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			85 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			85 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* powerpc HWCAP/HWCAP2 and AT_PLATFORM data pre-processing.
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   Copyright (C) 2015-2020 Free Software Foundation, Inc.
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   This file is part of the GNU C Library.
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   The GNU C Library is free software; you can redistribute it and/or
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   modify it under the terms of the GNU Lesser General Public
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   License as published by the Free Software Foundation; either
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   version 2.1 of the License, or (at your option) any later version.
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   The GNU C Library 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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   Lesser General Public License for more details.
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   You should have received a copy of the GNU Lesser General Public
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   License along with the GNU C Library; if not, see
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   <https://www.gnu.org/licenses/>.  */
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#include <unistd.h>
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#include <shlib-compat.h>
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#include <dl-procinfo.h>
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uint64_t __tcb_hwcap __attribute__ ((visibility ("hidden")));
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uint32_t __tcb_platform __attribute__ ((visibility ("hidden")));
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/* This function parses the HWCAP/HWCAP2 fields, adding the previous supported
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   ISA bits, as well as converting the AT_PLATFORM string to a number.  This
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   data is stored in two global variables that can be used later by the
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   powerpc-specific code to store it into the TCB.  */
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void
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__tcb_parse_hwcap_and_convert_at_platform (void)
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{
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  uint64_t h1, h2;
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  /* Read AT_PLATFORM string from auxv and convert it to a number.  */
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  __tcb_platform = _dl_string_platform (GLRO (dl_platform));
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  /* Read HWCAP and HWCAP2 from auxv.  */
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  h1 = GLRO (dl_hwcap);
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  h2 = GLRO (dl_hwcap2);
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  /* hwcap contains only the latest supported ISA, the code checks which is
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     and fills the previous supported ones.  */
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  if (h2 & PPC_FEATURE2_ARCH_2_07)
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    h1 |= PPC_FEATURE_ARCH_2_06
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       | PPC_FEATURE_ARCH_2_05
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       | PPC_FEATURE_POWER5_PLUS
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       | PPC_FEATURE_POWER5
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       | PPC_FEATURE_POWER4;
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  else if (h1 & PPC_FEATURE_ARCH_2_06)
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    h1 |= PPC_FEATURE_ARCH_2_05
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       | PPC_FEATURE_POWER5_PLUS
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       | PPC_FEATURE_POWER5
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       | PPC_FEATURE_POWER4;
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  else if (h1 & PPC_FEATURE_ARCH_2_05)
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    h1 |= PPC_FEATURE_POWER5_PLUS
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       | PPC_FEATURE_POWER5
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       | PPC_FEATURE_POWER4;
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  else if (h1 & PPC_FEATURE_POWER5_PLUS)
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    h1 |= PPC_FEATURE_POWER5
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       | PPC_FEATURE_POWER4;
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  else if (h1 & PPC_FEATURE_POWER5)
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    h1 |= PPC_FEATURE_POWER4;
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  /* Consolidate both HWCAP and HWCAP2 into a single doubleword so that
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     we can read both in a single load later.  */
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  __tcb_hwcap = h2;
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  __tcb_hwcap = (h1 << 32) | __tcb_hwcap;
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}
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#if IS_IN (rtld)
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versioned_symbol (ld, __tcb_parse_hwcap_and_convert_at_platform, \
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		  __parse_hwcap_and_convert_at_platform, GLIBC_2_23);
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#endif
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/* Export __parse_hwcap_and_convert_at_platform in libc.a.  This is used by
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   GCC to make sure that the HWCAP/Platform bits are stored in the TCB when
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   using __builtin_cpu_is()/__builtin_cpu_supports() in the static case.  */
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#ifndef SHARED
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weak_alias (__tcb_parse_hwcap_and_convert_at_platform, \
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	    __parse_hwcap_and_convert_at_platform);
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#endif
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