xref: /openbmc/linux/arch/x86/include/asm/msr.h (revision 95e9fd10)
1 #ifndef _ASM_X86_MSR_H
2 #define _ASM_X86_MSR_H
3 
4 #include <asm/msr-index.h>
5 
6 #ifndef __ASSEMBLY__
7 
8 #include <linux/types.h>
9 #include <linux/ioctl.h>
10 
11 #define X86_IOC_RDMSR_REGS	_IOWR('c', 0xA0, __u32[8])
12 #define X86_IOC_WRMSR_REGS	_IOWR('c', 0xA1, __u32[8])
13 
14 #ifdef __KERNEL__
15 
16 #include <asm/asm.h>
17 #include <asm/errno.h>
18 #include <asm/cpumask.h>
19 
20 struct msr {
21 	union {
22 		struct {
23 			u32 l;
24 			u32 h;
25 		};
26 		u64 q;
27 	};
28 };
29 
30 struct msr_info {
31 	u32 msr_no;
32 	struct msr reg;
33 	struct msr *msrs;
34 	int err;
35 };
36 
37 struct msr_regs_info {
38 	u32 *regs;
39 	int err;
40 };
41 
42 static inline unsigned long long native_read_tscp(unsigned int *aux)
43 {
44 	unsigned long low, high;
45 	asm volatile(".byte 0x0f,0x01,0xf9"
46 		     : "=a" (low), "=d" (high), "=c" (*aux));
47 	return low | ((u64)high << 32);
48 }
49 
50 /*
51  * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
52  * constraint has different meanings. For i386, "A" means exactly
53  * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead,
54  * it means rax *or* rdx.
55  */
56 #ifdef CONFIG_X86_64
57 #define DECLARE_ARGS(val, low, high)	unsigned low, high
58 #define EAX_EDX_VAL(val, low, high)	((low) | ((u64)(high) << 32))
59 #define EAX_EDX_ARGS(val, low, high)	"a" (low), "d" (high)
60 #define EAX_EDX_RET(val, low, high)	"=a" (low), "=d" (high)
61 #else
62 #define DECLARE_ARGS(val, low, high)	unsigned long long val
63 #define EAX_EDX_VAL(val, low, high)	(val)
64 #define EAX_EDX_ARGS(val, low, high)	"A" (val)
65 #define EAX_EDX_RET(val, low, high)	"=A" (val)
66 #endif
67 
68 static inline unsigned long long native_read_msr(unsigned int msr)
69 {
70 	DECLARE_ARGS(val, low, high);
71 
72 	asm volatile("rdmsr" : EAX_EDX_RET(val, low, high) : "c" (msr));
73 	return EAX_EDX_VAL(val, low, high);
74 }
75 
76 static inline unsigned long long native_read_msr_safe(unsigned int msr,
77 						      int *err)
78 {
79 	DECLARE_ARGS(val, low, high);
80 
81 	asm volatile("2: rdmsr ; xor %[err],%[err]\n"
82 		     "1:\n\t"
83 		     ".section .fixup,\"ax\"\n\t"
84 		     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
85 		     ".previous\n\t"
86 		     _ASM_EXTABLE(2b, 3b)
87 		     : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
88 		     : "c" (msr), [fault] "i" (-EIO));
89 	return EAX_EDX_VAL(val, low, high);
90 }
91 
92 static inline void native_write_msr(unsigned int msr,
93 				    unsigned low, unsigned high)
94 {
95 	asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory");
96 }
97 
98 /* Can be uninlined because referenced by paravirt */
99 notrace static inline int native_write_msr_safe(unsigned int msr,
100 					unsigned low, unsigned high)
101 {
102 	int err;
103 	asm volatile("2: wrmsr ; xor %[err],%[err]\n"
104 		     "1:\n\t"
105 		     ".section .fixup,\"ax\"\n\t"
106 		     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
107 		     ".previous\n\t"
108 		     _ASM_EXTABLE(2b, 3b)
109 		     : [err] "=a" (err)
110 		     : "c" (msr), "0" (low), "d" (high),
111 		       [fault] "i" (-EIO)
112 		     : "memory");
113 	return err;
114 }
115 
116 extern unsigned long long native_read_tsc(void);
117 
118 extern int rdmsr_safe_regs(u32 regs[8]);
119 extern int wrmsr_safe_regs(u32 regs[8]);
120 
121 static __always_inline unsigned long long __native_read_tsc(void)
122 {
123 	DECLARE_ARGS(val, low, high);
124 
125 	asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
126 
127 	return EAX_EDX_VAL(val, low, high);
128 }
129 
130 static inline unsigned long long native_read_pmc(int counter)
131 {
132 	DECLARE_ARGS(val, low, high);
133 
134 	asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
135 	return EAX_EDX_VAL(val, low, high);
136 }
137 
138 #ifdef CONFIG_PARAVIRT
139 #include <asm/paravirt.h>
140 #else
141 #include <linux/errno.h>
142 /*
143  * Access to machine-specific registers (available on 586 and better only)
144  * Note: the rd* operations modify the parameters directly (without using
145  * pointer indirection), this allows gcc to optimize better
146  */
147 
148 #define rdmsr(msr, val1, val2)					\
149 do {								\
150 	u64 __val = native_read_msr((msr));			\
151 	(void)((val1) = (u32)__val);				\
152 	(void)((val2) = (u32)(__val >> 32));			\
153 } while (0)
154 
155 static inline void wrmsr(unsigned msr, unsigned low, unsigned high)
156 {
157 	native_write_msr(msr, low, high);
158 }
159 
160 #define rdmsrl(msr, val)			\
161 	((val) = native_read_msr((msr)))
162 
163 #define wrmsrl(msr, val)						\
164 	native_write_msr((msr), (u32)((u64)(val)), (u32)((u64)(val) >> 32))
165 
166 /* wrmsr with exception handling */
167 static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
168 {
169 	return native_write_msr_safe(msr, low, high);
170 }
171 
172 /* rdmsr with exception handling */
173 #define rdmsr_safe(msr, p1, p2)					\
174 ({								\
175 	int __err;						\
176 	u64 __val = native_read_msr_safe((msr), &__err);	\
177 	(*p1) = (u32)__val;					\
178 	(*p2) = (u32)(__val >> 32);				\
179 	__err;							\
180 })
181 
182 static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
183 {
184 	int err;
185 
186 	*p = native_read_msr_safe(msr, &err);
187 	return err;
188 }
189 
190 #define rdtscl(low)						\
191 	((low) = (u32)__native_read_tsc())
192 
193 #define rdtscll(val)						\
194 	((val) = __native_read_tsc())
195 
196 #define rdpmc(counter, low, high)			\
197 do {							\
198 	u64 _l = native_read_pmc((counter));		\
199 	(low)  = (u32)_l;				\
200 	(high) = (u32)(_l >> 32);			\
201 } while (0)
202 
203 #define rdpmcl(counter, val) ((val) = native_read_pmc(counter))
204 
205 #define rdtscp(low, high, aux)					\
206 do {                                                            \
207 	unsigned long long _val = native_read_tscp(&(aux));     \
208 	(low) = (u32)_val;                                      \
209 	(high) = (u32)(_val >> 32);                             \
210 } while (0)
211 
212 #define rdtscpll(val, aux) (val) = native_read_tscp(&(aux))
213 
214 #endif	/* !CONFIG_PARAVIRT */
215 
216 #define wrmsrl_safe(msr, val) wrmsr_safe((msr), (u32)(val),		\
217 					     (u32)((val) >> 32))
218 
219 #define write_tsc(val1, val2) wrmsr(MSR_IA32_TSC, (val1), (val2))
220 
221 #define write_rdtscp_aux(val) wrmsr(MSR_TSC_AUX, (val), 0)
222 
223 struct msr *msrs_alloc(void);
224 void msrs_free(struct msr *msrs);
225 
226 #ifdef CONFIG_SMP
227 int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
228 int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
229 void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
230 void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
231 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
232 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
233 int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
234 int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
235 #else  /*  CONFIG_SMP  */
236 static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
237 {
238 	rdmsr(msr_no, *l, *h);
239 	return 0;
240 }
241 static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
242 {
243 	wrmsr(msr_no, l, h);
244 	return 0;
245 }
246 static inline void rdmsr_on_cpus(const struct cpumask *m, u32 msr_no,
247 				struct msr *msrs)
248 {
249        rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h));
250 }
251 static inline void wrmsr_on_cpus(const struct cpumask *m, u32 msr_no,
252 				struct msr *msrs)
253 {
254        wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h);
255 }
256 static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
257 				    u32 *l, u32 *h)
258 {
259 	return rdmsr_safe(msr_no, l, h);
260 }
261 static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
262 {
263 	return wrmsr_safe(msr_no, l, h);
264 }
265 static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
266 {
267 	return rdmsr_safe_regs(regs);
268 }
269 static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
270 {
271 	return wrmsr_safe_regs(regs);
272 }
273 #endif  /* CONFIG_SMP */
274 #endif /* __KERNEL__ */
275 #endif /* __ASSEMBLY__ */
276 #endif /* _ASM_X86_MSR_H */
277