LXR linux/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
  18static 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
  27static 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
  36static 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 */
  51static 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 */
  67static inline void stfle(u64 *stfle_fac_list, int size)
  68{
  69        unsigned long nr;
  70
  71        preempt_disable();
  72        asm volatile(
  73                "       stfl    0(0)\n"
  74                : "=m" (S390_lowcore.stfl_fac_list));
  75        nr = 4; /* bytes stored by stfl */
  76        memcpy(stfle_fac_list, &S390_lowcore.stfl_fac_list, 4);
  77        if (S390_lowcore.stfl_fac_list & 0x01000000) {
  78                /* More facility bits available with stfle */
  79                register unsigned long reg0 asm("0") = size - 1;
  80
  81                asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */
  82                             : "+d" (reg0)
  83                             : "a" (stfle_fac_list)
  84                             : "memory", "cc");
  85                nr = (reg0 + 1) * 8; /* # bytes stored by stfle */
  86        }
  87        memset((char *) stfle_fac_list + nr, 0, size * 8 - nr);
  88        preempt_enable();
  89}
  90
  91#endif /* __ASM_FACILITY_H */
  92