arch/s390/include/asm/barrier.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright IBM Corp. 1999, 2009
   4  *
   5  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   6  */
   7
   8 #ifndef __ASM_BARRIER_H
   9 #define __ASM_BARRIER_H
  10
  11 /*
  12  * Force strict CPU ordering.
  13  * And yes, this is required on UP too when we're talking
  14  * to devices.
  15  */
  16
  17 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  18 /* Fast-BCR without checkpoint synchronization */
  19 #define __ASM_BARRIER "bcr 14,0\n"
  20 #else
  21 #define __ASM_BARRIER "bcr 15,0\n"
  22 #endif
  23
  24 #define mb() do {  asm volatile(__ASM_BARRIER : : : "memory"); } while (0)
  25
  26 #define rmb()                           barrier()
  27 #define wmb()                           barrier()
  28 #define dma_rmb()                       mb()
  29 #define dma_wmb()                       mb()
  30 #define __smp_mb()                      mb()
  31 #define __smp_rmb()                     rmb()
  32 #define __smp_wmb()                     wmb()
  33
  34 #define __smp_store_release(p, v)                                       \
  35 do {                                                                    \
  36         compiletime_assert_atomic_type(*p);                             \
  37         barrier();                                                      \
  38         WRITE_ONCE(*p, v);                                              \
  39 } while (0)
  40
  41 #define __smp_load_acquire(p)                                           \
  42 ({                                                                      \
  43         typeof(*p) ___p1 = READ_ONCE(*p);                               \
  44         compiletime_assert_atomic_type(*p);                             \
  45         barrier();                                                      \
  46         ___p1;                                                          \
  47 })
  48
  49 #define __smp_mb__before_atomic()       barrier()
  50 #define __smp_mb__after_atomic()        barrier()
  51
  52 /**
  53  * array_index_mask_nospec - generate a mask for array_idx() that is
  54  * ~0UL when the bounds check succeeds and 0 otherwise
  55  * @index: array element index
  56  * @size: number of elements in array
  57  */
  58 #define array_index_mask_nospec array_index_mask_nospec
  59 static inline unsigned long array_index_mask_nospec(unsigned long index,
  60                                                     unsigned long size)
  61 {
  62         unsigned long mask;
  63
  64         if (__builtin_constant_p(size) && size > 0) {
  65                 asm("   clgr    %2,%1\n"
  66                     "   slbgr   %0,%0\n"
  67                     :"=d" (mask) : "d" (size-1), "d" (index) :"cc");
  68                 return mask;
  69         }
  70         asm("   clgr    %1,%2\n"
  71             "   slbgr   %0,%0\n"
  72             :"=d" (mask) : "d" (size), "d" (index) :"cc");
  73         return ~mask;
  74 }
  75
  76 #include <asm-generic/barrier.h>
  77
  78 #endif /* __ASM_BARRIER_H */