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-rw-r--r--arch/x86/kernel/reboot.c129
1 files changed, 70 insertions, 59 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index e73973769076..77215c23fba1 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -39,7 +39,8 @@ static int reboot_mode;
enum reboot_type reboot_type = BOOT_ACPI;
int reboot_force;
-/* This variable is used privately to keep track of whether or not
+/*
+ * This variable is used privately to keep track of whether or not
* reboot_type is still set to its default value (i.e., reboot= hasn't
* been set on the command line). This is needed so that we can
* suppress DMI scanning for reboot quirks. Without it, it's
@@ -51,7 +52,8 @@ static int reboot_default = 1;
static int reboot_cpu = -1;
#endif
-/* This is set if we need to go through the 'emergency' path.
+/*
+ * This is set if we need to go through the 'emergency' path.
* When machine_emergency_restart() is called, we may be on
* an inconsistent state and won't be able to do a clean cleanup
*/
@@ -60,22 +62,24 @@ static int reboot_emergency;
/* This is set by the PCI code if either type 1 or type 2 PCI is detected */
bool port_cf9_safe = false;
-/* 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)
- triple Force a triple fault (init)
- kbd Use the keyboard controller. cold reset (default)
- acpi Use the RESET_REG in the FADT
- efi Use efi reset_system runtime service
- pci Use the so-called "PCI reset register", CF9
- force Avoid anything that could hang.
+/*
+ * 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)
+ * triple Force a triple fault (init)
+ * kbd Use the keyboard controller. cold reset (default)
+ * acpi Use the RESET_REG in the FADT
+ * efi Use efi reset_system runtime service
+ * pci Use the so-called "PCI reset register", CF9
+ * force Avoid anything that could hang.
*/
static int __init reboot_setup(char *str)
{
for (;;) {
- /* Having anything passed on the command line via
+ /*
+ * Having anything passed on the command line via
* reboot= will cause us to disable DMI checking
* below.
*/
@@ -98,9 +102,11 @@ static int __init reboot_setup(char *str)
if (isdigit(*(str+2)))
reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
}
- /* we will leave sorting out the final value
- when we are ready to reboot, since we might not
- have detected BSP APIC ID or smp_num_cpu */
+ /*
+ * We will leave sorting out the final value
+ * when we are ready to reboot, since we might not
+ * have detected BSP APIC ID or smp_num_cpu
+ */
break;
#endif /* CONFIG_SMP */
@@ -162,14 +168,15 @@ void machine_real_restart(unsigned int type)
local_irq_disable();
- /* Write zero to CMOS register number 0x0f, which the BIOS POST
- routine will recognize as telling it to do a proper reboot. (Well
- that's what this book in front of me says -- it may only apply to
- the Phoenix BIOS though, it's not clear). At the same time,
- disable NMIs by setting the top bit in the CMOS address register,
- as we're about to do peculiar things to the CPU. I'm not sure if
- `outb_p' is needed instead of just `outb'. Use it to be on the
- safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
+ /*
+ * Write zero to CMOS register number 0x0f, which the BIOS POST
+ * routine will recognize as telling it to do a proper reboot. (Well
+ * that's what this book in front of me says -- it may only apply to
+ * the Phoenix BIOS though, it's not clear). At the same time,
+ * disable NMIs by setting the top bit in the CMOS address register,
+ * as we're about to do peculiar things to the CPU. I'm not sure if
+ * `outb_p' is needed instead of just `outb'. Use it to be on the
+ * safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
*/
spin_lock(&rtc_lock);
CMOS_WRITE(0x00, 0x8f);
@@ -180,11 +187,12 @@ void machine_real_restart(unsigned int type)
*/
load_cr3(initial_page_table);
- /* Write 0x1234 to absolute memory location 0x472. The BIOS reads
- this on booting to tell it to "Bypass memory test (also warm
- boot)". This seems like a fairly standard thing that gets set by
- REBOOT.COM programs, and the previous reset routine did this
- too. */
+ /*
+ * Write 0x1234 to absolute memory location 0x472. The BIOS reads
+ * this on booting to tell it to "Bypass memory test (also warm
+ * boot)". This seems like a fairly standard thing that gets set by
+ * REBOOT.COM programs, and the previous reset routine did this
+ * too. */
*((unsigned short *)0x472) = reboot_mode;
/* Patch the GDT in the low memory trampoline */
@@ -233,7 +241,8 @@ static int __init set_kbd_reboot(const struct dmi_system_id *d)
return 0;
}
-/* This is a single dmi_table handling all reboot quirks. Note that
+/*
+ * This is a single dmi_table handling all reboot quirks. Note that
* REBOOT_BIOS is only available for 32bit
*/
static struct dmi_system_id __initdata reboot_dmi_table[] = {
@@ -262,7 +271,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
},
},
- { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
+ { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
.callback = set_bios_reboot,
.ident = "Dell OptiPlex 745",
.matches = {
@@ -270,7 +279,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
},
},
- { /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
+ { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
.callback = set_bios_reboot,
.ident = "Dell OptiPlex 745",
.matches = {
@@ -279,7 +288,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
},
},
- { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
+ { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
.callback = set_bios_reboot,
.ident = "Dell OptiPlex 745",
.matches = {
@@ -288,7 +297,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
},
},
- { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
+ { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
.callback = set_bios_reboot,
.ident = "Dell OptiPlex 330",
.matches = {
@@ -297,7 +306,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
},
},
- { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
+ { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
.callback = set_bios_reboot,
.ident = "Dell OptiPlex 360",
.matches = {
@@ -306,7 +315,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
},
},
- { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G*/
+ { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
.callback = set_bios_reboot,
.ident = "Dell OptiPlex 760",
.matches = {
@@ -379,7 +388,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"),
},
},
- { /* Handle problems with rebooting on ASUS P4S800 */
+ { /* Handle problems with rebooting on ASUS P4S800 */
.callback = set_bios_reboot,
.ident = "ASUS P4S800",
.matches = {
@@ -389,7 +398,7 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
},
#endif /* CONFIG_X86_32 */
- { /* Handle reboot issue on Acer Aspire one */
+ { /* Handle reboot issue on Acer Aspire one */
.callback = set_kbd_reboot,
.ident = "Acer Aspire One A110",
.matches = {
@@ -466,12 +475,12 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
static int __init reboot_init(void)
{
- /* Only do the DMI check if reboot_type hasn't been overridden
+ /*
+ * Only do the DMI check if reboot_type hasn't been overridden
* on the command line
*/
- if (reboot_default) {
+ if (reboot_default)
dmi_check_system(reboot_dmi_table);
- }
return 0;
}
core_initcall(reboot_init);
@@ -492,14 +501,14 @@ static void vmxoff_nmi(int cpu, struct pt_regs *regs)
cpu_emergency_vmxoff();
}
-/* Use NMIs as IPIs to tell all CPUs to disable virtualization
- */
+/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
static void emergency_vmx_disable_all(void)
{
/* Just make sure we won't change CPUs while doing this */
local_irq_disable();
- /* We need to disable VMX on all CPUs before rebooting, otherwise
+ /*
+ * We need to disable VMX on all CPUs before rebooting, otherwise
* we risk hanging up the machine, because the CPU ignore INIT
* signals when VMX is enabled.
*
@@ -518,8 +527,7 @@ static void emergency_vmx_disable_all(void)
* is still enabling VMX.
*/
if (cpu_has_vmx() && cpu_vmx_enabled()) {
- /* Disable VMX on this CPU.
- */
+ /* Disable VMX on this CPU. */
cpu_vmxoff();
/* Halt and disable VMX on the other CPUs */
@@ -564,12 +572,12 @@ static void native_machine_emergency_restart(void)
/* Could also try the reset bit in the Hammer NB */
switch (reboot_type) {
case BOOT_KBD:
- mach_reboot_fixups(); /* for board specific fixups */
+ mach_reboot_fixups(); /* For board specific fixups */
for (i = 0; i < 10; i++) {
kb_wait();
udelay(50);
- outb(0xfe, 0x64); /* pulse reset low */
+ outb(0xfe, 0x64); /* Pulse reset low */
udelay(50);
}
if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
@@ -611,7 +619,7 @@ static void native_machine_emergency_restart(void)
case BOOT_CF9:
port_cf9_safe = true;
- /* fall through */
+ /* Fall through */
case BOOT_CF9_COND:
if (port_cf9_safe) {
@@ -649,7 +657,8 @@ void native_machine_shutdown(void)
/* Make certain I only run on the appropriate processor */
set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
- /* O.K Now that I'm on the appropriate processor,
+ /*
+ * O.K Now that I'm on the appropriate processor,
* stop all of the others.
*/
stop_other_cpus();
@@ -687,12 +696,11 @@ static void native_machine_restart(char *__unused)
static void native_machine_halt(void)
{
- /* stop other cpus and apics */
+ /* Stop other cpus and apics */
machine_shutdown();
tboot_shutdown(TB_SHUTDOWN_HALT);
- /* stop this cpu */
stop_this_cpu(NULL);
}
@@ -703,7 +711,7 @@ static void native_machine_power_off(void)
machine_shutdown();
pm_power_off();
}
- /* a fallback in case there is no PM info available */
+ /* A fallback in case there is no PM info available */
tboot_shutdown(TB_SHUTDOWN_HALT);
}
@@ -765,7 +773,8 @@ static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
cpu = raw_smp_processor_id();
- /* Don't do anything if this handler is invoked on crashing cpu.
+ /*
+ * Don't do anything if this handler is invoked on crashing cpu.
* Otherwise, system will completely hang. Crashing cpu can get
* an NMI if system was initially booted with nmi_watchdog parameter.
*/
@@ -789,7 +798,8 @@ static void smp_send_nmi_allbutself(void)
apic->send_IPI_allbutself(NMI_VECTOR);
}
-/* Halt all other CPUs, calling the specified function on each of them
+/*
+ * Halt all other CPUs, calling the specified function on each of them
*
* This function can be used to halt all other CPUs on crash
* or emergency reboot time. The function passed as parameter
@@ -800,7 +810,7 @@ void nmi_shootdown_cpus(nmi_shootdown_cb callback)
unsigned long msecs;
local_irq_disable();
- /* Make a note of crashing cpu. Will be used in NMI callback.*/
+ /* Make a note of crashing cpu. Will be used in NMI callback. */
crashing_cpu = safe_smp_processor_id();
shootdown_callback = callback;
@@ -809,8 +819,9 @@ void nmi_shootdown_cpus(nmi_shootdown_cb callback)
/* Would it be better to replace the trap vector here? */
if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
NMI_FLAG_FIRST, "crash"))
- return; /* return what? */
- /* Ensure the new callback function is set before sending
+ return; /* Return what? */
+ /*
+ * Ensure the new callback function is set before sending
* out the NMI
*/
wmb();
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