WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/mm/frame.c

  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
+#include <typedefs.h>
 #include <arch/types.h>
-#include <func.h>
 #include <mm/heap.h>
 #include <mm/frame.h>
-#include <mm/page.h>
 #include <mm/vm.h>
-#include <arch/mm/page.h>
-#include <config.h>
-#include <memstr.h>
 #include <panic.h>
 #include <debug.h>
+#include <list.h>
 #include <synch/spinlock.h>
 #include <arch/asm.h>
 #include <arch.h>
-count_t frames = 0;
-count_t frames_free;
-__u8 *frame_bitmap;
-count_t frame_bitmap_octets;
-static spinlock_t framelock;
 spinlock_t zone_head_lock;       /**< this lock protects zone_head list */
 link_t zone_head;                /**< list of all zones in the system */
+/** Initialize physical memory management
+ *
+ * Initialize physical memory managemnt.
+ */
 void frame_init(void)
+{
     if (config.cpu_active == 1) {
         zone_init();
-        /*
-         * The bootstrap processor will allocate all necessary memory for frame allocation.
-         */
-        frames = config.memory_size / FRAME_SIZE;
-        frame_bitmap_octets = frames / 8 + (frames % 8 > 0);
-        frame_bitmap = (__u8 *) malloc(frame_bitmap_octets);
-        if (!frame_bitmap)
-            panic("malloc/frame_bitmap\n");
-        /*
-         * Mark all frames free.
-         */
-        memsetb((__address) frame_bitmap, frame_bitmap_octets, 0);
-        frames_free = frames;
+    }
-    /*
-     * No frame allocations/reservations prior this point.
-     */
     frame_arch_init();
     if (config.cpu_active == 1) {
-        /*
-         * Create the memory address space map. Marked frames and frame
-         * regions cannot be used for allocation.
-         */
-        frame_region_not_free(config.base, config.base + config.kernel_size);
+                frame_region_not_free(config.base, config.base + config.kernel_size + CONFIG_STACK_SIZE);
-    }
+        }
+}
+/** Allocate a frame
+ *
+ * Allocate a frame of physical memory.
-/*
+ *
+ * @param flags Flags for host zone selection and address processing.
+ *
- * Allocate a frame.
+ * @return Allocated frame.
  */
 __address frame_alloc(int flags)
+{
-    int i;
     pri_t pri;
+    link_t *cur, *tmp;
+    zone_t *z;
+    zone_t *zone = NULL;
+    frame_t *frame = NULL;
+    __address v;
 loop:
     pri = cpu_priority_high();
-    spinlock_lock(&framelock);
+    spinlock_lock(&zone_head_lock);
-    if (frames_free) {
-        for (i=0; i < frames; i++) {
-            int m, n;
-            m = i / 8;
+    /*
-            n = i % 8;
+     * First, find suitable frame zone.
+     */
-            if ((frame_bitmap[m] & (1<<n)) == 0) {
+    for (cur = zone_head.next; cur != &zone_head; cur = cur->next) {
-                frame_bitmap[m] |= (1<<n);
+        z = list_get_instance(cur, zone_t, link);
-                frames_free--;
-                spinlock_unlock(&framelock);
+        spinlock_lock(&z->lock);
+        /*
-                cpu_priority_restore(pri);
+         * Check if the zone has any free frames.
+         */
-                if (flags & FRAME_KA) return PA2KA(i*FRAME_SIZE);
+        if (z->free_count) {
-                return i*FRAME_SIZE;
+            zone = z;
-            }
+            break;
+        }
-        panic("frames_free inconsistent (%d)\n", frames_free);
+        spinlock_unlock(&z->lock);
+    }
+    if (!zone) {
+        if (flags & FRAME_PANIC)
+            panic("Can't allocate frame.\n");
+        /*
+         * TODO: Sleep until frames are available again.
+         */
-    spinlock_unlock(&framelock);
+        spinlock_unlock(&zone_head_lock);
-    cpu_priority_restore(pri);
+        cpu_priority_restore(pri);
-    if (flags & FRAME_PANIC)
+        panic("Sleep not implemented.\n");
-        panic("unable to allocate frame\n");
+        goto loop;
+    }
+    tmp = zone->free_head.next;
+    frame = list_get_instance(tmp, frame_t, link);
+    frame->refcount++;
-    /* TODO: implement sleeping logic here */
+    list_remove(tmp);           /* remove frame from free_head */
+    list_append(tmp, &zone->busy_head); /* append frame to busy_head */
+    zone->free_count--;
+    zone->busy_count++;
+    v = zone->base + (frame - zone->frames) * FRAME_SIZE;
+    if (flags & FRAME_KA)
+        v = PA2KA(v);
+    spinlock_unlock(&zone->lock);
+    spinlock_unlock(&zone_head_lock);
-    panic("sleep not supported\n");
+    cpu_priority_restore(pri);
-    goto loop;
+    return v;
+}
+/** Free a frame.
-/*
+ *
+ * Find respective frame structrue for supplied addr.
- * Free a frame.
+ * Decrement frame reference count.
+ * If it drops to zero, move the frame structure to free list.
+ *
+ * @param addr Address of the frame to be freed. It must be a multiple of FRAME_SIZE.
  */
 void frame_free(__address addr)
+{
     pri_t pri;
+    link_t *cur;
+    zone_t *z;
+    zone_t *zone = NULL;
-    __u32 frame;
+    frame_t *frame;
+    ASSERT(addr % FRAME_SIZE == 0);
     pri = cpu_priority_high();
-    spinlock_lock(&framelock);
+    spinlock_lock(&zone_head_lock);
+    /*
-    frame = IS_KA(addr) ? KA2PA(addr) : addr;
+     * First, find host frame zone for addr.
+     */
-    frame /= FRAME_SIZE;
+    for (cur = zone_head.next; cur != &zone_head; cur = cur->next) {
-    if (frame < frames) {
+        z = list_get_instance(cur, zone_t, link);
-        int m, n;
+        spinlock_lock(&z->lock);
-        m = frame / 8;
+        if (IS_KA(addr))
-        n = frame % 8;
+            addr = KA2PA(addr);
+        /*
-        if (frame_bitmap[m] & (1<<n)) {
+         * Check if addr belongs to z.
+         */
+        if ((addr >= z->base) && (addr <= z->base + (z->free_count + z->busy_count) * FRAME_SIZE)) {
-            frame_bitmap[m] &= ~(1<<n);
+            zone = z;
-            frames_free++;
+            break;
+        }
-        else panic("frame already free\n");
+        spinlock_unlock(&z->lock);
+    }
-    else panic("frame number too big\n");
+    ASSERT(zone != NULL);
+    frame = &zone->frames[(addr - zone->base)/FRAME_SIZE];
+    ASSERT(frame->refcount);
+    if (!--frame->refcount) {
+        list_remove(&frame->link);          /* remove frame from busy_head */
+        list_append(&frame->link, &zone->free_head);    /* append frame to free_head */
+        zone->free_count++;
+        zone->busy_count--;
+    }
-    spinlock_unlock(&framelock);
+    spinlock_unlock(&zone->lock);
+    spinlock_unlock(&zone_head_lock);
     cpu_priority_restore(pri);
+}
+/** Mark frame not free.
-/*
+ *
- * Don't use this function for normal allocation. Use frame_alloc() instead.
+ * Find respective frame structrue for supplied addr.
- * Use this function to declare that some special frame is not free.
+ * Increment frame reference count and move the frame structure to busy list.
+ *
+ * @param addr Address of the frame to be marked. It must be a multiple of FRAME_SIZE.
  */
 void frame_not_free(__address addr)
+{
     pri_t pri;
+    link_t *cur;
+    zone_t *z;
+    zone_t *zone = NULL;
-    __u32 frame;
+    frame_t *frame;
+    ASSERT(addr % FRAME_SIZE == 0);
     pri = cpu_priority_high();
-    spinlock_lock(&framelock);
+    spinlock_lock(&zone_head_lock);
+    /*
-    frame = IS_KA(addr) ? KA2PA(addr) : addr;
+     * First, find host frame zone for addr.
+     */
-    frame /= FRAME_SIZE;
+    for (cur = zone_head.next; cur != &zone_head; cur = cur->next) {
-    if (frame < frames) {
+        z = list_get_instance(cur, zone_t, link);
-        int m, n;
+        spinlock_lock(&z->lock);
-        m = frame / 8;
+        if (IS_KA(addr))
-        n = frame % 8;
+            addr = KA2PA(addr);
+        /*
-        if ((frame_bitmap[m] & (1<<n)) == 0) {
+         * Check if addr belongs to z.
+         */
+        if ((addr >= z->base) && (addr <= z->base + (z->free_count + z->busy_count) * FRAME_SIZE)) {
-            frame_bitmap[m] |= (1<<n);
+            zone = z;
-            frames_free--;
+            break;
+        }
+        spinlock_unlock(&z->lock);
+    }
+    ASSERT(zone != NULL);
+    frame = &zone->frames[(addr - zone->base)/FRAME_SIZE];
+    if (!frame->refcount) {
+        frame->refcount++;
+        list_remove(&frame->link);          /* remove frame from free_head */
+        list_append(&frame->link, &zone->busy_head);    /* append frame to busy_head */
+        zone->free_count--;
+        zone->busy_count++;
+    }
-    spinlock_unlock(&framelock);
+    spinlock_unlock(&zone->lock);
+    spinlock_unlock(&zone_head_lock);
     cpu_priority_restore(pri);
+}
+/** Mark frame region not free.
+ *
+ * Mark frame region not free.
+ *
+ * @param start First address.
+ * @param stop Last address.
+ */
 void frame_region_not_free(__address start, __address stop)
+{
-    __address a;
+        __address a;
-    start /= FRAME_SIZE;
+        start /= FRAME_SIZE;
-    stop /= FRAME_SIZE;
+        stop /= FRAME_SIZE;
-    for (a = start; a <= stop; a++)
+        for (a = start; a <= stop; a++)
-        frame_not_free(a * FRAME_SIZE);
+                frame_not_free(a * FRAME_SIZE);
+}
 /** Initialize zonekeeping
+ *
  * Initialize zonekeeping.
  */
 void zone_init(void)
  */
 void frame_initialize(frame_t *frame, zone_t *zone)
+{
     frame->refcount = 0;
     link_initialize(&frame->link);
-    frame->zone = zone;
-}
-/** Get address of physical frame from its frame structure
- *
- * Get address of physical frame from its frame structure.
- *
- * @param frame Frame structure of the queried frame address.
- *
- * @return Address of frame associated with the argument.
- */
-__address frame_get_address(frame_t *frame)
-{
-    __address v;
-    zone_t *z;
-    pri_t pri;
-    z = frame->zone;
-    pri = cpu_priority_high();
-    spinlock_lock(&z->lock);
-    v = z->base + (frame - z->frames) * FRAME_SIZE;
-    if (z->flags & FRAME_KA)
-        v = PA2KA(v);
-    spinlock_unlock(&z->lock);
-    cpu_priority_restore(pri);
-    return v;
+}

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/mm/frame.c @ 1757 – Rev 367 → 368