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1 #ifndef _ASM_X86_MSR_H
2 #define _ASM_X86_MSR_H
3 
4 #include "msr-index.h"
5 
6 #ifndef __ASSEMBLY__
7 
8 #include <asm/asm.h>
9 #include <asm/errno.h>
10 #include <asm/cpumask.h>
11 #include <uapi/asm/msr.h>
12 
13 struct msr {
14 	union {
15 		struct {
16 			u32 l;
17 			u32 h;
18 		};
19 		u64 q;
20 	};
21 };
22 
23 struct msr_info {
24 	u32 msr_no;
25 	struct msr reg;
26 	struct msr *msrs;
27 	int err;
28 };
29 
30 struct msr_regs_info {
31 	u32 *regs;
32 	int err;
33 };
34 
35 struct saved_msr {
36 	bool valid;
37 	struct msr_info info;
38 };
39 
40 struct saved_msrs {
41 	unsigned int num;
42 	struct saved_msr *array;
43 };
44 
native_read_tscp(unsigned int * aux)45 static inline unsigned long long native_read_tscp(unsigned int *aux)
46 {
47 	unsigned long low, high;
48 	asm volatile(".byte 0x0f,0x01,0xf9"
49 		     : "=a" (low), "=d" (high), "=c" (*aux));
50 	return low | ((u64)high << 32);
51 }
52 
53 /*
54  * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
55  * constraint has different meanings. For i386, "A" means exactly
56  * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead,
57  * it means rax *or* rdx.
58  */
59 #ifdef CONFIG_X86_64
60 /* Using 64-bit values saves one instruction clearing the high half of low */
61 #define DECLARE_ARGS(val, low, high)	unsigned long low, high
62 #define EAX_EDX_VAL(val, low, high)	((low) | (high) << 32)
63 #define EAX_EDX_RET(val, low, high)	"=a" (low), "=d" (high)
64 #else
65 #define DECLARE_ARGS(val, low, high)	unsigned long long val
66 #define EAX_EDX_VAL(val, low, high)	(val)
67 #define EAX_EDX_RET(val, low, high)	"=A" (val)
68 #endif
69 
native_read_msr(unsigned int msr)70 static inline unsigned long long native_read_msr(unsigned int msr)
71 {
72 	DECLARE_ARGS(val, low, high);
73 
74 	asm volatile("rdmsr" : EAX_EDX_RET(val, low, high) : "c" (msr));
75 	return EAX_EDX_VAL(val, low, high);
76 }
77 
native_read_msr_safe(unsigned int msr,int * err)78 static inline unsigned long long native_read_msr_safe(unsigned int msr,
79 						      int *err)
80 {
81 	DECLARE_ARGS(val, low, high);
82 
83 	asm volatile("2: rdmsr ; xor %[err],%[err]\n"
84 		     "1:\n\t"
85 		     ".section .fixup,\"ax\"\n\t"
86 		     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
87 		     ".previous\n\t"
88 		     _ASM_EXTABLE(2b, 3b)
89 		     : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
90 		     : "c" (msr), [fault] "i" (-EIO));
91 	return EAX_EDX_VAL(val, low, high);
92 }
93 
native_write_msr(unsigned int msr,unsigned low,unsigned high)94 static inline void native_write_msr(unsigned int msr,
95 				    unsigned low, unsigned high)
96 {
97 	asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high) : "memory");
98 }
99 
100 /* Can be uninlined because referenced by paravirt */
native_write_msr_safe(unsigned int msr,unsigned low,unsigned high)101 notrace static inline int native_write_msr_safe(unsigned int msr,
102 					unsigned low, unsigned high)
103 {
104 	int err;
105 	asm volatile("2: wrmsr ; xor %[err],%[err]\n"
106 		     "1:\n\t"
107 		     ".section .fixup,\"ax\"\n\t"
108 		     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
109 		     ".previous\n\t"
110 		     _ASM_EXTABLE(2b, 3b)
111 		     : [err] "=a" (err)
112 		     : "c" (msr), "0" (low), "d" (high),
113 		       [fault] "i" (-EIO)
114 		     : "memory");
115 	return err;
116 }
117 
118 extern int rdmsr_safe_regs(u32 regs[8]);
119 extern int wrmsr_safe_regs(u32 regs[8]);
120 
121 /**
122  * rdtsc() - returns the current TSC without ordering constraints
123  *
124  * rdtsc() returns the result of RDTSC as a 64-bit integer.  The
125  * only ordering constraint it supplies is the ordering implied by
126  * "asm volatile": it will put the RDTSC in the place you expect.  The
127  * CPU can and will speculatively execute that RDTSC, though, so the
128  * results can be non-monotonic if compared on different CPUs.
129  */
rdtsc(void)130 static __always_inline unsigned long long rdtsc(void)
131 {
132 	DECLARE_ARGS(val, low, high);
133 
134 	asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
135 
136 	return EAX_EDX_VAL(val, low, high);
137 }
138 
139 /**
140  * rdtsc_ordered() - read the current TSC in program order
141  *
142  * rdtsc_ordered() returns the result of RDTSC as a 64-bit integer.
143  * It is ordered like a load to a global in-memory counter.  It should
144  * be impossible to observe non-monotonic rdtsc_unordered() behavior
145  * across multiple CPUs as long as the TSC is synced.
146  */
rdtsc_ordered(void)147 static __always_inline unsigned long long rdtsc_ordered(void)
148 {
149 	/*
150 	 * The RDTSC instruction is not ordered relative to memory
151 	 * access.  The Intel SDM and the AMD APM are both vague on this
152 	 * point, but empirically an RDTSC instruction can be
153 	 * speculatively executed before prior loads.  An RDTSC
154 	 * immediately after an appropriate barrier appears to be
155 	 * ordered as a normal load, that is, it provides the same
156 	 * ordering guarantees as reading from a global memory location
157 	 * that some other imaginary CPU is updating continuously with a
158 	 * time stamp.
159 	 */
160 	barrier_nospec();
161 	return rdtsc();
162 }
163 
164 /* Deprecated, keep it for a cycle for easier merging: */
165 #define rdtscll(now)	do { (now) = rdtsc_ordered(); } while (0)
166 
native_read_pmc(int counter)167 static inline unsigned long long native_read_pmc(int counter)
168 {
169 	DECLARE_ARGS(val, low, high);
170 
171 	asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
172 	return EAX_EDX_VAL(val, low, high);
173 }
174 
175 #ifdef CONFIG_PARAVIRT
176 #include <asm/paravirt.h>
177 #else
178 #include <linux/errno.h>
179 /*
180  * Access to machine-specific registers (available on 586 and better only)
181  * Note: the rd* operations modify the parameters directly (without using
182  * pointer indirection), this allows gcc to optimize better
183  */
184 
185 #define rdmsr(msr, low, high)					\
186 do {								\
187 	u64 __val = native_read_msr((msr));			\
188 	(void)((low) = (u32)__val);				\
189 	(void)((high) = (u32)(__val >> 32));			\
190 } while (0)
191 
wrmsr(unsigned msr,unsigned low,unsigned high)192 static inline void wrmsr(unsigned msr, unsigned low, unsigned high)
193 {
194 	native_write_msr(msr, low, high);
195 }
196 
197 #define rdmsrl(msr, val)			\
198 	((val) = native_read_msr((msr)))
199 
wrmsrl(unsigned msr,u64 val)200 static inline void wrmsrl(unsigned msr, u64 val)
201 {
202 	native_write_msr(msr, (u32)val, (u32)(val >> 32));
203 }
204 
205 /* wrmsr with exception handling */
wrmsr_safe(unsigned msr,unsigned low,unsigned high)206 static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
207 {
208 	return native_write_msr_safe(msr, low, high);
209 }
210 
211 /* rdmsr with exception handling */
212 #define rdmsr_safe(msr, low, high)				\
213 ({								\
214 	int __err;						\
215 	u64 __val = native_read_msr_safe((msr), &__err);	\
216 	(*low) = (u32)__val;					\
217 	(*high) = (u32)(__val >> 32);				\
218 	__err;							\
219 })
220 
rdmsrl_safe(unsigned msr,unsigned long long * p)221 static inline int rdmsrl_safe(unsigned msr, unsigned long long *p)
222 {
223 	int err;
224 
225 	*p = native_read_msr_safe(msr, &err);
226 	return err;
227 }
228 
229 #define rdpmc(counter, low, high)			\
230 do {							\
231 	u64 _l = native_read_pmc((counter));		\
232 	(low)  = (u32)_l;				\
233 	(high) = (u32)(_l >> 32);			\
234 } while (0)
235 
236 #define rdpmcl(counter, val) ((val) = native_read_pmc(counter))
237 
238 #endif	/* !CONFIG_PARAVIRT */
239 
240 /*
241  * 64-bit version of wrmsr_safe():
242  */
wrmsrl_safe(u32 msr,u64 val)243 static inline int wrmsrl_safe(u32 msr, u64 val)
244 {
245 	return wrmsr_safe(msr, (u32)val,  (u32)(val >> 32));
246 }
247 
248 #define write_tsc(low, high) wrmsr(MSR_IA32_TSC, (low), (high))
249 
250 #define write_rdtscp_aux(val) wrmsr(MSR_TSC_AUX, (val), 0)
251 
252 struct msr *msrs_alloc(void);
253 void msrs_free(struct msr *msrs);
254 int msr_set_bit(u32 msr, u8 bit);
255 int msr_clear_bit(u32 msr, u8 bit);
256 
257 #ifdef CONFIG_SMP
258 int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
259 int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
260 int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
261 int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
262 void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
263 void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
264 int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
265 int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
266 int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
267 int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
268 int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
269 int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
270 #else  /*  CONFIG_SMP  */
rdmsr_on_cpu(unsigned int cpu,u32 msr_no,u32 * l,u32 * h)271 static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
272 {
273 	rdmsr(msr_no, *l, *h);
274 	return 0;
275 }
wrmsr_on_cpu(unsigned int cpu,u32 msr_no,u32 l,u32 h)276 static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
277 {
278 	wrmsr(msr_no, l, h);
279 	return 0;
280 }
rdmsrl_on_cpu(unsigned int cpu,u32 msr_no,u64 * q)281 static inline int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
282 {
283 	rdmsrl(msr_no, *q);
284 	return 0;
285 }
wrmsrl_on_cpu(unsigned int cpu,u32 msr_no,u64 q)286 static inline int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
287 {
288 	wrmsrl(msr_no, q);
289 	return 0;
290 }
rdmsr_on_cpus(const struct cpumask * m,u32 msr_no,struct msr * msrs)291 static inline void rdmsr_on_cpus(const struct cpumask *m, u32 msr_no,
292 				struct msr *msrs)
293 {
294        rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h));
295 }
wrmsr_on_cpus(const struct cpumask * m,u32 msr_no,struct msr * msrs)296 static inline void wrmsr_on_cpus(const struct cpumask *m, u32 msr_no,
297 				struct msr *msrs)
298 {
299        wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h);
300 }
rdmsr_safe_on_cpu(unsigned int cpu,u32 msr_no,u32 * l,u32 * h)301 static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
302 				    u32 *l, u32 *h)
303 {
304 	return rdmsr_safe(msr_no, l, h);
305 }
wrmsr_safe_on_cpu(unsigned int cpu,u32 msr_no,u32 l,u32 h)306 static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
307 {
308 	return wrmsr_safe(msr_no, l, h);
309 }
rdmsrl_safe_on_cpu(unsigned int cpu,u32 msr_no,u64 * q)310 static inline int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
311 {
312 	return rdmsrl_safe(msr_no, q);
313 }
wrmsrl_safe_on_cpu(unsigned int cpu,u32 msr_no,u64 q)314 static inline int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
315 {
316 	return wrmsrl_safe(msr_no, q);
317 }
rdmsr_safe_regs_on_cpu(unsigned int cpu,u32 regs[8])318 static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
319 {
320 	return rdmsr_safe_regs(regs);
321 }
wrmsr_safe_regs_on_cpu(unsigned int cpu,u32 regs[8])322 static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
323 {
324 	return wrmsr_safe_regs(regs);
325 }
326 #endif  /* CONFIG_SMP */
327 #endif /* __ASSEMBLY__ */
328 #endif /* _ASM_X86_MSR_H */
329