vio_util.c revision 2793:a30c4090b49f
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27#pragma ident "%Z%%M% %I% %E% SMI" 28 29#include <sys/types.h> 30#include <sys/sysmacros.h> 31#include <sys/cmn_err.h> 32#include <sys/errno.h> 33#include <sys/kmem.h> 34#include <sys/ksynch.h> 35#include <sys/stream.h> 36#include <sys/ddi.h> 37#include <sys/sunddi.h> 38#include <sys/vio_util.h> 39 40/* 41 * Create a pool of mblks from which future vio_allocb() requests 42 * will be serviced. 43 * 44 * NOTE: num_mblks has to non-zero and a power-of-2 45 * 46 * Returns 0 on success or EINVAL if num_mblks is zero or not 47 * a power of 2. 48 */ 49int 50vio_create_mblks(uint64_t num_mblks, size_t mblk_size, vio_mblk_pool_t **poolp) 51{ 52 vio_mblk_pool_t *vmplp; 53 vio_mblk_t *vmp; 54 uint8_t *datap; 55 int i; 56 57 if (!(num_mblks) || (!ISP2(num_mblks))) { 58 *poolp = 0; 59 return (EINVAL); 60 } 61 62 vmplp = kmem_zalloc(sizeof (*vmplp), KM_SLEEP); 63 vmplp->quelen = num_mblks; 64 vmplp->quemask = num_mblks - 1; /* expects quelen is power-of-2 */ 65 vmplp->mblk_size = mblk_size; 66 67 mutex_init(&vmplp->hlock, NULL, MUTEX_DRIVER, 68 DDI_INTR_PRI(DDI_INTR_SOFTPRI_DEFAULT)); 69 mutex_init(&vmplp->tlock, NULL, MUTEX_DRIVER, 70 DDI_INTR_PRI(DDI_INTR_SOFTPRI_DEFAULT)); 71 72 vmplp->basep = kmem_zalloc(num_mblks * sizeof (vio_mblk_t), KM_SLEEP); 73 vmplp->datap = kmem_zalloc(num_mblks * mblk_size, KM_SLEEP); 74 vmplp->nextp = NULL; 75 76 /* create a queue of pointers to free vio_mblk_t's */ 77 vmplp->quep = kmem_zalloc(vmplp->quelen * sizeof (vio_mblk_t *), 78 KM_SLEEP); 79 vmplp->head = 0; 80 vmplp->tail = 0; 81 82 for (i = 0, datap = vmplp->datap; i < num_mblks; i++) { 83 84 vmp = &(vmplp->basep[i]); 85 vmp->vmplp = vmplp; 86 vmp->datap = datap; 87 vmp->reclaim.free_func = vio_freeb; 88 vmp->reclaim.free_arg = (caddr_t)vmp; 89 vmp->mp = desballoc(vmp->datap, mblk_size, BPRI_MED, 90 &vmp->reclaim); 91 92 if (vmp->mp == NULL) 93 continue; 94 95 /* put this vmp on the free stack */ 96 vmplp->quep[vmplp->tail] = vmp; 97 vmplp->tail = (vmplp->tail + 1) & vmplp->quemask; 98 99 datap += mblk_size; 100 } 101 102 *poolp = vmplp; 103 return (0); 104} 105 106/* 107 * Destroy the pool of mblks. This can only succeed when 108 * all allocated mblks have been returned to the pool. 109 * 110 * It is up to the caller to ensure that no further mblks are 111 * requested from the pool after destroy has been invoked. 112 * 113 * Returns 0 on success, EINVAL if handle is invalid, or 114 * EBUSY if not all mblks reclaimed yet. 115 */ 116int 117vio_destroy_mblks(vio_mblk_pool_t *vmplp) 118{ 119 uint64_t i; 120 uint64_t num_mblks; 121 vio_mblk_t *vmp; 122 123 if (vmplp == NULL) 124 return (EINVAL); 125 126 /* 127 * We can only destroy the pool once all the mblks have 128 * been reclaimed. 129 */ 130 if (vmplp->head != vmplp->tail) { 131 /* some mblks still in use */ 132 return (EBUSY); 133 } 134 135 num_mblks = vmplp->quelen; 136 137 /* 138 * Set pool flag to tell vio_freeb() which is invoked from freeb(), 139 * that it is being called in the context of vio_destroy_mblks(). 140 * This results in freeing only mblk_t and dblk_t structures for 141 * each mp. The associated data buffers are freed below as one big 142 * chunk through kmem_free(vmplp->datap). 143 */ 144 vmplp->flag |= VMPL_FLAG_DESTROYING; 145 for (i = 0; i < num_mblks; i++) { 146 vmp = &(vmplp->basep[i]); 147 if (vmp->mp) 148 freeb(vmp->mp); 149 } 150 vmplp->flag &= ~(VMPL_FLAG_DESTROYING); 151 152 kmem_free(vmplp->basep, num_mblks * sizeof (vio_mblk_t)); 153 kmem_free(vmplp->datap, num_mblks * vmplp->mblk_size); 154 kmem_free(vmplp->quep, num_mblks * sizeof (vio_mblk_t *)); 155 156 mutex_destroy(&vmplp->hlock); 157 mutex_destroy(&vmplp->tlock); 158 159 kmem_free(vmplp, sizeof (*vmplp)); 160 161 return (0); 162} 163 164/* 165 * Allocate a mblk from the free pool if one is available. 166 * Otherwise returns NULL. 167 */ 168mblk_t * 169vio_allocb(vio_mblk_pool_t *vmplp) 170{ 171 vio_mblk_t *vmp = NULL; 172 mblk_t *mp = NULL; 173 uint32_t head; 174 175 mutex_enter(&vmplp->hlock); 176 head = (vmplp->head + 1) & vmplp->quemask; 177 if (head != vmplp->tail) { 178 /* we have free mblks */ 179 vmp = vmplp->quep[vmplp->head]; 180 mp = vmp->mp; 181 vmplp->head = head; 182 } 183 mutex_exit(&vmplp->hlock); 184 185 return (mp); 186} 187 188/* 189 * Return a mblk to the free pool. Invoked when the upper IP 190 * layers do freemsg() etc on the mblk they were passed. 191 */ 192void 193vio_freeb(void *arg) 194{ 195 vio_mblk_t *vmp = (vio_mblk_t *)arg; 196 vio_mblk_pool_t *vmplp = vmp->vmplp; 197 198 if (vmplp->flag & VMPL_FLAG_DESTROYING) { 199 /* 200 * This flag indicates that freeb() is being called from 201 * vio_destroy_mblks(). 202 * We don't need to alloc a new mblk_t/dblk_t pair for 203 * this data buffer, return from here and the data buffer 204 * itself will be freed in vio_destroy_mblks(). 205 */ 206 return; 207 } 208 209 vmp->mp = desballoc(vmp->datap, vmplp->mblk_size, 210 BPRI_MED, &vmp->reclaim); 211 212 mutex_enter(&vmplp->tlock); 213 vmplp->quep[vmplp->tail] = vmp; 214 vmplp->tail = (vmplp->tail + 1) & vmplp->quemask; 215 mutex_exit(&vmplp->tlock); 216} 217