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 <generated/facilities.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 int __test_facility(unsigned long nr, void *facilities) 19 { 20 unsigned char *ptr; 21 22 if (nr >= MAX_FACILITY_BIT) 23 return 0; 24 ptr = (unsigned char *) facilities + (nr >> 3); 25 return (*ptr & (0x80 >> (nr & 7))) != 0; 26 } 27 28 /* 29 * The test_facility function uses the bit odering where the MSB is bit 0. 30 * That makes it easier to query facility bits with the bit number as 31 * documented in the Principles of Operation. 32 */ 33 static inline int test_facility(unsigned long nr) 34 { 35 unsigned long facilities_als[] = { FACILITIES_ALS }; 36 37 if (__builtin_constant_p(nr) && nr < sizeof(facilities_als) * 8) { 38 if (__test_facility(nr, &facilities_als)) 39 return 1; 40 } 41 return __test_facility(nr, &S390_lowcore.stfle_fac_list); 42 } 43 44 /** 45 * stfle - Store facility list extended 46 * @stfle_fac_list: array where facility list can be stored 47 * @size: size of passed in array in double words 48 */ 49 static inline void stfle(u64 *stfle_fac_list, int size) 50 { 51 unsigned long nr; 52 53 preempt_disable(); 54 asm volatile( 55 " stfl 0(0)\n" 56 : "=m" (S390_lowcore.stfl_fac_list)); 57 nr = 4; /* bytes stored by stfl */ 58 memcpy(stfle_fac_list, &S390_lowcore.stfl_fac_list, 4); 59 if (S390_lowcore.stfl_fac_list & 0x01000000) { 60 /* More facility bits available with stfle */ 61 register unsigned long reg0 asm("0") = size - 1; 62 63 asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */ 64 : "+d" (reg0) 65 : "a" (stfle_fac_list) 66 : "memory", "cc"); 67 nr = (reg0 + 1) * 8; /* # bytes stored by stfle */ 68 } 69 memset((char *) stfle_fac_list + nr, 0, size * 8 - nr); 70 preempt_enable(); 71 } 72 73 #endif /* __ASM_FACILITY_H */ 74