On Tue, 14 Jul 2015, Lukasz Anaczkowski wrote:
> This patch is based on work of "Yinghai Lu <[email protected]>"
> previously published at https://lkml.org/lkml/2013/1/21/563.
>
> In case when BIOS is populating MADT wiht both x2apic and local apic
> entries (as per ACPI spec), e.g. for Xeon Phi Knights Landing,
> kernel builds it's processor table in the following order:
> BSP, X2APIC, local APIC, resulting in processors on the same core
> are not separated by core count, i.e.
You are missing to explain WHY this is the wrong ordering.
> Core LCpu ApicId LCpu ApicId LCpu ApicId LCpu ApicId
> 0 0 ( 0 [0000]), 97 ( 1 [0001]), 145 ( 2 [0002]), 193 ( 3 [0003])
> 1 50 ( 4 [0004]), 98 ( 5 [0005]), 146 ( 6 [0006]), 194 ( 7 [0007])
> 2 51 ( 16 [0010]), 99 ( 17 [0011]), 147 ( 18 [0012]), 195 ( 19 [0013])
> 3 52 ( 20 [0014]), 100 ( 21 [0015]), 148 ( 22 [0016]), 196 ( 23 [0017])
> 4 53 ( 24 [0018]), 101 ( 25 [0019]), 149 ( 26 [001a]), 197 ( 27 [001b])
> 5 54 ( 28 [001c]), 102 ( 29 [001d]), 150 ( 30 [001e]), 198 ( 31 [001f])
> ...
>
> Please note, how LCpu are mixed for physical cores (Core).
>
> This patch fixes this behavior and resulting assignment is
> consistent with other Xeon processors, i.e.
You are missing to explain HOW you fix it. It's completely non obvious
why the conversion to an parse array makes it work.
> if (!count) {
> - x2count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_X2APIC,
> - acpi_parse_x2apic, MAX_LOCAL_APIC);
> - count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC,
> - acpi_parse_lapic, MAX_LOCAL_APIC);
> + memset(madt_proc, 0, sizeof(madt_proc));
> + madt_proc[0].id = ACPI_MADT_TYPE_LOCAL_APIC;
> + madt_proc[0].handler = acpi_parse_lapic;
> + madt_proc[1].id = ACPI_MADT_TYPE_LOCAL_X2APIC;
> + madt_proc[1].handler = acpi_parse_x2apic;
Here you revert the parse order.
> + acpi_table_parse_entries_array(ACPI_SIG_MADT,
> + sizeof(struct acpi_table_madt),
> + madt_proc, ARRAY_SIZE(madt_proc), MAX_LOCAL_APIC);
> + count = madt_proc[0].count;
> + x2count = madt_proc[1].count;
> }
> if (!count && !x2count) {
> printk(KERN_ERR PREFIX "No LAPIC entries present\n");
> @@ -1019,10 +1026,16 @@ static int __init acpi_parse_madt_lapic_entries(void)
> return count;
> }
>
> - x2count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_X2APIC_NMI,
> - acpi_parse_x2apic_nmi, 0);
> - count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_NMI,
> - acpi_parse_lapic_nmi, 0);
> + memset(madt_proc, 0, sizeof(madt_proc));
> + madt_proc[0].id = ACPI_MADT_TYPE_LOCAL_APIC_NMI;
> + madt_proc[0].handler = acpi_parse_lapic_nmi;
> + madt_proc[1].id = ACPI_MADT_TYPE_LOCAL_X2APIC_NMI;
> + madt_proc[1].handler = acpi_parse_x2apic_nmi;
Ditto
> int __init acpi_numa_init(void)
> @@ -331,10 +337,18 @@ int __init acpi_numa_init(void)
>
> /* SRAT: Static Resource Affinity Table */
> if (!acpi_table_parse(ACPI_SIG_SRAT, acpi_parse_srat)) {
> - acpi_table_parse_srat(ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY,
> - acpi_parse_x2apic_affinity, 0);
> - acpi_table_parse_srat(ACPI_SRAT_TYPE_CPU_AFFINITY,
> - acpi_parse_processor_affinity, 0);
> + struct acpi_subtable_proc srat_proc[2];
> +
> + memset(srat_proc, 0, sizeof(srat_proc));
> + srat_proc[0].id = ACPI_SRAT_TYPE_CPU_AFFINITY;
> + srat_proc[0].handler = acpi_parse_processor_affinity;
> + srat_proc[1].id = ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY;
> + srat_proc[1].handler = acpi_parse_x2apic_affinity;
Once more.
Please add proper explanations why the array parser is required and
why the parse order needs to be reverse.
Thanks,
tglx
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