1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
/*
* Copyright (C) 1997 Claus-Justus Heine
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
* $Source: /homes/cvs/ftape-stacked/ftape/lowlevel/ftape-buffer.c,v $
* $Revision: 1.3 $
* $Date: 1997/10/16 23:33:11 $
*
* This file contains the allocator/dealloctor for ftape's dynamic dma
* buffer.
*/
#include <asm/segment.h>
#include <linux/malloc.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/wrapper.h>
#include <asm/dma.h>
#include <linux/ftape.h>
#include "../lowlevel/ftape-rw.h"
#include "../lowlevel/ftape-read.h"
#include "../lowlevel/ftape-tracing.h"
/* DMA'able memory allocation stuff.
*/
/* Pure 2^n version of get_order */
static inline int __get_order(size_t size)
{
unsigned long order;
size = (size-1) >> (PAGE_SHIFT-1);
order = -1;
do {
size >>= 1;
order++;
} while (size);
return order;
}
static inline void *dmaalloc(size_t size)
{
unsigned long addr;
if (size == 0) {
return NULL;
}
addr = __get_dma_pages(GFP_KERNEL, __get_order(size));
if (addr) {
int i;
for (i = MAP_NR(addr); i < MAP_NR(addr+size); i++) {
mem_map_reserve(i);
}
}
return (void *)addr;
}
static inline void dmafree(void *addr, size_t size)
{
if (size > 0) {
int i;
for (i = MAP_NR((unsigned long)addr);
i < MAP_NR((unsigned long)addr+size); i++) {
mem_map_unreserve (i);
}
free_pages((unsigned long) addr, __get_order(size));
}
}
static int add_one_buffer(void)
{
TRACE_FUN(ft_t_flow);
if (ft_nr_buffers >= FT_MAX_NR_BUFFERS) {
TRACE_EXIT -ENOMEM;
}
ft_buffer[ft_nr_buffers] = kmalloc(sizeof(buffer_struct), GFP_KERNEL);
if (ft_buffer[ft_nr_buffers] == NULL) {
TRACE_EXIT -ENOMEM;
}
memset(ft_buffer[ft_nr_buffers], 0, sizeof(buffer_struct));
ft_buffer[ft_nr_buffers]->address = dmaalloc(FT_BUFF_SIZE);
if (ft_buffer[ft_nr_buffers]->address == NULL) {
kfree(ft_buffer[ft_nr_buffers]);
ft_buffer[ft_nr_buffers] = NULL;
TRACE_EXIT -ENOMEM;
}
ft_nr_buffers ++;
TRACE(ft_t_info, "buffer nr #%d @ %p, dma area @ %p",
ft_nr_buffers,
ft_buffer[ft_nr_buffers-1],
ft_buffer[ft_nr_buffers-1]->address);
TRACE_EXIT 0;
}
static void del_one_buffer(void)
{
TRACE_FUN(ft_t_flow);
if (ft_nr_buffers > 0) {
TRACE(ft_t_info, "releasing buffer nr #%d @ %p, dma area @ %p",
ft_nr_buffers,
ft_buffer[ft_nr_buffers-1],
ft_buffer[ft_nr_buffers-1]->address);
ft_nr_buffers --;
dmafree(ft_buffer[ft_nr_buffers]->address, FT_BUFF_SIZE);
kfree(ft_buffer[ft_nr_buffers]);
ft_buffer[ft_nr_buffers] = NULL;
}
TRACE_EXIT;
}
int ftape_set_nr_buffers(int cnt)
{
int delta = cnt - ft_nr_buffers;
TRACE_FUN(ft_t_flow);
if (delta > 0) {
while (delta--) {
if (add_one_buffer() < 0) {
TRACE_EXIT -ENOMEM;
}
}
} else if (delta < 0) {
while (delta++) {
del_one_buffer();
}
}
ftape_zap_read_buffers();
TRACE_EXIT 0;
}
|
