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coreboot-kgpe-d16/src/arch/x86/memcpy.c

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arch/x86: add missing license headers These were mostly written as part of the coreboot project, so get the standard coreboot license header. memmove.c came from the linux kernel, so also gets the standard coreboot v2 license header, but gets the added attribution that it was derived from the linux kernel. Unlike many coreboot files, this file may not be re-licensed as GPL V3. Change-Id: I1fdc26b543e059f7a42d4b886f7222f4c74b959d Signed-off-by: Martin Roth <martinroth@google.com> Reviewed-on: https://review.coreboot.org/12916 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2016-01-12 23:55:28 +01:00
/*
* This file is part of the coreboot project.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
Add faster, architecture dependent memcpy() Change-Id: I38d15f3f1ec65f0cb7974d2dd4ae6356433bddd8 Signed-off-by: Stefan Reinauer <reinauer@google.com> Reviewed-by: Duncan Laurie <dlaurie@google.com> Reviewed-on: http://review.coreboot.org/736 Reviewed-by: Ronald G. Minnich <rminnich@gmail.com> Tested-by: build bot (Jenkins)
2011-10-26 01:43:34 +02:00
#include <string.h>
Fix issues with x86 memcpy The x86 memcpy() implementation did not mention its implicit output registers ESI, EDI and ECX which might make this code miscompile when the compiler uses the value of EDI for the return value *after* the 'rep movsb' has completed. That would break the API of memcpy as this would return 'dst+len' instead of 'dst'. Fix this possible bug by removing the wrong comment and listing all output registers as such (using dummy stack variables that get optimized away). Also the leading 'cld' is superflous as the ABI mandates the direction flag to be cleared all the time when we're in C (see <http://gcc.gnu.org/gcc-4.3/changes.html>) and we have no ASM call sites that might require it to be cleared explicitly (SMM might come to mind, but it clears the DF itself before passing control to the C part of the SMI handler). Last but not least fix the prototype to match the one from <string.h>. Change-Id: I106422d41180c4ed876078cabb26b45e49f3fa93 Signed-off-by: Mathias Krause <minipli@googlemail.com> Reviewed-on: http://review.coreboot.org/836 Tested-by: build bot (Jenkins) Reviewed-by: Peter Stuge <peter@stuge.se>
2012-03-31 17:23:53 +02:00
void *memcpy(void *dest, const void *src, size_t n)
Add faster, architecture dependent memcpy() Change-Id: I38d15f3f1ec65f0cb7974d2dd4ae6356433bddd8 Signed-off-by: Stefan Reinauer <reinauer@google.com> Reviewed-by: Duncan Laurie <dlaurie@google.com> Reviewed-on: http://review.coreboot.org/736 Reviewed-by: Ronald G. Minnich <rminnich@gmail.com> Tested-by: build bot (Jenkins)
2011-10-26 01:43:34 +02:00
{
Fix issues with x86 memcpy The x86 memcpy() implementation did not mention its implicit output registers ESI, EDI and ECX which might make this code miscompile when the compiler uses the value of EDI for the return value *after* the 'rep movsb' has completed. That would break the API of memcpy as this would return 'dst+len' instead of 'dst'. Fix this possible bug by removing the wrong comment and listing all output registers as such (using dummy stack variables that get optimized away). Also the leading 'cld' is superflous as the ABI mandates the direction flag to be cleared all the time when we're in C (see <http://gcc.gnu.org/gcc-4.3/changes.html>) and we have no ASM call sites that might require it to be cleared explicitly (SMM might come to mind, but it clears the DF itself before passing control to the C part of the SMI handler). Last but not least fix the prototype to match the one from <string.h>. Change-Id: I106422d41180c4ed876078cabb26b45e49f3fa93 Signed-off-by: Mathias Krause <minipli@googlemail.com> Reviewed-on: http://review.coreboot.org/836 Tested-by: build bot (Jenkins) Reviewed-by: Peter Stuge <peter@stuge.se>
2012-03-31 17:23:53 +02:00
unsigned long d0, d1, d2;
asm volatile(
x86: make memcpy 64bit safe This does not optimize memcpy for 64bit, it merely makes it compile. Change-Id: I69ad6bd0c3d5f617d9222643abf7a2ba7c2a0359 Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org> Signed-off-by: Scott Duplichan <scott@notabs.org> Reviewed-on: http://review.coreboot.org/10575 Tested-by: build bot (Jenkins) Reviewed-by: Marc Jones <marc.jones@se-eng.com>
2015-06-18 01:09:10 +02:00
#ifdef __x86_64__
"rep ; movsd\n\t"
"mov %4,%%rcx\n\t"
#else
x86 memcpy: Copy 4 bytes at once This is a slight improvement over the rep movsb loop Change-Id: Id71d9bfe5330b154a5c62fac85ce3955ae89b057 Signed-off-by: Stefan Reinauer <reinauer@google.com> Reviewed-on: http://review.coreboot.org/1742 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2012-08-23 02:01:08 +02:00
"rep ; movsl\n\t"
"movl %4,%%ecx\n\t"
x86: make memcpy 64bit safe This does not optimize memcpy for 64bit, it merely makes it compile. Change-Id: I69ad6bd0c3d5f617d9222643abf7a2ba7c2a0359 Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org> Signed-off-by: Scott Duplichan <scott@notabs.org> Reviewed-on: http://review.coreboot.org/10575 Tested-by: build bot (Jenkins) Reviewed-by: Marc Jones <marc.jones@se-eng.com>
2015-06-18 01:09:10 +02:00
#endif
x86 memcpy: Copy 4 bytes at once This is a slight improvement over the rep movsb loop Change-Id: Id71d9bfe5330b154a5c62fac85ce3955ae89b057 Signed-off-by: Stefan Reinauer <reinauer@google.com> Reviewed-on: http://review.coreboot.org/1742 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2012-08-23 02:01:08 +02:00
"rep ; movsb\n\t"
: "=&c" (d0), "=&D" (d1), "=&S" (d2)
: "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src)
Fix issues with x86 memcpy The x86 memcpy() implementation did not mention its implicit output registers ESI, EDI and ECX which might make this code miscompile when the compiler uses the value of EDI for the return value *after* the 'rep movsb' has completed. That would break the API of memcpy as this would return 'dst+len' instead of 'dst'. Fix this possible bug by removing the wrong comment and listing all output registers as such (using dummy stack variables that get optimized away). Also the leading 'cld' is superflous as the ABI mandates the direction flag to be cleared all the time when we're in C (see <http://gcc.gnu.org/gcc-4.3/changes.html>) and we have no ASM call sites that might require it to be cleared explicitly (SMM might come to mind, but it clears the DF itself before passing control to the C part of the SMI handler). Last but not least fix the prototype to match the one from <string.h>. Change-Id: I106422d41180c4ed876078cabb26b45e49f3fa93 Signed-off-by: Mathias Krause <minipli@googlemail.com> Reviewed-on: http://review.coreboot.org/836 Tested-by: build bot (Jenkins) Reviewed-by: Peter Stuge <peter@stuge.se>
2012-03-31 17:23:53 +02:00
: "memory"
x86 memcpy: Copy 4 bytes at once This is a slight improvement over the rep movsb loop Change-Id: Id71d9bfe5330b154a5c62fac85ce3955ae89b057 Signed-off-by: Stefan Reinauer <reinauer@google.com> Reviewed-on: http://review.coreboot.org/1742 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2012-08-23 02:01:08 +02:00
);
Fix issues with x86 memcpy The x86 memcpy() implementation did not mention its implicit output registers ESI, EDI and ECX which might make this code miscompile when the compiler uses the value of EDI for the return value *after* the 'rep movsb' has completed. That would break the API of memcpy as this would return 'dst+len' instead of 'dst'. Fix this possible bug by removing the wrong comment and listing all output registers as such (using dummy stack variables that get optimized away). Also the leading 'cld' is superflous as the ABI mandates the direction flag to be cleared all the time when we're in C (see <http://gcc.gnu.org/gcc-4.3/changes.html>) and we have no ASM call sites that might require it to be cleared explicitly (SMM might come to mind, but it clears the DF itself before passing control to the C part of the SMI handler). Last but not least fix the prototype to match the one from <string.h>. Change-Id: I106422d41180c4ed876078cabb26b45e49f3fa93 Signed-off-by: Mathias Krause <minipli@googlemail.com> Reviewed-on: http://review.coreboot.org/836 Tested-by: build bot (Jenkins) Reviewed-by: Peter Stuge <peter@stuge.se>
2012-03-31 17:23:53 +02:00
return dest;
Add faster, architecture dependent memcpy() Change-Id: I38d15f3f1ec65f0cb7974d2dd4ae6356433bddd8 Signed-off-by: Stefan Reinauer <reinauer@google.com> Reviewed-by: Duncan Laurie <dlaurie@google.com> Reviewed-on: http://review.coreboot.org/736 Reviewed-by: Ronald G. Minnich <rminnich@gmail.com> Tested-by: build bot (Jenkins)
2011-10-26 01:43:34 +02:00
}
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