include/asm/msr.h

1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include "msr-index.h"
38  * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
44 /* Using 64-bit values saves one instruction clearing the high half of low */
45 #define DECLARE_ARGS(val, low, high)	unsigned long low, high  argument
46 #define EAX_EDX_VAL(val, low, high)	((low) | (high) << 32)  argument
47 #define EAX_EDX_RET(val, low, high)	"=a" (low), "=d" (high)  argument
49 #define DECLARE_ARGS(val, low, high)	unsigned long long val  argument
50 #define EAX_EDX_VAL(val, low, high)	(val)  argument
51 #define EAX_EDX_RET(val, low, high)	"=A" (val)  argument
55  * Be very careful with includes. This header is prone to include loops.
58 #include <linux/tracepoint-defs.h>
76  * on them - those are *purely* for accessing MSRs and nothing more. So don't even
77  * think of extending them - you will be slapped with a stinking trout or a frozen
82 	DECLARE_ARGS(val, low, high);  in __rdmsr()
87 		     : EAX_EDX_RET(val, low, high) : "c" (msr));  in __rdmsr()
89 	return EAX_EDX_VAL(val, low, high);  in __rdmsr()
92 static __always_inline void __wrmsr(unsigned int msr, u32 low, u32 high)  in __wrmsr()  argument
97 		     : : "c" (msr), "a"(low), "d" (high) : "memory");  in __wrmsr()
107 #define native_wrmsr(msr, low, high)			\  argument
108 	__wrmsr(msr, low, high)
129 	DECLARE_ARGS(val, low, high);  in native_read_msr_safe()
134 		     : [err] "=r" (*err), EAX_EDX_RET(val, low, high)  in native_read_msr_safe()
137 		do_trace_read_msr(msr, EAX_EDX_VAL(val, low, high), *err);  in native_read_msr_safe()
138 	return EAX_EDX_VAL(val, low, high);  in native_read_msr_safe()
143 native_write_msr(unsigned int msr, u32 low, u32 high)  in native_write_msr()  argument
145 	__wrmsr(msr, low, high);  in native_write_msr()
148 		do_trace_write_msr(msr, ((u64)high << 32 | low), 0);  in native_write_msr()
153 native_write_msr_safe(unsigned int msr, u32 low, u32 high)  in native_write_msr_safe()  argument
161 		     : "c" (msr), "0" (low), "d" (high)  in native_write_msr_safe()
164 		do_trace_write_msr(msr, ((u64)high << 32 | low), err);  in native_write_msr_safe()
172  * rdtsc() - returns the current TSC without ordering constraints
174  * rdtsc() returns the result of RDTSC as a 64-bit integer.  The
178  * results can be non-monotonic if compared on different CPUs.
182 	DECLARE_ARGS(val, low, high);  in rdtsc()
184 	asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));  in rdtsc()
186 	return EAX_EDX_VAL(val, low, high);  in rdtsc()
190  * rdtsc_ordered() - read the current TSC in program order
192  * rdtsc_ordered() returns the result of RDTSC as a 64-bit integer.
193  * It is ordered like a load to a global in-memory counter.  It should
194  * be impossible to observe non-monotonic rdtsc_unordered() behavior
199 	DECLARE_ARGS(val, low, high);  in rdtsc_ordered()
202 	 * The RDTSC instruction is not ordered relative to memory  in rdtsc_ordered()
206 	 * immediately after an appropriate barrier appears to be  in rdtsc_ordered()
218 			: EAX_EDX_RET(val, low, high)  in rdtsc_ordered()
222 	return EAX_EDX_VAL(val, low, high);  in rdtsc_ordered()
227 	DECLARE_ARGS(val, low, high);  in native_read_pmc()
229 	asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));  in native_read_pmc()
231 		do_trace_rdpmc(counter, EAX_EDX_VAL(val, low, high), 0);  in native_read_pmc()
232 	return EAX_EDX_VAL(val, low, high);  in native_read_pmc()
240  * Access to machine-specific registers (available on 586 and better only)
242  * pointer indirection), this allows gcc to optimize better
245 #define rdmsr(msr, low, high)					\  argument
248 	(void)((low) = (u32)__val);				\
249 	(void)((high) = (u32)(__val >> 32));			\
252 static inline void wrmsr(unsigned int msr, u32 low, u32 high)  in wrmsr()  argument
254 	native_write_msr(msr, low, high);  in wrmsr()
266 static inline int wrmsr_safe(unsigned int msr, u32 low, u32 high)  in wrmsr_safe()  argument
268 	return native_write_msr_safe(msr, low, high);  in wrmsr_safe()
272 #define rdmsr_safe(msr, low, high)				\  argument
276 	(*low) = (u32)__val;					\
277 	(*high) = (u32)(__val >> 32);				\
289 #define rdpmc(counter, low, high)			\  argument
292 	(low)  = (u32)_l;				\
293 	(high) = (u32)(_l >> 32);			\
301  * 64-bit version of wrmsr_safe():