Commit 1ae899e4 authored by Uros Bizjak's avatar Uros Bizjak Committed by Ingo Molnar
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x86/idle: Standardize argument types for MONITOR{,X} and MWAIT{,X} instruction wrappers on 'u32' 



MONITOR and MONITORX expect 32-bit unsigned integer arguments in the %ecx
and %edx registers. MWAIT and MWAITX expect 32-bit usigned int
argument in %eax and %ecx registers.

Some of the helpers around these instructions in <asm/mwait.h> are using
too wide types (long), standardize on u32 instead that makes it clear that
this is a hardware ABI.

[ mingo: Cleaned up the changelog. ]

Signed-off-by: default avatarUros Bizjak <ubizjak@gmail.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250402180827.3762-1-ubizjak@gmail.com
parent 1f13c60d

arch/x86/include/asm/mwait.h

+5 −8
Original line number Diff line number Diff line
@@ -25,23 +25,21 @@ 
#define TPAUSE_C01_STATE		1

#define TPAUSE_C02_STATE		0



static __always_inline void __monitor(const void *eax, unsigned long ecx,

			     unsigned long edx)

static __always_inline void __monitor(const void *eax, u32 ecx, u32 edx)

{

	/* "monitor %eax, %ecx, %edx;" */

	asm volatile(".byte 0x0f, 0x01, 0xc8;"

		     :: "a" (eax), "c" (ecx), "d"(edx));

}



static __always_inline void __monitorx(const void *eax, unsigned long ecx,

			      unsigned long edx)

static __always_inline void __monitorx(const void *eax, u32 ecx, u32 edx)

{

	/* "monitorx %eax, %ecx, %edx;" */

	asm volatile(".byte 0x0f, 0x01, 0xfa;"

		     :: "a" (eax), "c" (ecx), "d"(edx));

}



static __always_inline void __mwait(unsigned long eax, unsigned long ecx)

static __always_inline void __mwait(u32 eax, u32 ecx)

{

	mds_idle_clear_cpu_buffers();
@@ -76,8 +74,7 @@ static __always_inline void __mwait(unsigned long eax, unsigned long ecx) 
 * EAX                     (logical) address to monitor

 * ECX                     #GP if not zero

 */

static __always_inline void __mwaitx(unsigned long eax, unsigned long ebx,

				     unsigned long ecx)

static __always_inline void __mwaitx(u32 eax, u32 ebx, u32 ecx)

{

	/* No MDS buffer clear as this is AMD/HYGON only */
@@ -95,7 +92,7 @@ static __always_inline void __mwaitx(unsigned long eax, unsigned long ebx, 
 * executing mwait, it would otherwise go unnoticed and the next tick

 * would not be reprogrammed accordingly before mwait ever wakes up.

 */

static __always_inline void __sti_mwait(unsigned long eax, unsigned long ecx)

static __always_inline void __sti_mwait(u32 eax, u32 ecx)

{

	mds_idle_clear_cpu_buffers();

	/* "mwait %eax, %ecx;" */