Generalization of constraints on page allocation and implementation/use

[palacios.git] / linux_module / buddy.c

diff --git a/linux_module/buddy.c b/linux_module/buddy.c
index 26a7021..f21c95d 100644 (file)
--- a/linux_module/buddy.c
+++ b/linux_module/buddy.c
@@ -285,13 +285,14 @@ int buddy_remove_pool(struct buddy_memzone * zone,
  * Arguments:
  *       [IN] mp:    Buddy system memory allocator object.
  *       [IN] order: Block size to allocate (2^order bytes).
- *       [IN] constraints: bitmmask showing restrictions for scan. currently: 0=none, or LWK_BUDDY_CONSTRAINT_4GB
+ *       [IN] filter_func: returns nonzero if given paddr is OK to use
+ *       [IN] filter_state: opaque argument to filter_func
  * Returns:
  *       Success: Pointer to the start of the allocated memory block.
  *       Failure: NULL
  */
 uintptr_t
-buddy_alloc(struct buddy_memzone *zone, unsigned long order, int constraints)
+buddy_alloc(struct buddy_memzone *zone, unsigned long order, int (*filter_func)(void *paddr, void *filter_state), void *filter_state)
 {
     unsigned long j;
     struct buddy_mempool * mp = NULL;
@@ -301,11 +302,6 @@ buddy_alloc(struct buddy_memzone *zone, unsigned long order, int constraints)
     struct block * buddy_block = NULL;
     unsigned long flags = 0;
 
-    if (constraints && constraints!=LWK_BUDDY_CONSTRAINT_4GB) { 
-       ERROR("Do not know how to satisfy constraint mask 0x%x\n", constraints);
-       return (uintptr_t) NULL;
-    }
-
     BUG_ON(zone == NULL);
     BUG_ON(order > zone->max_order);
 
@@ -333,23 +329,22 @@ buddy_alloc(struct buddy_memzone *zone, unsigned long order, int constraints)
        list_for_each(cur, list) {
            block = list_entry(cur, struct block, link);
 
-           if (!constraints) {
-               // without a constraint, we just want the first one
+           if (!filter_func) {
+               // without a filter, we just want the first one
                break;
-           }
-           
-           if (constraints & LWK_BUDDY_CONSTRAINT_4GB) {
-               // under this constraint, we will only use if the entirity
-               // of the allocation within the block will be below 4 GB
+           } else {
+
                void *block_pa = (void*)__pa(block);
-               if ((block_pa + (1ULL<<order)) <= (void*)(0x100000000ULL)) {
+
+               if (filter_func(block_pa,filter_state)) { 
                    // this block will work
                    break;
                } else {
-                   // look for the next block
+                   // this block won't work
                    block=NULL;
                    continue;
                }
+
            }
        }