[PATCH 1/4] x86/asm: inline constant inputs in rdpkru(), wrpkru()
From: Alexey Dobriyan
Date: Fri Mar 07 2025 - 01:12:23 EST
Put immediate values directly into registers deleting dummy variables.
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---
arch/x86/include/asm/special_insns.h | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index 21ce480658b1..494a1aa19f05 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -79,7 +79,6 @@ void native_write_cr4(unsigned long val);
#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
static inline u32 rdpkru(void)
{
- u32 ecx = 0;
u32 edx, pkru;
/*
@@ -88,20 +87,18 @@ static inline u32 rdpkru(void)
*/
asm volatile(".byte 0x0f,0x01,0xee\n\t"
: "=a" (pkru), "=d" (edx)
- : "c" (ecx));
+ : "c" (0));
return pkru;
}
static inline void wrpkru(u32 pkru)
{
- u32 ecx = 0, edx = 0;
-
/*
* "wrpkru" instruction. Loads contents in EAX to PKRU,
* requires that ecx = edx = 0.
*/
asm volatile(".byte 0x0f,0x01,0xef\n\t"
- : : "a" (pkru), "c"(ecx), "d"(edx));
+ : : "a" (pkru), "c" (0), "d" (0));
}
#else
--
2.45.3