1 /* 2 * Written by Julian Elischer (julian@tfs.com) 3 * for TRW Financial Systems for use under the MACH(2.5) operating system. 4 * 5 * TRW Financial Systems, in accordance with their agreement with Carnegie 6 * Mellon University, makes this software available to CMU to distribute 7 * or use in any manner that they see fit as long as this message is kept with 8 * the software. For this reason TFS also grants any other persons or 9 * organisations permission to use or modify this software. 10 * 11 * TFS supplies this software to be publicly redistributed 12 * on the understanding that TFS is not responsible for the correct 13 * functioning of this software in any circumstances. 14 * 15 * $FreeBSD: src/sys/cam/cam_extend.c,v 1.3 1999/08/28 00:40:39 peter Exp $ 16 * $DragonFly: src/sys/bus/cam/cam_extend.c,v 1.4 2004/03/12 03:23:13 dillon Exp $ 17 */ 18 /* 19 * XXX XXX XXX XXX We should get DEVFS working so that we 20 * don't have to do this, possibly sparse, array based junk. 21 * XXX: We can do this now with dev_t, that's even better. 22 */ 23 /* 24 * Extensible arrays: Use a realloc like implementation to permit 25 * the arrays to be extend. 26 */ 27 #include <sys/param.h> 28 #include <sys/systm.h> 29 #include <sys/kernel.h> 30 #include <sys/malloc.h> 31 32 #include "cam_extend.h" 33 34 struct extend_array 35 { 36 int nelem; 37 void **ps; 38 }; 39 40 static void * 41 cam_extend_alloc(size_t s) 42 { 43 return(malloc(s, M_DEVBUF, M_INTWAIT)); 44 } 45 46 static void 47 cam_extend_free(void *p) 48 { 49 free(p, M_DEVBUF); 50 } 51 52 /* EXTEND_CHUNK: Number of extend slots to allocate whenever we need a new 53 * one. 54 */ 55 #ifndef EXTEND_CHUNK 56 #define EXTEND_CHUNK 8 57 #endif 58 59 struct extend_array * 60 cam_extend_new(void) 61 { 62 struct extend_array *p = cam_extend_alloc(sizeof(*p)); 63 if (p) { 64 p->nelem = 0; 65 p->ps = 0; 66 } 67 68 return p; 69 } 70 71 void * 72 cam_extend_set(struct extend_array *ea, int index, void *value) 73 { 74 if (index >= ea->nelem) { 75 void **space; 76 space = cam_extend_alloc(sizeof(void *) * (index + EXTEND_CHUNK)); 77 bzero(space, sizeof(void *) * (index + EXTEND_CHUNK)); 78 79 /* Make sure we have something to copy before we copy it */ 80 if (ea->nelem) { 81 bcopy(ea->ps, space, sizeof(void *) * ea->nelem); 82 cam_extend_free(ea->ps); 83 } 84 85 ea->ps = space; 86 ea->nelem = index + EXTEND_CHUNK; 87 } 88 if (ea->ps[index]) { 89 printf("extend_set: entry %d already has storage.\n", index); 90 return 0; 91 } 92 else 93 ea->ps[index] = value; 94 95 return value; 96 } 97 98 void * 99 cam_extend_get(struct extend_array *ea, 100 int index) 101 { 102 if (ea == NULL || index >= ea->nelem || index < 0) 103 return NULL; 104 return ea->ps[index]; 105 } 106 107 void 108 cam_extend_release(struct extend_array *ea, int index) 109 { 110 void *p = cam_extend_get(ea, index); 111 if (p) { 112 ea->ps[index] = 0; 113 } 114 } 115