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 13 #include <linux/minmax.h> 14 #include <linux/string.h> 15 #include <linux/types.h> 16 #include <linux/preempt.h> 17 #include <asm/alternative.h> 18 #include <asm/lowcore.h> 19 20 #define MAX_FACILITY_BIT (sizeof(stfle_fac_list) * 8) 21 22 extern u64 stfle_fac_list[16]; 23 24 static inline void __set_facility(unsigned long nr, void *facilities) 25 { 26 unsigned char *ptr = (unsigned char *) facilities; 27 28 if (nr >= MAX_FACILITY_BIT) 29 return; 30 ptr[nr >> 3] |= 0x80 >> (nr & 7); 31 } 32 33 static inline void __clear_facility(unsigned long nr, void *facilities) 34 { 35 unsigned char *ptr = (unsigned char *) facilities; 36 37 if (nr >= MAX_FACILITY_BIT) 38 return; 39 ptr[nr >> 3] &= ~(0x80 >> (nr & 7)); 40 } 41 42 static __always_inline bool __test_facility(unsigned long nr, void *facilities) 43 { 44 unsigned char *ptr; 45 46 if (nr >= MAX_FACILITY_BIT) 47 return false; 48 ptr = (unsigned char *) facilities + (nr >> 3); 49 return (*ptr & (0x80 >> (nr & 7))) != 0; 50 } 51 52 /* 53 * __test_facility_constant() generates a single instruction branch. If the 54 * tested facility is available (likely) the branch is patched into a nop. 55 * 56 * Do not use this function unless you know what you are doing. All users are 57 * supposed to use test_facility() which will do the right thing. 58 */ 59 static __always_inline bool __test_facility_constant(unsigned long nr) 60 { 61 asm goto( 62 ALTERNATIVE("brcl 15,%l[l_no]", "brcl 0,0", ALT_FACILITY(%[nr])) 63 : 64 : [nr] "i" (nr) 65 : 66 : l_no); 67 return true; 68 l_no: 69 return false; 70 } 71 72 /* 73 * The test_facility function uses the bit ordering where the MSB is bit 0. 74 * That makes it easier to query facility bits with the bit number as 75 * documented in the Principles of Operation. 76 */ 77 static __always_inline bool test_facility(unsigned long nr) 78 { 79 unsigned long facilities_als[] = { FACILITIES_ALS }; 80 81 if (!__is_defined(__DECOMPRESSOR) && __builtin_constant_p(nr)) { 82 if (nr < sizeof(facilities_als) * 8) { 83 if (__test_facility(nr, &facilities_als)) 84 return true; 85 } 86 return __test_facility_constant(nr); 87 } 88 return __test_facility(nr, &stfle_fac_list); 89 } 90 91 static inline unsigned long __stfle_asm(u64 *stfle_fac_list, int size) 92 { 93 unsigned long reg0 = size - 1; 94 95 asm volatile( 96 " lgr 0,%[reg0]\n" 97 " .insn s,0xb2b00000,%[list]\n" /* stfle */ 98 " lgr %[reg0],0\n" 99 : [reg0] "+&d" (reg0), [list] "+Q" (*stfle_fac_list) 100 : 101 : "memory", "cc", "0"); 102 return reg0; 103 } 104 105 /** 106 * stfle - Store facility list extended 107 * @stfle_fac_list: array where facility list can be stored 108 * @size: size of passed in array in double words 109 */ 110 static inline void __stfle(u64 *stfle_fac_list, int size) 111 { 112 unsigned long nr; 113 u32 stfl_fac_list; 114 115 asm volatile( 116 " stfl 0(0)\n" 117 : "=m" (get_lowcore()->stfl_fac_list)); 118 stfl_fac_list = get_lowcore()->stfl_fac_list; 119 memcpy(stfle_fac_list, &stfl_fac_list, 4); 120 nr = 4; /* bytes stored by stfl */ 121 if (stfl_fac_list & 0x01000000) { 122 /* More facility bits available with stfle */ 123 nr = __stfle_asm(stfle_fac_list, size); 124 nr = min_t(unsigned long, (nr + 1) * 8, size * 8); 125 } 126 memset((char *) stfle_fac_list + nr, 0, size * 8 - nr); 127 } 128 129 static inline void stfle(u64 *stfle_fac_list, int size) 130 { 131 preempt_disable(); 132 __stfle(stfle_fac_list, size); 133 preempt_enable(); 134 } 135 136 /** 137 * stfle_size - Actual size of the facility list as specified by stfle 138 * (number of double words) 139 */ 140 unsigned int stfle_size(void); 141 142 #endif /* __ASM_FACILITY_H */ 143