x86/asm-offsets: Export certain 'struct cpuinfo_x86' fields for 64-bit asm use too

Expose certain 'struct cpuinfo_x86' fields via asm-offsets for x86_64
too, so that it will be possible to set CPU capabilities from 64-bit
asm code.

32-bit already used these fields, so simply move those offset exports into
the unified asm-offsets.c file.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250514104242.1275040-12-ardb+git@google.com

Author: ardbiesheuvel

arch/x86/kernel/asm-offsets.c

@@ -33,6 +33,14 @@
 
 static void __used common(void)
 {
+	OFFSET(CPUINFO_x86, cpuinfo_x86, x86);
+	OFFSET(CPUINFO_x86_vendor, cpuinfo_x86, x86_vendor);
+	OFFSET(CPUINFO_x86_model, cpuinfo_x86, x86_model);
+	OFFSET(CPUINFO_x86_stepping, cpuinfo_x86, x86_stepping);
+	OFFSET(CPUINFO_cpuid_level, cpuinfo_x86, cpuid_level);
+	OFFSET(CPUINFO_x86_capability, cpuinfo_x86, x86_capability);
+	OFFSET(CPUINFO_x86_vendor_id, cpuinfo_x86, x86_vendor_id);
+
 	BLANK();
 	OFFSET(TASK_threadsp, task_struct, thread.sp);
 #ifdef CONFIG_STACKPROTECTOR

arch/x86/kernel/asm-offsets_32.c

@@ -12,15 +12,6 @@ void foo(void);
 
 void foo(void)
 {
-	OFFSET(CPUINFO_x86, cpuinfo_x86, x86);
-	OFFSET(CPUINFO_x86_vendor, cpuinfo_x86, x86_vendor);
-	OFFSET(CPUINFO_x86_model, cpuinfo_x86, x86_model);
-	OFFSET(CPUINFO_x86_stepping, cpuinfo_x86, x86_stepping);
-	OFFSET(CPUINFO_cpuid_level, cpuinfo_x86, cpuid_level);
-	OFFSET(CPUINFO_x86_capability, cpuinfo_x86, x86_capability);
-	OFFSET(CPUINFO_x86_vendor_id, cpuinfo_x86, x86_vendor_id);
-	BLANK();
-
 	OFFSET(PT_EBX, pt_regs, bx);
 	OFFSET(PT_ECX, pt_regs, cx);
 	OFFSET(PT_EDX, pt_regs, dx);