1 files changed, 407 insertions, 0 deletions
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
new file mode 100644
index 000000000..e16cccdd0
--- /dev/null
+++ b/arch/x86/include/asm/msr.h
@@ -0,0 +1,407 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_MSR_H
+#define _ASM_X86_MSR_H
+
+#include "msr-index.h"
+
+#ifndef __ASSEMBLY__
+
+#include <asm/asm.h>
+#include <asm/errno.h>
+#include <asm/cpumask.h>
+#include <uapi/asm/msr.h>
+
+struct msr {
+	union {
+		struct {
+			u32 l;
+			u32 h;
+		};
+		u64 q;
+	};
+};
+
+struct msr_info {
+	u32 msr_no;
+	struct msr reg;
+	struct msr *msrs;
+	int err;
+};
+
+struct msr_regs_info {
+	u32 *regs;
+	int err;
+};
+
+struct saved_msr {
+	bool valid;
+	struct msr_info info;
+};
+
+struct saved_msrs {
+	unsigned int num;
+	struct saved_msr *array;
+};
+
+/*
+ * both i386 and x86_64 returns 64-bit value in edx:eax, but gcc's "A"
+ * constraint has different meanings. For i386, "A" means exactly
+ * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead,
+ * it means rax *or* rdx.
+ */
+#ifdef CONFIG_X86_64
+/* Using 64-bit values saves one instruction clearing the high half of low */
+#define DECLARE_ARGS(val, low, high)	unsigned long low, high
+#define EAX_EDX_VAL(val, low, high)	((low) | (high) << 32)
+#define EAX_EDX_RET(val, low, high)	"=a" (low), "=d" (high)
+#else
+#define DECLARE_ARGS(val, low, high)	unsigned long long val
+#define EAX_EDX_VAL(val, low, high)	(val)
+#define EAX_EDX_RET(val, low, high)	"=A" (val)
+#endif
+
+/*
+ * Be very careful with includes. This header is prone to include loops.
+ */
+#include <asm/atomic.h>
+#include <linux/tracepoint-defs.h>
+
+#ifdef CONFIG_TRACEPOINTS
+DECLARE_TRACEPOINT(read_msr);
+DECLARE_TRACEPOINT(write_msr);
+DECLARE_TRACEPOINT(rdpmc);
+extern void do_trace_write_msr(unsigned int msr, u64 val, int failed);
+extern void do_trace_read_msr(unsigned int msr, u64 val, int failed);
+extern void do_trace_rdpmc(unsigned int msr, u64 val, int failed);
+#else
+static inline void do_trace_write_msr(unsigned int msr, u64 val, int failed) {}
+static inline void do_trace_read_msr(unsigned int msr, u64 val, int failed) {}
+static inline void do_trace_rdpmc(unsigned int msr, u64 val, int failed) {}
+#endif
+
+/*
+ * __rdmsr() and __wrmsr() are the two primitives which are the bare minimum MSR
+ * accessors and should not have any tracing or other functionality piggybacking
+ * on them - those are *purely* for accessing MSRs and nothing more. So don't even
+ * think of extending them - you will be slapped with a stinking trout or a frozen
+ * shark will reach you, wherever you are! You've been warned.
+ */
+static __always_inline unsigned long long __rdmsr(unsigned int msr)
+{
+	DECLARE_ARGS(val, low, high);
+
+	asm volatile("1: rdmsr\n"
+		     "2:\n"
+		     _ASM_EXTABLE_HANDLE(1b, 2b, ex_handler_rdmsr_unsafe)
+		     : EAX_EDX_RET(val, low, high) : "c" (msr));
+
+	return EAX_EDX_VAL(val, low, high);
+}
+
+static __always_inline void __wrmsr(unsigned int msr, u32 low, u32 high)
+{
+	asm volatile("1: wrmsr\n"
+		     "2:\n"
+		     _ASM_EXTABLE_HANDLE(1b, 2b, ex_handler_wrmsr_unsafe)
+		     : : "c" (msr), "a"(low), "d" (high) : "memory");
+}
+
+#define native_rdmsr(msr, val1, val2)			\
+do {							\
+	u64 __val = __rdmsr((msr));			\
+	(void)((val1) = (u32)__val);			\
+	(void)((val2) = (u32)(__val >> 32));		\
+} while (0)
+
+#define native_wrmsr(msr, low, high)			\
+	__wrmsr(msr, low, high)
+
+#define native_wrmsrl(msr, val)				\
+	__wrmsr((msr), (u32)((u64)(val)),		\
+		       (u32)((u64)(val) >> 32))
+
+static inline unsigned long long native_read_msr(unsigned int msr)
+{
+	unsigned long long val;
+
+	val = __rdmsr(msr);
+
+	if (tracepoint_enabled(read_msr))
+		do_trace_read_msr(msr, val, 0);
+
+	return val;
+}
+
+static inline unsigned long long native_read_msr_safe(unsigned int msr,
+						      int *err)
+{
+	DECLARE_ARGS(val, low, high);
+
+	asm volatile("2: rdmsr ; xor %[err],%[err]\n"
+		     "1:\n\t"
+		     ".section .fixup,\"ax\"\n\t"
+		     "3: mov %[fault],%[err]\n\t"
+		     "xorl %%eax, %%eax\n\t"
+		     "xorl %%edx, %%edx\n\t"
+		     "jmp 1b\n\t"
+		     ".previous\n\t"
+		     _ASM_EXTABLE(2b, 3b)
+		     : [err] "=r" (*err), EAX_EDX_RET(val, low, high)
+		     : "c" (msr), [fault] "i" (-EIO));
+	if (tracepoint_enabled(read_msr))
+		do_trace_read_msr(msr, EAX_EDX_VAL(val, low, high), *err);
+	return EAX_EDX_VAL(val, low, high);
+}
+
+/* Can be uninlined because referenced by paravirt */
+static inline void notrace
+native_write_msr(unsigned int msr, u32 low, u32 high)
+{
+	__wrmsr(msr, low, high);
+
+	if (tracepoint_enabled(write_msr))
+		do_trace_write_msr(msr, ((u64)high << 32 | low), 0);
+}
+
+/* Can be uninlined because referenced by paravirt */
+static inline int notrace
+native_write_msr_safe(unsigned int msr, u32 low, u32 high)
+{
+	int err;
+
+	asm volatile("2: wrmsr ; xor %[err],%[err]\n"
+		     "1:\n\t"
+		     ".section .fixup,\"ax\"\n\t"
+		     "3:  mov %[fault],%[err] ; jmp 1b\n\t"
+		     ".previous\n\t"
+		     _ASM_EXTABLE(2b, 3b)
+		     : [err] "=a" (err)
+		     : "c" (msr), "0" (low), "d" (high),
+		       [fault] "i" (-EIO)
+		     : "memory");
+	if (tracepoint_enabled(write_msr))
+		do_trace_write_msr(msr, ((u64)high << 32 | low), err);
+	return err;
+}
+
+extern int rdmsr_safe_regs(u32 regs[8]);
+extern int wrmsr_safe_regs(u32 regs[8]);
+
+/**
+ * rdtsc() - returns the current TSC without ordering constraints
+ *
+ * rdtsc() returns the result of RDTSC as a 64-bit integer.  The
+ * only ordering constraint it supplies is the ordering implied by
+ * "asm volatile": it will put the RDTSC in the place you expect.  The
+ * CPU can and will speculatively execute that RDTSC, though, so the
+ * results can be non-monotonic if compared on different CPUs.
+ */
+static __always_inline unsigned long long rdtsc(void)
+{
+	DECLARE_ARGS(val, low, high);
+
+	asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
+
+	return EAX_EDX_VAL(val, low, high);
+}
+
+/**
+ * rdtsc_ordered() - read the current TSC in program order
+ *
+ * rdtsc_ordered() returns the result of RDTSC as a 64-bit integer.
+ * It is ordered like a load to a global in-memory counter.  It should
+ * be impossible to observe non-monotonic rdtsc_unordered() behavior
+ * across multiple CPUs as long as the TSC is synced.
+ */
+static __always_inline unsigned long long rdtsc_ordered(void)
+{
+	DECLARE_ARGS(val, low, high);
+
+	/*
+	 * The RDTSC instruction is not ordered relative to memory
+	 * access.  The Intel SDM and the AMD APM are both vague on this
+	 * point, but empirically an RDTSC instruction can be
+	 * speculatively executed before prior loads.  An RDTSC
+	 * immediately after an appropriate barrier appears to be
+	 * ordered as a normal load, that is, it provides the same
+	 * ordering guarantees as reading from a global memory location
+	 * that some other imaginary CPU is updating continuously with a
+	 * time stamp.
+	 *
+	 * Thus, use the preferred barrier on the respective CPU, aiming for
+	 * RDTSCP as the default.
+	 */
+	asm volatile(ALTERNATIVE_2("rdtsc",
+				   "lfence; rdtsc", X86_FEATURE_LFENCE_RDTSC,
+				   "rdtscp", X86_FEATURE_RDTSCP)
+			: EAX_EDX_RET(val, low, high)
+			/* RDTSCP clobbers ECX with MSR_TSC_AUX. */
+			:: "ecx");
+
+	return EAX_EDX_VAL(val, low, high);
+}
+
+static inline unsigned long long native_read_pmc(int counter)
+{
+	DECLARE_ARGS(val, low, high);
+
+	asm volatile("rdpmc" : EAX_EDX_RET(val, low, high) : "c" (counter));
+	if (tracepoint_enabled(rdpmc))
+		do_trace_rdpmc(counter, EAX_EDX_VAL(val, low, high), 0);
+	return EAX_EDX_VAL(val, low, high);
+}
+
+#ifdef CONFIG_PARAVIRT_XXL
+#include <asm/paravirt.h>
+#else
+#include <linux/errno.h>
+/*
+ * Access to machine-specific registers (available on 586 and better only)
+ * Note: the rd* operations modify the parameters directly (without using
+ * pointer indirection), this allows gcc to optimize better
+ */
+
+#define rdmsr(msr, low, high)					\
+do {								\
+	u64 __val = native_read_msr((msr));			\
+	(void)((low) = (u32)__val);				\
+	(void)((high) = (u32)(__val >> 32));			\
+} while (0)
+
+static inline void wrmsr(unsigned int msr, u32 low, u32 high)
+{
+	native_write_msr(msr, low, high);
+}
+
+#define rdmsrl(msr, val)			\
+	((val) = native_read_msr((msr)))
+
+static inline void wrmsrl(unsigned int msr, u64 val)
+{
+	native_write_msr(msr, (u32)(val & 0xffffffffULL), (u32)(val >> 32));
+}
+
+/* wrmsr with exception handling */
+static inline int wrmsr_safe(unsigned int msr, u32 low, u32 high)
+{
+	return native_write_msr_safe(msr, low, high);
+}
+
+/* rdmsr with exception handling */
+#define rdmsr_safe(msr, low, high)				\
+({								\
+	int __err;						\
+	u64 __val = native_read_msr_safe((msr), &__err);	\
+	(*low) = (u32)__val;					\
+	(*high) = (u32)(__val >> 32);				\
+	__err;							\
+})
+
+static inline int rdmsrl_safe(unsigned int msr, unsigned long long *p)
+{
+	int err;
+
+	*p = native_read_msr_safe(msr, &err);
+	return err;
+}
+
+#define rdpmc(counter, low, high)			\
+do {							\
+	u64 _l = native_read_pmc((counter));		\
+	(low)  = (u32)_l;				\
+	(high) = (u32)(_l >> 32);			\
+} while (0)
+
+#define rdpmcl(counter, val) ((val) = native_read_pmc(counter))
+
+#endif	/* !CONFIG_PARAVIRT_XXL */
+
+/*
+ * 64-bit version of wrmsr_safe():
+ */
+static inline int wrmsrl_safe(u32 msr, u64 val)
+{
+	return wrmsr_safe(msr, (u32)val,  (u32)(val >> 32));
+}
+
+#define write_tsc(low, high) wrmsr(MSR_IA32_TSC, (low), (high))
+
+#define write_rdtscp_aux(val) wrmsr(MSR_TSC_AUX, (val), 0)
+
+struct msr *msrs_alloc(void);
+void msrs_free(struct msr *msrs);
+int msr_set_bit(u32 msr, u8 bit);
+int msr_clear_bit(u32 msr, u8 bit);
+
+#ifdef CONFIG_SMP
+int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
+int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
+int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
+int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
+void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
+void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
+int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
+int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
+int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
+int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q);
+int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
+int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
+#else  /*  CONFIG_SMP  */
+static inline int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
+{
+	rdmsr(msr_no, *l, *h);
+	return 0;
+}
+static inline int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+{
+	wrmsr(msr_no, l, h);
+	return 0;
+}
+static inline int rdmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
+{
+	rdmsrl(msr_no, *q);
+	return 0;
+}
+static inline int wrmsrl_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
+{
+	wrmsrl(msr_no, q);
+	return 0;
+}
+static inline void rdmsr_on_cpus(const struct cpumask *m, u32 msr_no,
+				struct msr *msrs)
+{
+	rdmsr_on_cpu(0, msr_no, &(msrs[0].l), &(msrs[0].h));
+}
+static inline void wrmsr_on_cpus(const struct cpumask *m, u32 msr_no,
+				struct msr *msrs)
+{
+	wrmsr_on_cpu(0, msr_no, msrs[0].l, msrs[0].h);
+}
+static inline int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no,
+				    u32 *l, u32 *h)
+{
+	return rdmsr_safe(msr_no, l, h);
+}
+static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
+{
+	return wrmsr_safe(msr_no, l, h);
+}
+static inline int rdmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 *q)
+{
+	return rdmsrl_safe(msr_no, q);
+}
+static inline int wrmsrl_safe_on_cpu(unsigned int cpu, u32 msr_no, u64 q)
+{
+	return wrmsrl_safe(msr_no, q);
+}
+static inline int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
+{
+	return rdmsr_safe_regs(regs);
+}
+static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
+{
+	return wrmsr_safe_regs(regs);
+}
+#endif  /* CONFIG_SMP */
+#endif /* __ASSEMBLY__ */
+#endif /* _ASM_X86_MSR_H */