x86: minor adjustments for do_boot_cpu

This patch provides minor adjustments for do_boot_cpus
in both architectures to allow for integration

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 20 insertions, 17 deletions

diff --git a/arch/x86/kernel/smpboot_32.c b/arch/x86/kernel/smpboot_32.c
index bd2f8863efa2..5165b11d8aac 100644
--- a/arch/x86/kernel/smpboot_32.c
+++ b/arch/x86/kernel/smpboot_32.c
@@ -556,7 +556,7 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
  * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu.
  */
 {
-        unsigned long boot_error;
+        unsigned long boot_error = 0;
         int timeout;
         unsigned long start_eip;
         unsigned short nmi_high = 0, nmi_low = 0;
@@ -566,11 +566,7 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
         };
         INIT_WORK(&c_idle.work, do_fork_idle);
 
-        /*
-         * Save current MTRR state in case it was changed since early boot
-         * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
-         */
-        mtrr_save_state();
+        alternatives_smp_switch(1);
 
         c_idle.idle = get_idle_for_cpu(cpu);
 
@@ -607,8 +603,6 @@ do_rest:
         /* start_eip had better be page-aligned! */
         start_eip = setup_trampoline();
 
-        alternatives_smp_switch(1);
-
         /* So we see what's up   */
         printk("Booting processor %d/%d ip %lx\n", cpu, apicid, start_eip);
         /* Stack for startup_32 can be just as for start_secondary onwards */
@@ -628,6 +622,12 @@ do_rest:
         store_NMI_vector(&nmi_high, &nmi_low);
 
         smpboot_setup_warm_reset_vector(start_eip);
+        /*
+         * Be paranoid about clearing APIC errors.
+         */
+        apic_write(APIC_ESR, 0);
+        apic_read(APIC_ESR);
+
 
         /*
          * Starting actual IPI sequence...
@@ -864,6 +864,12 @@ int __cpuinit native_cpu_up(unsigned int cpu)
                 return -EINVAL;
         }
 
+        /*
+         * Save current MTRR state in case it was changed since early boot
+         * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
+         */
+        mtrr_save_state();
+
         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 
         __smp_prepare_cpu(cpu);
diff --git a/arch/x86/kernel/smpboot_64.c b/arch/x86/kernel/smpboot_64.c
index e93fff42ec32..7d1b4cb380db 100644
--- a/arch/x86/kernel/smpboot_64.c
+++ b/arch/x86/kernel/smpboot_64.c
@@ -432,7 +432,7 @@ static void __cpuinit do_fork_idle(struct work_struct *work)
  */
 static int __cpuinit do_boot_cpu(int cpu, int apicid)
 {
-        unsigned long boot_error;
+        unsigned long boot_error = 0;
         int timeout;
         unsigned long start_rip;
         struct create_idle c_idle = {
@@ -531,11 +531,6 @@ do_rest:
         apic_read(APIC_ESR);
 
         /*
-         * Status is now clean
-         */
-        boot_error = 0;
-
-        /*
          * Starting actual IPI sequence...
          */
         boot_error = wakeup_secondary_via_INIT(apicid, start_rip);
@@ -564,7 +559,7 @@ do_rest:
                         print_cpu_info(&cpu_data(cpu));
                 } else {
                         boot_error = 1;
-                        if (*((volatile unsigned char *)phys_to_virt(SMP_TRAMPOLINE_BASE))
+                        if (*((volatile unsigned char *)trampoline_base)
                                         == 0xA5)
                                 /* trampoline started but...? */
                                 printk("Stuck ??\n");
@@ -583,10 +578,12 @@ do_rest:
                 cpu_clear(cpu, cpu_present_map);
                 cpu_clear(cpu, cpu_possible_map);
                 per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
-                return -EIO;
         }
 
-        return 0;
+        /* mark "stuck" area as not stuck */
+        *((volatile unsigned long *)trampoline_base) = 0;
+
+        return boot_error;
 }
 
 cycles_t cacheflush_time;