page allocator for alloc()

src/include/kernel/pagealloc.h

@@ -0,0 +1,11 @@
+#ifndef _PAGEALLOC_H_INCLUDE
+#define _PAGEALLOC_H_INCLUDE
+
+#include <stddef.h>
+#include <stdbool.h>
+
+void* pageallocator_alloc(size_t size);
+bool pageallocator_free(void* addr);
+void* pageallocator_realloc(void* addr, size_t size, bool* nonexistant);
+
+#endif

src/include/kernel/slab.h

@@ -1,11 +1,12 @@
 #ifndef _SLAB_H_INCLUDE
 #define _SLAB_H_INCLUDE
 
+
 #include <stddef.h>
 
 void* slab_alloc(size_t);
 void  slab_free(void*);
-
+size_t slab_getentrysize(void*);
 void slab_init();
 
 #endif

src/sys/mm/alloc.c

@@ -1,13 +1,18 @@
 #include <kernel/alloc.h>
 #include <kernel/slab.h>
 #include <string.h>
+#include <kernel/pagealloc.h>
 
 void* alloc(size_t size){
-	return slab_alloc(size);
+	if(size > 256) // slab implementation max size
+		return pageallocator_alloc(size);
+	else
+		return slab_alloc(size);
 }
 
 void free(void* addr){
-	slab_free(addr);
+	if(pageallocator_free(addr))
+		slab_free(addr);
 }
 
 void alloc_init(){
@@ -15,14 +20,29 @@ void alloc_init(){
 }
 
 void* realloc(void* addr, size_t size){
-	void* tmp = alloc(size);
+	
-	if(!tmp)
+	bool nonexistant;
+
+	void* newaddr = pageallocator_realloc(addr, size, &nonexistant);
+	
+	if(newaddr)
+		return newaddr;
+
+	if(nonexistant == 0)
 		return NULL;
 
-	memcpy(tmp, addr, size);
 
-	free(addr);
+	size_t slabsize = slab_getentrysize(addr);
 
-	return tmp;
+	newaddr = alloc(size);
+
+	if(!newaddr)
+		return NULL;
+	
+	memcpy(newaddr, addr, slabsize);
+
+	slab_free(addr);
+	
+	return newaddr;
 
 }

src/sys/mm/pagealloc.c

@@ -0,0 +1,136 @@
+#include <kernel/pagealloc.h>
+#include <kernel/slab.h>
+#include <arch/mmu.h>
+#include <arch/spinlock.h>
+#include <kernel/pmm.h>
+#include <string.h>
+
+typedef struct _page_allocation{
+        struct _page_allocation* next;
+        void* start;
+        size_t size;
+} page_allocation;
+
+static int lock;
+static page_allocation* list;
+
+void* pageallocator_alloc(size_t size){
+	
+	page_allocation* alloc = slab_alloc(sizeof(page_allocation));
+	
+	if(!alloc)
+		return NULL;
+
+	size_t pagec = size / PAGE_SIZE + (size % PAGE_SIZE ? 1 : 0);
+
+	// use vmm?
+	
+	alloc->start = pmm_hhdmalloc(pagec);
+
+	if(!alloc->start){
+		slab_free(alloc);
+		return NULL;
+	}
+
+	alloc->size  = size;
+	
+	spinlock_acquire(&lock);
+
+	if(list)
+		alloc->next = list;
+	
+	list = alloc;
+	
+	spinlock_release(&lock);
+	
+	return alloc->start;
+	
+}
+
+bool pageallocator_free(void* addr){
+	spinlock_acquire(&lock);
+	
+	page_allocation* it = list;
+	page_allocation* prev = NULL;
+
+	while(it){
+		void* end = it->start + it->size;
+		if(it->start <= addr && end > addr)
+			break;
+		prev = it;
+		it = it->next;
+	}
+	
+	if(!it){
+		spinlock_release(&lock);
+		return false;
+	}
+
+	if(!prev)
+		list = it->next;
+	else
+		prev->next = it->next;
+
+	spinlock_release(&lock);
+
+
+	size_t pagec = it->size / PAGE_SIZE + (it->size % PAGE_SIZE ? 1 : 0);
+		
+	// use vmm?
+	pmm_hhdmfree(it->start, pagec);
+	slab_free(it);
+
+	return true;
+}
+
+void* pageallocator_realloc(void* addr, size_t size, bool* nonexistant){
+	
+	spinlock_acquire(&lock);
+	
+	page_allocation* it = list;
+	page_allocation* prev = NULL;
+
+	while(it){
+		void* end = it->start + it->size;
+		if(it->start <= addr && end > addr)
+			break;
+		prev = it;
+		it = it->next;
+	}
+
+	if(!it){
+		*nonexistant = 1;
+		spinlock_release(&lock);
+		return NULL;
+	}
+	size_t oldpagec = it->size / PAGE_SIZE + (it->size % PAGE_SIZE ? 1 : 0);
+	size_t newpagec = size / PAGE_SIZE + (size % PAGE_SIZE ? 1 : 0);
+	
+	if(oldpagec == newpagec){
+		spinlock_release(&lock);
+		return it->start;
+	}
+
+	if(!prev)
+		list = it->next;
+	else
+		prev->next = it->next;
+
+	spinlock_release(&lock);
+	
+	void* new = pageallocator_alloc(size);
+
+	if(!new){
+		*nonexistant = 0;
+		return NULL;
+	}
+	
+	memcpy(new, it->start, it->size);
+	
+	// use vmm?
+	pmm_hhdmfree(it->start, oldpagec);
+	slab_free(it);
+
+	return new;
+
+}

src/sys/mm/slab.c

@@ -50,6 +50,11 @@ static inline slabdesc* getslabdesc(size_t size){
 
 }
 
+size_t slab_getentrysize(void* addr){
+	slab_t *slab = (size_t)addr & ~(0xFFF);
+        return slab->entrysize;
+}
+
 static void free(void* addr){
 	
 	// align down to page size