Messages in this thread | | | Date | Tue, 21 Jul 2015 10:27:21 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] x86, acpi: Handle xapic/x2apic entries in MADT |
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On Tue, 14 Jul 2015, Lukasz Anaczkowski wrote: > This patch is based on work of "Yinghai Lu <yinghai@kernel.org>" > 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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