37 lines
		
	
	
	
		
			1.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			37 lines
		
	
	
	
		
			1.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  * linux/arch/arm/include/asm/neon.h | ||
|  |  * | ||
|  |  * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org> | ||
|  |  * | ||
|  |  * This program is free software; you can redistribute it and/or modify | ||
|  |  * it under the terms of the GNU General Public License version 2 as | ||
|  |  * published by the Free Software Foundation. | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <asm/hwcap.h>
 | ||
|  | 
 | ||
|  | #define cpu_has_neon()		(!!(elf_hwcap & HWCAP_NEON))
 | ||
|  | 
 | ||
|  | #ifdef __ARM_NEON__
 | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * If you are affected by the BUILD_BUG below, it probably means that you are | ||
|  |  * using NEON code /and/ calling the kernel_neon_begin() function from the same | ||
|  |  * compilation unit. To prevent issues that may arise from GCC reordering or | ||
|  |  * generating(1) NEON instructions outside of these begin/end functions, the | ||
|  |  * only supported way of using NEON code in the kernel is by isolating it in a | ||
|  |  * separate compilation unit, and calling it from another unit from inside a | ||
|  |  * kernel_neon_begin/kernel_neon_end pair. | ||
|  |  * | ||
|  |  * (1) Current GCC (4.7) might generate NEON instructions at O3 level if | ||
|  |  *     -mpfu=neon is set. | ||
|  |  */ | ||
|  | 
 | ||
|  | #define kernel_neon_begin() \
 | ||
|  | 	BUILD_BUG_ON_MSG(1, "kernel_neon_begin() called from NEON code") | ||
|  | 
 | ||
|  | #else
 | ||
|  | void kernel_neon_begin(void); | ||
|  | #endif
 | ||
|  | void kernel_neon_end(void); |