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
/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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/*
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* Detect CPU feature bits at runtime (x86_64 only)
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*/
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#ifndef __CPU_UTILS_H__
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#define __CPU_UTILS_H__
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#include <stdbool.h>
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#define ENUM_CPU_BIT(name) \
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__ ## name ## _BIT, \
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name = (1U << __ ## name ## _BIT), \
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__ ## name ## _SEQ = __ ## name ## _BIT
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enum cpu_feature {
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ENUM_CPU_BIT(CPU_FLAG_NONE),
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ENUM_CPU_BIT(CPU_FLAG_SSE2),
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ENUM_CPU_BIT(CPU_FLAG_SSSE3),
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ENUM_CPU_BIT(CPU_FLAG_SSE41),
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ENUM_CPU_BIT(CPU_FLAG_PCLMUL),
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ENUM_CPU_BIT(CPU_FLAG_SSE42),
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ENUM_CPU_BIT(CPU_FLAG_SHA),
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ENUM_CPU_BIT(CPU_FLAG_AVX),
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ENUM_CPU_BIT(CPU_FLAG_AVX2),
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};
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#undef ENUM_CPU_BIT
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/* Private but in public header to allow inlining */
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extern unsigned long __cpu_flags;
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extern unsigned long __cpu_flags_orig;
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/* Public API */
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void cpu_detect_flags(void);
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void cpu_set_level(unsigned long topbit);
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void cpu_reset_level(void);
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void cpu_print_flags(void);
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static inline bool cpu_has_feature(enum cpu_feature f)
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{
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return __cpu_flags & f;
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}
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#endif
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