xref: /OK3568_Linux_fs/kernel/arch/x86/lib/iomem.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun #include <linux/string.h>
2*4882a593Smuzhiyun #include <linux/module.h>
3*4882a593Smuzhiyun #include <linux/io.h>
4*4882a593Smuzhiyun 
5*4882a593Smuzhiyun #define movs(type,to,from) \
6*4882a593Smuzhiyun 	asm volatile("movs" type:"=&D" (to), "=&S" (from):"0" (to), "1" (from):"memory")
7*4882a593Smuzhiyun 
8*4882a593Smuzhiyun /* Originally from i386/string.h */
rep_movs(void * to,const void * from,size_t n)9*4882a593Smuzhiyun static __always_inline void rep_movs(void *to, const void *from, size_t n)
10*4882a593Smuzhiyun {
11*4882a593Smuzhiyun 	unsigned long d0, d1, d2;
12*4882a593Smuzhiyun 	asm volatile("rep ; movsl\n\t"
13*4882a593Smuzhiyun 		     "testb $2,%b4\n\t"
14*4882a593Smuzhiyun 		     "je 1f\n\t"
15*4882a593Smuzhiyun 		     "movsw\n"
16*4882a593Smuzhiyun 		     "1:\ttestb $1,%b4\n\t"
17*4882a593Smuzhiyun 		     "je 2f\n\t"
18*4882a593Smuzhiyun 		     "movsb\n"
19*4882a593Smuzhiyun 		     "2:"
20*4882a593Smuzhiyun 		     : "=&c" (d0), "=&D" (d1), "=&S" (d2)
21*4882a593Smuzhiyun 		     : "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from)
22*4882a593Smuzhiyun 		     : "memory");
23*4882a593Smuzhiyun }
24*4882a593Smuzhiyun 
memcpy_fromio(void * to,const volatile void __iomem * from,size_t n)25*4882a593Smuzhiyun void memcpy_fromio(void *to, const volatile void __iomem *from, size_t n)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun 	if (unlikely(!n))
28*4882a593Smuzhiyun 		return;
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun 	/* Align any unaligned source IO */
31*4882a593Smuzhiyun 	if (unlikely(1 & (unsigned long)from)) {
32*4882a593Smuzhiyun 		movs("b", to, from);
33*4882a593Smuzhiyun 		n--;
34*4882a593Smuzhiyun 	}
35*4882a593Smuzhiyun 	if (n > 1 && unlikely(2 & (unsigned long)from)) {
36*4882a593Smuzhiyun 		movs("w", to, from);
37*4882a593Smuzhiyun 		n-=2;
38*4882a593Smuzhiyun 	}
39*4882a593Smuzhiyun 	rep_movs(to, (const void *)from, n);
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun EXPORT_SYMBOL(memcpy_fromio);
42*4882a593Smuzhiyun 
memcpy_toio(volatile void __iomem * to,const void * from,size_t n)43*4882a593Smuzhiyun void memcpy_toio(volatile void __iomem *to, const void *from, size_t n)
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun 	if (unlikely(!n))
46*4882a593Smuzhiyun 		return;
47*4882a593Smuzhiyun 
48*4882a593Smuzhiyun 	/* Align any unaligned destination IO */
49*4882a593Smuzhiyun 	if (unlikely(1 & (unsigned long)to)) {
50*4882a593Smuzhiyun 		movs("b", to, from);
51*4882a593Smuzhiyun 		n--;
52*4882a593Smuzhiyun 	}
53*4882a593Smuzhiyun 	if (n > 1 && unlikely(2 & (unsigned long)to)) {
54*4882a593Smuzhiyun 		movs("w", to, from);
55*4882a593Smuzhiyun 		n-=2;
56*4882a593Smuzhiyun 	}
57*4882a593Smuzhiyun 	rep_movs((void *)to, (const void *) from, n);
58*4882a593Smuzhiyun }
59*4882a593Smuzhiyun EXPORT_SYMBOL(memcpy_toio);
60*4882a593Smuzhiyun 
memset_io(volatile void __iomem * a,int b,size_t c)61*4882a593Smuzhiyun void memset_io(volatile void __iomem *a, int b, size_t c)
62*4882a593Smuzhiyun {
63*4882a593Smuzhiyun 	/*
64*4882a593Smuzhiyun 	 * TODO: memset can mangle the IO patterns quite a bit.
65*4882a593Smuzhiyun 	 * perhaps it would be better to use a dumb one:
66*4882a593Smuzhiyun 	 */
67*4882a593Smuzhiyun 	memset((void *)a, b, c);
68*4882a593Smuzhiyun }
69*4882a593Smuzhiyun EXPORT_SYMBOL(memset_io);
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