[PATCH v5 05/12] x86/apic: Unify interrupt mode setup for SMP-capable system

From: Dou Liyang
Date: Fri Jun 30 2017 - 00:09:39 EST


In the SMP-capable system, enable and setup the interrupt delivery
mode in native_smp_prepare_cpus().

This design mixs the APIC and SMP together, it has highly coupling.

Make the initialization of interrupt mode independent, Unify and
refine it to apic_intr_mode_init() for SMP-capable system.

Signed-off-by: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>
---
arch/x86/kernel/apic/apic.c | 41 ++++++++++++++++++++++++++++++++++++-----
arch/x86/kernel/smpboot.c | 13 ++-----------
2 files changed, 38 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 498edbe..bea8032 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1160,10 +1160,12 @@ void __init sync_Arb_IDs(void)
enum apic_intr_mode {
APIC_PIC,
APIC_VIRTUAL_WIRE,
+ APIC_VIRTUAL_WIRE_NO_CONFIG,
APIC_SYMMETRIC_IO,
+ APIC_SYMMETRIC_IO_NO_ROUTING,
};

-static int __init apic_intr_mode_select(void)
+static int __init apic_intr_mode_select(int *upmode)
{
/* Check kernel option */
if (disable_apic) {
@@ -1206,12 +1208,30 @@ static int __init apic_intr_mode_select(void)
if (!smp_found_config) {
disable_ioapic_support();

- if (!acpi_lapic)
+ if (!acpi_lapic) {
pr_info("APIC: ACPI MADT or MP tables are not detected\n");
+ *upmode = true;
+
+ return APIC_VIRTUAL_WIRE_NO_CONFIG;
+ }

return APIC_VIRTUAL_WIRE;
}

+#ifdef CONFIG_SMP
+ /* If SMP should be disabled, then really disable it! */
+ if (!setup_max_cpus) {
+ pr_info("APIC: SMP mode deactivated\n");
+ return APIC_SYMMETRIC_IO_NO_ROUTING;
+ }
+
+ if (read_apic_id() != boot_cpu_physical_apicid) {
+ panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
+ read_apic_id(), boot_cpu_physical_apicid);
+ /* Or can we switch back to PIC here? */
+ }
+#endif
+
/* Other checks of APIC options will be done in each setup function */

return APIC_SYMMETRIC_IO;
@@ -1269,20 +1289,31 @@ void __init init_bsp_APIC(void)
/* Init the interrupt delivery mode for the BSP */
void __init apic_intr_mode_init(void)
{
- switch (apic_intr_mode_select()) {
+ int upmode = false;
+
+ switch (apic_intr_mode_select(&upmode)) {
case APIC_PIC:
apic_printk(APIC_VERBOSE, KERN_INFO
"Keep in PIC mode(8259)\n");
return;
case APIC_VIRTUAL_WIRE:
+ case APIC_VIRTUAL_WIRE_NO_CONFIG:
apic_printk(APIC_VERBOSE, KERN_INFO
"Switch to virtual wire mode setup\n");
- return;
+ default_setup_apic_routing();
+ break;
case APIC_SYMMETRIC_IO:
apic_printk(APIC_VERBOSE, KERN_INFO
"Switch to symmectic I/O mode setup\n");
- return;
+ default_setup_apic_routing();
+ break;
+ case APIC_SYMMETRIC_IO_NO_ROUTING:
+ apic_printk(APIC_VERBOSE, KERN_INFO
+ "Switch to symmectic I/O mode setup in no SMP routine\n");
+ break;
}
+
+ apic_bsp_setup(upmode);
}

static void lapic_setup_esr(void)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index d6721f0..b9b2a43 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1321,18 +1321,17 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)

set_cpu_sibling_map(0);

+ apic_intr_mode_init();
+
switch (smp_sanity_check(max_cpus)) {
case SMP_NO_CONFIG:
disable_smp();
- if (APIC_init_uniprocessor())
- pr_notice("Local APIC not detected. Using dummy APIC emulation.\n");
return;
case SMP_NO_APIC:
disable_smp();
return;
case SMP_FORCE_UP:
disable_smp();
- apic_bsp_setup(false);
/* Setup local timer */
x86_init.timers.setup_percpu_clockev();
return;
@@ -1340,14 +1339,6 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
break;
}

- if (read_apic_id() != boot_cpu_physical_apicid) {
- panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
- read_apic_id(), boot_cpu_physical_apicid);
- /* Or can we switch back to PIC here? */
- }
-
- default_setup_apic_routing();
- apic_bsp_setup(false);
if (x2apic_mode)
cpu0_logical_apicid = apic_read(APIC_LDR);
else
--
2.5.5