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libsst-os/SST_CPUCache_x86.asm

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+;	SST_CPUCache_x86.asm
+;	Author: Patrick Baggett <ptbaggett@762studios.com>
+;	Created: 12/23/2011
+;
+;	Purpose: 
+;
+;	32-bit assembly for x86 CPU cache functions. Assembles with YASM 1.1/NASM 2.0+
+;
+;	License:
+;
+;	This program is free software. It comes without any warranty, to
+;	the extent permitted by applicable law. You can redistribute it
+;	and/or modify it under the terms of the Do What The Fuck You Want
+;	To Public License, Version 2, as published by Sam Hocevar. See
+;	http://sam.zoy.org/wtfpl/COPYING for more details.
+
+[bits 32]
+[segment .text]
+
+; Win32 symbol names
+[global _SST_OS_GetCacheLineSize]
+[global _SST_OS_FlushDCRange]
+[global _SST_OS_InvalidateICRange]
+[global _SST_OS_SyncCache]
+
+; ELF symbol names
+[global SST_OS_GetCacheLineSize]
+[global SST_OS_FlushDCRange]
+[global SST_OS_InvalidateICRange]
+[global SST_OS_SyncCache]
+
+
+;uint32_t SST_OS_GetCacheLineSize()
+_SST_OS_GetCacheLineSize:
+ SST_OS_GetCacheLineSize:
+	push ebx
+	mov eax, 0x80000006		;Cache info command
+	cpuid
+	movzx eax, cl			;ECX bits 0-7 = L2 cache line size (TODO: what about L1?)
+	pop ebx
+	ret
+	
+;void SST_OS_FlushDCRange(void* base, size_t range)
+_SST_OS_FlushDCRange:
+ SST_OS_FlushDCRange:
+ 
+	call SST_OS_GetCacheLineSize	;Get the cache line size
+	
+	mov edx, [esp+4]	;edx = base
+	mov ecx, [esp+8]	;ecx = range (in bytes)
+	
+	dc_flush_more:		;do {
+	clflush [edx]
+	add edx, eax		;base += cache_line_size
+	sub ecx, eax		;range -= cache_line_size
+	
+	cmp ecx, 0
+	jg dc_flush_more	; } while(range > 0)
+	
+	ret
+
+;SST_OS_InvalidateICRange(void* base, size_t range)
+_SST_OS_InvalidateICRange:
+ SST_OS_InvalidateICRange:
+ 
+	;A jmp instruction is sufficient. x86 CPUs have self-snooping caches.
+	jmp do_serialize
+ do_serialize:
+ 
+	ret
+
+
+; void SST_OS_SyncCache()
+_SST_OS_SyncCache:
+ SST_OS_SyncCache:
+	mfence
+	ret