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(stfle_fac_list) * 8)
  17
  18 extern u64 stfle_fac_list[16];
  19 extern u64 alt_stfle_fac_list[16];
  20
  21 static inline void __set_facility(unsigned long nr, void *facilities)
  22 {
  23         unsigned char *ptr = (unsigned char *) facilities;
  24
  25         if (nr >= MAX_FACILITY_BIT)
  26                 return;
  27         ptr[nr >> 3] |= 0x80 >> (nr & 7);
  28 }
  29
  30 static inline void __clear_facility(unsigned long nr, void *facilities)
  31 {
  32         unsigned char *ptr = (unsigned char *) facilities;
  33
  34         if (nr >= MAX_FACILITY_BIT)
  35                 return;
  36         ptr[nr >> 3] &= ~(0x80 >> (nr & 7));
  37 }
  38
  39 static inline int __test_facility(unsigned long nr, void *facilities)
  40 {
  41         unsigned char *ptr;
  42
  43         if (nr >= MAX_FACILITY_BIT)
  44                 return 0;
  45         ptr = (unsigned char *) facilities + (nr >> 3);
  46         return (*ptr & (0x80 >> (nr & 7))) != 0;
  47 }
  48
  49 /*
  50  * The test_facility function uses the bit ordering where the MSB is bit 0.
  51  * That makes it easier to query facility bits with the bit number as
  52  * documented in the Principles of Operation.
  53  */
  54 static inline int test_facility(unsigned long nr)
  55 {
  56         unsigned long facilities_als[] = { FACILITIES_ALS };
  57
  58         if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) {
  59                 if (__test_facility(nr, &facilities_als))
  60                         return 1;
  61         }
  62         return __test_facility(nr, &stfle_fac_list);
  63 }
  64
  65 static inline unsigned long __stfle_asm(u64 *stfle_fac_list, int size)
  66 {
  67         unsigned long reg0 = size - 1;
  68
  69         asm volatile(
  70                 "       lgr     0,%[reg0]\n"
  71                 "       .insn   s,0xb2b00000,%[list]\n" /* stfle */
  72                 "       lgr     %[reg0],0\n"
  73                 : [reg0] "+&d" (reg0), [list] "+Q" (*stfle_fac_list)
  74                 :
  75                 : "memory", "cc", "0");
  76         return reg0;
  77 }
  78
  79 /**
  80  * stfle - Store facility list extended
  81  * @stfle_fac_list: array where facility list can be stored
  82  * @size: size of passed in array in double words
  83  */
  84 static inline void __stfle(u64 *stfle_fac_list, int size)
  85 {
  86         unsigned long nr;
  87         u32 stfl_fac_list;
  88
  89         asm volatile(
  90                 "       stfl    0(0)\n"
  91                 : "=m" (S390_lowcore.stfl_fac_list));
  92         stfl_fac_list = S390_lowcore.stfl_fac_list;
  93         memcpy(stfle_fac_list, &stfl_fac_list, 4);
  94         nr = 4; /* bytes stored by stfl */
  95         if (stfl_fac_list & 0x01000000) {
  96                 /* More facility bits available with stfle */
  97                 nr = __stfle_asm(stfle_fac_list, size);
  98                 nr = min_t(unsigned long, (nr + 1) * 8, size * 8);
  99         }
 100         memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
 101 }
 102
 103 static inline void stfle(u64 *stfle_fac_list, int size)
 104 {
 105         preempt_disable();
 106         __stfle(stfle_fac_list, size);
 107         preempt_enable();
 108 }
 109
 110 #endif /* __ASM_FACILITY_H */