[PATCH 06/20] x86/msr: Standardize on 'u32' MSR indices in <asm/msr.h>

From: Ingo Molnar
Date: Wed Apr 09 2025 - 16:31:18 EST


This is the customary type used for hardware ABIs.

Suggested-by: Xin Li <xin@xxxxxxxxx>
Suggested-by: "H. Peter Anvin" <hpa@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/msr.h | 29 ++++++++++++++---------------
arch/x86/lib/msr.c | 4 ++--
2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index ec5c873a83a1..2f5a661719a4 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -63,12 +63,12 @@ struct saved_msrs {
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_write_msr(u32 msr, u64 val, int failed);
+extern void do_trace_read_msr(u32 msr, u64 val, int failed);
extern void do_trace_rdpmc(u32 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_write_msr(u32 msr, u64 val, int failed) {}
+static inline void do_trace_read_msr(u32 msr, u64 val, int failed) {}
static inline void do_trace_rdpmc(u32 msr, u64 val, int failed) {}
#endif

@@ -79,7 +79,7 @@ static inline void do_trace_rdpmc(u32 msr, u64 val, int failed) {}
* 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 u64 __rdmsr(unsigned int msr)
+static __always_inline u64 __rdmsr(u32 msr)
{
DECLARE_ARGS(val, low, high);

@@ -91,7 +91,7 @@ static __always_inline u64 __rdmsr(unsigned int msr)
return EAX_EDX_VAL(val, low, high);
}

-static __always_inline void __wrmsr(unsigned int msr, u32 low, u32 high)
+static __always_inline void __wrmsr(u32 msr, u32 low, u32 high)
{
asm volatile("1: wrmsr\n"
"2:\n"
@@ -113,7 +113,7 @@ do { \
__wrmsr((msr), (u32)((u64)(val)), \
(u32)((u64)(val) >> 32))

-static inline u64 native_read_msr(unsigned int msr)
+static inline u64 native_read_msr(u32 msr)
{
u64 val;

@@ -125,8 +125,7 @@ static inline u64 native_read_msr(unsigned int msr)
return val;
}

-static inline u64 native_read_msr_safe(unsigned int msr,
- int *err)
+static inline u64 native_read_msr_safe(u32 msr, int *err)
{
DECLARE_ARGS(val, low, high);

@@ -142,7 +141,7 @@ static inline u64 native_read_msr_safe(unsigned int msr,

/* Can be uninlined because referenced by paravirt */
static inline void notrace
-native_write_msr(unsigned int msr, u32 low, u32 high)
+native_write_msr(u32 msr, u32 low, u32 high)
{
__wrmsr(msr, low, high);

@@ -152,7 +151,7 @@ native_write_msr(unsigned int msr, u32 low, u32 high)

/* Can be uninlined because referenced by paravirt */
static inline int notrace
-native_write_msr_safe(unsigned int msr, u32 low, u32 high)
+native_write_msr_safe(u32 msr, u32 low, u32 high)
{
int err;

@@ -251,7 +250,7 @@ do { \
(void)((high) = (u32)(__val >> 32)); \
} while (0)

-static inline void wrmsr(unsigned int msr, u32 low, u32 high)
+static inline void wrmsr(u32 msr, u32 low, u32 high)
{
native_write_msr(msr, low, high);
}
@@ -259,13 +258,13 @@ static inline void wrmsr(unsigned int msr, u32 low, u32 high)
#define rdmsrl(msr, val) \
((val) = native_read_msr((msr)))

-static inline void wrmsrl(unsigned int msr, u64 val)
+static inline void wrmsrl(u32 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)
+static inline int wrmsr_safe(u32 msr, u32 low, u32 high)
{
return native_write_msr_safe(msr, low, high);
}
@@ -280,7 +279,7 @@ static inline int wrmsr_safe(unsigned int msr, u32 low, u32 high)
__err; \
})

-static inline int rdmsrl_safe(unsigned int msr, u64 *p)
+static inline int rdmsrl_safe(u32 msr, u64 *p)
{
int err;

diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c
index 20f5c36e5fde..7b90f547b109 100644
--- a/arch/x86/lib/msr.c
+++ b/arch/x86/lib/msr.c
@@ -122,14 +122,14 @@ int msr_clear_bit(u32 msr, u8 bit)
EXPORT_SYMBOL_GPL(msr_clear_bit);

#ifdef CONFIG_TRACEPOINTS
-void do_trace_write_msr(unsigned int msr, u64 val, int failed)
+void do_trace_write_msr(u32 msr, u64 val, int failed)
{
trace_write_msr(msr, val, failed);
}
EXPORT_SYMBOL(do_trace_write_msr);
EXPORT_TRACEPOINT_SYMBOL(write_msr);

-void do_trace_read_msr(unsigned int msr, u64 val, int failed)
+void do_trace_read_msr(u32 msr, u64 val, int failed)
{
trace_read_msr(msr, val, failed);
}
--
2.45.2