map_fill_region can now utilize higher order pages

4 files changed, 38 insertions, 7 deletions

diff --git a/arch/riscv/kernel/vmem.c b/arch/riscv/kernel/vmem.c
index d1d77a1..80644bd 100644
--- a/arch/riscv/kernel/vmem.c
+++ b/arch/riscv/kernel/vmem.c
@@ -83,7 +83,7 @@ static void __destroy_branch(struct vm_branch_t *b)
 		return;
 
 	for(size_t i = 0; i < BASE_PAGE_SIZE / sizeof(pm_t); ++i){
-		if(is_branch(b->leaf[i]));
+		if(is_branch(b->leaf[i]))
 			__destroy_branch((struct vm_branch_t *)pte_addr(b->leaf[i]));
 
 		free_page(MM_KPAGE, (pm_t)pte_addr(b->leaf[i]));
diff --git a/common/vmem.c b/common/vmem.c
index eee85a0..3795d0b 100644
--- a/common/vmem.c
+++ b/common/vmem.c
@@ -1,6 +1,6 @@
-#include <vmem.h>
 #include <apos/vmem.h>
 #include <apos/mem_nodes.h>
+#include <vmem.h>
 
 #define mark_region_used(r) ((r) = 1)
 #define mark_region_unused(r) ((r) = 0)
@@ -342,14 +342,35 @@ size_t uvmem_size()
 	return __uvmem_size;
 }
 
-/* TODO: add in ability to notice when a page can be mapped to a higher order */
+/* assuming start is chosen to start on an aligned border, this should choose
+ * the 'optimal' fit for the mapping.
+ *
+ * NOTE: not actually optimal, this doesn't bother to go through possible
+ * permutations etc. which would be slow and I don't want to implement it.
+ */
 vm_t map_fill_region(struct vm_branch_t *b, vm_t start, size_t bytes, uint8_t flags)
 {
-	size_t pages = bytes / BASE_PAGE_SIZE;
 	pm_t offset = 0;
-	for(size_t i = 0; i < pages; ++i){
-		offset = alloc_page(BASE_PAGE, offset);
-		map_vmem(b, offset, start + i * BASE_PAGE_SIZE, flags, BASE_PAGE);
+	pm_t runner = start;
+	size_t pages = __pages(bytes);
+	enum mm_order_t top = __mm_max_order;
+
+	for(; pages; top--){
+		size_t o_size = __o_size(top);
+		size_t o_pages = __pages(o_size);
+
+		if(!aligned(runner, o_size))
+			continue;
+
+		while(pages > o_pages){
+			offset = alloc_page(top, offset);
+			if(!offset)
+				break;
+
+			map_vmem(b, offset, runner, flags, top);
+			pages -= o_pages;
+			runner += o_size;
+		}
 	}
 
 	return start;
diff --git a/include/apos/utils.h b/include/apos/utils.h
index 318ba0a..b973d49 100644
--- a/include/apos/utils.h
+++ b/include/apos/utils.h
@@ -54,6 +54,14 @@ static inline size_t align_down(size_t val, size_t a)
 	return val - (val % a);
 }
 
+static inline bool aligned(size_t val, size_t a)
+{
+	if (!a)
+		return true;
+
+	return val % a == 0;
+}
+
 static inline size_t asciinum(char c)
 {
 	if(c >= '0' && c <= '9')
diff --git a/include/apos/vmem.h b/include/apos/vmem.h
index fd1a165..4cc4895 100644
--- a/include/apos/vmem.h
+++ b/include/apos/vmem.h
@@ -30,6 +30,8 @@ struct sp_mem {
 #define __pa(x) (((char *)(x)) + RAM_BASE - VM_DMAP)
 #define __page(x) ((x) / BASE_PAGE_SIZE)
 #define __addr(x) ((x) * BASE_PAGE_SIZE)
+#define __pages(x) (__page(x))
+#define __bytes(x) (__addr(x))
 
 /* general overview of the different functions:
  * internally they all work with pages, but they are called and return usable