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Merge branch 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Browse Source 
Pull x86 reboot changes from Ingo Molnar:
 "The biggest change is a gentler method of rebooting/stopping via IRQs
  first and then via NMIs.  There are several cleanups in the tree as
  well."

* 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/reboot: Update nonmi_ipi parameter
  x86/reboot: Use NMI to assist in shutting down if IRQ fails
  Revert "x86, reboot: Use NMI instead of REBOOT_VECTOR to stop cpus"
  x86/reboot: Clean up coding style
  x86/reboot: Reduce to a single DMI table for reboot quirks
This commit is contained in:
Linus Torvalds 2012-05-23 11:31:22 -07:00
commit 2335a8366f
2 changed files with 188 additions and 195 deletions
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277
arch/x86/kernel/reboot.c
View File

@ -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 */
@ -150,6 +156,82 @@ static int __init set_bios_reboot(const struct dmi_system_id *d)
return 0;
}
extern const unsigned char machine_real_restart_asm[];
extern const u64 machine_real_restart_gdt[3];
void machine_real_restart(unsigned int type)
{
void *restart_va;
unsigned long restart_pa;
void (*restart_lowmem)(unsigned int);
u64 *lowmem_gdt;
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.)
*/
spin_lock(&rtc_lock);
CMOS_WRITE(0x00, 0x8f);
spin_unlock(&rtc_lock);
/*
* Switch back to the initial page table.
*/
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. */
*((unsigned short *)0x472) = reboot_mode;
/* Patch the GDT in the low memory trampoline */
lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
restart_pa = virt_to_phys(restart_va);
restart_lowmem = (void (*)(unsigned int))restart_pa;
/* GDT[0]: GDT self-pointer */
lowmem_gdt[0] =
(u64)(sizeof(machine_real_restart_gdt) - 1) +
((u64)virt_to_phys(lowmem_gdt) << 16);
/* GDT[1]: 64K real mode code segment */
lowmem_gdt[1] =
GDT_ENTRY(0x009b, restart_pa, 0xffff);
/* Jump to the identity-mapped low memory code */
restart_lowmem(type);
}
#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
*/
static int __init set_pci_reboot(const struct dmi_system_id *d)
{
if (reboot_type != BOOT_CF9) {
reboot_type = BOOT_CF9;
printk(KERN_INFO "%s series board detected. "
"Selecting PCI-method for reboots.\n", d->ident);
}
return 0;
}
static int __init set_kbd_reboot(const struct dmi_system_id *d)
{
if (reboot_type != BOOT_KBD) {
@ -159,7 +241,12 @@ 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
* REBOOT_BIOS is only available for 32bit
*/
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",
@ -184,7 +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 = {
@ -192,7 +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 = {
@ -201,7 +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 = {
@ -210,7 +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 = {
@ -219,7 +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 = {
@ -228,7 +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 = {
@ -301,7 +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 = {
@ -309,7 +396,9 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
},
},
{ /* Handle reboot issue on Acer Aspire one */
#endif /* CONFIG_X86_32 */
{ /* Handle reboot issue on Acer Aspire one */
.callback = set_kbd_reboot,
.ident = "Acer Aspire One A110",
.matches = {
@ -317,96 +406,6 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = {
DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
},
},
{ }
};
static int __init reboot_init(void)
{
/* Only do the DMI check if reboot_type hasn't been overridden
* on the command line
*/
if (reboot_default) {
dmi_check_system(reboot_dmi_table);
}
return 0;
}
core_initcall(reboot_init);
extern const unsigned char machine_real_restart_asm[];
extern const u64 machine_real_restart_gdt[3];
void machine_real_restart(unsigned int type)
{
void *restart_va;
unsigned long restart_pa;
void (*restart_lowmem)(unsigned int);
u64 *lowmem_gdt;
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.)
*/
spin_lock(&rtc_lock);
CMOS_WRITE(0x00, 0x8f);
spin_unlock(&rtc_lock);
/*
* Switch back to the initial page table.
*/
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. */
*((unsigned short *)0x472) = reboot_mode;
/* Patch the GDT in the low memory trampoline */
lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
restart_pa = virt_to_phys(restart_va);
restart_lowmem = (void (*)(unsigned int))restart_pa;
/* GDT[0]: GDT self-pointer */
lowmem_gdt[0] =
(u64)(sizeof(machine_real_restart_gdt) - 1) +
((u64)virt_to_phys(lowmem_gdt) << 16);
/* GDT[1]: 64K real mode code segment */
lowmem_gdt[1] =
GDT_ENTRY(0x009b, restart_pa, 0xffff);
/* Jump to the identity-mapped low memory code */
restart_lowmem(type);
}
#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
*/
static int __init set_pci_reboot(const struct dmi_system_id *d)
{
if (reboot_type != BOOT_CF9) {
reboot_type = BOOT_CF9;
printk(KERN_INFO "%s series board detected. "
"Selecting PCI-method for reboots.\n", d->ident);
}
return 0;
}
static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
{ /* Handle problems with rebooting on Apple MacBook5 */
.callback = set_pci_reboot,
.ident = "Apple MacBook5",
@ -474,17 +473,17 @@ static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
{ }
};
static int __init pci_reboot_init(void)
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) {
dmi_check_system(pci_reboot_dmi_table);
}
if (reboot_default)
dmi_check_system(reboot_dmi_table);
return 0;
}
core_initcall(pci_reboot_init);
core_initcall(reboot_init);
static inline void kb_wait(void)
{
@ -502,14 +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.
*
@ -528,8 +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 */
@ -574,12 +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) {
@ -621,7 +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) {
@ -659,7 +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();
@ -697,12 +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);
}
@ -713,7 +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);
}
@ -775,7 +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.
*/
@ -799,7 +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
@ -810,7 +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;
@ -819,8 +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();

106
arch/x86/kernel/smp.c
View File

@ -109,6 +109,9 @@
* about nothing of note with C stepping upwards.
*/
static atomic_t stopping_cpu = ATOMIC_INIT(-1);
static bool smp_no_nmi_ipi = false;
/*
* this function sends a 'reschedule' IPI to another CPU.
* it goes straight through and wastes no time serializing
@ -149,8 +152,6 @@ void native_send_call_func_ipi(const struct cpumask *mask)
free_cpumask_var(allbutself);
}
static atomic_t stopping_cpu = ATOMIC_INIT(-1);
static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs)
{
/* We are registered on stopping cpu too, avoid spurious NMI */
@ -162,47 +163,6 @@ static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs)
return NMI_HANDLED;
}
static void native_nmi_stop_other_cpus(int wait)
{
unsigned long flags;
unsigned long timeout;
if (reboot_force)
return;
/*
* Use an own vector here because smp_call_function
* does lots of things not suitable in a panic situation.
*/
if (num_online_cpus() > 1) {
/* did someone beat us here? */
if (atomic_cmpxchg(&stopping_cpu, -1, safe_smp_processor_id()) != -1)
return;
if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,
NMI_FLAG_FIRST, "smp_stop"))
/* Note: we ignore failures here */
return;
/* sync above data before sending NMI */
wmb();
apic->send_IPI_allbutself(NMI_VECTOR);
/*
* Don't wait longer than a second if the caller
* didn't ask us to wait.
*/
timeout = USEC_PER_SEC;
while (num_online_cpus() > 1 && (wait || timeout--))
udelay(1);
}
local_irq_save(flags);
disable_local_APIC();
local_irq_restore(flags);
}
/*
* this function calls the 'stop' function on all other CPUs in the system.
*/
@ -215,7 +175,7 @@ asmlinkage void smp_reboot_interrupt(void)
irq_exit();
}
static void native_irq_stop_other_cpus(int wait)
static void native_stop_other_cpus(int wait)
{
unsigned long flags;
unsigned long timeout;
@ -226,13 +186,25 @@ static void native_irq_stop_other_cpus(int wait)
/*
* Use an own vector here because smp_call_function
* does lots of things not suitable in a panic situation.
* On most systems we could also use an NMI here,
* but there are a few systems around where NMI
* is problematic so stay with an non NMI for now
* (this implies we cannot stop CPUs spinning with irq off
* currently)
*/
/*
* We start by using the REBOOT_VECTOR irq.
* The irq is treated as a sync point to allow critical
* regions of code on other cpus to release their spin locks
* and re-enable irqs. Jumping straight to an NMI might
* accidentally cause deadlocks with further shutdown/panic
* code. By syncing, we give the cpus up to one second to
* finish their work before we force them off with the NMI.
*/
if (num_online_cpus() > 1) {
/* did someone beat us here? */
if (atomic_cmpxchg(&stopping_cpu, -1, safe_smp_processor_id()) != -1)
return;
/* sync above data before sending IRQ */
wmb();
apic->send_IPI_allbutself(REBOOT_VECTOR);
/*
@ -243,17 +215,37 @@ static void native_irq_stop_other_cpus(int wait)
while (num_online_cpus() > 1 && (wait || timeout--))
udelay(1);
}
/* if the REBOOT_VECTOR didn't work, try with the NMI */
if ((num_online_cpus() > 1) && (!smp_no_nmi_ipi)) {
if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,
NMI_FLAG_FIRST, "smp_stop"))
/* Note: we ignore failures here */
/* Hope the REBOOT_IRQ is good enough */
goto finish;
/* sync above data before sending IRQ */
wmb();
pr_emerg("Shutting down cpus with NMI\n");
apic->send_IPI_allbutself(NMI_VECTOR);
/*
* Don't wait longer than a 10 ms if the caller
* didn't ask us to wait.
*/
timeout = USEC_PER_MSEC * 10;
while (num_online_cpus() > 1 && (wait || timeout--))
udelay(1);
}
finish:
local_irq_save(flags);
disable_local_APIC();
local_irq_restore(flags);
}
static void native_smp_disable_nmi_ipi(void)
{
smp_ops.stop_other_cpus = native_irq_stop_other_cpus;
}
/*
* Reschedule call back.
*/
@ -287,8 +279,8 @@ void smp_call_function_single_interrupt(struct pt_regs *regs)
static int __init nonmi_ipi_setup(char *str)
{
native_smp_disable_nmi_ipi();
return 1;
smp_no_nmi_ipi = true;
return 1;
}
__setup("nonmi_ipi", nonmi_ipi_setup);
@ -298,7 +290,7 @@ struct smp_ops smp_ops = {
.smp_prepare_cpus = native_smp_prepare_cpus,
.smp_cpus_done = native_smp_cpus_done,
.stop_other_cpus = native_nmi_stop_other_cpus,
.stop_other_cpus = native_stop_other_cpus,
.smp_send_reschedule = native_smp_send_reschedule,
.cpu_up = native_cpu_up,