xnu-1228.tar.gz

[apple/xnu.git] / bsd / dev / dtrace / blist.h

diff --git a/bsd/dev/dtrace/blist.h b/bsd/dev/dtrace/blist.h
new file mode 100644 (file)
index 0000000..6988eb4
--- /dev/null
+++ b/bsd/dev/dtrace/blist.h
@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 1998 Matthew Dillon.  Terms of use and redistribution in all
+ * forms are covered by the BSD copyright in the file "/usr/src/COPYRIGHT".
+ *
+ * Implements bitmap resource lists.
+ *
+ *     Usage:
+ *             blist = blist_create(blocks)
+ *             (void)  blist_destroy(blist)
+ *             blkno = blist_alloc(blist, count)
+ *             (void)  blist_free(blist, blkno, count)
+ *             (void)  blist_resize(&blist, count, freeextra)
+ *             
+ *
+ *     Notes:
+ *             on creation, the entire list is marked reserved.  You should
+ *             first blist_free() the sections you want to make available
+ *             for allocation before doing general blist_alloc()/free()
+ *             ops.
+ *
+ *             SWAPBLK_NONE is returned on failure.  This module is typically
+ *             capable of managing up to (2^31) blocks per blist, though
+ *             the memory utilization would be insane if you actually did
+ *             that.  Managing something like 512MB worth of 4K blocks 
+ *             eats around 32 KBytes of memory. 
+ *
+ * $FreeBSD: src/sys/sys/blist.h,v 1.2 1999/08/28 00:51:33 peter Exp $
+ */
+
+#ifndef _SYS_BLIST_H_
+#define _SYS_BLIST_H_
+
+#define LOG2(v)                (((u_daddr_t)(v) >= 0x80000000U) ? 31 : \
+                       ((u_daddr_t)(v) >= 0x40000000U) ? 30 : \
+                       ((u_daddr_t)(v) >= 0x20000000U) ? 29 : \
+                       ((u_daddr_t)(v) >= 0x10000000U) ? 28 : \
+                       ((u_daddr_t)(v) >= 0x08000000U) ? 27 : \
+                       ((u_daddr_t)(v) >= 0x04000000U) ? 26 : \
+                       ((u_daddr_t)(v) >= 0x02000000U) ? 25 : \
+                       ((u_daddr_t)(v) >= 0x01000000U) ? 24 : \
+                       ((u_daddr_t)(v) >= 0x00800000U) ? 23 : \
+                       ((u_daddr_t)(v) >= 0x00400000U) ? 22 : \
+                       ((u_daddr_t)(v) >= 0x00200000U) ? 21 : \
+                       ((u_daddr_t)(v) >= 0x00100000U) ? 20 : \
+                       ((u_daddr_t)(v) >= 0x00080000U) ? 19 : \
+                       ((u_daddr_t)(v) >= 0x00040000U) ? 18 : \
+                       ((u_daddr_t)(v) >= 0x00020000U) ? 17 : \
+                       ((u_daddr_t)(v) >= 0x00010000U) ? 16 : \
+                       ((u_daddr_t)(v) >= 0x00008000U) ? 15 : \
+                       ((u_daddr_t)(v) >= 0x00004000U) ? 14 : \
+                       ((u_daddr_t)(v) >= 0x00002000U) ? 13 : \
+                       ((u_daddr_t)(v) >= 0x00001000U) ? 12 : \
+                       ((u_daddr_t)(v) >= 0x00000800U) ? 11 : \
+                       ((u_daddr_t)(v) >= 0x00000400U) ? 10 : \
+                       ((u_daddr_t)(v) >= 0x00000200U) ? 9 : \
+                       ((u_daddr_t)(v) >= 0x00000100U) ? 8 : \
+                       ((u_daddr_t)(v) >= 0x00000080U) ? 7 : \
+                       ((u_daddr_t)(v) >= 0x00000040U) ? 6 : \
+                       ((u_daddr_t)(v) >= 0x00000020U) ? 5 : \
+                       ((u_daddr_t)(v) >= 0x00000010U) ? 4 : \
+                       ((u_daddr_t)(v) >= 0x00000008U) ? 3 : \
+                       ((u_daddr_t)(v) >= 0x00000004U) ? 2 : \
+                       ((u_daddr_t)(v) >= 0x00000002U) ? 1 : 0)
+
+/*
+ * blmeta and bl_bitmap_t MUST be a power of 2 in size.
+ */
+
+typedef struct blmeta {
+       union {
+           daddr_t     bmu_avail;      /* space available under us     */
+           u_daddr_t   bmu_bitmap;     /* bitmap if we are a leaf      */
+       } u;
+       daddr_t         bm_bighint;     /* biggest contiguous block hint*/
+} blmeta_t;
+
+typedef struct blist {
+       daddr_t         bl_blocks;      /* area of coverage             */
+       daddr_t         bl_radix;       /* coverage radix               */
+       daddr_t         bl_skip;        /* starting skip                */
+       daddr_t         bl_free;        /* number of free blocks        */
+       blmeta_t        *bl_root;       /* root of radix tree           */
+       daddr_t         bl_rootblks;    /* daddr_t blks allocated for tree */
+} *blist_t;
+
+#define BLIST_META_RADIX       16
+#define BLIST_META_RADIX_SHIFT LOG2(BLIST_META_RADIX)
+#define BLIST_BMAP_RADIX       (sizeof(u_daddr_t)*8)
+#define BLIST_BMAP_RADIX_SHIFT LOG2(BLIST_BMAP_RADIX)
+
+#define BLIST_MAX_ALLOC                BLIST_BMAP_RADIX
+
+extern blist_t blist_create(daddr_t blocks);
+extern void blist_destroy(blist_t blist);
+extern daddr_t blist_alloc(blist_t blist, daddr_t count);
+extern void blist_free(blist_t blist, daddr_t blkno, daddr_t count);
+extern void blist_print(blist_t blist);
+extern void blist_resize(blist_t *pblist, daddr_t count, int freenew);
+
+#endif /* _SYS_BLIST_H_ */