[PATCH v7 06/13] x86/apic: Mark the apic_intr_mode extern for sanity check cleanup

From: Dou Liyang
Date: Fri Jul 14 2017 - 01:55:57 EST


Calling native_smp_prepare_cpus() to prepare for SMP bootup, does
some sanity checking, enables APIC mode and disables SMP feature.

Now, APIC mode setup has been unified to apic_intr_mode_init(),
some sanity checks are redundant and need to be cleanup.

Mark the apic_intr_mode extern to refine the switch and remove
the redundant sanity check.

Signed-off-by: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>
---
arch/x86/include/asm/apic.h | 9 +++++++
arch/x86/kernel/apic/apic.c | 12 ++++------
arch/x86/kernel/smpboot.c | 57 +++++++--------------------------------------
3 files changed, 22 insertions(+), 56 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 4e550c7..01f3fc8 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -53,6 +53,15 @@ extern int local_apic_timer_c2_ok;
extern int disable_apic;
extern unsigned int lapic_timer_frequency;

+extern enum apic_intr_mode_id apic_intr_mode;
+enum apic_intr_mode_id {
+ APIC_PIC,
+ APIC_VIRTUAL_WIRE,
+ APIC_VIRTUAL_WIRE_NO_CONFIG,
+ APIC_SYMMETRIC_IO,
+ APIC_SYMMETRIC_IO_NO_ROUTING
+};
+
#ifdef CONFIG_SMP
extern void __inquire_remote_apic(int apicid);
#else /* CONFIG_SMP */
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index bf29778..7e2b130 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1235,13 +1235,7 @@ void __init sync_Arb_IDs(void)
APIC_INT_LEVELTRIG | APIC_DM_INIT);
}

-enum apic_intr_mode {
- APIC_PIC,
- APIC_VIRTUAL_WIRE,
- APIC_VIRTUAL_WIRE_NO_CONFIG,
- APIC_SYMMETRIC_IO,
- APIC_SYMMETRIC_IO_NO_ROUTING,
-};
+enum apic_intr_mode_id apic_intr_mode;

static int __init apic_intr_mode_select(void)
{
@@ -1367,7 +1361,9 @@ void __init apic_intr_mode_init(void)
{
bool upmode = false;

- switch (apic_intr_mode_select()) {
+ apic_intr_mode = apic_intr_mode_select();
+
+ switch (apic_intr_mode) {
case APIC_PIC:
pr_info("APIC: keep in PIC mode(8259)\n");
return;
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 5ca41a5..f006f07 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1183,17 +1183,10 @@ static __init void disable_smp(void)
cpumask_set_cpu(0, topology_core_cpumask(0));
}

-enum {
- SMP_OK,
- SMP_NO_CONFIG,
- SMP_NO_APIC,
- SMP_FORCE_UP,
-};
-
/*
* Various sanity checks.
*/
-static int __init smp_sanity_check(unsigned max_cpus)
+static void __init smp_sanity_check(void)
{
preempt_disable();

@@ -1231,16 +1224,6 @@ static int __init smp_sanity_check(unsigned max_cpus)
}

/*
- * If we couldn't find an SMP configuration at boot time,
- * get out of here now!
- */
- if (!smp_found_config && !acpi_lapic) {
- preempt_enable();
- pr_notice("SMP motherboard not detected\n");
- return SMP_NO_CONFIG;
- }
-
- /*
* Should not be necessary because the MP table should list the boot
* CPU too, but we do it for the sake of robustness anyway.
*/
@@ -1250,29 +1233,6 @@ static int __init smp_sanity_check(unsigned max_cpus)
physid_set(hard_smp_processor_id(), phys_cpu_present_map);
}
preempt_enable();
-
- /*
- * If we couldn't find a local APIC, then get out of here now!
- */
- if (APIC_INTEGRATED(boot_cpu_apic_version) &&
- !boot_cpu_has(X86_FEATURE_APIC)) {
- if (!disable_apic) {
- pr_err("BIOS bug, local APIC #%d not detected!...\n",
- boot_cpu_physical_apicid);
- pr_err("... forcing use of dummy APIC emulation (tell your hw vendor)\n");
- }
- return SMP_NO_APIC;
- }
-
- /*
- * If SMP should be disabled, then really disable it!
- */
- if (!max_cpus) {
- pr_info("SMP mode deactivated\n");
- return SMP_FORCE_UP;
- }
-
- return SMP_OK;
}

static void __init smp_cpu_index_default(void)
@@ -1331,19 +1291,20 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)

apic_intr_mode_init();

- switch (smp_sanity_check(max_cpus)) {
- case SMP_NO_CONFIG:
- disable_smp();
- return;
- case SMP_NO_APIC:
+ smp_sanity_check();
+
+ switch (apic_intr_mode) {
+ case APIC_PIC:
+ case APIC_VIRTUAL_WIRE_NO_CONFIG:
disable_smp();
return;
- case SMP_FORCE_UP:
+ case APIC_SYMMETRIC_IO_NO_ROUTING:
disable_smp();
/* Setup local timer */
x86_init.timers.setup_percpu_clockev();
return;
- case SMP_OK:
+ case APIC_VIRTUAL_WIRE:
+ case APIC_SYMMETRIC_IO:
break;
}

--
2.5.5