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Diffstat (limited to 'arch/arc/include/uapi/asm/swab.h')
| -rw-r--r-- | arch/arc/include/uapi/asm/swab.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/arc/include/uapi/asm/swab.h b/arch/arc/include/uapi/asm/swab.h new file mode 100644 index 00000000000..095599a7319 --- /dev/null +++ b/arch/arc/include/uapi/asm/swab.h @@ -0,0 +1,98 @@ +/* + * 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 |