xref: /openbmc/linux/arch/x86/include/asm/msr.h (revision 79f08d9e)
1 #ifndef _ASM_X86_MSR_H
2 #define _ASM_X86_MSR_H
3 
4 #include <uapi/asm/msr.h>
5 
6 #ifndef __ASSEMBLY__
7 
8 #include <asm/asm.h>
9 #include <asm/errno.h>
10 #include <asm/cpumask.h>
11 
12 struct msr {
13 	union {
14 		struct {
15 			u32 l;
16 			u32 h;
17 		};
18 		u64 q;
19 	};
20 };
21 
22 struct msr_info {
23 	u32 msr_no;
24 	struct msr reg;
25 	struct msr *msrs;
26 	int err;
27 };
28 
29 struct msr_regs_info {
30 	u32 *regs;
31 	int err;
32 };
33 
34 static inline unsigned long long native_read_tscp(unsigned int *aux)
35 {
36 	unsigned long low, high;
37 	asm volatile(".byte 0x0f,0x01,0xf9"
38 		     : "=a" (low), "=d" (high), "=c" (*aux));
39 	return low | ((u64)high << 32);
40 }
41 
42 /*
43  * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
44  * constraint has different meanings. For i386, "A" means exactly
45  * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead,
46  * it means rax *or* rdx.
47  */
48 #ifdef CONFIG_X86_64
49 #define DECLARE_ARGS(val, low, high)	unsigned low, high
50 #define EAX_EDX_VAL(val, low, high)	((low) | ((u64)(high) << 32))
51 #define EAX_EDX_ARGS(val, low, high)	"a" (low), "d" (high)
52 #define EAX_EDX_RET(val, low, high)	"=a" (low), "=d" (high)
53 #else
54 #define DECLARE_ARGS(val, low, high)	unsigned long long val
55 #define EAX_EDX_VAL(val, low, high)	(val)
56 #define EAX_EDX_ARGS(val, low, high)	"A" (val)
57 #define EAX_EDX_RET(val, low, high)	"=A" (val)
58 #endif
59 
60 static inline unsigned long long native_read_msr(unsigned int msr)
61 {
62 	DECLARE_ARGS(val, low, high);
63 
64 	asm volatile("rdmsr" : EAX_EDX_RET(val, low, high) : "c" (msr));
65 	return EAX_EDX_VAL(val, low, high);
66 }
67 
68 static inline unsigned long long native_read_msr_safe(unsigned int msr,
69 						      int *err)
70 {
71 	DECLARE_ARGS(val, low, high);
72 
73 	asm volatile("2: rdmsr ; xor %[err],%[err]\n"
74 		     "1:\n\t"
75 		     ".section .fixup,\"ax\"\n\t"
76 		     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
77 		     ".previous\n\t"
78 		     _ASM_EXTABLE(2b, 3b)
79 		     : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
80 		     : "c" (msr), [fault] "i" (-EIO));
81 	return EAX_EDX_VAL(val, low, high);
82 }
83 
84 static inline void native_write_msr(unsigned int msr,
85 				    unsigned low, unsigned high)
86 {
87 	asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory");
88 }
89 
90 /* Can be uninlined because referenced by paravirt */
91 notrace static inline int native_write_msr_safe(unsigned int msr,
92 					unsigned low, unsigned high)
93 {
94 	int err;
95 	asm volatile("2: wrmsr ; xor %[err],%[err]\n"
96 		     "1:\n\t"
97 		     ".section .fixup,\"ax\"\n\t"
98 		     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
99 		     ".previous\n\t"
100 		     _ASM_EXTABLE(2b, 3b)
101 		     : [err] "=a" (err)
102 		     : "c" (msr), "0" (low), "d" (high),
103 		       [fault] "i" (-EIO)
104 		     : "memory");
105 	return err;
106 }
107 
108 extern unsigned long long native_read_tsc(void);
109 
110 extern int rdmsr_safe_regs(u32 regs[8]);
111 extern int wrmsr_safe_regs(u32 regs[8]);
112 
113 static __always_inline unsigned long long __native_read_tsc(void)
114 {
115 	DECLARE_ARGS(val, low, high);
116 
117 	asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
118 
119 	return EAX_EDX_VAL(val, low, high);
120 }
121 
122 static inline unsigned long long native_read_pmc(int counter)
123 {
124 	DECLARE_ARGS(val, low, high);
125 
126 	asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
127 	return EAX_EDX_VAL(val, low, high);
128 }
129 
130 #ifdef CONFIG_PARAVIRT
131 #include <asm/paravirt.h>
132 #else
133 #include <linux/errno.h>
134 /*
135  * Access to machine-specific registers (available on 586 and better only)
136  * Note: the rd* operations modify the parameters directly (without using
137  * pointer indirection), this allows gcc to optimize better
138  */
139 
140 #define rdmsr(msr, low, high)					\
141 do {								\
142 	u64 __val = native_read_msr((msr));			\
143 	(void)((low) = (u32)__val);				\
144 	(void)((high) = (u32)(__val >> 32));			\
145 } while (0)
146 
147 static inline void wrmsr(unsigned msr, unsigned low, unsigned high)
148 {
149 	native_write_msr(msr, low, high);
150 }
151 
152 #define rdmsrl(msr, val)			\
153 	((val) = native_read_msr((msr)))
154 
155 #define wrmsrl(msr, val)						\
156 	native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32))
157 
158 /* wrmsr with exception handling */
159 static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
160 {
161 	return native_write_msr_safe(msr, low, high);
162 }
163 
164 /* rdmsr with exception handling */
165 #define rdmsr_safe(msr, low, high)				\
166 ({								\
167 	int __err;						\
168 	u64 __val = native_read_msr_safe((msr), &__err);	\
169 	(*low) = (u32)__val;					\
170 	(*high) = (u32)(__val >> 32);				\
171 	__err;							\
172 })
173 
174 static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
175 {
176 	int err;
177 
178 	*p = native_read_msr_safe(msr, &err);
179 	return err;
180 }
181 
182 #define rdtscl(low)						\
183 	((low) = (u32)__native_read_tsc())
184 
185 #define rdtscll(val)						\
186 	((val) = __native_read_tsc())
187 
188 #define rdpmc(counter, low, high)			\
189 do {							\
190 	u64 _l = native_read_pmc((counter));		\
191 	(low)  = (u32)_l;				\
192 	(high) = (u32)(_l >> 32);			\
193 } while (0)
194 
195 #define rdpmcl(counter, val) ((val) = native_read_pmc(counter))
196 
197 #define rdtscp(low, high, aux)					\
198 do {                                                            \
199 	unsigned long long _val = native_read_tscp(&(aux));     \
200 	(low) = (u32)_val;                                      \
201 	(high) = (u32)(_val >> 32);                             \
202 } while (0)
203 
204 #define rdtscpll(val, aux) (val) = native_read_tscp(&(aux))
205 
206 #endif	/* !CONFIG_PARAVIRT */
207 
208 #define wrmsrl_safe(msr, val) wrmsr_safe((msr), (u32)(val),		\
209 					     (u32)((val) >> 32))
210 
211 #define write_tsc(low, high) wrmsr(MSR_IA32_TSC, (low), (high))
212 
213 #define write_rdtscp_aux(val) wrmsr(MSR_TSC_AUX, (val), 0)
214 
215 struct msr *msrs_alloc(void);
216 void msrs_free(struct msr *msrs);
217 
218 #ifdef CONFIG_SMP
219 int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
220 int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
221 int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
222 int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
223 void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
224 void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
225 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
226 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
227 int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
228 int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
229 int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
230 int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
231 #else  /*  CONFIG_SMP  */
232 static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
233 {
234 	rdmsr(msr_no, *l, *h);
235 	return 0;
236 }
237 static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
238 {
239 	wrmsr(msr_no, l, h);
240 	return 0;
241 }
242 static inline int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
243 {
244 	rdmsrl(msr_no, *q);
245 	return 0;
246 }
247 static inline int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
248 {
249 	wrmsrl(msr_no, q);
250 	return 0;
251 }
252 static inline void rdmsr_on_cpus(const struct cpumask *m, u32 msr_no,
253 				struct msr *msrs)
254 {
255        rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h));
256 }
257 static inline void wrmsr_on_cpus(const struct cpumask *m, u32 msr_no,
258 				struct msr *msrs)
259 {
260        wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h);
261 }
262 static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
263 				    u32 *l, u32 *h)
264 {
265 	return rdmsr_safe(msr_no, l, h);
266 }
267 static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
268 {
269 	return wrmsr_safe(msr_no, l, h);
270 }
271 static inline int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
272 {
273 	return rdmsrl_safe(msr_no, q);
274 }
275 static inline int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
276 {
277 	return wrmsrl_safe(msr_no, q);
278 }
279 static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
280 {
281 	return rdmsr_safe_regs(regs);
282 }
283 static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
284 {
285 	return wrmsr_safe_regs(regs);
286 }
287 #endif  /* CONFIG_SMP */
288 #endif /* __ASSEMBLY__ */
289 #endif /* _ASM_X86_MSR_H */
290