mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/kdave/btrfs-progs.git
synced 2024-11-15 08:14:21 +08:00
03f41ac508
The accelerated crc32c needs to check for two CPU features, the crc32c instructions is in SSE 4.2 and 'pclmulqdq' is a separate. There's still old hardware used that does not have the PCLMUL instructions. Detect it and make it the condition. The pclmul is not supported on old compilers so also add a configure-time detection and leave the SSE 4.2 only implementation as the accelerated one if possible. Issue: #676 Signed-off-by: David Sterba <dsterba@suse.com>
61 lines
1.6 KiB
C
61 lines
1.6 KiB
C
/*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public
|
|
* License v2 as published by the Free Software Foundation.
|
|
*
|
|
* 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.
|
|
*
|
|
* You should have received a copy of the GNU General Public
|
|
* License along with this program; if not, write to the
|
|
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
* Boston, MA 021110-1307, USA.
|
|
*/
|
|
|
|
/*
|
|
* Detect CPU feature bits at runtime (x86_64 only)
|
|
*/
|
|
|
|
#ifndef __CPU_UTILS_H__
|
|
#define __CPU_UTILS_H__
|
|
|
|
#include <stdbool.h>
|
|
|
|
#define ENUM_CPU_BIT(name) \
|
|
__ ## name ## _BIT, \
|
|
name = (1U << __ ## name ## _BIT), \
|
|
__ ## name ## _SEQ = __ ## name ## _BIT
|
|
|
|
enum cpu_feature {
|
|
ENUM_CPU_BIT(CPU_FLAG_NONE),
|
|
ENUM_CPU_BIT(CPU_FLAG_SSE2),
|
|
ENUM_CPU_BIT(CPU_FLAG_SSSE3),
|
|
ENUM_CPU_BIT(CPU_FLAG_SSE41),
|
|
ENUM_CPU_BIT(CPU_FLAG_PCLMUL),
|
|
ENUM_CPU_BIT(CPU_FLAG_SSE42),
|
|
ENUM_CPU_BIT(CPU_FLAG_SHA),
|
|
ENUM_CPU_BIT(CPU_FLAG_AVX),
|
|
ENUM_CPU_BIT(CPU_FLAG_AVX2),
|
|
};
|
|
|
|
#undef ENUM_CPU_BIT
|
|
|
|
/* Private but in public header to allow inlining */
|
|
extern unsigned long __cpu_flags;
|
|
extern unsigned long __cpu_flags_orig;
|
|
|
|
/* Public API */
|
|
void cpu_detect_flags(void);
|
|
void cpu_set_level(unsigned long topbit);
|
|
void cpu_reset_level(void);
|
|
void cpu_print_flags(void);
|
|
|
|
static inline bool cpu_has_feature(enum cpu_feature f)
|
|
{
|
|
return __cpu_flags & f;
|
|
}
|
|
|
|
#endif
|