1 #include <linux/string.h> 2 #include <linux/module.h> 3 #include <linux/io.h> 4 5 #define movs(type,to,from) \ 6 asm volatile("movs" type:"=&D" (to), "=&S" (from):"0" (to), "1" (from):"memory") 7 8 /* Originally from i386/string.h */ 9 static __always_inline void rep_movs(void *to, const void *from, size_t n) 10 { 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 25 void memcpy_fromio(void *to, const volatile void __iomem *from, size_t n) 26 { 27 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); 40 } 41 EXPORT_SYMBOL(memcpy_fromio); 42 43 void memcpy_toio(volatile void __iomem *to, const void *from, size_t n) 44 { 45 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); 58 } 59 EXPORT_SYMBOL(memcpy_toio); 60 61 void 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 } 69 EXPORT_SYMBOL(memset_io); 70