[PATCH] i386: move apic init in init_IRQs

From: Eric W. Biederman
Date: Tue Oct 04 2005 - 10:06:47 EST



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@xxxxxxxxxxxx>


---

arch/i386/kernel/apic.c | 83 ++++++++++++++++++++-----
arch/i386/kernel/i8259.c | 4 +
arch/i386/kernel/io_apic.c | 6 ++
arch/i386/kernel/smpboot.c | 68 +++++---------------
arch/i386/kernel/time.c | 14 ++++
include/asm-i386/apic.h | 3 +
include/asm-i386/hw_irq.h | 1
include/asm-i386/mach-default/smpboot_hooks.h | 15 -----
include/asm-i386/mach-visws/smpboot_hooks.h | 7 --
init/main.c | 11 ---
10 files changed, 106 insertions(+), 106 deletions(-)

a3b2016a27cf9d583dce93f2375af7277049000f
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -803,6 +803,7 @@ no_apic:

void __init init_apic_mappings(void)
{
+ unsigned int orig_apicid;
unsigned long apic_phys;

/*
@@ -824,8 +825,11 @@ void __init init_apic_mappings(void)
* 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 @@ static unsigned int calibration_result;

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 @@ void __init setup_boot_APIC_clock(void)
*/
setup_APIC_timer(calibration_result);

- local_irq_enable();
+ local_irq_restore(flags);
}

void __devinit setup_secondary_APIC_clock(void)
@@ -1254,40 +1260,81 @@ fastcall void smp_error_interrupt(struct
}

/*
- * 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();
+ setup_local_APIC();

- phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
+#ifdef CONFIG_X86_IO_APIC
+ /*
+ * Now start the IO-APICs
+ */
+ if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
+ setup_IO_APIC();
+#endif
+ return 0;
+}

- setup_local_APIC();
+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)
- if (!skip_ioapic_setup && nr_ioapics)
- setup_IO_APIC();
+ if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
+ IO_APIC_late_time_init();
#endif
setup_boot_APIC_clock();
-
- return 0;
}
diff --git a/arch/i386/kernel/i8259.c b/arch/i386/kernel/i8259.c
--- a/arch/i386/kernel/i8259.c
+++ b/arch/i386/kernel/i8259.c
@@ -435,4 +435,8 @@ void __init init_IRQ(void)
setup_irq(FPU_IRQ, &fpu_irq);

irq_ctx_init(smp_processor_id());
+
+#ifdef CONFIG_X86_LOCAL_APIC
+ APIC_init();
+#endif
}
diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -2310,11 +2310,15 @@ void __init setup_IO_APIC(void)
sync_Arb_IDs();
setup_IO_APIC_irqs();
init_IO_APIC_traps();
- check_timer();
if (!acpi_ioapic)
print_IO_APIC();
}

+void __init IO_APIC_late_time_init(void)
+{
+ check_timer();
+}
+
/*
* Called after all the initialization is done. If we didnt find any
* APIC bugs then we can allow the modify fast path
diff --git a/arch/i386/kernel/smpboot.c b/arch/i386/kernel/smpboot.c
--- a/arch/i386/kernel/smpboot.c
+++ b/arch/i386/kernel/smpboot.c
@@ -1074,6 +1074,16 @@ void *xquad_portio;
EXPORT_SYMBOL(xquad_portio);
#endif

+/*
+ * Fall back to non SMP mode after errors.
+ *
+ */
+static __init void disable_smp(void)
+{
+ cpu_set(0, cpu_sibling_map[0]);
+ cpu_set(0, cpu_core_map[0]);
+}
+
static void __init smp_boot_cpus(unsigned int max_cpus)
{
int apicid, cpu, bit, kicked;
@@ -1086,7 +1096,6 @@ static void __init smp_boot_cpus(unsigne
printk("CPU%d: ", 0);
print_cpu_info(&cpu_data[0]);

- boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
boot_cpu_logical_apicid = logical_smp_processor_id();
x86_cpu_to_apicid[0] = boot_cpu_physical_apicid;

@@ -1098,68 +1107,27 @@ static void __init smp_boot_cpus(unsigne
cpus_clear(cpu_core_map[0]);
cpu_set(0, cpu_core_map[0]);

+ map_cpu_to_logical_apicid();
+
/*
* If we couldn't find an SMP configuration at boot time,
* get out of here now!
*/
if (!smp_found_config && !acpi_lapic) {
printk(KERN_NOTICE "SMP motherboard not detected.\n");
- smpboot_clear_io_apic_irqs();
- phys_cpu_present_map = physid_mask_of_physid(0);
- if (APIC_init_uniprocessor())
- printk(KERN_NOTICE "Local APIC not detected."
- " Using dummy APIC emulation.\n");
- map_cpu_to_logical_apicid();
- cpu_set(0, cpu_sibling_map[0]);
- cpu_set(0, cpu_core_map[0]);
+ disable_smp();
return;
}

/*
- * 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);
- }
-
- /*
- * If we couldn't find a local APIC, then get out of here now!
- */
- if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) && !cpu_has_apic) {
- 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");
- smpboot_clear_io_apic_irqs();
- phys_cpu_present_map = physid_mask_of_physid(0);
- cpu_set(0, cpu_sibling_map[0]);
- cpu_set(0, cpu_core_map[0]);
- return;
- }
-
- verify_local_APIC();
-
- /*
* If SMP should be disabled, then really disable it!
*/
- if (!max_cpus) {
- smp_found_config = 0;
- printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
- smpboot_clear_io_apic_irqs();
- phys_cpu_present_map = physid_mask_of_physid(0);
- cpu_set(0, cpu_sibling_map[0]);
- cpu_set(0, cpu_core_map[0]);
+ if (!max_cpus || (enable_local_apic < 0)) {
+ printk(KERN_INFO "SMP mode deactivated.\n");
+ disable_smp();
return;
}

- connect_bsp_APIC();
- setup_local_APIC();
- map_cpu_to_logical_apicid();
-
-
setup_portio_remap();

/*
@@ -1240,10 +1208,6 @@ static void __init smp_boot_cpus(unsigne
cpu_set(0, cpu_sibling_map[0]);
cpu_set(0, cpu_core_map[0]);

- smpboot_setup_io_apic();
-
- setup_boot_APIC_clock();
-
/*
* Synchronize the TSC with the AP
*/
diff --git a/arch/i386/kernel/time.c b/arch/i386/kernel/time.c
--- a/arch/i386/kernel/time.c
+++ b/arch/i386/kernel/time.c
@@ -444,8 +444,8 @@ static int time_init_device(void)

device_initcall(time_init_device);

-#ifdef CONFIG_HPET_TIMER
extern void (*late_time_init)(void);
+#ifdef CONFIG_HPET_TIMER
/* Duplicate of time_init() below, with hpet_enable part added */
static void __init hpet_time_init(void)
{
@@ -462,6 +462,12 @@ static void __init hpet_time_init(void)
printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name);

time_init_hook();
+
+#if CONFIG_X86_LOCAL_APIC
+ if (enable_local_apic >= 0) {
+ APIC_late_time_init();
+ }
+#endif
}
#endif

@@ -486,4 +492,10 @@ void __init time_init(void)
printk(KERN_INFO "Using %s for high-res timesource\n",cur_timer->name);

time_init_hook();
+
+#if CONFIG_X86_LOCAL_APIC
+ if (enable_local_apic >= 0) {
+ late_time_init = APIC_late_time_init;
+ }
+#endif
}
diff --git a/include/asm-i386/apic.h b/include/asm-i386/apic.h
--- a/include/asm-i386/apic.h
+++ b/include/asm-i386/apic.h
@@ -118,7 +118,8 @@ extern void release_lapic_nmi(void);
extern void disable_timer_nmi_watchdog(void);
extern void enable_timer_nmi_watchdog(void);
extern void nmi_watchdog_tick (struct pt_regs * regs);
-extern int APIC_init_uniprocessor (void);
+extern int APIC_init(void);
+extern void APIC_late_time_init(void);
extern void disable_APIC_timer(void);
extern void enable_APIC_timer(void);

diff --git a/include/asm-i386/hw_irq.h b/include/asm-i386/hw_irq.h
--- a/include/asm-i386/hw_irq.h
+++ b/include/asm-i386/hw_irq.h
@@ -55,6 +55,7 @@ void init_8259A(int aeoi);
void FASTCALL(send_IPI_self(int vector));
void init_VISWS_APIC_irqs(void);
void setup_IO_APIC(void);
+void IO_APIC_late_time_init(void);
void disable_IO_APIC(void);
void print_IO_APIC(void);
int IO_APIC_get_PCI_irq_vector(int bus, int slot, int fn);
diff --git a/include/asm-i386/mach-default/smpboot_hooks.h b/include/asm-i386/mach-default/smpboot_hooks.h
--- a/include/asm-i386/mach-default/smpboot_hooks.h
+++ b/include/asm-i386/mach-default/smpboot_hooks.h
@@ -1,11 +1,6 @@
/* two abstractions specific to kernel/smpboot.c, mainly to cater to visws
* which needs to alter them. */

-static inline void smpboot_clear_io_apic_irqs(void)
-{
- io_apic_irqs = 0;
-}
-
static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)
{
CMOS_WRITE(0xa, 0xf);
@@ -32,13 +27,3 @@ static inline void smpboot_restore_warm_

*((volatile long *) phys_to_virt(0x467)) = 0;
}
-
-static inline void smpboot_setup_io_apic(void)
-{
- /*
- * Here we can be sure that there is an IO-APIC in the system. Let's
- * go and set it up:
- */
- if (!skip_ioapic_setup && nr_ioapics)
- setup_IO_APIC();
-}
diff --git a/include/asm-i386/mach-visws/smpboot_hooks.h b/include/asm-i386/mach-visws/smpboot_hooks.h
--- a/include/asm-i386/mach-visws/smpboot_hooks.h
+++ b/include/asm-i386/mach-visws/smpboot_hooks.h
@@ -11,14 +11,7 @@ static inline void smpboot_setup_warm_re

/* for visws do nothing for any of these */

-static inline void smpboot_clear_io_apic_irqs(void)
-{
-}
-
static inline void smpboot_restore_warm_reset_vector(void)
{
}

-static inline void smpboot_setup_io_apic(void)
-{
-}
diff --git a/init/main.c b/init/main.c
--- a/init/main.c
+++ b/init/main.c
@@ -64,10 +64,6 @@
#endif
#endif

-#ifdef CONFIG_X86_LOCAL_APIC
-#include <asm/smp.h>
-#endif
-
/*
* Versions of gcc older than that listed below may actually compile
* and link okay, but the end product can have subtle run time bugs.
@@ -314,14 +310,7 @@ extern void setup_arch(char **);

#ifndef CONFIG_SMP

-#ifdef CONFIG_X86_LOCAL_APIC
-static void __init smp_init(void)
-{
- APIC_init_uniprocessor();
-}
-#else
#define smp_init() do { } while (0)
-#endif

static inline void setup_per_cpu_areas(void) { }
static inline void smp_prepare_cpus(unsigned int maxcpus) { }
-
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