root/arch/parisc/include/uapi/asm/swab.h

INCLUDED FROM

DEFINITIONS

1. __arch_swab16
2. __arch_swab24
3. __arch_swab32
4. __arch_swab64

   1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2 #ifndef _PARISC_SWAB_H
   3 #define _PARISC_SWAB_H
   4 
   5 #include <asm/bitsperlong.h>
   6 #include <linux/types.h>
   7 #include <linux/compiler.h>
   8 
   9 #define __SWAB_64_THRU_32__
  10 
  11 static inline __attribute_const__ __u16 __arch_swab16(__u16 x)
  12 {
  13         __asm__("dep %0, 15, 8, %0\n\t"         /* deposit 00ab -> 0bab */
  14                 "shd %%r0, %0, 8, %0"           /* shift 000000ab -> 00ba */
  15                 : "=r" (x)
  16                 : "0" (x));
  17         return x;
  18 }
  19 #define __arch_swab16 __arch_swab16
  20 
  21 static inline __attribute_const__ __u32 __arch_swab24(__u32 x)
  22 {
  23         __asm__("shd %0, %0, 8, %0\n\t"         /* shift xabcxabc -> cxab */
  24                 "dep %0, 15, 8, %0\n\t"         /* deposit cxab -> cbab */
  25                 "shd %%r0, %0, 8, %0"           /* shift 0000cbab -> 0cba */
  26                 : "=r" (x)
  27                 : "0" (x));
  28         return x;
  29 }
  30 
  31 static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
  32 {
  33         unsigned int temp;
  34         __asm__("shd %0, %0, 16, %1\n\t"        /* shift abcdabcd -> cdab */
  35                 "dep %1, 15, 8, %1\n\t"         /* deposit cdab -> cbab */
  36                 "shd %0, %1, 8, %0"             /* shift abcdcbab -> dcba */
  37                 : "=r" (x), "=&r" (temp)
  38                 : "0" (x));
  39         return x;
  40 }
  41 #define __arch_swab32 __arch_swab32
  42 
  43 #if __BITS_PER_LONG > 32
  44 /*
  45 ** From "PA-RISC 2.0 Architecture", HP Professional Books.
  46 ** See Appendix I page 8 , "Endian Byte Swapping".
  47 **
  48 ** Pretty cool algorithm: (* == zero'd bits)
  49 **      PERMH   01234567 -> 67452301 into %0
  50 **      HSHL    67452301 -> 7*5*3*1* into %1
  51 **      HSHR    67452301 -> *6*4*2*0 into %0
  52 **      OR      %0 | %1  -> 76543210 into %0 (all done!)
  53 */
  54 static inline __attribute_const__ __u64 __arch_swab64(__u64 x)
  55 {
  56         __u64 temp;
  57         __asm__("permh,3210 %0, %0\n\t"
  58                 "hshl %0, 8, %1\n\t"
  59                 "hshr,u %0, 8, %0\n\t"
  60                 "or %1, %0, %0"
  61                 : "=r" (x), "=&r" (temp)
  62                 : "0" (x));
  63         return x;
  64 }
  65 #define __arch_swab64 __arch_swab64
  66 #endif /* __BITS_PER_LONG > 32 */
  67 
  68 #endif /* _PARISC_SWAB_H */