[PATCH] i386: move apic init in init_IRQs
All kinds of ugliness exists because we don't initialize
the apics during init_IRQs.
- We calibrate jiffies in non apic mode even when we are using apics.
- We have to have special code to initialize the apics when non-smp.
- The legacy i8259 must exist and be setup correctly, even
when we won't use it past initialization.
- The kexec on panic code must restore the state of the io_apics.
- init/main.c needs a special case for !smp smp_init on x86
In addition to pure code movement I needed a couple
of non-obvious changes:
- Move setup_boot_APIC_clock into APIC_late_time_init for
simplicity.
- Use cpu_khz to generate a better approximation of loops_per_jiffies
so I can verify the timer interrupt is working.
- Call setup_apic_nmi_watchdog again after cpu_khz is initialized on
the boot cpu.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 5546dde..8d81b7b 100644
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -803,6 +803,7 @@
void __init init_apic_mappings(void)
{
+ unsigned int orig_apicid;
unsigned long apic_phys;
/*
@@ -824,8 +825,11 @@
* Fetch the APIC ID of the BSP in case we have a
* default configuration (or the MP table is broken).
*/
- if (boot_cpu_physical_apicid == -1U)
- boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
+ orig_apicid = boot_cpu_physical_apicid;
+ boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
+ if ((orig_apicid != -1U) && (orig_apicid != boot_cpu_physical_apicid))
+ printk(KERN_WARNING "Boot APIC ID in local APIC unexpected (%d vs %d)",
+ orig_apicid, boot_cpu_physical_apicid);
#ifdef CONFIG_X86_IO_APIC
{
@@ -1046,9 +1050,11 @@
void __init setup_boot_APIC_clock(void)
{
+ unsigned long flags;
apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n");
using_apic_timer = 1;
+ local_irq_save(flags);
local_irq_disable();
calibration_result = calibrate_APIC_clock();
@@ -1057,7 +1063,7 @@
*/
setup_APIC_timer(calibration_result);
- local_irq_enable();
+ local_irq_restore(flags);
}
void __devinit setup_secondary_APIC_clock(void)
@@ -1254,40 +1260,81 @@
}
/*
- * This initializes the IO-APIC and APIC hardware if this is
- * a UP kernel.
+ * This initializes the IO-APIC and APIC hardware.
*/
-int __init APIC_init_uniprocessor (void)
+int __init APIC_init(void)
{
- if (enable_local_apic < 0)
- clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
-
- if (!smp_found_config && !cpu_has_apic)
+ if (enable_local_apic < 0) {
+ printk(KERN_INFO "APIC disabled\n");
return -1;
+ }
+
+ /* See if we have a SMP configuration or have forced enabled
+ * the local apic.
+ */
+ if (!smp_found_config && !acpi_lapic && !cpu_has_apic) {
+ enable_local_apic = -1;
+ return -1;
+ }
/*
- * Complain if the BIOS pretends there is one.
+ * Complain if the BIOS pretends there is an apic.
+ * Then get out because we don't have an a local apic.
*/
if (!cpu_has_apic && APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
boot_cpu_physical_apicid);
+ printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n");
+ enable_local_apic = -1;
return -1;
}
verify_local_APIC();
+ /*
+ * Should not be necessary because the MP table should list the boot
+ * CPU too, but we do it for the sake of robustness anyway.
+ * Makes no sense to do this check in clustered apic mode, so skip it
+ */
+ if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
+ printk("weird, boot CPU (#%d) not listed by the BIOS.\n",
+ boot_cpu_physical_apicid);
+ physid_set(hard_smp_processor_id(), phys_cpu_present_map);
+ }
+
+ /*
+ * Switch from PIC to APIC mode.
+ */
connect_bsp_APIC();
-
- phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
-
setup_local_APIC();
#ifdef CONFIG_X86_IO_APIC
- if (smp_found_config)
- if (!skip_ioapic_setup && nr_ioapics)
- setup_IO_APIC();
+ /*
+ * Now start the IO-APICs
+ */
+ if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
+ setup_IO_APIC();
+#endif
+ return 0;
+}
+
+void __init APIC_late_time_init(void)
+{
+ /* Improve our loops per jiffy estimate */
+ loops_per_jiffy = ((1000 + HZ - 1)/HZ)*cpu_khz;
+ boot_cpu_data.loops_per_jiffy = loops_per_jiffy;
+ cpu_data[0].loops_per_jiffy = loops_per_jiffy;
+
+ /* setup_apic_nmi_watchdog doesn't work properly before cpu_khz is
+ * initialized. So redo it here to ensure the boot cpu is setup
+ * properly.
+ */
+ if (nmi_watchdog == NMI_LOCAL_APIC)
+ setup_apic_nmi_watchdog();
+
+#ifdef CONFIG_X86_IO_APIC
+ if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
+ IO_APIC_late_time_init();
#endif
setup_boot_APIC_clock();
-
- return 0;
}