| /* |
| * CDDL HEADER START |
| * |
| * The contents of this file are subject to the terms of the |
| * Common Development and Distribution License (the "License"). |
| * You may not use this file except in compliance with the License. |
| * |
| * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE |
| * or http://www.opensolaris.org/os/licensing. |
| * See the License for the specific language governing permissions |
| * and limitations under the License. |
| * |
| * When distributing Covered Code, include this CDDL HEADER in each |
| * file and include the License file at usr/src/OPENSOLARIS.LICENSE. |
| * If applicable, add the following below this CDDL HEADER, with the |
| * fields enclosed by brackets "[]" replaced with your own identifying |
| * information: Portions Copyright [yyyy] [name of copyright owner] |
| * |
| * CDDL HEADER END |
| */ |
| |
| /* |
| * Copyright 2006 Sun Microsystems, Inc. All rights reserved. |
| * Use is subject to license terms. |
| */ |
| |
| #include <sys/isa_defs.h> |
| #include <sys/nvpair.h> |
| #include <sys/sysmacros.h> |
| |
| /* |
| * This allocator is very simple. |
| * - it uses a pre-allocated buffer for memory allocations. |
| * - it does _not_ free memory in the pre-allocated buffer. |
| * |
| * The reason for the selected implementation is simplicity. |
| * This allocator is designed for the usage in interrupt context when |
| * the caller may not wait for free memory. |
| */ |
| |
| /* pre-allocated buffer for memory allocations */ |
| typedef struct nvbuf { |
| uintptr_t nvb_buf; /* address of pre-allocated buffer */ |
| uintptr_t nvb_lim; /* limit address in the buffer */ |
| uintptr_t nvb_cur; /* current address in the buffer */ |
| } nvbuf_t; |
| |
| /* |
| * Initialize the pre-allocated buffer allocator. The caller needs to supply |
| * |
| * buf address of pre-allocated buffer |
| * bufsz size of pre-allocated buffer |
| * |
| * nv_fixed_init() calculates the remaining members of nvbuf_t. |
| */ |
| static int |
| nv_fixed_init(nv_alloc_t *nva, va_list valist) |
| { |
| uintptr_t base = va_arg(valist, uintptr_t); |
| uintptr_t lim = base + va_arg(valist, size_t); |
| nvbuf_t *nvb = (nvbuf_t *)P2ROUNDUP(base, sizeof (uintptr_t)); |
| |
| if (base == 0 || (uintptr_t)&nvb[1] > lim) |
| return (EINVAL); |
| |
| nvb->nvb_buf = (uintptr_t)&nvb[0]; |
| nvb->nvb_cur = (uintptr_t)&nvb[1]; |
| nvb->nvb_lim = lim; |
| nva->nva_arg = nvb; |
| |
| return (0); |
| } |
| |
| static void * |
| nv_fixed_alloc(nv_alloc_t *nva, size_t size) |
| { |
| nvbuf_t *nvb = nva->nva_arg; |
| uintptr_t new = nvb->nvb_cur; |
| |
| if (size == 0 || new + size > nvb->nvb_lim) |
| return (NULL); |
| |
| nvb->nvb_cur = P2ROUNDUP(new + size, sizeof (uintptr_t)); |
| |
| return ((void *)new); |
| } |
| |
| /*ARGSUSED*/ |
| static void |
| nv_fixed_free(nv_alloc_t *nva, void *buf, size_t size) |
| { |
| /* don't free memory in the pre-allocated buffer */ |
| } |
| |
| static void |
| nv_fixed_reset(nv_alloc_t *nva) |
| { |
| nvbuf_t *nvb = nva->nva_arg; |
| |
| nvb->nvb_cur = (uintptr_t)&nvb[1]; |
| } |
| |
| const nv_alloc_ops_t nv_fixed_ops_def = { |
| .nv_ao_init = nv_fixed_init, |
| .nv_ao_fini = NULL, |
| .nv_ao_alloc = nv_fixed_alloc, |
| .nv_ao_free = nv_fixed_free, |
| .nv_ao_reset = nv_fixed_reset |
| }; |
| |
| const nv_alloc_ops_t *nv_fixed_ops = &nv_fixed_ops_def; |
| |
| #if defined(_KERNEL) |
| EXPORT_SYMBOL(nv_fixed_ops); |
| #endif |