0,0 → 1,151 |
/* |
* Copyright (c) 2005 Sergey Bondari |
* All rights reserved. |
* |
* Redistribution and use in source and binary forms, with or without |
* modification, are permitted provided that the following conditions |
* are met: |
* |
* - Redistributions of source code must retain the above copyright |
* notice, this list of conditions and the following disclaimer. |
* - Redistributions in binary form must reproduce the above copyright |
* notice, this list of conditions and the following disclaimer in the |
* documentation and/or other materials provided with the distribution. |
* - The name of the author may not be used to endorse or promote products |
* derived from this software without specific prior written permission. |
* |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
*/ |
|
/** @addtogroup ia32 |
* @{ |
*/ |
/** @file |
*/ |
|
#ifndef KERN_ia32_MEMSTR_H_ |
#define KERN_ia32_MEMSTR_H_ |
|
/** Copy memory |
* |
* Copy a given number of bytes (3rd argument) |
* from the memory location defined by 2nd argument |
* to the memory location defined by 1st argument. |
* The memory areas cannot overlap. |
* |
* @param dst Destination |
* @param src Source |
* @param cnt Number of bytes |
* @return Destination |
*/ |
static inline void * memcpy(void * dst, const void * src, size_t cnt) |
{ |
unative_t d0, d1, d2; |
|
asm volatile( |
/* copy all full dwords */ |
"rep movsl\n\t" |
/* load count again */ |
"movl %4, %%ecx\n\t" |
/* ecx = ecx mod 4 */ |
"andl $3, %%ecx\n\t" |
/* are there last <=3 bytes? */ |
"jz 1f\n\t" |
/* copy last <=3 bytes */ |
"rep movsb\n\t" |
/* exit from asm block */ |
"1:\n" |
: "=&c" (d0), "=&D" (d1), "=&S" (d2) |
: "0" ((unative_t) (cnt / 4)), "g" ((unative_t) cnt), "1" ((unative_t) dst), "2" ((unative_t) src) |
: "memory"); |
|
return dst; |
} |
|
|
/** Compare memory regions for equality |
* |
* Compare a given number of bytes (3rd argument) |
* at memory locations defined by 1st and 2nd argument |
* for equality. If bytes are equal function returns 0. |
* |
* @param src Region 1 |
* @param dst Region 2 |
* @param cnt Number of bytes |
* @return Zero if bytes are equal, non-zero otherwise |
*/ |
static inline int memcmp(const void * src, const void * dst, size_t cnt) |
{ |
uint32_t d0, d1, d2; |
int ret; |
|
asm ( |
"repe cmpsb\n\t" |
"je 1f\n\t" |
"movl %3, %0\n\t" |
"addl $1, %0\n\t" |
"1:\n" |
: "=a" (ret), "=&S" (d0), "=&D" (d1), "=&c" (d2) |
: "0" (0), "1" ((unative_t) src), "2" ((unative_t) dst), "3" ((unative_t) cnt) |
); |
|
return ret; |
} |
|
/** Fill memory with words |
* Fill a given number of words (2nd argument) |
* at memory defined by 1st argument with the |
* word value defined by 3rd argument. |
* |
* @param dst Destination |
* @param cnt Number of words |
* @param x Value to fill |
*/ |
static inline void memsetw(uintptr_t dst, size_t cnt, uint16_t x) |
{ |
uint32_t d0, d1; |
|
asm volatile ( |
"rep stosw\n\t" |
: "=&D" (d0), "=&c" (d1), "=&a" (x) |
: "0" (dst), "1" (cnt), "2" (x) |
: "memory" |
); |
|
} |
|
/** Fill memory with bytes |
* Fill a given number of bytes (2nd argument) |
* at memory defined by 1st argument with the |
* word value defined by 3rd argument. |
* |
* @param dst Destination |
* @param cnt Number of bytes |
* @param x Value to fill |
*/ |
static inline void memsetb(uintptr_t dst, size_t cnt, uint8_t x) |
{ |
uint32_t d0, d1; |
|
asm volatile ( |
"rep stosb\n\t" |
: "=&D" (d0), "=&c" (d1), "=&a" (x) |
: "0" (dst), "1" (cnt), "2" (x) |
: "memory" |
); |
|
} |
|
#endif |
|
/** @} |
*/ |