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

On Thu, 12 Mar 2026 15:23:14 +0800
Chengwen Feng <fengchengwen@huawei.com> wrote:

> 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

It's not just a rename.  This should mention that the addition of error
checks and hence the resulting signature change.

> 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>
From a reread, a few minor style consistency things inline.

> ---
>  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/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)

Seems local style for null pointer checks is
	if (!gicc)
Just for consistency we should follow that.

> +		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++) {

Given more recent acceptance of the following perhaps it is neater here.

	for (int cpu = 0; cpu < nr_cpu_ids; cpu++) {

Amazingly there aren't any for loops in this file so we can do what we
like from a consistency point of view.


> +		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/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)

Similar to above. Local style for NULL checks is
	if (!rintc)
so this should follow that.
> +		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++) {

Can pull the int into the loop her as well.

> +		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

>  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;
I'd put a blank line here (similar to the code you added just above).
>  	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;
Again, I'd put a blank line here.

>  	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;
and here.
>  		cpu_node = acpi_find_processor_node(table_hdr, acpi_id);
>  
>  		while (cpu_node) {

On 3/12/2026 7:07 PM, Jonathan Cameron wrote:
> On Thu, 12 Mar 2026 15:23:14 +0800
> Chengwen Feng <fengchengwen@huawei.com> wrote:
> 
>> 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
> 
> It's not just a rename.  This should mention that the addition of error
> checks and hence the resulting signature change.

Sorry for overlooking this, it has already been fixed in v7.
And v7 also fix below review comments.

Thanks

> 
>> 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>
> From a reread, a few minor style consistency things inline.
> 

...

>