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Commit 19e00d59 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

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
parents 197fe6b0 eeeda4cd

arch/x86/kernel/cpu/common.c

+18 −11
Original line number Diff line number Diff line
@@ -1266,6 +1266,19 @@ static void dbg_restore_debug_regs(void) 
#define dbg_restore_debug_regs()

#endif /* ! CONFIG_KGDB */



static void wait_for_master_cpu(int cpu)

{

#ifdef CONFIG_SMP

	/*

	 * wait for ACK from master CPU before continuing

	 * with AP initialization

	 */

	WARN_ON(cpumask_test_and_set_cpu(cpu, cpu_initialized_mask));

	while (!cpumask_test_cpu(cpu, cpu_callout_mask))

		cpu_relax();

#endif

}



/*

 * cpu_init() initializes state that is per-CPU. Some data is already

 * initialized (naturally) in the bootstrap process, such as the GDT
@@ -1281,16 +1294,17 @@ void cpu_init(void) 
	struct task_struct *me;

	struct tss_struct *t;

	unsigned long v;

	int cpu;

	int cpu = stack_smp_processor_id();

	int i;



	wait_for_master_cpu(cpu);



	/*

	 * Load microcode on this cpu if a valid microcode is available.

	 * This is early microcode loading procedure.

	 */

	load_ucode_ap();



	cpu = stack_smp_processor_id();

	t = &per_cpu(init_tss, cpu);

	oist = &per_cpu(orig_ist, cpu);
@@ -1302,9 +1316,6 @@ void cpu_init(void) 


	me = current;



	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask))

		panic("CPU#%d already initialized!\n", cpu);



	pr_debug("Initializing CPU#%d\n", cpu);



	clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
@@ -1381,13 +1392,9 @@ void cpu_init(void) 
	struct tss_struct *t = &per_cpu(init_tss, cpu);

	struct thread_struct *thread = &curr->thread;



	show_ucode_info_early();

	wait_for_master_cpu(cpu);



	if (cpumask_test_and_set_cpu(cpu, cpu_initialized_mask)) {

		printk(KERN_WARNING "CPU#%d already initialized!\n", cpu);

		for (;;)

			local_irq_enable();

	}

	show_ucode_info_early();



	printk(KERN_INFO "Initializing CPU#%d\n", cpu);

arch/x86/kernel/smpboot.c

+30 −68
Original line number Diff line number Diff line
@@ -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

		 */

		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

				 */

		pr_debug("Before Callout %d\n", cpu);

				cpumask_set_cpu(cpu, cpu_callout_mask);

		pr_debug("After Callout %d\n", cpu);

				boot_error = 0;

				break;

			}

			udelay(100);

			schedule();

		}

	}



	if (!boot_error) {

		/*

		 * Wait 5s total for a response

		 * Wait till AP completes initial initialization

		 */

		for (timeout = 0; timeout < 50000; timeout++) {

			if (cpumask_test_cpu(cpu, cpu_callin_mask))

				break;	/* It has booted */

			udelay(100);

		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 */

arch/x86/tools/relocs.c

+1 −1
Original line number Diff line number Diff line
@@ -695,7 +695,7 @@ static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel, 
 *

 */

static int per_cpu_shndx	= -1;

Elf_Addr per_cpu_load_addr;

static Elf_Addr per_cpu_load_addr;



static void percpu_init(void)

{

arch/x86/xen/smp.c

+2 −0
Original line number Diff line number Diff line
@@ -365,6 +365,8 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle) 
	struct desc_struct *gdt;

	unsigned long gdt_mfn;



	/* used to tell cpu_init() that it can proceed with initialization */

	cpumask_set_cpu(cpu, cpu_callout_mask);

	if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))

		return 0;