2023-07-28 12:44:06

by Thomas Gleixner

Subject: [patch v2 11/38] x86/apic: Use BAD_APICID consistently;

APIC ID checks compare with BAD_APICID all over the place, but some
initializers and some code which fiddles with global data structure use
-1[U] instead. That simply cannot work at all.

Fix it up and use BAD_APICID consistenly all over the place.

Signed-off-by: Thomas Gleixner <[email protected]>
---
arch/x86/kernel/acpi/boot.c | 2 +-
arch/x86/kernel/apic/apic.c | 6 ++----
2 files changed, 3 insertions(+), 5 deletions(-)

--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -852,7 +852,7 @@ int acpi_unmap_cpu(int cpu)
set_apicid_to_node(per_cpu(x86_cpu_to_apicid, cpu), NUMA_NO_NODE);
#endif

- per_cpu(x86_cpu_to_apicid, cpu) = -1;
+ per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
set_cpu_present(cpu, false);
num_processors--;

--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -70,7 +70,7 @@ unsigned int num_processors;
unsigned disabled_cpus;

/* Processor that is doing the boot up */
-unsigned int boot_cpu_physical_apicid __ro_after_init = -1U;
+unsigned int boot_cpu_physical_apicid __ro_after_init = BAD_APICID;
EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);

u8 boot_cpu_apic_version __ro_after_init;
@@ -2316,9 +2316,7 @@ static int nr_logical_cpuids = 1;
/*
* Used to store mapping between logical CPU IDs and APIC IDs.
*/
-int cpuid_to_apicid[] = {
- [0 ... NR_CPUS - 1] = -1,
-};
+int cpuid_to_apicid[] = { [0 ... NR_CPUS - 1] = BAD_APICID, };

bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
{

2023-07-29 00:29:57

by Thomas Gleixner

Subject: Re: [patch v2 11/38] x86/apic: Use BAD_APICID consistently;

On Fri, Jul 28 2023 at 15:36, Sohil Mehta wrote:

> There is an extra semicolon at the end of the patch subject.

Oops

> On 7/28/2023 5:12 AM, Thomas Gleixner wrote:
>> APIC ID checks compare with BAD_APICID all over the place, but some
>> initializers and some code which fiddles with global data structure use
>> -1[U] instead. That simply cannot work at all.
>>
>> Fix it up and use BAD_APICID consistenly all over the place.
>>
>
> s/consistenly/consistently

Indeed.

2023-07-29 00:31:47

by Sohil Mehta

Subject: Re: [patch v2 11/38] x86/apic: Use BAD_APICID consistently;

There is an extra semicolon at the end of the patch subject.

On 7/28/2023 5:12 AM, Thomas Gleixner wrote:
> APIC ID checks compare with BAD_APICID all over the place, but some
> initializers and some code which fiddles with global data structure use
> -1[U] instead. That simply cannot work at all.
>
> Fix it up and use BAD_APICID consistenly all over the place.
>

s/consistenly/consistently

-Sohil