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 static inline unsigned long __stfle_asm(u64 *stfle_fac_list, int size)
  63 {
  64         register unsigned long reg0 asm("0") = size - 1;
  65
  66         asm volatile(
  67                 ".insn s,0xb2b00000,0(%1)" /* stfle */
  68                 : "+d" (reg0)
  69                 : "a" (stfle_fac_list)
  70                 : "memory", "cc");
  71         return reg0;
  72 }
  73
  74 /**
  75  * stfle - Store facility list extended
  76  * @stfle_fac_list: array where facility list can be stored
  77  * @size: size of passed in array in double words
  78  */
  79 static inline void __stfle(u64 *stfle_fac_list, int size)
  80 {
  81         unsigned long nr;
  82
  83         asm volatile(
  84                 "       stfl    0(0)\n"
  85                 : "=m" (S390_lowcore.stfl_fac_list));
  86         nr = 4; /* bytes stored by stfl */
  87         memcpy(stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
  88         if (S390_lowcore.stfl_fac_list & 0x01000000) {
  89                 /* More facility bits available with stfle */
  90                 nr = __stfle_asm(stfle_fac_list, size);
  91                 nr = min_t(unsigned long, (nr + 1) * 8, size * 8);
  92         }
  93         memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
  94 }
  95
  96 static inline void stfle(u64 *stfle_fac_list, int size)
  97 {
  98         preempt_disable();
  99         __stfle(stfle_fac_list, size);
 100         preempt_enable();
 101 }
 102
 103 #endif /* __ASM_FACILITY_H */