| #include <linux/string.h> |
| #include <linux/module.h> |
| #include <linux/io.h> |
| |
| #define movs(type,to,from) \ |
| asm volatile("movs" type:"=&D" (to), "=&S" (from):"0" (to), "1" (from):"memory") |
| |
| /* Originally from i386/string.h */ |
| static __always_inline void rep_movs(void *to, const void *from, size_t n) |
| { |
| unsigned long d0, d1, d2; |
| asm volatile("rep ; movsl\n\t" |
| "testb $2,%b4\n\t" |
| "je 1f\n\t" |
| "movsw\n" |
| "1:\ttestb $1,%b4\n\t" |
| "je 2f\n\t" |
| "movsb\n" |
| "2:" |
| : "=&c" (d0), "=&D" (d1), "=&S" (d2) |
| : "0" (n / 4), "q" (n), "1" ((long)to), "2" ((long)from) |
| : "memory"); |
| } |
| |
| static void string_memcpy_fromio(void *to, const volatile void __iomem *from, size_t n) |
| { |
| if (unlikely(!n)) |
| return; |
| |
| /* Align any unaligned source IO */ |
| if (unlikely(1 & (unsigned long)from)) { |
| movs("b", to, from); |
| n--; |
| } |
| if (n > 1 && unlikely(2 & (unsigned long)from)) { |
| movs("w", to, from); |
| n-=2; |
| } |
| rep_movs(to, (const void *)from, n); |
| } |
| |
| static void string_memcpy_toio(volatile void __iomem *to, const void *from, size_t n) |
| { |
| if (unlikely(!n)) |
| return; |
| |
| /* Align any unaligned destination IO */ |
| if (unlikely(1 & (unsigned long)to)) { |
| movs("b", to, from); |
| n--; |
| } |
| if (n > 1 && unlikely(2 & (unsigned long)to)) { |
| movs("w", to, from); |
| n-=2; |
| } |
| rep_movs((void *)to, (const void *) from, n); |
| } |
| |
| static void unrolled_memcpy_fromio(void *to, const volatile void __iomem *from, size_t n) |
| { |
| const volatile char __iomem *in = from; |
| char *out = to; |
| int i; |
| |
| for (i = 0; i < n; ++i) |
| out[i] = readb(&in[i]); |
| } |
| |
| static void unrolled_memcpy_toio(volatile void __iomem *to, const void *from, size_t n) |
| { |
| volatile char __iomem *out = to; |
| const char *in = from; |
| int i; |
| |
| for (i = 0; i < n; ++i) |
| writeb(in[i], &out[i]); |
| } |
| |
| static void unrolled_memset_io(volatile void __iomem *a, int b, size_t c) |
| { |
| volatile char __iomem *mem = a; |
| int i; |
| |
| for (i = 0; i < c; ++i) |
| writeb(b, &mem[i]); |
| } |
| |
| void memcpy_fromio(void *to, const volatile void __iomem *from, size_t n) |
| { |
| if (cc_platform_has(CC_ATTR_GUEST_UNROLL_STRING_IO)) |
| unrolled_memcpy_fromio(to, from, n); |
| else |
| string_memcpy_fromio(to, from, n); |
| } |
| EXPORT_SYMBOL(memcpy_fromio); |
| |
| void memcpy_toio(volatile void __iomem *to, const void *from, size_t n) |
| { |
| if (cc_platform_has(CC_ATTR_GUEST_UNROLL_STRING_IO)) |
| unrolled_memcpy_toio(to, from, n); |
| else |
| string_memcpy_toio(to, from, n); |
| } |
| EXPORT_SYMBOL(memcpy_toio); |
| |
| void memset_io(volatile void __iomem *a, int b, size_t c) |
| { |
| if (cc_platform_has(CC_ATTR_GUEST_UNROLL_STRING_IO)) { |
| unrolled_memset_io(a, b, c); |
| } else { |
| /* |
| * TODO: memset can mangle the IO patterns quite a bit. |
| * perhaps it would be better to use a dumb one: |
| */ |
| memset((void *)a, b, c); |
| } |
| } |
| EXPORT_SYMBOL(memset_io); |