aboutsummaryrefslogtreecommitdiff
path: root/xorg-server/hw/xfree86/os-support/misc/SlowBcopy.c
blob: 254748ff6c1f2762e791c431039d42e06870c568 (plain)
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
/*******************************************************************************
  for Alpha Linux
*******************************************************************************/

/* 
 *   Create a dependency that should be immune from the effect of register
 *   renaming as is commonly seen in superscalar processors.  This should
 *   insert a minimum of 100-ns delays between reads/writes at clock rates
 *   up to 100 MHz---GGL
 *   
 *   Slowbcopy(char *src, char *dst, int count)   
 *   
 */

#ifdef HAVE_XORG_CONFIG_H
#include <xorg-config.h>
#endif

#include <X11/X.h>
#include "xf86.h"
#include "xf86Priv.h"
#include "xf86_OSlib.h"
#include "compiler.h"

static int really_slow_bcopy;

void
xf86SetReallySlowBcopy(void)
{
    really_slow_bcopy = 1;
}

#if defined(__i386__) || defined(__amd64__)
static void
xf86_really_slow_bcopy(unsigned char *src, unsigned char *dst, int len)
{
    while (len--) {
        *dst++ = *src++;
        outb(0x80, 0x00);
    }
}
#endif

/* The outb() isn't needed on my machine, but who knows ... -- ost */
void
xf86SlowBcopy(unsigned char *src, unsigned char *dst, int len)
{
#if defined(__i386__) || defined(__amd64__)
    if (really_slow_bcopy) {
        xf86_really_slow_bcopy(src, dst, len);
        return;
    }
#endif
    while (len--)
        *dst++ = *src++;
}

#ifdef __alpha__

#ifdef linux

unsigned long _bus_base(void);

#define useSparse() (!_bus_base())

#define SPARSE (7)

#else

#define useSparse() 0

#define SPARSE 0

#endif

void
xf86SlowBCopyFromBus(unsigned char *src, unsigned char *dst, int count)
{
    if (useSparse()) {
        unsigned long addr;
        long result;

        addr = (unsigned long) src;
        while (count) {
            result = *(volatile int *) addr;
            result >>= ((addr >> SPARSE) & 3) * 8;
            *dst++ = (unsigned char) (0xffUL & result);
            addr += 1 << SPARSE;
            count--;
            outb(0x80, 0x00);
        }
    }
    else
        xf86SlowBcopy(src, dst, count);
}

void
xf86SlowBCopyToBus(unsigned char *src, unsigned char *dst, int count)
{
    if (useSparse()) {
        unsigned long addr;

        addr = (unsigned long) dst;
        while (count) {
            *(volatile unsigned int *) addr =
                (unsigned short) (*src) * 0x01010101;
            src++;
            addr += 1 << SPARSE;
            count--;
            outb(0x80, 0x00);
        }
    }
    else
        xf86SlowBcopy(src, dst, count);
}
#endif