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/slab.h>
  30 #include <linux/delay.h>
  31
  32 #include <linux/zftape.h>
  33
  34 #include <linux/vmalloc.h>
  35
  36 #include "../zftape/zftape-init.h"
  37 #include "../zftape/zftape-eof.h"
  38 #include "../zftape/zftape-ctl.h"
  39 #include "../zftape/zftape-write.h"
  40 #include "../zftape/zftape-read.h"
  41 #include "../zftape/zftape-rw.h"
  42 #include "../zftape/zftape-vtbl.h"
  43
  44 /*  global variables
  45  */
  46
  47 /*  local varibales
  48  */
  49 static unsigned int used_memory;
  50 static unsigned int peak_memory;
  51
  52 void zft_memory_stats(void)
  53 {
  54         TRACE_FUN(ft_t_flow);
  55
  56         TRACE(ft_t_noise, "Memory usage (vmalloc allocations):\n"
  57               KERN_INFO "total allocated: %d\n"
  58               KERN_INFO "peak allocation: %d",
  59               used_memory, peak_memory);
  60         peak_memory = used_memory;
  61         TRACE_EXIT;
  62 }
  63
  64 int zft_vcalloc_once(void *new, size_t size)
  65 {
  66         TRACE_FUN(ft_t_flow);
  67         if (zft_vmalloc_once(new, size) < 0) {
  68                 TRACE_EXIT -ENOMEM;
  69         }
  70         memset(*(void **)new, '\0', size);
  71         TRACE_EXIT 0;
  72 }
  73 int zft_vmalloc_once(void *new, size_t size)
  74 {
  75         TRACE_FUN(ft_t_flow);
  76
  77         if (*(void **)new != NULL || size == 0) {
  78                 TRACE_EXIT 0;
  79         }
  80         if ((*(void **)new = vmalloc(size)) == NULL) {
  81                 TRACE_EXIT -ENOMEM;
  82         }
  83         used_memory += size;
  84         if (peak_memory < used_memory) {
  85                 peak_memory = used_memory;
  86         }
  87         TRACE_ABORT(0, ft_t_noise,
  88                     "allocated buffer @ %p, %d bytes", *(void **)new, size);
  89 }
  90 int zft_vmalloc_always(void *new, size_t size)
  91 {
  92         TRACE_FUN(ft_t_flow);
  93
  94         zft_vfree(new, size);
  95         TRACE_EXIT zft_vmalloc_once(new, size);
  96 }
  97 void zft_vfree(void *old, size_t size)
  98 {
  99         TRACE_FUN(ft_t_flow);
 100
 101         if (*(void **)old) {
 102                 vfree(*(void **)old);
 103                 used_memory -= size;
 104                 TRACE(ft_t_noise, "released buffer @ %p, %d bytes",
 105                       *(void **)old, size);
 106                 *(void **)old = NULL;
 107         }
 108         TRACE_EXIT;
 109 }
 110
 111 void *zft_kmalloc(size_t size)
 112 {
 113         void *new;
 114
 115         while ((new = kmalloc(size, GFP_KERNEL)) == NULL) {
 116                 msleep_interruptible(100);
 117         }
 118         memset(new, 0, size);
 119         used_memory += size;
 120         if (peak_memory < used_memory) {
 121                 peak_memory = used_memory;
 122         }
 123         return new;
 124 }
 125
 126 void zft_kfree(void *old, size_t size)
 127 {
 128         kfree(old);
 129         used_memory -= size;
 130 }
 131
 132 /* there are some more buffers that are allocated on demand.
 133  * cleanup_module() calles this function to be sure to have released
 134  * them
 135  */
 136 void zft_uninit_mem(void)
 137 {
 138         TRACE_FUN(ft_t_flow);
 139
 140         zft_vfree(&zft_hseg_buf, FT_SEGMENT_SIZE);
 141         zft_vfree(&zft_deblock_buf, FT_SEGMENT_SIZE); zft_deblock_segment = -1;
 142         zft_free_vtbl();
 143         if (zft_cmpr_lock(0 /* don't load */) == 0) {
 144                 (*zft_cmpr_ops->cleanup)();
 145                 (*zft_cmpr_ops->reset)(); /* unlock it again */
 146         }
 147         zft_memory_stats();
 148         TRACE_EXIT;
 149 }