drivers/staging/lustre/lustre/libcfs/libcfs_mem.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 021110-1307, USA
  20  *
  21  * GPL HEADER END
  22  */
  23 /*
  24  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
  25  * Copyright (c) 2012, Intel Corporation.
  26  */
  27 /*
  28  * This file is part of Lustre, http://www.lustre.org/
  29  * Lustre is a trademark of Sun Microsystems, Inc.
  30  *
  31  * Author: liang@whamcloud.com
  32  */
  33
  34 #define DEBUG_SUBSYSTEM S_LNET
  35
  36 #include "../../include/linux/libcfs/libcfs.h"
  37
  38 struct cfs_var_array {
  39         unsigned int            va_count;       /* # of buffers */
  40         unsigned int            va_size;        /* size of each var */
  41         struct cfs_cpt_table    *va_cptab;      /* cpu partition table */
  42         void                    *va_ptrs[0];    /* buffer addresses */
  43 };
  44
  45 /*
  46  * free per-cpu data, see more detail in cfs_percpt_free
  47  */
  48 void
  49 cfs_percpt_free(void *vars)
  50 {
  51         struct  cfs_var_array *arr;
  52         int     i;
  53
  54         arr = container_of(vars, struct cfs_var_array, va_ptrs[0]);
  55
  56         for (i = 0; i < arr->va_count; i++) {
  57                 if (arr->va_ptrs[i] != NULL)
  58                         LIBCFS_FREE(arr->va_ptrs[i], arr->va_size);
  59         }
  60
  61         LIBCFS_FREE(arr, offsetof(struct cfs_var_array,
  62                                   va_ptrs[arr->va_count]));
  63 }
  64 EXPORT_SYMBOL(cfs_percpt_free);
  65
  66 /*
  67  * allocate per cpu-partition variables, returned value is an array of pointers,
  68  * variable can be indexed by CPU partition ID, i.e:
  69  *
  70  *      arr = cfs_percpt_alloc(cfs_cpu_pt, size);
  71  *      then caller can access memory block for CPU 0 by arr[0],
  72  *      memory block for CPU 1 by arr[1]...
  73  *      memory block for CPU N by arr[N]...
  74  *
  75  * cacheline aligned.
  76  */
  77 void *
  78 cfs_percpt_alloc(struct cfs_cpt_table *cptab, unsigned int size)
  79 {
  80         struct cfs_var_array    *arr;
  81         int                     count;
  82         int                     i;
  83
  84         count = cfs_cpt_number(cptab);
  85
  86         LIBCFS_ALLOC(arr, offsetof(struct cfs_var_array, va_ptrs[count]));
  87         if (!arr)
  88                 return NULL;
  89
  90         arr->va_size    = size = L1_CACHE_ALIGN(size);
  91         arr->va_count   = count;
  92         arr->va_cptab   = cptab;
  93
  94         for (i = 0; i < count; i++) {
  95                 LIBCFS_CPT_ALLOC(arr->va_ptrs[i], cptab, i, size);
  96                 if (!arr->va_ptrs[i]) {
  97                         cfs_percpt_free((void *)&arr->va_ptrs[0]);
  98                         return NULL;
  99                 }
 100         }
 101
 102         return (void *)&arr->va_ptrs[0];
 103 }
 104 EXPORT_SYMBOL(cfs_percpt_alloc);
 105
 106 /*
 107  * return number of CPUs (or number of elements in per-cpu data)
 108  * according to cptab of @vars
 109  */
 110 int
 111 cfs_percpt_number(void *vars)
 112 {
 113         struct cfs_var_array *arr;
 114
 115         arr = container_of(vars, struct cfs_var_array, va_ptrs[0]);
 116
 117         return arr->va_count;
 118 }
 119 EXPORT_SYMBOL(cfs_percpt_number);
 120
 121 /*
 122  * return memory block shadowed from current CPU
 123  */
 124 void *
 125 cfs_percpt_current(void *vars)
 126 {
 127         struct cfs_var_array *arr;
 128         int    cpt;
 129
 130         arr = container_of(vars, struct cfs_var_array, va_ptrs[0]);
 131         cpt = cfs_cpt_current(arr->va_cptab, 0);
 132         if (cpt < 0)
 133                 return NULL;
 134
 135         return arr->va_ptrs[cpt];
 136 }
 137
 138 void *
 139 cfs_percpt_index(void *vars, int idx)
 140 {
 141         struct cfs_var_array *arr;
 142
 143         arr = container_of(vars, struct cfs_var_array, va_ptrs[0]);
 144
 145         LASSERT(idx >= 0 && idx < arr->va_count);
 146         return arr->va_ptrs[idx];
 147 }
 148
 149 /*
 150  * free variable array, see more detail in cfs_array_alloc
 151  */
 152 void
 153 cfs_array_free(void *vars)
 154 {
 155         struct cfs_var_array    *arr;
 156         int                     i;
 157
 158         arr = container_of(vars, struct cfs_var_array, va_ptrs[0]);
 159
 160         for (i = 0; i < arr->va_count; i++) {
 161                 if (!arr->va_ptrs[i])
 162                         continue;
 163
 164                 LIBCFS_FREE(arr->va_ptrs[i], arr->va_size);
 165         }
 166         LIBCFS_FREE(arr, offsetof(struct cfs_var_array,
 167                                   va_ptrs[arr->va_count]));
 168 }
 169 EXPORT_SYMBOL(cfs_array_free);
 170
 171 /*
 172  * allocate a variable array, returned value is an array of pointers.
 173  * Caller can specify length of array by @count, @size is size of each
 174  * memory block in array.
 175  */
 176 void *
 177 cfs_array_alloc(int count, unsigned int size)
 178 {
 179         struct cfs_var_array    *arr;
 180         int                     i;
 181
 182         LIBCFS_ALLOC(arr, offsetof(struct cfs_var_array, va_ptrs[count]));
 183         if (!arr)
 184                 return NULL;
 185
 186         arr->va_count   = count;
 187         arr->va_size    = size;
 188
 189         for (i = 0; i < count; i++) {
 190                 LIBCFS_ALLOC(arr->va_ptrs[i], size);
 191
 192                 if (!arr->va_ptrs[i]) {
 193                         cfs_array_free((void *)&arr->va_ptrs[0]);
 194                         return NULL;
 195                 }
 196         }
 197
 198         return (void *)&arr->va_ptrs[0];
 199 }
 200 EXPORT_SYMBOL(cfs_array_alloc);