xref: /OK3568_Linux_fs/external/xserver/hw/xfree86/os-support/misc/SlowBcopy.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*******************************************************************************
2*4882a593Smuzhiyun   for Alpha Linux
3*4882a593Smuzhiyun *******************************************************************************/
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun /*
6*4882a593Smuzhiyun  *   Create a dependency that should be immune from the effect of register
7*4882a593Smuzhiyun  *   renaming as is commonly seen in superscalar processors.  This should
8*4882a593Smuzhiyun  *   insert a minimum of 100-ns delays between reads/writes at clock rates
9*4882a593Smuzhiyun  *   up to 100 MHz---GGL
10*4882a593Smuzhiyun  *
11*4882a593Smuzhiyun  *   Slowbcopy(char *src, char *dst, int count)
12*4882a593Smuzhiyun  *
13*4882a593Smuzhiyun  */
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun #ifdef HAVE_XORG_CONFIG_H
16*4882a593Smuzhiyun #include <xorg-config.h>
17*4882a593Smuzhiyun #endif
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun #include <X11/X.h>
20*4882a593Smuzhiyun #include "xf86.h"
21*4882a593Smuzhiyun #include "xf86Priv.h"
22*4882a593Smuzhiyun #include "xf86_OSlib.h"
23*4882a593Smuzhiyun #include "compiler.h"
24*4882a593Smuzhiyun 
25*4882a593Smuzhiyun static int really_slow_bcopy;
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun void
xf86SetReallySlowBcopy(void)28*4882a593Smuzhiyun xf86SetReallySlowBcopy(void)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun     really_slow_bcopy = 1;
31*4882a593Smuzhiyun }
32*4882a593Smuzhiyun 
33*4882a593Smuzhiyun #if defined(__i386__) || defined(__amd64__)
34*4882a593Smuzhiyun static void
xf86_really_slow_bcopy(unsigned char * src,unsigned char * dst,int len)35*4882a593Smuzhiyun xf86_really_slow_bcopy(unsigned char *src, unsigned char *dst, int len)
36*4882a593Smuzhiyun {
37*4882a593Smuzhiyun     while (len--) {
38*4882a593Smuzhiyun         *dst++ = *src++;
39*4882a593Smuzhiyun         outb(0x80, 0x00);
40*4882a593Smuzhiyun     }
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun #endif
43*4882a593Smuzhiyun 
44*4882a593Smuzhiyun /* The outb() isn't needed on my machine, but who knows ... -- ost */
45*4882a593Smuzhiyun void
xf86SlowBcopy(unsigned char * src,unsigned char * dst,int len)46*4882a593Smuzhiyun xf86SlowBcopy(unsigned char *src, unsigned char *dst, int len)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun #if defined(__i386__) || defined(__amd64__)
49*4882a593Smuzhiyun     if (really_slow_bcopy) {
50*4882a593Smuzhiyun         xf86_really_slow_bcopy(src, dst, len);
51*4882a593Smuzhiyun         return;
52*4882a593Smuzhiyun     }
53*4882a593Smuzhiyun #endif
54*4882a593Smuzhiyun     while (len--)
55*4882a593Smuzhiyun         *dst++ = *src++;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun 
58*4882a593Smuzhiyun #ifdef __alpha__
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun #ifdef __linux__
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun unsigned long _bus_base(void);
63*4882a593Smuzhiyun 
64*4882a593Smuzhiyun #define useSparse() (!_bus_base())
65*4882a593Smuzhiyun 
66*4882a593Smuzhiyun #define SPARSE (7)
67*4882a593Smuzhiyun 
68*4882a593Smuzhiyun #else
69*4882a593Smuzhiyun 
70*4882a593Smuzhiyun #define useSparse() 0
71*4882a593Smuzhiyun 
72*4882a593Smuzhiyun #define SPARSE 0
73*4882a593Smuzhiyun 
74*4882a593Smuzhiyun #endif
75*4882a593Smuzhiyun 
76*4882a593Smuzhiyun void
xf86SlowBCopyFromBus(unsigned char * src,unsigned char * dst,int count)77*4882a593Smuzhiyun xf86SlowBCopyFromBus(unsigned char *src, unsigned char *dst, int count)
78*4882a593Smuzhiyun {
79*4882a593Smuzhiyun     if (useSparse()) {
80*4882a593Smuzhiyun         unsigned long addr;
81*4882a593Smuzhiyun         long result;
82*4882a593Smuzhiyun 
83*4882a593Smuzhiyun         addr = (unsigned long) src;
84*4882a593Smuzhiyun         while (count) {
85*4882a593Smuzhiyun             result = *(volatile int *) addr;
86*4882a593Smuzhiyun             result >>= ((addr >> SPARSE) & 3) * 8;
87*4882a593Smuzhiyun             *dst++ = (unsigned char) (0xffUL & result);
88*4882a593Smuzhiyun             addr += 1 << SPARSE;
89*4882a593Smuzhiyun             count--;
90*4882a593Smuzhiyun             outb(0x80, 0x00);
91*4882a593Smuzhiyun         }
92*4882a593Smuzhiyun     }
93*4882a593Smuzhiyun     else
94*4882a593Smuzhiyun         xf86SlowBcopy(src, dst, count);
95*4882a593Smuzhiyun }
96*4882a593Smuzhiyun 
97*4882a593Smuzhiyun void
xf86SlowBCopyToBus(unsigned char * src,unsigned char * dst,int count)98*4882a593Smuzhiyun xf86SlowBCopyToBus(unsigned char *src, unsigned char *dst, int count)
99*4882a593Smuzhiyun {
100*4882a593Smuzhiyun     if (useSparse()) {
101*4882a593Smuzhiyun         unsigned long addr;
102*4882a593Smuzhiyun 
103*4882a593Smuzhiyun         addr = (unsigned long) dst;
104*4882a593Smuzhiyun         while (count) {
105*4882a593Smuzhiyun             *(volatile unsigned int *) addr =
106*4882a593Smuzhiyun                 (unsigned short) (*src) * 0x01010101;
107*4882a593Smuzhiyun             src++;
108*4882a593Smuzhiyun             addr += 1 << SPARSE;
109*4882a593Smuzhiyun             count--;
110*4882a593Smuzhiyun             outb(0x80, 0x00);
111*4882a593Smuzhiyun         }
112*4882a593Smuzhiyun     }
113*4882a593Smuzhiyun     else
114*4882a593Smuzhiyun         xf86SlowBcopy(src, dst, count);
115*4882a593Smuzhiyun }
116*4882a593Smuzhiyun #endif
117