xref: /openbmc/linux/arch/x86/lib/msr-smp.c (revision 8e9356c6)
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 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 *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 *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 *msrs)
140 {
141 	__rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu);
142 }
143 EXPORT_SYMBOL(wrmsr_on_cpus);
144 
145 /* These "safe" variants are slower and should be used when the target MSR
146    may not actually exist. */
147 static void __rdmsr_safe_on_cpu(void *info)
148 {
149 	struct msr_info *rv = info;
150 
151 	rv->err = rdmsr_safe(rv->msr_no, &rv->reg.l, &rv->reg.h);
152 }
153 
154 static void __wrmsr_safe_on_cpu(void *info)
155 {
156 	struct msr_info *rv = info;
157 
158 	rv->err = wrmsr_safe(rv->msr_no, rv->reg.l, rv->reg.h);
159 }
160 
161 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
162 {
163 	int err;
164 	struct msr_info rv;
165 
166 	memset(&rv, 0, sizeof(rv));
167 
168 	rv.msr_no = msr_no;
169 	err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu, &rv, 1);
170 	*l = rv.reg.l;
171 	*h = rv.reg.h;
172 
173 	return err ? err : rv.err;
174 }
175 EXPORT_SYMBOL(rdmsr_safe_on_cpu);
176 
177 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
178 {
179 	int err;
180 	struct msr_info rv;
181 
182 	memset(&rv, 0, sizeof(rv));
183 
184 	rv.msr_no = msr_no;
185 	rv.reg.l = l;
186 	rv.reg.h = h;
187 	err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
188 
189 	return err ? err : rv.err;
190 }
191 EXPORT_SYMBOL(wrmsr_safe_on_cpu);
192 
193 int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
194 {
195 	int err;
196 	struct msr_info rv;
197 
198 	memset(&rv, 0, sizeof(rv));
199 
200 	rv.msr_no = msr_no;
201 	rv.reg.q = q;
202 
203 	err = smp_call_function_single(cpu, __wrmsr_safe_on_cpu, &rv, 1);
204 
205 	return err ? err : rv.err;
206 }
207 EXPORT_SYMBOL(wrmsrl_safe_on_cpu);
208 
209 int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
210 {
211 	int err;
212 	struct msr_info rv;
213 
214 	memset(&rv, 0, sizeof(rv));
215 
216 	rv.msr_no = msr_no;
217 	err = smp_call_function_single(cpu, __rdmsr_safe_on_cpu, &rv, 1);
218 	*q = rv.reg.q;
219 
220 	return err ? err : rv.err;
221 }
222 EXPORT_SYMBOL(rdmsrl_safe_on_cpu);
223 
224 /*
225  * These variants are significantly slower, but allows control over
226  * the entire 32-bit GPR set.
227  */
228 static void __rdmsr_safe_regs_on_cpu(void *info)
229 {
230 	struct msr_regs_info *rv = info;
231 
232 	rv->err = rdmsr_safe_regs(rv->regs);
233 }
234 
235 static void __wrmsr_safe_regs_on_cpu(void *info)
236 {
237 	struct msr_regs_info *rv = info;
238 
239 	rv->err = wrmsr_safe_regs(rv->regs);
240 }
241 
242 int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
243 {
244 	int err;
245 	struct msr_regs_info rv;
246 
247 	rv.regs   = regs;
248 	rv.err    = -EIO;
249 	err = smp_call_function_single(cpu, __rdmsr_safe_regs_on_cpu, &rv, 1);
250 
251 	return err ? err : rv.err;
252 }
253 EXPORT_SYMBOL(rdmsr_safe_regs_on_cpu);
254 
255 int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 *regs)
256 {
257 	int err;
258 	struct msr_regs_info rv;
259 
260 	rv.regs = regs;
261 	rv.err  = -EIO;
262 	err = smp_call_function_single(cpu, __wrmsr_safe_regs_on_cpu, &rv, 1);
263 
264 	return err ? err : rv.err;
265 }
266 EXPORT_SYMBOL(wrmsr_safe_regs_on_cpu);
267