[PATCH v6 1/3] ACPI: Rename get_acpi_id_for_cpu() to acpi_get_cpu_uid() on non-x86

Chengwen Feng
2026-03-12T07:23:58Z

To unify the CPU ACPI ID retrieval interface across architectures,
rename the existing get_acpi_id_for_cpu() function to
acpi_get_cpu_uid() on arm64/riscv/loongarch platforms.

This is a pure rename with no functional change, preparing for a
consistent ACPI Processor UID retrieval interface across all ACPI-enabled
platforms.

Note: Move the ARM64-specific get_cpu_for_acpi_id() implementation to
arch/arm64/kernel/acpi_numa.c to fix compilation errors from
circular header dependencies introduced by the rename.

Cc: stable@vger.kernel.org
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
arch/arm64/include/asm/acpi.h | 16 +---------
arch/arm64/kernel/acpi.c | 16 ++++++++++
arch/arm64/kernel/acpi_numa.c | 15 ++++++++++
arch/loongarch/include/asm/acpi.h | 5 ----
arch/loongarch/kernel/acpi.c | 9 ++++++
arch/riscv/include/asm/acpi.h | 4 ---
arch/riscv/kernel/acpi.c | 16 ++++++++++
arch/riscv/kernel/acpi_numa.c | 8 +++--
drivers/acpi/pptt.c | 47 +++++++++++++++++++++---------
drivers/acpi/riscv/rhct.c | 7 ++++-
drivers/perf/arm_cspmu/arm_cspmu.c | 6 ++--
include/linux/acpi.h | 13 +++++++++
12 files changed, 120 insertions(+), 42 deletions(-)

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index c07a58b96329..106a08556cbf 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -114,22 +114,8 @@ static inline bool acpi_has_cpu_in_madt(void)
}

struct acpi_madt_generic_interrupt *acpi_cpu_get_madt_gicc(int cpu);
-static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
-{
- return acpi_cpu_get_madt_gicc(cpu)->uid;
-}
-
-static inline int get_cpu_for_acpi_id(u32 uid)
-{
- int cpu;
-
- for (cpu = 0; cpu < nr_cpu_ids; cpu++)
- if (acpi_cpu_get_madt_gicc(cpu) &&
- uid == get_acpi_id_for_cpu(cpu))
- return cpu;

- return -EINVAL;
-}
+int get_cpu_for_acpi_id(u32 uid);

static inline void arch_fix_phys_package_id(int num, u32 slot) { }
void __init acpi_init_cpus(void);
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index af90128cfed5..984a11788265 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -458,3 +458,19 @@ int acpi_unmap_cpu(int cpu)
}
EXPORT_SYMBOL(acpi_unmap_cpu);
#endif /* CONFIG_ACPI_HOTPLUG_CPU */
+
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid)
+{
+ struct acpi_madt_generic_interrupt *gicc;
+
+ if (cpu >= nr_cpu_ids)
+ return -EINVAL;
+
+ gicc = acpi_cpu_get_madt_gicc(cpu);
+ if (gicc == NULL)
+ return -ENODEV;
+
+ *uid = gicc->uid;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_get_cpu_uid);
diff --git a/arch/arm64/kernel/acpi_numa.c b/arch/arm64/kernel/acpi_numa.c
index 2465f291c7e1..56e2e486e49b 100644
--- a/arch/arm64/kernel/acpi_numa.c
+++ b/arch/arm64/kernel/acpi_numa.c
@@ -34,6 +34,21 @@ int __init acpi_numa_get_nid(unsigned int cpu)
return acpi_early_node_map[cpu];
}

+int get_cpu_for_acpi_id(u32 uid)
+{
+ u32 cpu_uid;
+ int cpu;
+ int ret;
+
+ for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
+ ret = acpi_get_cpu_uid(cpu, &cpu_uid);
+ if (ret == 0 && uid == cpu_uid)
+ return cpu;
+ }
+
+ return -EINVAL;
+}
+
static int __init acpi_parse_gicc_pxm(union acpi_subtable_headers *header,
const unsigned long end)
{
diff --git a/arch/loongarch/include/asm/acpi.h b/arch/loongarch/include/asm/acpi.h
index 7376840fa9f7..eda9d4d0a493 100644
--- a/arch/loongarch/include/asm/acpi.h
+++ b/arch/loongarch/include/asm/acpi.h
@@ -40,11 +40,6 @@ extern struct acpi_madt_core_pic acpi_core_pic[MAX_CORE_PIC];

extern int __init parse_acpi_topology(void);

-static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
-{
- return acpi_core_pic[cpu_logical_map(cpu)].processor_id;
-}
-
#endif /* !CONFIG_ACPI */

#define ACPI_TABLE_UPGRADE_MAX_PHYS ARCH_LOW_ADDRESS_LIMIT
diff --git a/arch/loongarch/kernel/acpi.c b/arch/loongarch/kernel/acpi.c
index 1367ca759468..058f0dbe8e8f 100644
--- a/arch/loongarch/kernel/acpi.c
+++ b/arch/loongarch/kernel/acpi.c
@@ -385,3 +385,12 @@ int acpi_unmap_cpu(int cpu)
EXPORT_SYMBOL(acpi_unmap_cpu);

#endif /* CONFIG_ACPI_HOTPLUG_CPU */
+
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid)
+{
+ if (cpu >= nr_cpu_ids)
+ return -EINVAL;
+ *uid = acpi_core_pic[cpu_logical_map(cpu)].processor_id;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_get_cpu_uid);
diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h
index 6e13695120bc..26ab37c171bc 100644
--- a/arch/riscv/include/asm/acpi.h
+++ b/arch/riscv/include/asm/acpi.h
@@ -61,10 +61,6 @@ static inline void arch_fix_phys_package_id(int num, u32 slot) { }

void acpi_init_rintc_map(void);
struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu);
-static inline u32 get_acpi_id_for_cpu(int cpu)
-{
- return acpi_cpu_get_madt_rintc(cpu)->uid;
-}

int acpi_get_riscv_isa(struct acpi_table_header *table,
unsigned int cpu, const char **isa);
diff --git a/arch/riscv/kernel/acpi.c b/arch/riscv/kernel/acpi.c
index 71698ee11621..bde810d02c4f 100644
--- a/arch/riscv/kernel/acpi.c
+++ b/arch/riscv/kernel/acpi.c
@@ -337,3 +337,19 @@ int raw_pci_write(unsigned int domain, unsigned int bus,
}

#endif /* CONFIG_PCI */
+
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid)
+{
+ struct acpi_madt_rintc *rintc;
+
+ if (cpu >= nr_cpu_ids)
+ return -EINVAL;
+
+ rintc = acpi_cpu_get_madt_rintc(cpu);
+ if (rintc == NULL)
+ return -ENODEV;
+
+ *uid = rintc->uid;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_get_cpu_uid);
diff --git a/arch/riscv/kernel/acpi_numa.c b/arch/riscv/kernel/acpi_numa.c
index 130769e3a99c..cd8adc9857e3 100644
--- a/arch/riscv/kernel/acpi_numa.c
+++ b/arch/riscv/kernel/acpi_numa.c
@@ -37,11 +37,15 @@ static int __init acpi_numa_get_nid(unsigned int cpu)

static inline int get_cpu_for_acpi_id(u32 uid)
{
+ u32 cpu_uid;
int cpu;
+ int ret;

- for (cpu = 0; cpu < nr_cpu_ids; cpu++)
- if (uid == get_acpi_id_for_cpu(cpu))
+ for (cpu = 0; cpu < nr_cpu_ids; cpu++) {
+ ret = acpi_get_cpu_uid(cpu, &cpu_uid);
+ if (ret == 0 && uid == cpu_uid)
return cpu;
+ }

return -EINVAL;
}
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index de5f8c018333..d034a217e85b 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c
@@ -459,11 +459,14 @@ static void cache_setup_acpi_cpu(struct acpi_table_header *table,
{
struct acpi_pptt_cache *found_cache;
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
- u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ u32 acpi_cpu_id;
struct cacheinfo *this_leaf;
unsigned int index = 0;
struct acpi_pptt_processor *cpu_node = NULL;

+ if (acpi_get_cpu_uid(cpu, &acpi_cpu_id) != 0)
+ return;
+
while (index < get_cpu_cacheinfo(cpu)->num_leaves) {
this_leaf = this_cpu_ci->info_list + index;
found_cache = acpi_find_cache_node(table, acpi_cpu_id,
@@ -546,7 +549,10 @@ static int topology_get_acpi_cpu_tag(struct acpi_table_header *table,
unsigned int cpu, int level, int flag)
{
struct acpi_pptt_processor *cpu_node;
- u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ u32 acpi_cpu_id;
+
+ if (acpi_get_cpu_uid(cpu, &acpi_cpu_id) != 0)
+ return -ENOENT;

cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
if (cpu_node) {
@@ -614,18 +620,22 @@ static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag)
*
* Check the node representing a CPU for a given flag.
*
- * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or
- * the table revision isn't new enough.
+ * Return: -ENOENT if can't get CPU's ACPI Processor UID, the PPTT doesn't
+ * exist, the CPU cannot be found or the table revision isn't new
+ * enough.
* 1, any passed flag set
* 0, flag unset
*/
static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag)
{
struct acpi_table_header *table;
- u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ u32 acpi_cpu_id;
struct acpi_pptt_processor *cpu_node = NULL;
int ret = -ENOENT;

+ if (acpi_get_cpu_uid(cpu, &acpi_cpu_id) != 0)
+ return -ENOENT;
+
table = acpi_get_pptt();
if (!table)
return -ENOENT;
@@ -651,7 +661,8 @@ static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag)
* in the PPTT. Errors caused by lack of a PPTT table, or otherwise, return 0
* indicating we didn't find any cache levels.
*
- * Return: -ENOENT if no PPTT table or no PPTT processor struct found.
+ * Return: -ENOENT if no PPTT table, can't get CPU's ACPI Process UID or no PPTT
+ * processor struct found.
* 0 on success.
*/
int acpi_get_cache_info(unsigned int cpu, unsigned int *levels,
@@ -671,7 +682,8 @@ int acpi_get_cache_info(unsigned int cpu, unsigned int *levels,

pr_debug("Cache Setup: find cache levels for CPU=%d\n", cpu);

- acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ if (acpi_get_cpu_uid(cpu, &acpi_cpu_id))
+ return -ENOENT;
cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
if (!cpu_node)
return -ENOENT;
@@ -780,8 +792,9 @@ int find_acpi_cpu_topology_package(unsigned int cpu)
* It may not exist in single CPU systems. In simple multi-CPU systems,
* it may be equal to the package topology level.
*
- * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found
- * or there is no toplogy level above the CPU..
+ * Return: -ENOENT if the PPTT doesn't exist, can't get CPU's ACPI
+ * Processor UID, the CPU cannot be found or there is no toplogy level
+ * above the CPU.
* Otherwise returns a value which represents the package for this CPU.
*/

@@ -797,7 +810,8 @@ int find_acpi_cpu_topology_cluster(unsigned int cpu)
if (!table)
return -ENOENT;

- acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ if (acpi_get_cpu_uid(cpu, &acpi_cpu_id) != 0)
+ return -ENOENT;
cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
if (!cpu_node || !cpu_node->parent)
return -ENOENT;
@@ -872,7 +886,8 @@ static void acpi_pptt_get_child_cpus(struct acpi_table_header *table_hdr,
cpumask_clear(cpus);

for_each_possible_cpu(cpu) {
- acpi_id = get_acpi_id_for_cpu(cpu);
+ if (acpi_get_cpu_uid(cpu, &acpi_id) != 0)
+ continue;
cpu_node = acpi_find_processor_node(table_hdr, acpi_id);

while (cpu_node) {
@@ -966,10 +981,13 @@ int find_acpi_cache_level_from_id(u32 cache_id)
for_each_possible_cpu(cpu) {
bool empty;
int level = 1;
- u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ u32 acpi_cpu_id;
struct acpi_pptt_cache *cache;
struct acpi_pptt_processor *cpu_node;

+ if (acpi_get_cpu_uid(cpu, &acpi_cpu_id) != 0)
+ continue;
+
cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
if (!cpu_node)
continue;
@@ -1030,10 +1048,13 @@ int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, cpumask_t *cpus)
for_each_possible_cpu(cpu) {
bool empty;
int level = 1;
- u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ u32 acpi_cpu_id;
struct acpi_pptt_cache *cache;
struct acpi_pptt_processor *cpu_node;

+ if (acpi_get_cpu_uid(cpu, &acpi_cpu_id) != 0)
+ continue;
+
cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
if (!cpu_node)
continue;
diff --git a/drivers/acpi/riscv/rhct.c b/drivers/acpi/riscv/rhct.c
index caa2c16e1697..8f3f38c64a88 100644
--- a/drivers/acpi/riscv/rhct.c
+++ b/drivers/acpi/riscv/rhct.c
@@ -44,10 +44,15 @@ int acpi_get_riscv_isa(struct acpi_table_header *table, unsigned int cpu, const
struct acpi_rhct_isa_string *isa_node;
struct acpi_table_rhct *rhct;
u32 *hart_info_node_offset;
- u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ u32 acpi_cpu_id;
+ int ret;

BUG_ON(acpi_disabled);

+ ret = acpi_get_cpu_uid(cpu, &acpi_cpu_id);
+ if (ret != 0)
+ return ret;
+
if (!table) {
rhct = acpi_get_rhct();
if (!rhct)
diff --git a/drivers/perf/arm_cspmu/arm_cspmu.c b/drivers/perf/arm_cspmu/arm_cspmu.c
index 34430b68f602..ed72c3d1f796 100644
--- a/drivers/perf/arm_cspmu/arm_cspmu.c
+++ b/drivers/perf/arm_cspmu/arm_cspmu.c
@@ -1107,15 +1107,17 @@ static int arm_cspmu_acpi_get_cpus(struct arm_cspmu *cspmu)
{
struct acpi_apmt_node *apmt_node;
int affinity_flag;
+ u32 cpu_uid;
int cpu;
+ int ret;

apmt_node = arm_cspmu_apmt_node(cspmu->dev);
affinity_flag = apmt_node->flags & ACPI_APMT_FLAGS_AFFINITY;

if (affinity_flag == ACPI_APMT_FLAGS_AFFINITY_PROC) {
for_each_possible_cpu(cpu) {
- if (apmt_node->proc_affinity ==
- get_acpi_id_for_cpu(cpu)) {
+ ret = acpi_get_cpu_uid(cpu, &cpu_uid);
+ if (ret == 0 && apmt_node->proc_affinity == cpu_uid) {
cpumask_set_cpu(cpu, &cspmu->associated_cpus);
break;
}
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 4d2f0bed7a06..035094a55f18 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -324,6 +324,19 @@ int acpi_unmap_cpu(int cpu);

acpi_handle acpi_get_processor_handle(int cpu);

+#ifndef CONFIG_X86
+/*
+ * acpi_get_cpu_uid() - Get ACPI Processor UID of a specified CPU from MADT table
+ * @cpu: Logical CPU number (0-based)
+ * @uid: Pointer to store the ACPI Processor UID (valid only on successful return)
+ *
+ * Return: 0 on successful retrieval (the ACPI Processor ID is stored in *uid);
+ * -EINVAL if the CPU number is invalid or out of range;
+ * -ENODEV if the ACPI Processor UID for the specified CPU is not found.
+ */
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid);
+#endif
+
#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr);
#endif
--
2.17.1