x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64
With the revamped realmode trampoline code, it is trivial to extend
support for reboot=bios to x86-64. Furthermore, while we are at it,
remove the restriction that only we can only override the reboot CPU
on 32 bits.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 25b48ed..6ddb9cd 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -20,14 +20,12 @@
#include <asm/virtext.h>
#include <asm/cpu.h>
#include <asm/nmi.h>
+#include <asm/smp.h>
-#ifdef CONFIG_X86_32
-# include <linux/ctype.h>
-# include <linux/mc146818rtc.h>
-# include <asm/realmode.h>
-#else
-# include <asm/x86_init.h>
-#endif
+#include <linux/ctype.h>
+#include <linux/mc146818rtc.h>
+#include <asm/realmode.h>
+#include <asm/x86_init.h>
/*
* Power off function, if any
@@ -49,7 +47,7 @@
*/
static int reboot_default = 1;
-#if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
+#ifdef CONFIG_SMP
static int reboot_cpu = -1;
#endif
@@ -67,8 +65,8 @@
* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
* warm Don't set the cold reboot flag
* cold Set the cold reboot flag
- * bios Reboot by jumping through the BIOS (only for X86_32)
- * smp Reboot by executing reset on BSP or other CPU (only for X86_32)
+ * bios Reboot by jumping through the BIOS
+ * smp Reboot by executing reset on BSP or other CPU
* triple Force a triple fault (init)
* kbd Use the keyboard controller. cold reset (default)
* acpi Use the RESET_REG in the FADT
@@ -95,7 +93,6 @@
reboot_mode = 0;
break;
-#ifdef CONFIG_X86_32
#ifdef CONFIG_SMP
case 's':
if (isdigit(*(str+1))) {
@@ -112,7 +109,6 @@
#endif /* CONFIG_SMP */
case 'b':
-#endif
case 'a':
case 'k':
case 't':
@@ -138,7 +134,6 @@
__setup("reboot=", reboot_setup);
-#ifdef CONFIG_X86_32
/*
* Reboot options and system auto-detection code provided by
* Dell Inc. so their systems "just work". :-)
@@ -157,11 +152,8 @@
return 0;
}
-void machine_real_restart(unsigned int type)
+void __noreturn machine_real_restart(unsigned int type)
{
- void (*restart_lowmem)(unsigned int) = (void (*)(unsigned int))
- real_mode_header->machine_real_restart_asm;
-
local_irq_disable();
/*
@@ -181,7 +173,11 @@
/*
* Switch back to the initial page table.
*/
+#ifdef CONFIG_X86_32
load_cr3(initial_page_table);
+#else
+ write_cr3(real_mode_header->trampoline_pgd);
+#endif
/*
* Write 0x1234 to absolute memory location 0x472. The BIOS reads
@@ -192,14 +188,21 @@
*((unsigned short *)0x472) = reboot_mode;
/* Jump to the identity-mapped low memory code */
- restart_lowmem(type);
+#ifdef CONFIG_X86_32
+ asm volatile("jmpl *%0" : :
+ "rm" (real_mode_header->machine_real_restart_asm),
+ "a" (type));
+#else
+ asm volatile("ljmpl *%0" : :
+ "m" (real_mode_header->machine_real_restart_asm),
+ "D" (type));
+#endif
+ unreachable();
}
#ifdef CONFIG_APM_MODULE
EXPORT_SYMBOL(machine_real_restart);
#endif
-#endif /* CONFIG_X86_32 */
-
/*
* Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
*/
@@ -223,11 +226,9 @@
}
/*
- * This is a single dmi_table handling all reboot quirks. Note that
- * REBOOT_BIOS is only available for 32bit
+ * This is a single dmi_table handling all reboot quirks.
*/
static struct dmi_system_id __initdata reboot_dmi_table[] = {
-#ifdef CONFIG_X86_32
{ /* Handle problems with rebooting on Dell E520's */
.callback = set_bios_reboot,
.ident = "Dell E520",
@@ -377,7 +378,6 @@
DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
},
},
-#endif /* CONFIG_X86_32 */
{ /* Handle reboot issue on Acer Aspire one */
.callback = set_kbd_reboot,
@@ -576,13 +576,11 @@
reboot_type = BOOT_KBD;
break;
-#ifdef CONFIG_X86_32
case BOOT_BIOS:
machine_real_restart(MRR_BIOS);
reboot_type = BOOT_KBD;
break;
-#endif
case BOOT_ACPI:
acpi_reboot();
@@ -624,12 +622,10 @@
/* The boot cpu is always logical cpu 0 */
int reboot_cpu_id = 0;
-#ifdef CONFIG_X86_32
/* See if there has been given a command line override */
if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
cpu_online(reboot_cpu))
reboot_cpu_id = reboot_cpu;
-#endif
/* Make certain the cpu I'm about to reboot on is online */
if (!cpu_online(reboot_cpu_id))