1 #include <linux/module.h> 2 #include <linux/preempt.h> 3 #include <linux/smp.h> 4 #include <asm/msr.h> 5 6 static void __rdmsr_on_cpu(void *info) 7 { 8 struct msr_info *rv = info; 9 struct msr *reg; 10 int this_cpu = raw_smp_processor_id(); 11 12 if (rv->msrs) 13 reg = per_cpu_ptr(rv->msrs, this_cpu); 14 else 15 reg = &rv->reg; 16 17 rdmsr(rv->msr_no, reg->l, reg->h); 18 } 19 20 static void __wrmsr_on_cpu(void *info) 21 { 22 struct msr_info *rv = info; 23 struct msr *reg; 24 int this_cpu = raw_smp_processor_id(); 25 26 if (rv->msrs) 27 reg = per_cpu_ptr(rv->msrs, this_cpu); 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 wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) 51 { 52 int err; 53 struct msr_info rv; 54 55 memset(&rv, 0, sizeof(rv)); 56 57 rv.msr_no = msr_no; 58 rv.reg.l = l; 59 rv.reg.h = h; 60 err = smp_call_function_single(cpu, __wrmsr_on_cpu, &rv, 1); 61 62 return err; 63 } 64 EXPORT_SYMBOL(wrmsr_on_cpu); 65 66 static void __rwmsr_on_cpus(const struct cpumask *mask, u32 msr_no, 67 struct msr *msrs, 68 void (*msr_func) (void *info)) 69 { 70 struct msr_info rv; 71 int this_cpu; 72 73 memset(&rv, 0, sizeof(rv)); 74 75 rv.msrs = msrs; 76 rv.msr_no = msr_no; 77 78 this_cpu = get_cpu(); 79 80 if (cpumask_test_cpu(this_cpu, mask)) 81 msr_func(&rv); 82 83 smp_call_function_many(mask, msr_func, &rv, 1); 84 put_cpu(); 85 } 86 87 /* rdmsr on a bunch of CPUs 88 * 89 * @mask: which CPUs 90 * @msr_no: which MSR 91 * @msrs: array of MSR values 92 * 93 */ 94 void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs) 95 { 96 __rwmsr_on_cpus(mask, msr_no, msrs, __rdmsr_on_cpu); 97 } 98 EXPORT_SYMBOL(rdmsr_on_cpus); 99 100 /* 101 * wrmsr on a bunch of CPUs 102 * 103 * @mask: which CPUs 104 * @msr_no: which MSR 105 * @msrs: array of MSR values 106 * 107 */ 108 void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs) 109 { 110 __rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu); 111 } 112 EXPORT_SYMBOL(wrmsr_on_cpus); 113 114 /* These "safe" variants are slower and should be used when the target MSR 115 may not actually exist. */ 116 static void __rdmsr_safe_on_cpu(void *info) 117 { 118 struct msr_info *rv = info; 119 120 rv->err = rdmsr_safe(rv->msr_no, &rv->reg.l, &rv->reg.h); 121 } 122 123 static void __wrmsr_safe_on_cpu(void *info) 124 { 125 struct msr_info *rv = info; 126 127 rv->err = wrmsr_safe(rv->msr_no, rv->reg.l, rv->reg.h); 128 } 129 130 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h) 131 { 132 int err; 133 struct msr_info rv; 134 135 memset(&rv, 0, sizeof(rv)); 136 137 rv.msr_no = msr_no; 138 err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu, &rv, 1); 139 *l = rv.reg.l; 140 *h = rv.reg.h; 141 142 return err ? err : rv.err; 143 } 144 EXPORT_SYMBOL(rdmsr_safe_on_cpu); 145 146 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h) 147 { 148 int err; 149 struct msr_info rv; 150 151 memset(&rv, 0, sizeof(rv)); 152 153 rv.msr_no = msr_no; 154 rv.reg.l = l; 155 rv.reg.h = h; 156 err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1); 157 158 return err ? err : rv.err; 159 } 160 EXPORT_SYMBOL(wrmsr_safe_on_cpu); 161 162 /* 163 * These variants are significantly slower, but allows control over 164 * the entire 32-bit GPR set. 165 */ 166 static void __rdmsr_safe_regs_on_cpu(void *info) 167 { 168 struct msr_regs_info *rv = info; 169 170 rv->err = rdmsr_safe_regs(rv->regs); 171 } 172 173 static void __wrmsr_safe_regs_on_cpu(void *info) 174 { 175 struct msr_regs_info *rv = info; 176 177 rv->err = wrmsr_safe_regs(rv->regs); 178 } 179 180 int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs) 181 { 182 int err; 183 struct msr_regs_info rv; 184 185 rv.regs = regs; 186 rv.err = -EIO; 187 err = smp_call_function_single(cpu, __rdmsr_safe_regs_on_cpu, &rv, 1); 188 189 return err ? err : rv.err; 190 } 191 EXPORT_SYMBOL(rdmsr_safe_regs_on_cpu); 192 193 int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs) 194 { 195 int err; 196 struct msr_regs_info rv; 197 198 rv.regs = regs; 199 rv.err = -EIO; 200 err = smp_call_function_single(cpu, __wrmsr_safe_regs_on_cpu, &rv, 1); 201 202 return err ? err : rv.err; 203 } 204 EXPORT_SYMBOL(wrmsr_safe_regs_on_cpu); 205