linux-kernel - [PATCH] x86/kexec: Merge x86_32 and x86

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Message-ID: <20250305162649.130270-1-ubizjak@gmail.com>
Date: Wed,  5 Mar 2025 17:26:37 +0100
From: Uros Bizjak <ubizjak@...il.com>
To: x86@...nel.org,
	linux-kernel@...r.kernel.org
Cc: Uros Bizjak <ubizjak@...il.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...nel.org>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	"H. Peter Anvin" <hpa@...or.com>
Subject: [PATCH] x86/kexec: Merge x86_32 and x86_64 code using macros from asm.h

Merge common x86_32 and x86_64 code in crash_setup_regs()
using macros from asm/asm.h.

The compiled object files before and after the patch are unchanged.

Signed-off-by: Uros Bizjak <ubizjak@...il.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: "H. Peter Anvin" <hpa@...or.com>
---
 arch/x86/include/asm/asm.h   |  2 ++
 arch/x86/include/asm/kexec.h | 44 +++++++++++++++---------------------
 2 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
index 975ae7a9397e..2bccc063d30b 100644
--- a/arch/x86/include/asm/asm.h
+++ b/arch/x86/include/asm/asm.h
@@ -41,6 +41,8 @@
 #define _ASM_SUB	__ASM_SIZE(sub)
 #define _ASM_XADD	__ASM_SIZE(xadd)
 #define _ASM_MUL	__ASM_SIZE(mul)
+#define _ASM_PUSHF	__ASM_SIZE(pushf)
+#define _ASM_POP	__ASM_SIZE(pop)
 
 #define _ASM_AX		__ASM_REG(ax)
 #define _ASM_BX		__ASM_REG(bx)
diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 8ad187462b68..56040ae6bda0 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -18,6 +18,7 @@
 #include <linux/string.h>
 #include <linux/kernel.h>
 
+#include <asm/asm.h>
 #include <asm/page.h>
 #include <asm/ptrace.h>
 
@@ -71,29 +72,15 @@ static inline void crash_setup_regs(struct pt_regs *newregs,
 	if (oldregs) {
 		memcpy(newregs, oldregs, sizeof(*newregs));
 	} else {
-#ifdef CONFIG_X86_32
-		asm volatile("movl %%ebx,%0" : "=m"(newregs->bx));
-		asm volatile("movl %%ecx,%0" : "=m"(newregs->cx));
-		asm volatile("movl %%edx,%0" : "=m"(newregs->dx));
-		asm volatile("movl %%esi,%0" : "=m"(newregs->si));
-		asm volatile("movl %%edi,%0" : "=m"(newregs->di));
-		asm volatile("movl %%ebp,%0" : "=m"(newregs->bp));
-		asm volatile("movl %%eax,%0" : "=m"(newregs->ax));
-		asm volatile("movl %%esp,%0" : "=m"(newregs->sp));
-		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
-		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
-		asm volatile("movl %%ds, %%eax;" :"=a"(newregs->ds));
-		asm volatile("movl %%es, %%eax;" :"=a"(newregs->es));
-		asm volatile("pushfl; popl %0" :"=m"(newregs->flags));
-#else
-		asm volatile("movq %%rbx,%0" : "=m"(newregs->bx));
-		asm volatile("movq %%rcx,%0" : "=m"(newregs->cx));
-		asm volatile("movq %%rdx,%0" : "=m"(newregs->dx));
-		asm volatile("movq %%rsi,%0" : "=m"(newregs->si));
-		asm volatile("movq %%rdi,%0" : "=m"(newregs->di));
-		asm volatile("movq %%rbp,%0" : "=m"(newregs->bp));
-		asm volatile("movq %%rax,%0" : "=m"(newregs->ax));
-		asm volatile("movq %%rsp,%0" : "=m"(newregs->sp));
+		asm volatile(_ASM_MOV " %%" _ASM_BX ",%0" : "=m"(newregs->bx));
+		asm volatile(_ASM_MOV " %%" _ASM_CX ",%0" : "=m"(newregs->cx));
+		asm volatile(_ASM_MOV " %%" _ASM_DX ",%0" : "=m"(newregs->dx));
+		asm volatile(_ASM_MOV " %%" _ASM_SI ",%0" : "=m"(newregs->si));
+		asm volatile(_ASM_MOV " %%" _ASM_DI ",%0" : "=m"(newregs->di));
+		asm volatile(_ASM_MOV " %%" _ASM_BP ",%0" : "=m"(newregs->bp));
+		asm volatile(_ASM_MOV " %%" _ASM_AX ",%0" : "=m"(newregs->ax));
+		asm volatile(_ASM_MOV " %%" _ASM_SP ",%0" : "=m"(newregs->sp));
+#ifdef CONFIG_X86_64
 		asm volatile("movq %%r8,%0" : "=m"(newregs->r8));
 		asm volatile("movq %%r9,%0" : "=m"(newregs->r9));
 		asm volatile("movq %%r10,%0" : "=m"(newregs->r10));
@@ -102,10 +89,15 @@ static inline void crash_setup_regs(struct pt_regs *newregs,
 		asm volatile("movq %%r13,%0" : "=m"(newregs->r13));
 		asm volatile("movq %%r14,%0" : "=m"(newregs->r14));
 		asm volatile("movq %%r15,%0" : "=m"(newregs->r15));
-		asm volatile("movl %%ss, %%eax;" :"=a"(newregs->ss));
-		asm volatile("movl %%cs, %%eax;" :"=a"(newregs->cs));
-		asm volatile("pushfq; popq %0" :"=m"(newregs->flags));
 #endif
+		asm volatile("movl %%ss,%k0" :"=a"(newregs->ss));
+		asm volatile("movl %%cs,%k0" :"=a"(newregs->cs));
+#ifdef CONFIG_X86_32
+		asm volatile("movl %%ds,%k0" :"=a"(newregs->ds));
+		asm volatile("movl %%es,%k0" :"=a"(newregs->es));
+#endif
+		asm volatile(_ASM_PUSHF "\n\t"
+			     _ASM_POP " %0" : "=m"(newregs->flags));
 		newregs->ip = _THIS_IP_;
 	}
 }
-- 
2.42.0