x86: Move sysctls into arch/x86

Move the following sysctl tables into arch/x86/kernel/setup.c:

  panic_on_{unrecoverable_nmi,io_nmi}
  bootloader_{type,version}
  io_delay_type
  unknown_nmi_panic
  acpi_realmode_flags

Variables moved from include/linux/ to arch/x86/include/asm/ because there
is no longer need for them outside arch/x86/kernel:

  acpi_realmode_flags
  panic_on_{unrecoverable_nmi,io_nmi}

Include <asm/nmi.h> in arch/s86/kernel/setup.h in order to bring in
panic_on_{io_nmi,unrecovered_nmi}.

This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kerenel/sysctl.c.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250218-jag-mv_ctltables-v1-8-cd3698ab8d29@kernel.org

arch/x86/include/asm/setup.h

@@ -46,6 +46,7 @@ void setup_bios_corruption_check(void);
 void early_platform_quirks(void);
 
 extern unsigned long saved_video_mode;
+extern unsigned long acpi_realmode_flags;
 
 extern void reserve_standard_io_resources(void);
 extern void i386_reserve_resources(void);

arch/x86/include/asm/traps.h

@@ -35,8 +35,6 @@ static inline int get_si_code(unsigned long condition)
 		return TRAP_BRKPT;
 }
 
-extern int panic_on_unrecovered_nmi;
-
 void math_emulate(struct math_emu_info *);
 
 bool fault_in_kernel_space(unsigned long address);

arch/x86/kernel/setup.c

@@ -56,6 +56,9 @@
 #include <asm/unwind.h>
 #include <asm/vsyscall.h>
 #include <linux/vmalloc.h>
+#if defined(CONFIG_X86_LOCAL_APIC)
+#include <asm/nmi.h>
+#endif
 
 /*
  * max_low_pfn_mapped: highest directly mapped pfn < 4 GB
@@ -146,6 +149,69 @@ static size_t ima_kexec_buffer_size;
 /* Boot loader ID and version as integers, for the benefit of proc_dointvec */
 int bootloader_type, bootloader_version;
 
+static const struct ctl_table x86_sysctl_table[] = {
+	{
+		.procname	= "panic_on_unrecovered_nmi",
+		.data		= &panic_on_unrecovered_nmi,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "panic_on_io_nmi",
+		.data		= &panic_on_io_nmi,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "bootloader_type",
+		.data		= &bootloader_type,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "bootloader_version",
+		.data		= &bootloader_version,
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.proc_handler	= proc_dointvec,
+	},
+	{
+		.procname	= "io_delay_type",
+		.data		= &io_delay_type,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+#if defined(CONFIG_X86_LOCAL_APIC)
+	{
+		.procname       = "unknown_nmi_panic",
+		.data           = &unknown_nmi_panic,
+		.maxlen         = sizeof(int),
+		.mode           = 0644,
+		.proc_handler   = proc_dointvec,
+	},
+#endif
+#if defined(CONFIG_ACPI_SLEEP)
+	{
+		.procname	= "acpi_video_flags",
+		.data		= &acpi_realmode_flags,
+		.maxlen		= sizeof(unsigned long),
+		.mode		= 0644,
+		.proc_handler	= proc_doulongvec_minmax,
+	},
+#endif
+};
+
+static int __init init_x86_sysctl(void)
+{
+	register_sysctl_init("kernel", x86_sysctl_table);
+	return 0;
+}
+arch_initcall(init_x86_sysctl);
+
 /*
  * Setup options
  */

include/linux/acpi.h

@@ -330,7 +330,6 @@ static inline bool acpi_sci_irq_valid(void)
 }
 
 extern int sbf_port;
-extern unsigned long acpi_realmode_flags;
 
 int acpi_register_gsi (struct device *dev, u32 gsi, int triggering, int polarity);
 int acpi_gsi_to_irq (u32 gsi, unsigned int *irq);

kernel/sysctl.c

@@ -1831,16 +1831,6 @@ static const struct ctl_table kern_table[] = {
 		.mode		= 0444,
 		.proc_handler	= proc_dointvec,
 	},
-#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
-	{
-		.procname       = "unknown_nmi_panic",
-		.data           = &unknown_nmi_panic,
-		.maxlen         = sizeof (int),
-		.mode           = 0644,
-		.proc_handler   = proc_dointvec,
-	},
-#endif
-
 #if (defined(CONFIG_X86_32) || defined(CONFIG_PARISC)) && \
 	defined(CONFIG_DEBUG_STACKOVERFLOW)
 	{
@@ -1851,43 +1841,6 @@ static const struct ctl_table kern_table[] = {
 		.proc_handler	= proc_dointvec,
 	},
 #endif
-#if defined(CONFIG_X86)
-	{
-		.procname	= "panic_on_unrecovered_nmi",
-		.data		= &panic_on_unrecovered_nmi,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
-	{
-		.procname	= "panic_on_io_nmi",
-		.data		= &panic_on_io_nmi,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
-	{
-		.procname	= "bootloader_type",
-		.data		= &bootloader_type,
-		.maxlen		= sizeof (int),
-		.mode		= 0444,
-		.proc_handler	= proc_dointvec,
-	},
-	{
-		.procname	= "bootloader_version",
-		.data		= &bootloader_version,
-		.maxlen		= sizeof (int),
-		.mode		= 0444,
-		.proc_handler	= proc_dointvec,
-	},
-	{
-		.procname	= "io_delay_type",
-		.data		= &io_delay_type,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
-#endif
 #if defined(CONFIG_MMU)
 	{
 		.procname	= "randomize_va_space",
@@ -1906,15 +1859,6 @@ static const struct ctl_table kern_table[] = {
 		.proc_handler	= proc_dointvec,
 	},
 #endif
-#if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
-	{
-		.procname	= "acpi_video_flags",
-		.data		= &acpi_realmode_flags,
-		.maxlen		= sizeof (unsigned long),
-		.mode		= 0644,
-		.proc_handler	= proc_doulongvec_minmax,
-	},
-#endif
 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
 	{
 		.procname	= "ignore-unaligned-usertrap",