1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited 4 */ 5 #ifndef __ASM_PERCPU_H 6 #define __ASM_PERCPU_H 7 8 #include <asm/cmpxchg.h> 9 #include <asm/loongarch.h> 10 11 /* 12 * The "address" (in fact, offset from $r21) of a per-CPU variable is close to 13 * the loading address of main kernel image, but far from where the modules are 14 * loaded. Tell the compiler this fact when using explicit relocs. 15 */ 16 #if defined(MODULE) && defined(CONFIG_AS_HAS_EXPLICIT_RELOCS) 17 # if __has_attribute(model) 18 # define PER_CPU_ATTRIBUTES __attribute__((model("extreme"))) 19 # else 20 # error compiler support for the model attribute is necessary when a recent assembler is used 21 # endif 22 #endif 23 24 /* Use r21 for fast access */ 25 register unsigned long __my_cpu_offset __asm__("$r21"); 26 27 static inline void set_my_cpu_offset(unsigned long off) 28 { 29 __my_cpu_offset = off; 30 csr_write64(off, PERCPU_BASE_KS); 31 } 32 33 #define __my_cpu_offset \ 34 ({ \ 35 __asm__ __volatile__("":"+r"(__my_cpu_offset)); \ 36 __my_cpu_offset; \ 37 }) 38 39 #define PERCPU_OP(op, asm_op, c_op) \ 40 static __always_inline unsigned long __percpu_##op(void *ptr, \ 41 unsigned long val, int size) \ 42 { \ 43 unsigned long ret; \ 44 \ 45 switch (size) { \ 46 case 4: \ 47 __asm__ __volatile__( \ 48 "am"#asm_op".w" " %[ret], %[val], %[ptr] \n" \ 49 : [ret] "=&r" (ret), [ptr] "+ZB"(*(u32 *)ptr) \ 50 : [val] "r" (val)); \ 51 break; \ 52 case 8: \ 53 __asm__ __volatile__( \ 54 "am"#asm_op".d" " %[ret], %[val], %[ptr] \n" \ 55 : [ret] "=&r" (ret), [ptr] "+ZB"(*(u64 *)ptr) \ 56 : [val] "r" (val)); \ 57 break; \ 58 default: \ 59 ret = 0; \ 60 BUILD_BUG(); \ 61 } \ 62 \ 63 return ret c_op val; \ 64 } 65 66 PERCPU_OP(add, add, +) 67 PERCPU_OP(and, and, &) 68 PERCPU_OP(or, or, |) 69 #undef PERCPU_OP 70 71 static __always_inline unsigned long __percpu_read(void __percpu *ptr, int size) 72 { 73 unsigned long ret; 74 75 switch (size) { 76 case 1: 77 __asm__ __volatile__ ("ldx.b %[ret], $r21, %[ptr] \n" 78 : [ret] "=&r"(ret) 79 : [ptr] "r"(ptr) 80 : "memory"); 81 break; 82 case 2: 83 __asm__ __volatile__ ("ldx.h %[ret], $r21, %[ptr] \n" 84 : [ret] "=&r"(ret) 85 : [ptr] "r"(ptr) 86 : "memory"); 87 break; 88 case 4: 89 __asm__ __volatile__ ("ldx.w %[ret], $r21, %[ptr] \n" 90 : [ret] "=&r"(ret) 91 : [ptr] "r"(ptr) 92 : "memory"); 93 break; 94 case 8: 95 __asm__ __volatile__ ("ldx.d %[ret], $r21, %[ptr] \n" 96 : [ret] "=&r"(ret) 97 : [ptr] "r"(ptr) 98 : "memory"); 99 break; 100 default: 101 ret = 0; 102 BUILD_BUG(); 103 } 104 105 return ret; 106 } 107 108 static __always_inline void __percpu_write(void __percpu *ptr, unsigned long val, int size) 109 { 110 switch (size) { 111 case 1: 112 __asm__ __volatile__("stx.b %[val], $r21, %[ptr] \n" 113 : 114 : [val] "r" (val), [ptr] "r" (ptr) 115 : "memory"); 116 break; 117 case 2: 118 __asm__ __volatile__("stx.h %[val], $r21, %[ptr] \n" 119 : 120 : [val] "r" (val), [ptr] "r" (ptr) 121 : "memory"); 122 break; 123 case 4: 124 __asm__ __volatile__("stx.w %[val], $r21, %[ptr] \n" 125 : 126 : [val] "r" (val), [ptr] "r" (ptr) 127 : "memory"); 128 break; 129 case 8: 130 __asm__ __volatile__("stx.d %[val], $r21, %[ptr] \n" 131 : 132 : [val] "r" (val), [ptr] "r" (ptr) 133 : "memory"); 134 break; 135 default: 136 BUILD_BUG(); 137 } 138 } 139 140 static __always_inline unsigned long __percpu_xchg(void *ptr, unsigned long val, int size) 141 { 142 switch (size) { 143 case 1: 144 case 2: 145 return __xchg_small((volatile void *)ptr, val, size); 146 147 case 4: 148 return __xchg_asm("amswap.w", (volatile u32 *)ptr, (u32)val); 149 150 case 8: 151 return __xchg_asm("amswap.d", (volatile u64 *)ptr, (u64)val); 152 153 default: 154 BUILD_BUG(); 155 } 156 157 return 0; 158 } 159 160 /* this_cpu_cmpxchg */ 161 #define _protect_cmpxchg_local(pcp, o, n) \ 162 ({ \ 163 typeof(*raw_cpu_ptr(&(pcp))) __ret; \ 164 preempt_disable_notrace(); \ 165 __ret = cmpxchg_local(raw_cpu_ptr(&(pcp)), o, n); \ 166 preempt_enable_notrace(); \ 167 __ret; \ 168 }) 169 170 #define _percpu_read(pcp) \ 171 ({ \ 172 typeof(pcp) __retval; \ 173 __retval = (typeof(pcp))__percpu_read(&(pcp), sizeof(pcp)); \ 174 __retval; \ 175 }) 176 177 #define _percpu_write(pcp, val) \ 178 do { \ 179 __percpu_write(&(pcp), (unsigned long)(val), sizeof(pcp)); \ 180 } while (0) \ 181 182 #define _pcp_protect(operation, pcp, val) \ 183 ({ \ 184 typeof(pcp) __retval; \ 185 preempt_disable_notrace(); \ 186 __retval = (typeof(pcp))operation(raw_cpu_ptr(&(pcp)), \ 187 (val), sizeof(pcp)); \ 188 preempt_enable_notrace(); \ 189 __retval; \ 190 }) 191 192 #define _percpu_add(pcp, val) \ 193 _pcp_protect(__percpu_add, pcp, val) 194 195 #define _percpu_add_return(pcp, val) _percpu_add(pcp, val) 196 197 #define _percpu_and(pcp, val) \ 198 _pcp_protect(__percpu_and, pcp, val) 199 200 #define _percpu_or(pcp, val) \ 201 _pcp_protect(__percpu_or, pcp, val) 202 203 #define _percpu_xchg(pcp, val) ((typeof(pcp)) \ 204 _pcp_protect(__percpu_xchg, pcp, (unsigned long)(val))) 205 206 #define this_cpu_add_4(pcp, val) _percpu_add(pcp, val) 207 #define this_cpu_add_8(pcp, val) _percpu_add(pcp, val) 208 209 #define this_cpu_add_return_4(pcp, val) _percpu_add_return(pcp, val) 210 #define this_cpu_add_return_8(pcp, val) _percpu_add_return(pcp, val) 211 212 #define this_cpu_and_4(pcp, val) _percpu_and(pcp, val) 213 #define this_cpu_and_8(pcp, val) _percpu_and(pcp, val) 214 215 #define this_cpu_or_4(pcp, val) _percpu_or(pcp, val) 216 #define this_cpu_or_8(pcp, val) _percpu_or(pcp, val) 217 218 #define this_cpu_read_1(pcp) _percpu_read(pcp) 219 #define this_cpu_read_2(pcp) _percpu_read(pcp) 220 #define this_cpu_read_4(pcp) _percpu_read(pcp) 221 #define this_cpu_read_8(pcp) _percpu_read(pcp) 222 223 #define this_cpu_write_1(pcp, val) _percpu_write(pcp, val) 224 #define this_cpu_write_2(pcp, val) _percpu_write(pcp, val) 225 #define this_cpu_write_4(pcp, val) _percpu_write(pcp, val) 226 #define this_cpu_write_8(pcp, val) _percpu_write(pcp, val) 227 228 #define this_cpu_xchg_1(pcp, val) _percpu_xchg(pcp, val) 229 #define this_cpu_xchg_2(pcp, val) _percpu_xchg(pcp, val) 230 #define this_cpu_xchg_4(pcp, val) _percpu_xchg(pcp, val) 231 #define this_cpu_xchg_8(pcp, val) _percpu_xchg(pcp, val) 232 233 #define this_cpu_cmpxchg_1(ptr, o, n) _protect_cmpxchg_local(ptr, o, n) 234 #define this_cpu_cmpxchg_2(ptr, o, n) _protect_cmpxchg_local(ptr, o, n) 235 #define this_cpu_cmpxchg_4(ptr, o, n) _protect_cmpxchg_local(ptr, o, n) 236 #define this_cpu_cmpxchg_8(ptr, o, n) _protect_cmpxchg_local(ptr, o, n) 237 238 #include <asm-generic/percpu.h> 239 240 #endif /* __ASM_PERCPU_H */ 241