1 #include <linux/module.h>
2 #include <linux/preempt.h>
3 #include <linux/smp.h>
4 #include <asm/msr.h>
5
__rdmsr_on_cpu(void * info)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
__wrmsr_on_cpu(void * info)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
rdmsr_on_cpu(unsigned int cpu,u32 msr_no,u32 * l,u32 * h)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
wrmsr_on_cpu(unsigned int cpu,u32 msr_no,u32 l,u32 h)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
__rwmsr_on_cpus(const struct cpumask * mask,u32 msr_no,struct msr * msrs,void (* msr_func)(void * info))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 */
rdmsr_on_cpus(const struct cpumask * mask,u32 msr_no,struct msr * msrs)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 */
wrmsr_on_cpus(const struct cpumask * mask,u32 msr_no,struct msr * msrs)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. */
__rdmsr_safe_on_cpu(void * info)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
__wrmsr_safe_on_cpu(void * info)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
rdmsr_safe_on_cpu(unsigned int cpu,u32 msr_no,u32 * l,u32 * h)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
wrmsr_safe_on_cpu(unsigned int cpu,u32 msr_no,u32 l,u32 h)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 */
__rdmsr_safe_regs_on_cpu(void * info)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
__wrmsr_safe_regs_on_cpu(void * info)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
rdmsr_safe_regs_on_cpu(unsigned int cpu,u32 * regs)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
wrmsr_safe_regs_on_cpu(unsigned int cpu,u32 * regs)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