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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 a7fcf28d43 ("x86/asm/entry: Replace this_cpu_sp0() with
current_top_of_stack() to x86_32") to 32-bit Xen PV guests.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: David 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: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Boris Ostrovsky 2015-04-01 10:12:14 -04:00 committed by Ingo Molnar
parent 40e4f2d177
commit 3f85483bd8
3 changed files with 24 additions and 27 deletions
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1
arch/x86/include/asm/smp.h
View File

@ -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);

37
arch/x86/kernel/smpboot.c
View File

@ -779,6 +779,26 @@ out:
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);

13
arch/x86/xen/smp.c
View File

@ -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;