1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/export.h> 3 #include <linux/preempt.h> 4 #include <linux/smp.h> 5 #include <linux/completion.h> 6 #include <asm/msr.h> 7 8 static void __rdmsr_on_cpu(void *info) 9 { 10 struct msr_info *rv = info; 11 struct msr *reg; 12 13 if (rv->msrs) 14 reg = this_cpu_ptr(rv->msrs); 15 else 16 reg = &rv->reg; 17 18 rdmsr(rv->msr_no, reg->l, reg->h); 19 } 20 21 static void __wrmsr_on_cpu(void *info) 22 { 23 struct msr_info *rv = info; 24 struct msr *reg; 25 26 if (rv->msrs) 27 reg = this_cpu_ptr(rv->msrs); 28 else 29 reg = &rv->reg; 30 31 wrmsr(rv->msr_no, reg->l, reg->h); 32 } 33 34 int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) 35 { 36 int err; 37 struct msr_info rv; 38 39 memset(&rv, 0, sizeof(rv)); 40 41 rv.msr_no = msr_no; 42 err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1); 43 *l = rv.reg.l; 44 *h = rv.reg.h; 45 46 return err; 47 } 48 EXPORT_SYMBOL(rdmsr_on_cpu); 49 50 int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q) 51 { 52 int err; 53 struct msr_info rv; 54 55 memset(&rv, 0, sizeof(rv)); 56 57 rv.msr_no = msr_no; 58 err = smp_call_function_single(cpu, __rdmsr_on_cpu, &rv, 1); 59 *q = rv.reg.q; 60 61 return err; 62 } 63 EXPORT_SYMBOL(rdmsrl_on_cpu); 64 65 int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) 66 { 67 int err; 68 struct msr_info rv; 69 70 memset(&rv, 0, sizeof(rv)); 71 72 rv.msr_no = msr_no; 73 rv.reg.l = l; 74 rv.reg.h = h; 75 err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1); 76 77 return err; 78 } 79 EXPORT_SYMBOL(wrmsr_on_cpu); 80 81 int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q) 82 { 83 int err; 84 struct msr_info rv; 85 86 memset(&rv, 0, sizeof(rv)); 87 88 rv.msr_no = msr_no; 89 rv.reg.q = q; 90 91 err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1); 92 93 return err; 94 } 95 EXPORT_SYMBOL(wrmsrl_on_cpu); 96 97 static void __rwmsr_on_cpus(const struct cpumask *mask, u32 msr_no, 98 struct msr __percpu *msrs, 99 void (*msr_func) (void *info)) 100 { 101 struct msr_info rv; 102 int this_cpu; 103 104 memset(&rv, 0, sizeof(rv)); 105 106 rv.msrs = msrs; 107 rv.msr_no = msr_no; 108 109 this_cpu = get_cpu(); 110 111 if (cpumask_test_cpu(this_cpu, mask)) 112 msr_func(&rv); 113 114 smp_call_function_many(mask, msr_func, &rv, 1); 115 put_cpu(); 116 } 117 118 /* rdmsr on a bunch of CPUs 119 * 120 * @mask: which CPUs 121 * @msr_no: which MSR 122 * @msrs: array of MSR values 123 * 124 */ 125 void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr __percpu *msrs) 126 { 127 __rwmsr_on_cpus(mask, msr_no, msrs, __rdmsr_on_cpu); 128 } 129 EXPORT_SYMBOL(rdmsr_on_cpus); 130 131 /* 132 * wrmsr on a bunch of CPUs 133 * 134 * @mask: which CPUs 135 * @msr_no: which MSR 136 * @msrs: array of MSR values 137 * 138 */ 139 void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr __percpu *msrs) 140 { 141 __rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu); 142 } 143 EXPORT_SYMBOL(wrmsr_on_cpus); 144 145 struct msr_info_completion { 146 struct msr_info msr; 147 struct completion done; 148 }; 149 150 /* These "safe" variants are slower and should be used when the target MSR 151 may not actually exist. */ 152 static void __rdmsr_safe_on_cpu(void *info) 153 { 154 struct msr_info_completion *rv = info; 155 156 rv->msr.err = rdmsr_safe(rv->msr.msr_no, &rv->msr.reg.l, &rv->msr.reg.h); 157 complete(&rv->done); 158 } 159 160 static void __wrmsr_safe_on_cpu(void *info) 161 { 162 struct msr_info *rv = info; 163 164 rv->err = wrmsr_safe(rv->msr_no, rv->reg.l, rv->reg.h); 165 } 166 167 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) 168 { 169 struct msr_info_completion rv; 170 call_single_data_t csd; 171 int err; 172 173 INIT_CSD(&csd, __rdmsr_safe_on_cpu, &rv); 174 175 memset(&rv, 0, sizeof(rv)); 176 init_completion(&rv.done); 177 rv.msr.msr_no = msr_no; 178 179 err = smp_call_function_single_async(cpu, &csd); 180 if (!err) { 181 wait_for_completion(&rv.done); 182 err = rv.msr.err; 183 } 184 *l = rv.msr.reg.l; 185 *h = rv.msr.reg.h; 186 187 return err; 188 } 189 EXPORT_SYMBOL(rdmsr_safe_on_cpu); 190 191 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) 192 { 193 int err; 194 struct msr_info rv; 195 196 memset(&rv, 0, sizeof(rv)); 197 198 rv.msr_no = msr_no; 199 rv.reg.l = l; 200 rv.reg.h = h; 201 err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1); 202 203 return err ? err : rv.err; 204 } 205 EXPORT_SYMBOL(wrmsr_safe_on_cpu); 206 207 int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q) 208 { 209 int err; 210 struct msr_info rv; 211 212 memset(&rv, 0, sizeof(rv)); 213 214 rv.msr_no = msr_no; 215 rv.reg.q = q; 216 217 err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1); 218 219 return err ? err : rv.err; 220 } 221 EXPORT_SYMBOL(wrmsrl_safe_on_cpu); 222 223 int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q) 224 { 225 u32 low, high; 226 int err; 227 228 err = rdmsr_safe_on_cpu(cpu, msr_no, &low, &high); 229 *q = (u64)high << 32 | low; 230 231 return err; 232 } 233 EXPORT_SYMBOL(rdmsrl_safe_on_cpu); 234 235 /* 236 * These variants are significantly slower, but allows control over 237 * the entire 32-bit GPR set. 238 */ 239 static void __rdmsr_safe_regs_on_cpu(void *info) 240 { 241 struct msr_regs_info *rv = info; 242 243 rv->err = rdmsr_safe_regs(rv->regs); 244 } 245 246 static void __wrmsr_safe_regs_on_cpu(void *info) 247 { 248 struct msr_regs_info *rv = info; 249 250 rv->err = wrmsr_safe_regs(rv->regs); 251 } 252 253 int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]) 254 { 255 int err; 256 struct msr_regs_info rv; 257 258 rv.regs = regs; 259 rv.err = -EIO; 260 err = smp_call_function_single(cpu, __rdmsr_safe_regs_on_cpu, &rv, 1); 261 262 return err ? err : rv.err; 263 } 264 EXPORT_SYMBOL(rdmsr_safe_regs_on_cpu); 265 266 int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]) 267 { 268 int err; 269 struct msr_regs_info rv; 270 271 rv.regs = regs; 272 rv.err = -EIO; 273 err = smp_call_function_single(cpu, __wrmsr_safe_regs_on_cpu, &rv, 1); 274 275 return err ? err : rv.err; 276 } 277 EXPORT_SYMBOL(wrmsr_safe_regs_on_cpu); 278