kernel-src/include/kernel/vmm.h

@@ -2,6 +2,7 @@
 #define _VMM_H
 
 #include <arch/mmu.h>
+#include <spinlock.h>
 
 #define VMM_FLAGS_PAGESIZE 1
 #define VMM_FLAGS_ALLOCATE 2
@@ -29,7 +30,7 @@ typedef struct vmmrange_t{
 } vmmrange_t;
 
 typedef struct {
-	// TODO lock
+	spinlock_t lock;
 	struct vmmcache_t *next;
 	size_t freecount;
 	uintmax_t firstfree;
@@ -43,6 +44,7 @@ typedef struct vmmcache_t {
 } vmmcache_t;
 
 typedef struct {
+	spinlock_t lock;
 	vmmrange_t *ranges;
 	void *start;
 	void *end;

kernel-src/include/spinlock.h

@@ -0,0 +1,22 @@
+#ifndef _SPINLOCK_H
+#define _SPINLOCK_H
+
+#include <stdbool.h>
+
+typedef int spinlock_t;
+
+#define SPINLOCK_INIT(x) x = 0;
+
+static inline void spinlock_acquire(spinlock_t *lock){
+	while(!__sync_bool_compare_and_swap(lock, 0, 1)) asm("pause");
+}
+
+static inline bool spinlock_try(spinlock_t *lock){
+	return __sync_bool_compare_and_swap(lock, 0, 1);
+}
+
+static inline void spinlock_release(spinlock_t *lock){
+	*lock = 0;
+}
+
+#endif

kernel-src/mm/pmm.c

@@ -3,12 +3,14 @@
 #include <logging.h>
 #include <string.h>
 #include <arch/mmu.h>
+#include <spinlock.h>
 
 uintptr_t hhdmbase;
 static size_t memorysize;
 static size_t physicalpagecount;
 
 typedef struct {
+	spinlock_t lock;
 	uintmax_t base;
 	uintmax_t top;
 	uintmax_t searchstart;
@@ -75,11 +77,12 @@ static inline void initsection(int section, uintmax_t base, uintmax_t top) {
 		.top = top,
 		.searchstart = base
 	};
+	SPINLOCK_INIT(bmsections[section].lock);
 }
 
 void *pmm_alloc(size_t size, int section) {
 	for (int i = section; i >= 0; --i) {
-		// TODO lock section
+		spinlock_acquire(&bmsections[i].lock);
 		uintmax_t page = getfreearea(&bmsections[i], size);
 
 		if (page) {
@@ -88,10 +91,11 @@ void *pmm_alloc(size_t size, int section) {
 
 			for (size_t j = 0; j < size; ++j)
 				bmset((void *)((page + j) * PAGE_SIZE), 0);
-			// TODO unlock
+
+			spinlock_release(&bmsections[i].lock);
 			return (void *)(page * PAGE_SIZE);
 		}
-		// TODO unlock section
+		spinlock_release(&bmsections[i].lock);
 	}
 	return NULL;
 }
@@ -101,7 +105,7 @@ void pmm_free(void *addr, size_t size) {
 
 	for (int i = 0; i < PMM_SECTION_COUNT; ++i) {
 		if (page >= bmsections[i].base && page < bmsections[i].top) {
-			// TODO lock
+			spinlock_acquire(&bmsections[i].lock);
 
 			if ((uintptr_t)addr / PAGE_SIZE < bmsections[i].searchstart)
 				bmsections[i].searchstart = (uintptr_t)addr / PAGE_SIZE;
@@ -109,7 +113,7 @@ void pmm_free(void *addr, size_t size) {
 			for (uintmax_t j = 0; j < size; ++j)
 				bmset((void *)((page + j) * PAGE_SIZE), 1);
 
-			// TODO unlock
+			spinlock_release(&bmsections[i].lock);
 			return;
 		}
 	}

kernel-src/mm/slab.c

@@ -125,7 +125,7 @@ static slab_t *returnobject(scache_t *cache, void *obj) {
 }
 
 void *slab_allocate(scache_t *cache) {
-	// TODO lock
+	spinlock_acquire(&cache->lock);
 	slab_t *slab = NULL;
 	if (cache->partial != NULL)
 		slab = cache->partial;
@@ -170,12 +170,12 @@ void *slab_allocate(scache_t *cache) {
 	}
 
 	cleanup:
-	// TODO unlock
+	spinlock_release(&cache->lock);
 	return ret;
 }
 
 void slab_free(scache_t *cache, void *addr) {
-	// TODO lock
+	spinlock_acquire(&cache->lock);
 
 	slab_t *slab = returnobject(cache, addr);
 	__assert(slab);
@@ -205,8 +205,7 @@ void slab_free(scache_t *cache, void *addr) {
 		slab->prev = NULL;
 		cache->partial = slab;
 	}
-
+	spinlock_release(&cache->lock);
-	// TODO unlock
 }
 
 scache_t *slab_newcache(size_t size, size_t alignment, void (*ctor)(scache_t *, void *), void (*dtor)(scache_t *, void *)) {
@@ -227,6 +226,7 @@ scache_t *slab_newcache(size_t size, size_t alignment, void (*ctor)(scache_t *,
 	cache->full = NULL;
 	cache->empty = NULL;
 	cache->partial = NULL;
+	SPINLOCK_INIT(cache->lock);
 
 	printf("slab: new cache: size %lu align %lu truesize %lu objcount %lu\n", cache->size, cache->alignment, cache->truesize, cache->slabobjcount);
 
@@ -256,13 +256,11 @@ static size_t purge(scache_t *cache, size_t maxcount){
 }
 
 void slab_freecache(scache_t *cache) {
-	// TODO lock
+	spinlock_acquire(&cache->lock);
 	__assert(cache->partial == NULL);
 	__assert(cache->full == NULL);
 
 	purge(cache, (size_t)-1);
 
 	slab_free(&selfcache, cache);
-
-	// TODO unlock
 }

kernel-src/mm/vmm.c

@@ -9,7 +9,6 @@
 #define RANGE_TOP(x) (void *)((uintptr_t)x->start + x->size)
 
 static vmmcache_t *newcache() {
-	// TODO initialize lock
 	vmmcache_t *ptr = pmm_alloc(1, PMM_SECTION_DEFAULT);
 	if (ptr == NULL)
 		return NULL;
@@ -17,6 +16,7 @@ static vmmcache_t *newcache() {
 	ptr->header.freecount = VMM_RANGES_PER_CACHE; 
 	ptr->header.firstfree = 0;
 	ptr->header.next = NULL;
+	SPINLOCK_INIT(ptr->header.lock);
 
 	for (uintmax_t i = 0; i < VMM_RANGES_PER_CACHE; ++i) {
 		ptr->ranges[i].size = 0;
@@ -42,23 +42,22 @@ static vmmrange_t *allocrange() {
 	vmmcache_t *cache = cachelist;
 	vmmrange_t *range = NULL;
 	while (cache) {
-		// TODO lock
+		spinlock_acquire(&cache->header.lock);
 		if (cache->header.freecount > 0) {
 			--cache->header.freecount;
 			uintmax_t r = getentrynumber(cache);
 			cache->header.firstfree = r + 1;
 			range = &cache->ranges[r];
 			range->size = -1; // set as allocated temporarily
+			spinlock_release(&cache->header.lock);
 			break;
 		} else if (cache->header.next == NULL)
 			cache->header.next = newcache();
 
 		cache = cache->header.next;
-		// TODO unlock
+		spinlock_release(&cache->header.lock);
 	}
 
-	// TODO unlock cache
-
 	return range;
 }
 
@@ -233,7 +232,7 @@ bool vmm_pagefault(void *addr, bool user, int actions) {
 	if (space == NULL || (space == &kernelspace && user))
 		return false;
 
-	// TODO lock
+	spinlock_acquire(&space->lock);
 	vmmrange_t *range = getrange(space, addr);
 
 	bool status = false;
@@ -267,7 +266,7 @@ bool vmm_pagefault(void *addr, bool user, int actions) {
 	status = true;
 
 	cleanup:
-	// TODO unlock
+	spinlock_release(&space->lock);
 	return status;
 }
 
@@ -288,7 +287,7 @@ void *vmm_map(void *addr, volatile size_t size, int flags, mmuflags_t mmuflags,
 	if (space == NULL)
 		return NULL;
 
-	// TODO lock space
+	spinlock_acquire(&space->lock);
 
 	void *start = getfreerange(space, addr, size);
 	void *retaddr = NULL;
@@ -345,7 +344,7 @@ void *vmm_map(void *addr, volatile size_t size, int flags, mmuflags_t mmuflags,
 	if (start == NULL && range) {
 		// TODO free range
 	}
-	// TODO unlock
+	spinlock_release(&space->lock);
 	return retaddr;
 }
 
@@ -363,11 +362,11 @@ void vmm_unmap(void *addr, size_t size, int flags) {
 	if (space == NULL)
 		return;
 
-	// TODO lock space
+	spinlock_acquire(&space->lock);
 
 	unmap(space, addr, size);
 
-	// TODO unlock space
+	spinlock_release(&space->lock);
 }
 
 vmmcontext_t *vmm_newcontext() {

kernel-src/sys/timer.c

@@ -4,7 +4,7 @@
 #include <kernel/interrupt.h>
 
 void timer_isr(timer_t *timer, context_t *context) {
-	// TODO lock
+	spinlock_acquire(&timer->lock);
 	__assert(timer->queue);
 	timer->tickcurrent = timer->queue->absolutetick;
 	timerentry_t *oldentry = timer->queue;
@@ -16,13 +16,13 @@ void timer_isr(timer_t *timer, context_t *context) {
 		timer->arm(timer->queue->absolutetick - timer->tickcurrent);
 	}
 
-	// TODO unlock
+	spinlock_release(&timer->lock);
 	oldentry->func(oldentry->private, context);
 }
 
 void timer_insert(timer_t *timer, timerentry_t* entry, time_t us) {
 	long oldipl = interrupt_setipl(IPL_TIMER);
-	// TODO lock
+	spinlock_acquire(&timer->lock);
 
 	timer->tickcurrent += timer->stop(timer);
 
@@ -56,7 +56,7 @@ void timer_insert(timer_t *timer, timerentry_t* entry, time_t us) {
 	__assert(timer->queue->absolutetick > timer->tickcurrent);
 	timer->arm(timer->queue->absolutetick - timer->tickcurrent);
 
-	// TODO unlock
+	spinlock_release(&timer->lock);
 	interrupt_setipl(oldipl);
 }
 
@@ -68,6 +68,7 @@ timer_t *timer_new(time_t ticksperus, void (*arm)(time_t), time_t (*stop)()) {
 	timer->ticksperus = ticksperus;
 	timer->arm = arm;
 	timer->stop = stop;
+	SPINLOCK_INIT(timer->lock);
 
 	return timer;
 }