Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix APIC ID sizing bug on larger systems, clean up MAX_APICS confusion
  x86, acpi: Parse all SRAT cpu entries even above the cpu number limitation
  x86, acpi: Add MAX_LOCAL_APIC for 32bit
  x86: io_apic: Split setup_ioapic_ids_from_mpc()
  x86: io_apic: Fix CONFIG_X86_IO_APIC=n breakage
  x86: apic: Move probe_nr_irqs_gsi() into ioapic_init_mappings()
  x86: Allow platforms to force enable apic

1 files changed, 55 insertions, 34 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index fb7657822aad..316a3b6b1121 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1532,13 +1532,60 @@ static int __init detect_init_APIC(void)
 	return 0;
 }
 #else
+
+static int apic_verify(void)
+{
+	u32 features, h, l;
+
+	/*
+	 * The APIC feature bit should now be enabled
+	 * in `cpuid'
+	 */
+	features = cpuid_edx(1);
+	if (!(features & (1 << X86_FEATURE_APIC))) {
+		pr_warning("Could not enable APIC!\n");
+		return -1;
+	}
+	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
+	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
+
+	/* The BIOS may have set up the APIC at some other address */
+	rdmsr(MSR_IA32_APICBASE, l, h);
+	if (l & MSR_IA32_APICBASE_ENABLE)
+		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
+
+	pr_info("Found and enabled local APIC!\n");
+	return 0;
+}
+
+int apic_force_enable(void)
+{
+	u32 h, l;
+
+	if (disable_apic)
+		return -1;
+
+	/*
+	 * Some BIOSes disable the local APIC in the APIC_BASE
+	 * MSR. This can only be done in software for Intel P6 or later
+	 * and AMD K7 (Model > 1) or later.
+	 */
+	rdmsr(MSR_IA32_APICBASE, l, h);
+	if (!(l & MSR_IA32_APICBASE_ENABLE)) {
+		pr_info("Local APIC disabled by BIOS -- reenabling.\n");
+		l &= ~MSR_IA32_APICBASE_BASE;
+		l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
+		wrmsr(MSR_IA32_APICBASE, l, h);
+		enabled_via_apicbase = 1;
+	}
+	return apic_verify();
+}
+
 /*
  * Detect and initialize APIC
  */
 static int __init detect_init_APIC(void)
 {
-	u32 h, l, features;
-
 	/* Disabled by kernel option? */
 	if (disable_apic)
 		return -1;
@@ -1568,38 +1615,12 @@ static int __init detect_init_APIC(void)
 				"you can enable it with \"lapic\"\n");
 			return -1;
 		}
-		/*
-		 * Some BIOSes disable the local APIC in the APIC_BASE
-		 * MSR. This can only be done in software for Intel P6 or later
-		 * and AMD K7 (Model > 1) or later.
-		 */
-		rdmsr(MSR_IA32_APICBASE, l, h);
-		if (!(l & MSR_IA32_APICBASE_ENABLE)) {
-			pr_info("Local APIC disabled by BIOS -- reenabling.\n");
-			l &= ~MSR_IA32_APICBASE_BASE;
-			l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
-			wrmsr(MSR_IA32_APICBASE, l, h);
-			enabled_via_apicbase = 1;
-		}
-	}
-	/*
-	 * The APIC feature bit should now be enabled
-	 * in `cpuid'
-	 */
-	features = cpuid_edx(1);
-	if (!(features & (1 << X86_FEATURE_APIC))) {
-		pr_warning("Could not enable APIC!\n");
-		return -1;
+		if (apic_force_enable())
+			return -1;
+	} else {
+		if (apic_verify())
+			return -1;
 	}
-	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
-	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
-
-	/* The BIOS may have set up the APIC at some other address */
-	rdmsr(MSR_IA32_APICBASE, l, h);
-	if (l & MSR_IA32_APICBASE_ENABLE)
-		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
-
-	pr_info("Found and enabled local APIC!\n");
 
 	apic_pm_activate();
 
@@ -1687,7 +1708,7 @@ void __init init_apic_mappings(void)
  * This initializes the IO-APIC and APIC hardware if this is
  * a UP kernel.
  */
-int apic_version[MAX_APICS];
+int apic_version[MAX_LOCAL_APIC];
 
 int __init APIC_init_uniprocessor(void)
 {