Signed-off-by: Yinghai Lu <yhlu.kernel@mgail.com>
---
arch/x86/kernel/apic_32.c | 20 +++++++++++
arch/x86/kernel/apic_64.c | 82 ++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 101 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c
index 0d9c000..87566a3 100644
--- a/arch/x86/kernel/apic_32.c
+++ b/arch/x86/kernel/apic_32.c
@@ -1214,6 +1214,25 @@ void __cpuinit end_local_APIC_setup(void)
apic_pm_activate();
}
+#ifdef CONFIG_X86_64
+/*
+ * Detect and enable local APICs on non-SMP boards.
+ * Original code written by Keir Fraser.
+ * On AMD64 we trust the BIOS - if it says no APIC it is likely
+ * not correctly set up (usually the APIC timer won't work etc.)
+ */
+static int __init detect_init_APIC(void)
+{
+ if (!cpu_has_apic) {
+ printk(KERN_INFO "No local APIC present\n");
+ return -1;
+ }
+
+ mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
+ boot_cpu_physical_apicid = 0;
+ return 0;
+}
+#else
/*
* Detect and initialize APIC
*/
@@ -1292,6 +1311,7 @@ no_apic:
printk(KERN_INFO "No local APIC present or hardware disabled\n");
return -1;
}
+#endif
#ifdef CONFIG_X86_64
void __init early_init_lapic_mapping(void)
diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 16a30c2..b7268f5 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -684,7 +684,6 @@ int setup_profiling_timer(unsigned int multiplier)
return -EINVAL;
}
-
/*
* Local APIC start and shutdown
*/
@@ -1264,6 +1263,7 @@ end:
}
#endif /* HAVE_X2APIC */
+#ifdef CONFIG_X86_64
/*
* Detect and enable local APICs on non-SMP boards.
* Original code written by Keir Fraser.
@@ -1281,6 +1281,86 @@ static int __init detect_init_APIC(void)
boot_cpu_physical_apicid = 0;
return 0;
}
+#else
+/*
+ * Detect and initialize APIC
+ */
+static int __init detect_init_APIC(void)
+{
+ u32 h, l, features;
+
+ /* Disabled by kernel option? */
+ if (disable_apic)
+ return -1;
+
+ switch (boot_cpu_data.x86_vendor) {
+ case X86_VENDOR_AMD:
+ if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
+ (boot_cpu_data.x86 == 15))
+ break;
+ goto no_apic;
+ case X86_VENDOR_INTEL:
+ if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
+ (boot_cpu_data.x86 == 5 && cpu_has_apic))
+ break;
+ goto no_apic;
+ default:
+ goto no_apic;
+ }
+
+ if (!cpu_has_apic) {
+ /*
+ * Over-ride BIOS and try to enable the local APIC only if
+ * "lapic" specified.
+ */
+ if (!force_enable_local_apic) {
+ printk(KERN_INFO "Local APIC disabled by BIOS -- "
+ "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)) {
+ printk(KERN_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))) {
+ printk(KERN_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;
+
+ printk(KERN_INFO "Found and enabled local APIC!\n");
+
+ apic_pm_activate();
+
+ return 0;
+
+no_apic:
+ printk(KERN_INFO "No local APIC present or hardware disabled\n");
+ return -1;
+}
+#endif
#ifdef CONFIG_X86_64
void __init early_init_lapic_mapping(void)
--
1.5.4.5
--
