diff options
Diffstat (limited to 'sys-kernel_arch-sources-g14_files-9008-fix-cpu-hotplug.patch')
| -rw-r--r-- | sys-kernel_arch-sources-g14_files-9008-fix-cpu-hotplug.patch | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/sys-kernel_arch-sources-g14_files-9008-fix-cpu-hotplug.patch b/sys-kernel_arch-sources-g14_files-9008-fix-cpu-hotplug.patch new file mode 100644 index 000000000000..f80a0850d67a --- /dev/null +++ b/sys-kernel_arch-sources-g14_files-9008-fix-cpu-hotplug.patch @@ -0,0 +1,73 @@ +Date: Fri, 13 Aug 2021 11:18:42 -0500 [thread overview] +Message-ID: <20210813161842.222414-1-mario.limonciello@amd.com> (raw) + +A number of systems are showing "hotplug capable" CPUs when they +are not really hotpluggable. This is because the MADT has extra +CPU entries to support different CPUs that may be inserted into +the socket with different numbers of cores. + +Starting with ACPI 6.3 the spec has an Online Capable bit in the +MADT used to determine whether or not a CPU is hotplug capable +when the enabled bit is not set. + +Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html?#local-apic-flags +Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> +--- + arch/x86/kernel/acpi/boot.c | 10 ++++++++++ + include/acpi/actbl2.h | 1 + + 2 files changed, 11 insertions(+) + +Changes from v1->v2: + * Check the revision field in MADT to determine if it matches the + bump from ACPI 6.3 as suggested by Hanjun Guo + * Update description + +diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c +index e55e0c1fad8c..bfa69a5c9c0b 100644 +--- a/arch/x86/kernel/acpi/boot.c ++++ b/arch/x86/kernel/acpi/boot.c +@@ -53,6 +53,8 @@ int acpi_ioapic; + int acpi_strict; + int acpi_disable_cmcff; + ++bool acpi_support_online_capable; ++ + /* ACPI SCI override configuration */ + u8 acpi_sci_flags __initdata; + u32 acpi_sci_override_gsi __initdata = INVALID_ACPI_IRQ; +@@ -138,6 +140,8 @@ static int __init acpi_parse_madt(struct acpi_table_header *table) + + pr_debug("Local APIC address 0x%08x\n", madt->address); + } ++ if (madt->header.revision >= 5) ++ acpi_support_online_capable = true; + + default_acpi_madt_oem_check(madt->header.oem_id, + madt->header.oem_table_id); +@@ -239,6 +243,12 @@ acpi_parse_lapic(union acpi_subtable_headers * header, const unsigned long end) + if (processor->id == 0xff) + return 0; + ++ /* don't register processors that can not be onlined */ ++ if (acpi_support_online_capable && ++ !(processor->lapic_flags & ACPI_MADT_ENABLED) && ++ !(processor->lapic_flags & ACPI_MADT_ONLINE_CAPABLE)) ++ return 0; ++ + /* + * We need to register disabled CPU as well to permit + * counting disabled CPUs. This allows us to size +diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h +index 2069ac38a4e2..fae45e383987 100644 +--- a/include/acpi/actbl2.h ++++ b/include/acpi/actbl2.h +@@ -808,6 +808,7 @@ struct acpi_madt_multiproc_wakeup_mailbox { + /* MADT Local APIC flags */ + + #define ACPI_MADT_ENABLED (1) /* 00: Processor is usable if set */ ++#define ACPI_MADT_ONLINE_CAPABLE (2) /* 01: System HW supports enabling processor at runtime */ + + /* MADT MPS INTI flags (inti_flags) */ + +-- +2.25.1
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