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acpi/acpi.c: Follow spec more closely for MADT

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Secondary threads need to be added after the primary threads.

Change-Id: I3a98560760b662a7ba7efb46f5f7882fb0f7bb1f
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/69225
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
This commit is contained in:
Arthur Heymans
2022-11-04 14:00:35 +01:00
committed by Kyösti Mälkki
parent b885be4d2a
commit 8547429d39
1 changed files with 29 additions and 10 deletions
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27
src/acpi/acpi.c
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@@ -157,20 +157,39 @@ unsigned long acpi_create_madt_one_lapic(unsigned long current, u32 index, u32 l
return current; return current;
} }
/* Increase if necessary. Currently all x86 CPUs only have 2 SMP threads */
#define MAX_THREAD_ID 1
/*
* From ACPI 6.4 spec:
* "The advent of multi-threaded processors yielded multiple logical processors
* executing on common processor hardware. ACPI defines logical processors in
* an identical manner as physical processors. To ensure that non
* multi-threading aware OSPM implementations realize optimal performance on
* platforms containing multi-threaded processors, two guidelines should be
* followed. The first is the same as above, that is, OSPM should initialize
* processors in the order that they appear in the MADT. The second is that
* platform firmware should list the first logical processor of each of the
* individual multi-threaded processors in the MADT before listing any of the
* second logical processors. This approach should be used for all successive
* logical processors."
*/
static unsigned long acpi_create_madt_lapics(unsigned long current) static unsigned long acpi_create_madt_lapics(unsigned long current)
{ {
struct device *cpu; struct device *cpu;
int index, apic_ids[CONFIG_MAX_CPUS] = {0}, num_cpus = 0; int index, apic_ids[CONFIG_MAX_CPUS] = {0}, num_cpus = 0, sort_start = 0;
for (unsigned int thread_id = 0; thread_id <= MAX_THREAD_ID; thread_id++) {
for (cpu = all_devices; cpu; cpu = cpu->next) { for (cpu = all_devices; cpu; cpu = cpu->next) {
if (!is_enabled_cpu(cpu)) if (!is_enabled_cpu(cpu))
continue; continue;
if (num_cpus >= ARRAY_SIZE(apic_ids)) if (num_cpus >= ARRAY_SIZE(apic_ids))
break; break;
if (cpu->path.apic.thread_id != thread_id)
continue;
apic_ids[num_cpus++] = cpu->path.apic.apic_id; apic_ids[num_cpus++] = cpu->path.apic.apic_id;
} }
if (num_cpus > 1) bubblesort(&apic_ids[sort_start], num_cpus - sort_start, NUM_ASCENDING);
bubblesort(apic_ids, num_cpus, NUM_ASCENDING); sort_start = num_cpus;
}
for (index = 0; index < num_cpus; index++) for (index = 0; index < num_cpus; index++)
current = acpi_create_madt_one_lapic(current, index, apic_ids[index]); current = acpi_create_madt_one_lapic(current, index, apic_ids[index]);