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

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Pull x86 bootup updates from Ingo Molnar:
 "The changes in this cycle were:

   - Fix rare SMP-boot hang (mostly in virtual environments)

   - Fix build warning with certain (rare) toolchains"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/relocs: Make per_cpu_load_addr static
  x86/smpboot: Initialize secondary CPU only if master CPU will wait for it
This commit is contained in:
Linus Torvalds
2014-10-13 18:16:32 +02:00
parent 197fe6b0e6 eeeda4cd06
commit 19e00d593e
4 changed files with 53 additions and 82 deletions
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102
arch/x86/kernel/smpboot.c
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@@ -111,7 +111,6 @@ atomic_t init_deasserted;
static void smp_callin(void)
{
int cpuid, phys_id;
unsigned long timeout;
/*
* If waken up by an INIT in an 82489DX configuration
@@ -130,37 +129,6 @@ static void smp_callin(void)
* (This works even if the APIC is not enabled.)
*/
phys_id = read_apic_id();
if (cpumask_test_cpu(cpuid, cpu_callin_mask)) {
panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__,
phys_id, cpuid);
}
pr_debug("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
/*
* STARTUP IPIs are fragile beasts as they might sometimes
* trigger some glue motherboard logic. Complete APIC bus
* silence for 1 second, this overestimates the time the
* boot CPU is spending to send the up to 2 STARTUP IPIs
* by a factor of two. This should be enough.
*/
/*
* Waiting 2s total for startup (udelay is not yet working)
*/
timeout = jiffies + 2*HZ;
while (time_before(jiffies, timeout)) {
/*
* Has the boot CPU finished it's STARTUP sequence?
*/
if (cpumask_test_cpu(cpuid, cpu_callout_mask))
break;
cpu_relax();
}
if (!time_before(jiffies, timeout)) {
panic("%s: CPU%d started up but did not get a callout!\n",
__func__, cpuid);
}
/*
* the boot CPU has finished the init stage and is spinning
@@ -790,8 +758,8 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
unsigned long start_ip = real_mode_header->trampoline_start;
unsigned long boot_error = 0;
int timeout;
int cpu0_nmi_registered = 0;
unsigned long timeout;
/* Just in case we booted with a single CPU. */
alternatives_enable_smp();
@@ -838,6 +806,15 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
}
}
/*
* AP might wait on cpu_callout_mask in cpu_init() with
* cpu_initialized_mask set if previous attempt to online
* it timed-out. Clear cpu_initialized_mask so that after
* INIT/SIPI it could start with a clean state.
*/
cpumask_clear_cpu(cpu, cpu_initialized_mask);
smp_mb();
/*
* Wake up a CPU in difference cases:
* - Use the method in the APIC driver if it's defined
@@ -852,53 +829,38 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
if (!boot_error) {
/*
* allow APs to start initializing.
* Wait 10s total for a response from AP
*/
pr_debug("Before Callout %d\n", cpu);
cpumask_set_cpu(cpu, cpu_callout_mask);
pr_debug("After Callout %d\n", cpu);
/*
* Wait 5s total for a response
*/
for (timeout = 0; timeout < 50000; timeout++) {
if (cpumask_test_cpu(cpu, cpu_callin_mask))
break; /* It has booted */
boot_error = -1;
timeout = jiffies + 10*HZ;
while (time_before(jiffies, timeout)) {
if (cpumask_test_cpu(cpu, cpu_initialized_mask)) {
/*
* Tell AP to proceed with initialization
*/
cpumask_set_cpu(cpu, cpu_callout_mask);
boot_error = 0;
break;
}
udelay(100);
schedule();
}
}
if (!boot_error) {
/*
* Wait till AP completes initial initialization
*/
while (!cpumask_test_cpu(cpu, cpu_callin_mask)) {
/*
* Allow other tasks to run while we wait for the
* AP to come online. This also gives a chance
* for the MTRR work(triggered by the AP coming online)
* to be completed in the stop machine context.
*/
udelay(100);
schedule();
}
if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
print_cpu_msr(&cpu_data(cpu));
pr_debug("CPU%d: has booted.\n", cpu);
} else {
boot_error = 1;
if (*trampoline_status == 0xA5A5A5A5)
/* trampoline started but...? */
pr_err("CPU%d: Stuck ??\n", cpu);
else
/* trampoline code not run */
pr_err("CPU%d: Not responding\n", cpu);
if (apic->inquire_remote_apic)
apic->inquire_remote_apic(apicid);
}
}
if (boot_error) {
/* Try to put things back the way they were before ... */
numa_remove_cpu(cpu); /* was set by numa_add_cpu */
/* was set by do_boot_cpu() */
cpumask_clear_cpu(cpu, cpu_callout_mask);
/* was set by cpu_init() */
cpumask_clear_cpu(cpu, cpu_initialized_mask);
}
/* mark "stuck" area as not stuck */