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/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* 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.
*
* vineetg: May 2011
* -Support single cycle endian-swap insn in ARC700 4.10
*
* vineetg: June 2009
* -Better htonl implementation (5 instead of 9 ALU instructions)
* -Hardware assisted single cycle bswap (Use Case of ARC custom instrn)
*/
#ifndef __ASM_ARC_SWAB_H
#define __ASM_ARC_SWAB_H
#include <linux/types.h>
/* Native single cycle endian swap insn */
#ifdef CONFIG_ARC_HAS_SWAPE
#define __arch_swab32(x) \
({ \
unsigned int tmp = x; \
__asm__( \
" swape %0, %1 \n" \
: "=r" (tmp) \
: "r" (tmp)); \
tmp; \
})
#else
/* Several ways of Endian-Swap Emulation for ARC
* 0: kernel generic
* 1: ARC optimised "C"
* 2: ARC Custom instruction
*/
#define ARC_BSWAP_TYPE 1
#if (ARC_BSWAP_TYPE == 1) /******* Software only ********/
/* The kernel default implementation of htonl is
* return x<<24 | x>>24 |
* (x & (__u32)0x0000ff00UL)<<8 | (x & (__u32)0x00ff0000UL)>>8;
*
* This generates 9 instructions on ARC (excluding the ld/st)
*
* 8051fd8c: ld r3,[r7,20] ; Mem op : Get the value to be swapped
* 8051fd98: asl r5,r3,24 ; get 3rd Byte
* 8051fd9c: lsr r2,r3,24 ; get 0th Byte
* 8051fda0: and r4,r3,0xff00
* 8051fda8: asl r4,r4,8 ; get 1st Byte
* 8051fdac: and r3,r3,0x00ff0000
* 8051fdb4: or r2,r2,r5 ; combine 0th and 3rd Bytes
* 8051fdb8: lsr r3,r3,8 ; 2nd Byte at correct place in Dst Reg
* 8051fdbc: or r2,r2,r4 ; combine 0,3 Bytes with 1st Byte
* 8051fdc0: or r2,r2,r3 ; combine 0,3,1 Bytes with 2nd Byte
* 8051fdc4: st r2,[r1,20] ; Mem op : save result back to mem
*
* Joern suggested a better "C" algorithm which is great since
* (1) It is portable to any architecure
* (2) At the same time it takes advantage of ARC ISA (rotate intrns)
*/
#define __arch_swab32(x) \
({ unsigned long __in = (x), __tmp; \
__tmp = __in << 8 | __in >> 24; /* ror tmp,in,24 */ \
__in = __in << 24 | __in >> 8; /* ror in,in,8 */ \
__tmp ^= __in; \
__tmp &= 0xff00ff; \
__tmp ^ __in; \
})
#elif (ARC_BSWAP_TYPE == 2) /* Custom single cycle bwap instruction */
#define __arch_swab32(x) \
({ \
unsigned int tmp = x; \
__asm__( \
" .extInstruction bswap, 7, 0x00, SUFFIX_NONE, SYNTAX_2OP \n"\
" bswap %0, %1 \n"\
: "=r" (tmp) \
: "r" (tmp)); \
tmp; \
})
#endif /* ARC_BSWAP_TYPE=zzz */
#endif /* CONFIG_ARC_HAS_SWAPE */
#if !defined(__STRICT_ANSI__) || defined(__KERNEL__)
#define __SWAB_64_THRU_32__
#endif
#endif
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