Commit-ID:  3f85483bd80ef1de8cbbf0361be59f6a069b59d4
Gitweb:     http://git.kernel.org/tip/3f85483bd80ef1de8cbbf0361be59f6a069b59d4
Author:     Boris Ostrovsky <boris.ostrov...@oracle.com>
AuthorDate: Wed, 1 Apr 2015 10:12:14 -0400
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Thu, 2 Apr 2015 12:06:41 +0200

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 a7fcf28d431e ("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.ostrov...@oracle.com>
Reviewed-by: David Vrabel <david.vra...@citrix.com>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Brian Gerst <brge...@gmail.com>
Cc: Denys Vlasenko <dvlas...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: konrad.w...@oracle.com
Cc: xen-de...@lists.xenproject.org
Link: 
http://lkml.kernel.org/r/1427897534-5086-1-git-send-email-boris.ostrov...@oracle.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
 arch/x86/include/asm/smp.h |  1 +
 arch/x86/kernel/smpboot.c  | 37 ++++++++++++++++++++++---------------
 arch/x86/xen/smp.c         | 13 +------------
 3 files changed, 24 insertions(+), 27 deletions(-)

diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 8cd1cc3..81d02fc 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -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);
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 7b20ffd..5b298a9 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -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);
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 765b768..7413ee3 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -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;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to