arch/s390/include/asm/facility.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_FACILITY_H
   9 #define __ASM_FACILITY_H
  10
  11 #include <asm/facility-defs.h>
  12 #include <linux/string.h>
  13 #include <linux/preempt.h>
  14 #include <asm/lowcore.h>
  15
  16 #define MAX_FACILITY_BIT (sizeof(((struct lowcore *)0)->stfle_fac_list) * 8)
  17
  18 static inline void __set_facility(unsigned long nr, void *facilities)
  19 {
  20         unsigned char *ptr = (unsigned char *) facilities;
  21
  22         if (nr >= MAX_FACILITY_BIT)
  23                 return;
  24         ptr[nr >> 3] |= 0x80 >> (nr & 7);
  25 }
  26
  27 static inline void __clear_facility(unsigned long nr, void *facilities)
  28 {
  29         unsigned char *ptr = (unsigned char *) facilities;
  30
  31         if (nr >= MAX_FACILITY_BIT)
  32                 return;
  33         ptr[nr >> 3] &= ~(0x80 >> (nr & 7));
  34 }
  35
  36 static inline int __test_facility(unsigned long nr, void *facilities)
  37 {
  38         unsigned char *ptr;
  39
  40         if (nr >= MAX_FACILITY_BIT)
  41                 return 0;
  42         ptr = (unsigned char *) facilities + (nr >> 3);
  43         return (*ptr & (0x80 >> (nr & 7))) != 0;
  44 }
  45
  46 /*
  47  * The test_facility function uses the bit odering where the MSB is bit 0.
  48  * That makes it easier to query facility bits with the bit number as
  49  * documented in the Principles of Operation.
  50  */
  51 static inline int test_facility(unsigned long nr)
  52 {
  53         unsigned long facilities_als[] = { FACILITIES_ALS };
  54
  55         if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) {
  56                 if (__test_facility(nr, &facilities_als))
  57                         return 1;
  58         }
  59         return __test_facility(nr, &S390_lowcore.stfle_fac_list);
  60 }
  61
  62 /**
  63  * stfle - Store facility list extended
  64  * @stfle_fac_list: array where facility list can be stored
  65  * @size: size of passed in array in double words
  66  */
  67 static inline void __stfle(u64 *stfle_fac_list, int size)
  68 {
  69         unsigned long nr;
  70
  71         asm volatile(
  72                 "       stfl    0(0)\n"
  73                 : "=m" (S390_lowcore.stfl_fac_list));
  74         nr = 4; /* bytes stored by stfl */
  75         memcpy(stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
  76         if (S390_lowcore.stfl_fac_list & 0x01000000) {
  77                 /* More facility bits available with stfle */
  78                 register unsigned long reg0 asm("0") = size - 1;
  79
  80                 asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */
  81                              : "+d" (reg0)
  82                              : "a" (stfle_fac_list)
  83                              : "memory", "cc");
  84                 nr = (reg0 + 1) * 8; /* # bytes stored by stfle */
  85         }
  86         memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
  87 }
  88
  89 static inline void stfle(u64 *stfle_fac_list, int size)
  90 {
  91         preempt_disable();
  92         __stfle(stfle_fac_list, size);
  93         preempt_enable();
  94 }
  95
  96 #endif /* __ASM_FACILITY_H */