blob: df50451d94ef7edf095defd0253aa7bb329123ab [file] [log] [blame]
Linus Torvalds170d13c2019-01-04 17:52:49 -08001#include <linux/string.h>
2#include <linux/module.h>
3#include <linux/io.h>
4
Linus Torvaldsc228d292019-01-31 11:10:20 -08005#define movs(type,to,from) \
6 asm volatile("movs" type:"=&D" (to), "=&S" (from):"0" (to), "1" (from):"memory")
7
Linus Torvalds170d13c2019-01-04 17:52:49 -08008/* Originally from i386/string.h */
Linus Torvaldsc228d292019-01-31 11:10:20 -08009static __always_inline void rep_movs(void *to, const void *from, size_t n)
Linus Torvalds170d13c2019-01-04 17:52:49 -080010{
11 unsigned long d0, d1, d2;
12 asm volatile("rep ; movsl\n\t"
13 "testb $2,%b4\n\t"
14 "je 1f\n\t"
15 "movsw\n"
16 "1:\ttestb $1,%b4\n\t"
17 "je 2f\n\t"
18 "movsb\n"
19 "2:"
20 : "=&c" (d0), "=&D" (d1), "=&S" (d2)
21 : "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from)
22 : "memory");
23}
24
25void memcpy_fromio(void *to, const volatile void __iomem *from, size_t n)
26{
Linus Torvaldsc228d292019-01-31 11:10:20 -080027 if (unlikely(!n))
28 return;
29
30 /* Align any unaligned source IO */
31 if (unlikely(1 & (unsigned long)from)) {
32 movs("b", to, from);
33 n--;
34 }
35 if (n > 1 && unlikely(2 & (unsigned long)from)) {
36 movs("w", to, from);
37 n-=2;
38 }
39 rep_movs(to, (const void *)from, n);
Linus Torvalds170d13c2019-01-04 17:52:49 -080040}
41EXPORT_SYMBOL(memcpy_fromio);
42
43void memcpy_toio(volatile void __iomem *to, const void *from, size_t n)
44{
Linus Torvaldsc228d292019-01-31 11:10:20 -080045 if (unlikely(!n))
46 return;
47
48 /* Align any unaligned destination IO */
49 if (unlikely(1 & (unsigned long)to)) {
50 movs("b", to, from);
51 n--;
52 }
53 if (n > 1 && unlikely(2 & (unsigned long)to)) {
54 movs("w", to, from);
55 n-=2;
56 }
57 rep_movs((void *)to, (const void *) from, n);
Linus Torvalds170d13c2019-01-04 17:52:49 -080058}
59EXPORT_SYMBOL(memcpy_toio);
60
61void memset_io(volatile void __iomem *a, int b, size_t c)
62{
63 /*
64 * TODO: memset can mangle the IO patterns quite a bit.
65 * perhaps it would be better to use a dumb one:
66 */
67 memset((void *)a, b, c);
68}
69EXPORT_SYMBOL(memset_io);