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Diffstat (limited to 'src/kernel/mem/seg.c')
-rw-r--r--src/kernel/mem/seg.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/src/kernel/mem/seg.c b/src/kernel/mem/seg.c
index e3eca67..4a33db3 100644
--- a/src/kernel/mem/seg.c
+++ b/src/kernel/mem/seg.c
@@ -2,6 +2,8 @@
#include "mem.h"
#include <core/sys.h>
+/* Call this function when mapping a segment to a page directory.
+ Calls the appropriate map method and updates the segment's and pagedir's information. */
struct segment_map *seg_map(struct segment* seg, struct page_directory *pagedir, size_t offset) {
struct segment_map *sm = seg->map(seg, pagedir, offset);
if (sm == 0) return 0;
@@ -13,6 +15,9 @@ struct segment_map *seg_map(struct segment* seg, struct page_directory *pagedir,
return sm;
}
+/* Call this function when unmapping a segment from a page directory.
+ The segment will automatically be deleted if it is not mapped.
+ Calls the appropriate unmap method and updates the segment's and pagedir's information. */
void seg_unmap(struct segment_map *map) {
map->seg->unmap(map);
if (map->pagedir->mappedSegs == map) {
@@ -32,7 +37,14 @@ void seg_unmap(struct segment_map *map) {
}
// ************************************ SIMPLESEG stuff *************
+
+static struct segment_map* simpleseg_map(struct segment* seg, struct page_directory* pagedir, size_t offset);
+static void simpleseg_unmap(struct segment_map*);
+static void simpleseg_delete(struct segment *seg);
+static int simpleseg_handleFault(struct segment_map* map, size_t addr, int write);
+/* Call this when creating a simpleseg.
+ Creates the simpleseg structure and the segment structure and fills them up. */
struct segment* simpleseg_make(size_t start, size_t len, int writable) {
struct simpleseg *ss = kmalloc(sizeof(struct simpleseg));
struct segment *se = kmalloc(sizeof(struct segment));
@@ -46,6 +58,7 @@ struct segment* simpleseg_make(size_t start, size_t len, int writable) {
return se;
}
+/* For internal use only. Called when a simpleseg is mapped to a pagedirectory. */
struct segment_map* simpleseg_map(struct segment* seg, struct page_directory* pagedir, size_t offset) {
struct segment_map *sm = kmalloc(sizeof(struct segment_map));
sm->start = ((struct simpleseg*)(seg->seg_data))->start;
@@ -53,6 +66,8 @@ struct segment_map* simpleseg_map(struct segment* seg, struct page_directory* pa
return sm;
}
+/* For internal use only. Called when a simpleseg is unmapped.
+ Frees all the allocated pages. */
void simpleseg_unmap(struct segment_map* sm) {
size_t i;
for (i = sm->start; i < sm->start + sm->len; i += 0x1000) {
@@ -60,6 +75,7 @@ void simpleseg_unmap(struct segment_map* sm) {
}
}
+/* For internal use only. Handles a page fault. Can allocate and map a frame if necessary. */
int simpleseg_handleFault(struct segment_map* sm, size_t addr, int write) {
struct simpleseg *ss = sm->seg->seg_data;
if (write && !ss->writable) return 1;
@@ -70,14 +86,16 @@ int simpleseg_handleFault(struct segment_map* sm, size_t addr, int write) {
return 0;
}
+/* For internal use only. Called when the simpleseg is deleted. Does nothing. */
void simpleseg_delete(struct segment* seg) {
}
+/* Call this to resize a simpleseg. Ajusts the size and frees pages if the new size is smaller.*/
int simpleseg_resize(struct segment_map *map, size_t len) {
size_t i;
if (map == 0) return -1;
- if (map->seg->delete != simpleseg_delete) return -2;
+ if (map->seg->delete != simpleseg_delete) return -2; //check segment is a simpleseg
struct simpleseg *s = (struct simpleseg*)map->seg->seg_data;
if (len & 0xFFF) len = (len & 0xFFFFF000) + 0x1000;