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Commit 3f85483b authored by Boris Ostrovsky's avatar Boris Ostrovsky Committed by Ingo Molnar
Browse files

x86/cpu: Factor out common CPU initialization code, fix 32-bit Xen PV guests 



Some of x86 bare-metal and Xen CPU initialization code is common
between the two and therefore can be factored out to avoid code
duplication.

As a side effect, doing so will also extend the fix provided by
commit a7fcf28d ("x86/asm/entry: Replace this_cpu_sp0() with
current_top_of_stack() to x86_32") to 32-bit Xen PV guests.

Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: konrad.wilk@oracle.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1427897534-5086-1-git-send-email-boris.ostrovsky@oracle.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 40e4f2d1

arch/x86/include/asm/smp.h

+1 −0
Original line number Diff line number Diff line
@@ -154,6 +154,7 @@ void cpu_die_common(unsigned int cpu); 
void native_smp_prepare_boot_cpu(void);

void native_smp_prepare_cpus(unsigned int max_cpus);

void native_smp_cpus_done(unsigned int max_cpus);

void common_cpu_up(unsigned int cpunum, struct task_struct *tidle);

int native_cpu_up(unsigned int cpunum, struct task_struct *tidle);

int native_cpu_disable(void);

void native_cpu_die(unsigned int cpu);

arch/x86/kernel/smpboot.c

+22 −15
Original line number Diff line number Diff line
@@ -779,6 +779,26 @@ wakeup_cpu_via_init_nmi(int cpu, unsigned long start_ip, int apicid, 
	return boot_error;

}



void common_cpu_up(unsigned int cpu, struct task_struct *idle)

{

	/* Just in case we booted with a single CPU. */

	alternatives_enable_smp();



	per_cpu(current_task, cpu) = idle;



#ifdef CONFIG_X86_32

	/* Stack for startup_32 can be just as for start_secondary onwards */

	irq_ctx_init(cpu);

	per_cpu(cpu_current_top_of_stack, cpu) =

		(unsigned long)task_stack_page(idle) + THREAD_SIZE;

#else

	clear_tsk_thread_flag(idle, TIF_FORK);

	initial_gs = per_cpu_offset(cpu);

#endif

	per_cpu(kernel_stack, cpu) =

		(unsigned long)task_stack_page(idle) + THREAD_SIZE;

}



/*

 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad

 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
@@ -796,24 +816,9 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle) 
	int cpu0_nmi_registered = 0;

	unsigned long timeout;



	/* Just in case we booted with a single CPU. */

	alternatives_enable_smp();



	idle->thread.sp = (unsigned long) (((struct pt_regs *)

			  (THREAD_SIZE +  task_stack_page(idle))) - 1);

	per_cpu(current_task, cpu) = idle;



#ifdef CONFIG_X86_32

	/* Stack for startup_32 can be just as for start_secondary onwards */

	irq_ctx_init(cpu);

	per_cpu(cpu_current_top_of_stack, cpu) =

		(unsigned long)task_stack_page(idle) + THREAD_SIZE;

#else

	clear_tsk_thread_flag(idle, TIF_FORK);

	initial_gs = per_cpu_offset(cpu);

#endif

	per_cpu(kernel_stack, cpu) =

		(unsigned long)task_stack_page(idle) + THREAD_SIZE;

	early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);

	initial_code = (unsigned long)start_secondary;

	stack_start  = idle->thread.sp;
@@ -954,6 +959,8 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle) 
	/* the FPU context is blank, nobody can own it */

	__cpu_disable_lazy_restore(cpu);



	common_cpu_up(cpu, tidle);



	err = do_boot_cpu(apicid, cpu, tidle);

	if (err) {

		pr_err("do_boot_cpu failed(%d) to wakeup CPU#%u\n", err, cpu);

arch/x86/xen/smp.c

+1 −12
Original line number Diff line number Diff line
@@ -445,14 +445,7 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle) 
{

	int rc;



	per_cpu(current_task, cpu) = idle;

#ifdef CONFIG_X86_32

	irq_ctx_init(cpu);

#else

	clear_tsk_thread_flag(idle, TIF_FORK);

#endif

	per_cpu(kernel_stack, cpu) =

		(unsigned long)task_stack_page(idle) + THREAD_SIZE;

	common_cpu_up(cpu, idle);



	xen_setup_runstate_info(cpu);

	xen_setup_timer(cpu);
@@ -467,10 +460,6 @@ static int xen_cpu_up(unsigned int cpu, struct task_struct *idle) 
	if (rc)

		return rc;



	if (num_online_cpus() == 1)

		/* Just in case we booted with a single CPU. */

		alternatives_enable_smp();



	rc = xen_smp_intr_init(cpu);

	if (rc)

		return rc;