drivers/char/ftape/zftape/zftape-buffers.c

   1 /*
   2  *      Copyright (C) 1995-1997 Claus-Justus Heine.
   3
   4  This program is free software; you can redistribute it and/or modify
   5  it under the terms of the GNU General Public License as published by
   6  the Free Software Foundation; either version 2, or (at your option)
   7  any later version.
   8
   9  This program is distributed in the hope that it will be useful,
  10  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  GNU General Public License for more details.
  13
  14  You should have received a copy of the GNU General Public License
  15  along with this program; see the file COPYING.  If not, write to
  16  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18  *
  19  * $Source: /homes/cvs/ftape-stacked/ftape/zftape/zftape-buffers.c,v $
  20  * $Revision: 1.2 $
  21  * $Date: 1997/10/05 19:18:59 $
  22  *
  23  *      This file contains the dynamic buffer allocation routines
  24  *      of zftape
  25  */
  26
  27 #include <linux/errno.h>
  28 #include <linux/mm.h>
  29 #include <linux/malloc.h>
  30 #include <asm/segment.h>
  31
  32 #include <linux/zftape.h>
  33
  34 #if LINUX_VERSION_CODE >= KERNEL_VER(2,1,0)
  35 #include <linux/vmalloc.h>
  36 #endif
  37
  38 #include "../zftape/zftape-init.h"
  39 #include "../zftape/zftape-eof.h"
  40 #include "../zftape/zftape-ctl.h"
  41 #include "../zftape/zftape-write.h"
  42 #include "../zftape/zftape-read.h"
  43 #include "../zftape/zftape-rw.h"
  44 #include "../zftape/zftape-vtbl.h"
  45
  46 /*  global variables
  47  */
  48
  49 /*  local varibales
  50  */
  51 static unsigned int used_memory;
  52 static unsigned int peak_memory;
  53
  54 void zft_memory_stats(void)
  55 {
  56         TRACE_FUN(ft_t_flow);
  57
  58         TRACE(ft_t_noise, "Memory usage (vmalloc allocations):\n"
  59               KERN_INFO "total allocated: %d\n"
  60               KERN_INFO "peak allocation: %d",
  61               used_memory, peak_memory);
  62         peak_memory = used_memory;
  63         TRACE_EXIT;
  64 }
  65
  66 int zft_vcalloc_once(void *new, size_t size)
  67 {
  68         TRACE_FUN(ft_t_flow);
  69         if (zft_vmalloc_once(new, size) < 0) {
  70                 TRACE_EXIT -ENOMEM;
  71         }
  72         memset(*(void **)new, '\0', size);
  73         TRACE_EXIT 0;
  74 }
  75 int zft_vmalloc_once(void *new, size_t size)
  76 {
  77         TRACE_FUN(ft_t_flow);
  78
  79         if (*(void **)new != NULL || size == 0) {
  80                 TRACE_EXIT 0;
  81         }
  82         if ((*(void **)new = vmalloc(size)) == NULL) {
  83                 TRACE_EXIT -ENOMEM;
  84         }
  85         used_memory += size;
  86         if (peak_memory < used_memory) {
  87                 peak_memory = used_memory;
  88         }
  89         TRACE_ABORT(0, ft_t_noise,
  90                     "allocated buffer @ %p, %d bytes", *(void **)new, size);
  91 }
  92 int zft_vcalloc_always(void *new, size_t size)
  93 {
  94         TRACE_FUN(ft_t_flow);
  95
  96         zft_vfree(new, size);
  97         TRACE_EXIT zft_vcalloc_once(new, size);
  98 }
  99 int zft_vmalloc_always(void *new, size_t size)
 100 {
 101         TRACE_FUN(ft_t_flow);
 102
 103         zft_vfree(new, size);
 104         TRACE_EXIT zft_vmalloc_once(new, size);
 105 }
 106 void zft_vfree(void *old, size_t size)
 107 {
 108         TRACE_FUN(ft_t_flow);
 109
 110         if (*(void **)old) {
 111                 vfree(*(void **)old);
 112                 used_memory -= size;
 113                 TRACE(ft_t_noise, "released buffer @ %p, %d bytes",
 114                       *(void **)old, size);
 115                 *(void **)old = NULL;
 116         }
 117         TRACE_EXIT;
 118 }
 119
 120 void *zft_kmalloc(size_t size)
 121 {
 122         void *new;
 123
 124         while ((new = kmalloc(size, GFP_KERNEL)) == NULL) {
 125                 current->state   = TASK_INTERRUPTIBLE;
 126                 schedule_timeout(HZ/10);
 127         }
 128         memset(new, 0, size);
 129         used_memory += size;
 130         if (peak_memory < used_memory) {
 131                 peak_memory = used_memory;
 132         }
 133         return new;
 134 }
 135
 136 void zft_kfree(void *old, size_t size)
 137 {
 138         kfree(old);
 139         used_memory -= size;
 140 }
 141
 142 /* there are some more buffers that are allocated on demand.
 143  * cleanup_module() calles this function to be sure to have released
 144  * them
 145  */
 146 void zft_uninit_mem(void)
 147 {
 148         TRACE_FUN(ft_t_flow);
 149
 150         zft_vfree(&zft_hseg_buf, FT_SEGMENT_SIZE);
 151         zft_vfree(&zft_deblock_buf, FT_SEGMENT_SIZE); zft_deblock_segment = -1;
 152         zft_free_vtbl();
 153         if (zft_cmpr_lock(0 /* don't load */) == 0) {
 154                 (*zft_cmpr_ops->cleanup)();
 155                 (*zft_cmpr_ops->reset)(); /* unlock it again */
 156         }
 157         zft_memory_stats();
 158         TRACE_EXIT;
 159 }