Re: [Patch v3 1/2] introduce variable acpi_lapic into ia64

[Baoquan He <bhe@redhat.com>]

Hi Rafael,

Thanks for previous comments and suggestions.


I added the acpi_lapic in ia64. However I didn't find ia64 machine to
test it. Could you or anyone please help test this 2 patches?

I don't know how to test UP system running SMP kernel with no LAPIC in
MADT when it's ia64 arch. 

Test steps for ia64 kdump:

1) get a multi-cpus ia64 machine, build a upstream kernel with SMP and
ACPI
2)install kexec-tools, and edit /etc/sysconfig/kdump to make sure
"nr_cpus=1" is in KDUMP_COMMANDLINE_APPEND. Then load the kdump kernel
by below command:

"kdumpctl restart" or "systemctl restart kdump"

3) After kdump kernel loaded, execute below shell command. This can make
crash happen in 2nd cpu.

taskset -c 1 sh -c "echo c >/proc/sysrq-trigger"


4) From console, below error message should not be printed any more. And
the cpu related to 2nd lapid is present, this can be checked by console
message and adding debugging code.

"acpi LNXCPU:0a: BIOS reported wrong ACPI id 0 for the processor."

--------
For x86_64, the UP test is taken by adding "disableapic nr_cpus=1" into
cmdline of grub. The test for kdump is the same as above ia64.

Thanks
Baoquan


On 05/05/14 at 12:48pm, Baoquan He wrote:
> This variable was defined and assigned in x86, is used to indicate
> whether LAPIC exists in MADT. Now introduce it into ia64 to help
> make correct judgment when get information for acpi processor later.
> 
> Signed-off-by: Baoquan He <bhe@redhat.com>
> ---
>  arch/ia64/include/asm/acpi.h | 1 +
>  arch/ia64/kernel/acpi.c      | 3 +++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/arch/ia64/include/asm/acpi.h b/arch/ia64/include/asm/acpi.h
> index d651102..b478219 100644
> --- a/arch/ia64/include/asm/acpi.h
> +++ b/arch/ia64/include/asm/acpi.h
> @@ -85,6 +85,7 @@ ia64_acpi_release_global_lock (unsigned int *lock)
>  	((Acq) = ia64_acpi_release_global_lock(&facs->global_lock))
>  
>  #ifdef	CONFIG_ACPI
> +extern int acpi_lapic;
>  #define acpi_disabled 0	/* ACPI always enabled on IA64 */
>  #define acpi_noirq 0	/* ACPI always enabled on IA64 */
>  #define acpi_pci_disabled 0 /* ACPI PCI always enabled on IA64 */
> diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
> index 0d407b3..615ef81 100644
> --- a/arch/ia64/kernel/acpi.c
> +++ b/arch/ia64/kernel/acpi.c
> @@ -56,6 +56,7 @@
>  
>  #define PREFIX			"ACPI: "
>  
> +int acpi_lapic;
>  unsigned int acpi_cpei_override;
>  unsigned int acpi_cpei_phys_cpuid;
>  
> @@ -676,6 +677,8 @@ int __init early_acpi_boot_init(void)
>  	if (ret < 1)
>  		printk(KERN_ERR PREFIX
>  		       "Error parsing MADT - no LAPIC entries\n");
> +	else
> +		acpi_lapic = 1;
>  
>  #ifdef CONFIG_SMP
>  	if (available_cpus == 0) {
> -- 
> 1.8.5.3
>