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

[Dou Liyang]

Hi Thomas,

At 07/03/2017 02:07 AM, Thomas Gleixner wrote:

On Fri, 30 Jun 2017, Dou Liyang wrote:

-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;


That store and extra argument is pointless.


+
+   return APIC_VIRTUAL_WIRE_NO_CONFIG;


You added an extra return code, which you can use exactly for that purpose
at the callsite.



Actually indeed. Great! Why didn't I think of that?



Aside of that, if you use int * then use numbers, if you use bool then use
true/false. But mixing that is horrible.



Yes, it is, I will remove the 'upmode' argument.


Thanks,

dou.


+   }


Thanks,

tglx

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

[Dou Liyang]

Hi Thomas,

At 07/03/2017 02:07 AM, Thomas Gleixner wrote:

On Fri, 30 Jun 2017, Dou Liyang wrote:

-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;


That store and extra argument is pointless.


+
+   return APIC_VIRTUAL_WIRE_NO_CONFIG;


You added an extra return code, which you can use exactly for that purpose
at the callsite.



Actually indeed. Great! Why didn't I think of that?



Aside of that, if you use int * then use numbers, if you use bool then use
true/false. But mixing that is horrible.



Yes, it is, I will remove the 'upmode' argument.


Thanks,

dou.


+   }


Thanks,

tglx

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

[Thomas Gleixner]

On Fri, 30 Jun 2017, Dou Liyang wrote:
> -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;

That store and extra argument is pointless. 

> +
> + return APIC_VIRTUAL_WIRE_NO_CONFIG;

You added an extra return code, which you can use exactly for that purpose
at the callsite.


Aside of that, if you use int * then use numbers, if you use bool then use
true/false. But mixing that is horrible.

> + }

Thanks,

tglx

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

[Thomas Gleixner]

On Fri, 30 Jun 2017, Dou Liyang wrote:
> -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;

That store and extra argument is pointless. 

> +
> + return APIC_VIRTUAL_WIRE_NO_CONFIG;

You added an extra return code, which you can use exactly for that purpose
at the callsite.


Aside of that, if you use int * then use numbers, if you use bool then use
true/false. But mixing that is horrible.

> + }

Thanks,

tglx

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

[Dou Liyang]

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 
---
 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()) {
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

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

[Dou Liyang]

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 
---
 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()) {
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