diff options
| author | Rong Bao <rong.bao@csmantle.top> | 2026-07-23 22:27:29 +0800 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2026-07-23 22:27:29 +0800 |
| commit | 4e8f58620f6717f72f3d88a2c8f25c0c656d0ba7 (patch) | |
| tree | 30e271ceeb13086674b575f4f54c9d9a073e2906 | |
| parent | ea68d444a658783234a06f05414e41cf93a18fb2 (diff) | |
LoongArch: Retrieve CPU package ID from PPTT when available
Currently, the LoongArch CPU topology initialization code calculates
each core's package ID by dividing its physical ID by loongson_sysconf.
cores_per_package. This relies on the assumption that cores_per_package
counts in the same domain as physical IDs.
On Loongson-3B6000 (XB612B0V_1.2), cores_per_package matches the visible
core count -- 24 in this case. However, the physical IDs range from 0 to
31 in a noncontinuous fashion:
$ cat /proc/cpuinfo | grep -i -F 'global_id'
global_id : 0
global_id : 1
global_id : 4
global_id : 5
global_id : 6
global_id : 7
global_id : 8
global_id : 9
global_id : 10
global_id : 11
global_id : 14
global_id : 15
global_id : 16
global_id : 17
global_id : 20
global_id : 21
global_id : 22
global_id : 23
global_id : 26
global_id : 27
global_id : 28
global_id : 29
global_id : 30
global_id : 31
Retrieve the exact package ID from ACPI PPTT when available, in the same
style as retrieving the core ID and thread ID in parse_acpi_topology().
Use this information in loongson_init_secondary() when the PPTT readout
is successful. The original division logic is kept as a fallback.
Meanwhile, since some existing code paths like loongson3_cpufreq expect
a continuous integer sequence of package IDs in [0, MAX_PACKAGES) when
retrieving from cpu_data[], here we also canonicalize the package ID to
be filled in parse_acpi_topology() to meet such an expectation.
Cc: stable@vger.kernel.org
Tested-by: Mingcong Bai <jeffbai@aosc.io>
Co-developed-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Rong Bao <rong.bao@csmantle.top>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
| -rw-r--r-- | arch/loongarch/kernel/acpi.c | 27 | ||||
| -rw-r--r-- | arch/loongarch/kernel/smp.c | 4 |
2 files changed, 28 insertions, 3 deletions
diff --git a/arch/loongarch/kernel/acpi.c b/arch/loongarch/kernel/acpi.c index 8f650c9ffecd..873e90990771 100644 --- a/arch/loongarch/kernel/acpi.c +++ b/arch/loongarch/kernel/acpi.c @@ -201,10 +201,12 @@ static void __init acpi_process_madt(void) } int pptt_enabled; +static int acpi_nr_packages; +static int acpi_package_ids[MAX_PACKAGES]; int __init parse_acpi_topology(void) { - int cpu, topology_id; + int i, cpu, topology_id; for_each_possible_cpu(cpu) { topology_id = find_acpi_cpu_topology(cpu, 0); @@ -222,6 +224,29 @@ int __init parse_acpi_topology(void) cpu_data[cpu].core = topology_id; } + + topology_id = find_acpi_cpu_topology_package(cpu); + if (topology_id < 0) { + pr_warn("Invalid BIOS PPTT\n"); + return -ENOENT; + } + + for (i = 0; i < acpi_nr_packages; i++) + if (acpi_package_ids[i] == topology_id) + break; + + if (i == acpi_nr_packages) + acpi_package_ids[acpi_nr_packages++] = topology_id; + + cpu_data[cpu].package = topology_id; + } + + for_each_possible_cpu(cpu) { + for (i = 0; i < acpi_nr_packages; i++) + if (cpu_data[cpu].package == acpi_package_ids[i]) { + cpu_data[cpu].package = i; /* Canonicalize */ + break; + } } pptt_enabled = 1; diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c index 5d792256bbb9..d4b5d1b6bb01 100644 --- a/arch/loongarch/kernel/smp.c +++ b/arch/loongarch/kernel/smp.c @@ -426,10 +426,10 @@ void loongson_init_secondary(void) numa_add_cpu(cpu); #endif per_cpu(cpu_state, cpu) = CPU_ONLINE; - cpu_data[cpu].package = - cpu_logical_map(cpu) / loongson_sysconf.cores_per_package; cpu_data[cpu].core = pptt_enabled ? cpu_data[cpu].core : cpu_logical_map(cpu) % loongson_sysconf.cores_per_package; + cpu_data[cpu].package = pptt_enabled ? cpu_data[cpu].package : + cpu_logical_map(cpu) / loongson_sysconf.cores_per_package; cpu_data[cpu].global_id = cpu_logical_map(cpu); } |