1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2013 ARM Ltd. 4 */ 5 #ifndef __ASM_PERCPU_H 6 #define __ASM_PERCPU_H 7 8 #include <linux/preempt.h> 9 10 #include <asm/alternative.h> 11 #include <asm/cmpxchg.h> 12 #include <asm/stack_pointer.h> 13 14 static inline void set_my_cpu_offset(unsigned long off) 15 { 16 asm volatile(ALTERNATIVE("msr tpidr_el1, %0", 17 "msr tpidr_el2, %0", 18 ARM64_HAS_VIRT_HOST_EXTN) 19 :: "r" (off) : "memory"); 20 } 21 22 static inline unsigned long __hyp_my_cpu_offset(void) 23 { 24 /* 25 * Non-VHE hyp code runs with preemption disabled. No need to hazard 26 * the register access against barrier() as in __kern_my_cpu_offset. 27 */ 28 return read_sysreg(tpidr_el2); 29 } 30 31 static inline unsigned long __kern_my_cpu_offset(void) 32 { 33 unsigned long off; 34 35 /* 36 * We want to allow caching the value, so avoid using volatile and 37 * instead use a fake stack read to hazard against barrier(). 38 */ 39 asm(ALTERNATIVE("mrs %0, tpidr_el1", 40 "mrs %0, tpidr_el2", 41 ARM64_HAS_VIRT_HOST_EXTN) 42 : "=r" (off) : 43 "Q" (*(const unsigned long *)current_stack_pointer)); 44 45 return off; 46 } 47 48 #ifdef __KVM_NVHE_HYPERVISOR__ 49 #define __my_cpu_offset __hyp_my_cpu_offset() 50 #else 51 #define __my_cpu_offset __kern_my_cpu_offset() 52 #endif 53 54 #define PERCPU_RW_OPS(sz) \ 55 static inline unsigned long __percpu_read_##sz(void *ptr) \ 56 { \ 57 return READ_ONCE(*(u##sz *)ptr); \ 58 } \ 59 \ 60 static inline void __percpu_write_##sz(void *ptr, unsigned long val) \ 61 { \ 62 WRITE_ONCE(*(u##sz *)ptr, (u##sz)val); \ 63 } 64 65 #define __PERCPU_OP_CASE(w, sfx, name, sz, op_llsc, op_lse) \ 66 static inline void \ 67 __percpu_##name##_case_##sz(void *ptr, unsigned long val) \ 68 { \ 69 unsigned int loop; \ 70 u##sz tmp; \ 71 \ 72 asm volatile (ARM64_LSE_ATOMIC_INSN( \ 73 /* LL/SC */ \ 74 "1: ldxr" #sfx "\t%" #w "[tmp], %[ptr]\n" \ 75 #op_llsc "\t%" #w "[tmp], %" #w "[tmp], %" #w "[val]\n" \ 76 " stxr" #sfx "\t%w[loop], %" #w "[tmp], %[ptr]\n" \ 77 " cbnz %w[loop], 1b", \ 78 /* LSE atomics */ \ 79 #op_lse "\t%" #w "[val], %[ptr]\n" \ 80 __nops(3)) \ 81 : [loop] "=&r" (loop), [tmp] "=&r" (tmp), \ 82 [ptr] "+Q"(*(u##sz *)ptr) \ 83 : [val] "r" ((u##sz)(val))); \ 84 } 85 86 #define __PERCPU_RET_OP_CASE(w, sfx, name, sz, op_llsc, op_lse) \ 87 static inline u##sz \ 88 __percpu_##name##_return_case_##sz(void *ptr, unsigned long val) \ 89 { \ 90 unsigned int loop; \ 91 u##sz ret; \ 92 \ 93 asm volatile (ARM64_LSE_ATOMIC_INSN( \ 94 /* LL/SC */ \ 95 "1: ldxr" #sfx "\t%" #w "[ret], %[ptr]\n" \ 96 #op_llsc "\t%" #w "[ret], %" #w "[ret], %" #w "[val]\n" \ 97 " stxr" #sfx "\t%w[loop], %" #w "[ret], %[ptr]\n" \ 98 " cbnz %w[loop], 1b", \ 99 /* LSE atomics */ \ 100 #op_lse "\t%" #w "[val], %" #w "[ret], %[ptr]\n" \ 101 #op_llsc "\t%" #w "[ret], %" #w "[ret], %" #w "[val]\n" \ 102 __nops(2)) \ 103 : [loop] "=&r" (loop), [ret] "=&r" (ret), \ 104 [ptr] "+Q"(*(u##sz *)ptr) \ 105 : [val] "r" ((u##sz)(val))); \ 106 \ 107 return ret; \ 108 } 109 110 #define PERCPU_OP(name, op_llsc, op_lse) \ 111 __PERCPU_OP_CASE(w, b, name, 8, op_llsc, op_lse) \ 112 __PERCPU_OP_CASE(w, h, name, 16, op_llsc, op_lse) \ 113 __PERCPU_OP_CASE(w, , name, 32, op_llsc, op_lse) \ 114 __PERCPU_OP_CASE( , , name, 64, op_llsc, op_lse) 115 116 #define PERCPU_RET_OP(name, op_llsc, op_lse) \ 117 __PERCPU_RET_OP_CASE(w, b, name, 8, op_llsc, op_lse) \ 118 __PERCPU_RET_OP_CASE(w, h, name, 16, op_llsc, op_lse) \ 119 __PERCPU_RET_OP_CASE(w, , name, 32, op_llsc, op_lse) \ 120 __PERCPU_RET_OP_CASE( , , name, 64, op_llsc, op_lse) 121 122 PERCPU_RW_OPS(8) 123 PERCPU_RW_OPS(16) 124 PERCPU_RW_OPS(32) 125 PERCPU_RW_OPS(64) 126 PERCPU_OP(add, add, stadd) 127 PERCPU_OP(andnot, bic, stclr) 128 PERCPU_OP(or, orr, stset) 129 PERCPU_RET_OP(add, add, ldadd) 130 131 #undef PERCPU_RW_OPS 132 #undef __PERCPU_OP_CASE 133 #undef __PERCPU_RET_OP_CASE 134 #undef PERCPU_OP 135 #undef PERCPU_RET_OP 136 137 /* 138 * It would be nice to avoid the conditional call into the scheduler when 139 * re-enabling preemption for preemptible kernels, but doing that in a way 140 * which builds inside a module would mean messing directly with the preempt 141 * count. If you do this, peterz and tglx will hunt you down. 142 */ 143 #define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2) \ 144 ({ \ 145 int __ret; \ 146 preempt_disable_notrace(); \ 147 __ret = cmpxchg_double_local( raw_cpu_ptr(&(ptr1)), \ 148 raw_cpu_ptr(&(ptr2)), \ 149 o1, o2, n1, n2); \ 150 preempt_enable_notrace(); \ 151 __ret; \ 152 }) 153 154 #define _pcp_protect(op, pcp, ...) \ 155 ({ \ 156 preempt_disable_notrace(); \ 157 op(raw_cpu_ptr(&(pcp)), __VA_ARGS__); \ 158 preempt_enable_notrace(); \ 159 }) 160 161 #define _pcp_protect_return(op, pcp, args...) \ 162 ({ \ 163 typeof(pcp) __retval; \ 164 preempt_disable_notrace(); \ 165 __retval = (typeof(pcp))op(raw_cpu_ptr(&(pcp)), ##args); \ 166 preempt_enable_notrace(); \ 167 __retval; \ 168 }) 169 170 #define this_cpu_read_1(pcp) \ 171 _pcp_protect_return(__percpu_read_8, pcp) 172 #define this_cpu_read_2(pcp) \ 173 _pcp_protect_return(__percpu_read_16, pcp) 174 #define this_cpu_read_4(pcp) \ 175 _pcp_protect_return(__percpu_read_32, pcp) 176 #define this_cpu_read_8(pcp) \ 177 _pcp_protect_return(__percpu_read_64, pcp) 178 179 #define this_cpu_write_1(pcp, val) \ 180 _pcp_protect(__percpu_write_8, pcp, (unsigned long)val) 181 #define this_cpu_write_2(pcp, val) \ 182 _pcp_protect(__percpu_write_16, pcp, (unsigned long)val) 183 #define this_cpu_write_4(pcp, val) \ 184 _pcp_protect(__percpu_write_32, pcp, (unsigned long)val) 185 #define this_cpu_write_8(pcp, val) \ 186 _pcp_protect(__percpu_write_64, pcp, (unsigned long)val) 187 188 #define this_cpu_add_1(pcp, val) \ 189 _pcp_protect(__percpu_add_case_8, pcp, val) 190 #define this_cpu_add_2(pcp, val) \ 191 _pcp_protect(__percpu_add_case_16, pcp, val) 192 #define this_cpu_add_4(pcp, val) \ 193 _pcp_protect(__percpu_add_case_32, pcp, val) 194 #define this_cpu_add_8(pcp, val) \ 195 _pcp_protect(__percpu_add_case_64, pcp, val) 196 197 #define this_cpu_add_return_1(pcp, val) \ 198 _pcp_protect_return(__percpu_add_return_case_8, pcp, val) 199 #define this_cpu_add_return_2(pcp, val) \ 200 _pcp_protect_return(__percpu_add_return_case_16, pcp, val) 201 #define this_cpu_add_return_4(pcp, val) \ 202 _pcp_protect_return(__percpu_add_return_case_32, pcp, val) 203 #define this_cpu_add_return_8(pcp, val) \ 204 _pcp_protect_return(__percpu_add_return_case_64, pcp, val) 205 206 #define this_cpu_and_1(pcp, val) \ 207 _pcp_protect(__percpu_andnot_case_8, pcp, ~val) 208 #define this_cpu_and_2(pcp, val) \ 209 _pcp_protect(__percpu_andnot_case_16, pcp, ~val) 210 #define this_cpu_and_4(pcp, val) \ 211 _pcp_protect(__percpu_andnot_case_32, pcp, ~val) 212 #define this_cpu_and_8(pcp, val) \ 213 _pcp_protect(__percpu_andnot_case_64, pcp, ~val) 214 215 #define this_cpu_or_1(pcp, val) \ 216 _pcp_protect(__percpu_or_case_8, pcp, val) 217 #define this_cpu_or_2(pcp, val) \ 218 _pcp_protect(__percpu_or_case_16, pcp, val) 219 #define this_cpu_or_4(pcp, val) \ 220 _pcp_protect(__percpu_or_case_32, pcp, val) 221 #define this_cpu_or_8(pcp, val) \ 222 _pcp_protect(__percpu_or_case_64, pcp, val) 223 224 #define this_cpu_xchg_1(pcp, val) \ 225 _pcp_protect_return(xchg_relaxed, pcp, val) 226 #define this_cpu_xchg_2(pcp, val) \ 227 _pcp_protect_return(xchg_relaxed, pcp, val) 228 #define this_cpu_xchg_4(pcp, val) \ 229 _pcp_protect_return(xchg_relaxed, pcp, val) 230 #define this_cpu_xchg_8(pcp, val) \ 231 _pcp_protect_return(xchg_relaxed, pcp, val) 232 233 #define this_cpu_cmpxchg_1(pcp, o, n) \ 234 _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) 235 #define this_cpu_cmpxchg_2(pcp, o, n) \ 236 _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) 237 #define this_cpu_cmpxchg_4(pcp, o, n) \ 238 _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) 239 #define this_cpu_cmpxchg_8(pcp, o, n) \ 240 _pcp_protect_return(cmpxchg_relaxed, pcp, o, n) 241 242 #include <asm-generic/percpu.h> 243 244 /* Redefine macros for nVHE hyp under DEBUG_PREEMPT to avoid its dependencies. */ 245 #if defined(__KVM_NVHE_HYPERVISOR__) && defined(CONFIG_DEBUG_PREEMPT) 246 #undef this_cpu_ptr 247 #define this_cpu_ptr raw_cpu_ptr 248 #undef __this_cpu_read 249 #define __this_cpu_read raw_cpu_read 250 #undef __this_cpu_write 251 #define __this_cpu_write raw_cpu_write 252 #endif 253 254 #endif /* __ASM_PERCPU_H */ 255