1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * CDDL HEADER START 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*0Sstevel@tonic-gate * with the License. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*0Sstevel@tonic-gate * See the License for the specific language governing permissions 12*0Sstevel@tonic-gate * and limitations under the License. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*0Sstevel@tonic-gate * 20*0Sstevel@tonic-gate * CDDL HEADER END 21*0Sstevel@tonic-gate */ 22*0Sstevel@tonic-gate /* 23*0Sstevel@tonic-gate * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24*0Sstevel@tonic-gate * Use is subject to license terms. 25*0Sstevel@tonic-gate */ 26*0Sstevel@tonic-gate 27*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 28*0Sstevel@tonic-gate 29*0Sstevel@tonic-gate #include <sys/stropts.h> 30*0Sstevel@tonic-gate #include <sys/isa_defs.h> 31*0Sstevel@tonic-gate #include <sys/nvpair.h> 32*0Sstevel@tonic-gate #include <sys/sysmacros.h> 33*0Sstevel@tonic-gate #if defined(_KERNEL) && !defined(_BOOT) 34*0Sstevel@tonic-gate #include <sys/varargs.h> 35*0Sstevel@tonic-gate #else 36*0Sstevel@tonic-gate #include <stdarg.h> 37*0Sstevel@tonic-gate #include <strings.h> 38*0Sstevel@tonic-gate #endif 39*0Sstevel@tonic-gate 40*0Sstevel@tonic-gate /* 41*0Sstevel@tonic-gate * This allocator is very simple. 42*0Sstevel@tonic-gate * - it uses a pre-allocated buffer for memory allocations. 43*0Sstevel@tonic-gate * - it does _not_ free memory in the pre-allocated buffer. 44*0Sstevel@tonic-gate * 45*0Sstevel@tonic-gate * The reason for the selected implemention is simplicity. 46*0Sstevel@tonic-gate * This allocator is designed for the usage in interrupt context when 47*0Sstevel@tonic-gate * the caller may not wait for free memory. 48*0Sstevel@tonic-gate */ 49*0Sstevel@tonic-gate 50*0Sstevel@tonic-gate /* pre-allocated buffer for memory allocations */ 51*0Sstevel@tonic-gate typedef struct nvbuf { 52*0Sstevel@tonic-gate uintptr_t nvb_buf; /* address of pre-allocated buffer */ 53*0Sstevel@tonic-gate uintptr_t nvb_lim; /* limit address in the buffer */ 54*0Sstevel@tonic-gate uintptr_t nvb_cur; /* current address in the buffer */ 55*0Sstevel@tonic-gate } nvbuf_t; 56*0Sstevel@tonic-gate 57*0Sstevel@tonic-gate /* 58*0Sstevel@tonic-gate * Initialize the pre-allocated buffer allocator. The caller needs to supply 59*0Sstevel@tonic-gate * 60*0Sstevel@tonic-gate * buf address of pre-allocated buffer 61*0Sstevel@tonic-gate * bufsz size of pre-allocated buffer 62*0Sstevel@tonic-gate * 63*0Sstevel@tonic-gate * nv_fixed_init() calculates the remaining members of nvbuf_t. 64*0Sstevel@tonic-gate */ 65*0Sstevel@tonic-gate static int 66*0Sstevel@tonic-gate nv_fixed_init(nv_alloc_t *nva, va_list valist) 67*0Sstevel@tonic-gate { 68*0Sstevel@tonic-gate uintptr_t base = va_arg(valist, uintptr_t); 69*0Sstevel@tonic-gate uintptr_t lim = base + va_arg(valist, size_t); 70*0Sstevel@tonic-gate nvbuf_t *nvb = (nvbuf_t *)P2ROUNDUP(base, sizeof (uintptr_t)); 71*0Sstevel@tonic-gate 72*0Sstevel@tonic-gate if (base == NULL || (uintptr_t)&nvb[1] > lim) 73*0Sstevel@tonic-gate return (EINVAL); 74*0Sstevel@tonic-gate 75*0Sstevel@tonic-gate nvb->nvb_buf = (uintptr_t)&nvb[0]; 76*0Sstevel@tonic-gate nvb->nvb_cur = (uintptr_t)&nvb[1]; 77*0Sstevel@tonic-gate nvb->nvb_lim = lim; 78*0Sstevel@tonic-gate nva->nva_arg = nvb; 79*0Sstevel@tonic-gate 80*0Sstevel@tonic-gate return (0); 81*0Sstevel@tonic-gate } 82*0Sstevel@tonic-gate 83*0Sstevel@tonic-gate static void * 84*0Sstevel@tonic-gate nv_fixed_alloc(nv_alloc_t *nva, size_t size) 85*0Sstevel@tonic-gate { 86*0Sstevel@tonic-gate nvbuf_t *nvb = nva->nva_arg; 87*0Sstevel@tonic-gate uintptr_t new = nvb->nvb_cur; 88*0Sstevel@tonic-gate 89*0Sstevel@tonic-gate if (size == 0 || new + size > nvb->nvb_lim) 90*0Sstevel@tonic-gate return (NULL); 91*0Sstevel@tonic-gate 92*0Sstevel@tonic-gate nvb->nvb_cur = P2ROUNDUP(new + size, sizeof (uintptr_t)); 93*0Sstevel@tonic-gate 94*0Sstevel@tonic-gate return ((void *)new); 95*0Sstevel@tonic-gate } 96*0Sstevel@tonic-gate 97*0Sstevel@tonic-gate /*ARGSUSED*/ 98*0Sstevel@tonic-gate static void 99*0Sstevel@tonic-gate nv_fixed_free(nv_alloc_t *nva, void *buf, size_t size) 100*0Sstevel@tonic-gate { 101*0Sstevel@tonic-gate /* don't free memory in the pre-allocated buffer */ 102*0Sstevel@tonic-gate } 103*0Sstevel@tonic-gate 104*0Sstevel@tonic-gate static void 105*0Sstevel@tonic-gate nv_fixed_reset(nv_alloc_t *nva) 106*0Sstevel@tonic-gate { 107*0Sstevel@tonic-gate nvbuf_t *nvb = nva->nva_arg; 108*0Sstevel@tonic-gate 109*0Sstevel@tonic-gate nvb->nvb_cur = (uintptr_t)&nvb[1]; 110*0Sstevel@tonic-gate } 111*0Sstevel@tonic-gate 112*0Sstevel@tonic-gate const nv_alloc_ops_t nv_fixed_ops_def = { 113*0Sstevel@tonic-gate nv_fixed_init, /* nv_ao_init() */ 114*0Sstevel@tonic-gate NULL, /* nv_ao_fini() */ 115*0Sstevel@tonic-gate nv_fixed_alloc, /* nv_ao_alloc() */ 116*0Sstevel@tonic-gate nv_fixed_free, /* nv_ao_free() */ 117*0Sstevel@tonic-gate nv_fixed_reset /* nv_ao_reset() */ 118*0Sstevel@tonic-gate }; 119*0Sstevel@tonic-gate 120*0Sstevel@tonic-gate const nv_alloc_ops_t *nv_fixed_ops = &nv_fixed_ops_def; 121