[PATCH v10 0/8] ACPI: Unify CPU UID interface and fix ARM64 TPH steer-tag issue

[PATCH v10 0/8] ACPI: Unify CPU UID interface and fix ARM64 TPH steer-tag issue

[Chengwen Feng]

This patchset unifies ACPI Processor UID retrieval across
arm64/loongarch/riscv/x86 via acpi_get_cpu_uid() (with input validation)
and fixes ARM64 CPU steer-tag retrieval failure in PCI/TPH:

1-4: Add acpi_get_cpu_uid() for arm64/loongarch/riscv/x86 (update
     respective users)
5: Centralize acpi_get_cpu_uid() declaration in include/linux/acpi.h
6: Clean up perf/arm_cspmu
7: Clean up ACPI/PPTT and remove unused get_acpi_id_for_cpu()
8: Pass ACPI Processor UID to Cache Locality _DSM

The interface refactor ensures consistent CPU UID retrieval across
architectures (no functional changes for valid inputs) and provides the
unified interface required for the ARM64 TPH fix.

---
Changes in v10:
- Refine commit header&log according to Punit's and Bjorn's review
- Split perf/arm_cspmu as a separate commit which address Punit's
  review

Changes in v9:
- Address Bjorn's review: split commits to each platform so that make
  them easy to review

Changes in v8:
- Moving arm64's get_cpu_for_acpi_id() to kernel/acpi.c which address
  Jeremy's review

Chengwen Feng (8):
  arm64: acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
  LoongArch: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
  RISC-V: ACPI: Add acpi_get_cpu_uid() for unified ACPI CPU UID
    retrieval
  x86/acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
  ACPI: Centralize acpi_get_cpu_uid() declaration in
    include/linux/acpi.h
  perf: arm_cspmu: Switch to acpi_get_cpu_uid() from
    get_acpi_id_for_cpu()
  ACPI: PPTT: Use acpi_get_cpu_uid() and remove get_acpi_id_for_cpu()
  PCI/TPH: Pass ACPI Processor UID to Cache Locality _DSM

 Documentation/PCI/tph.rst          |  4 +--
 arch/arm64/include/asm/acpi.h      | 17 +---------
 arch/arm64/kernel/acpi.c           | 30 ++++++++++++++++++
 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      |  9 ++++--
 arch/x86/include/asm/cpu.h         |  1 -
 arch/x86/include/asm/smp.h         |  1 -
 arch/x86/kernel/acpi/boot.c        | 20 ++++++++++++
 arch/x86/xen/enlighten_hvm.c       |  5 +--
 drivers/acpi/pptt.c                | 50 ++++++++++++++++++++++--------
 drivers/acpi/riscv/rhct.c          |  7 ++++-
 drivers/pci/tph.c                  | 16 +++++++---
 drivers/perf/arm_cspmu/arm_cspmu.c |  6 ++--
 include/linux/acpi.h               | 11 +++++++
 include/linux/pci-tph.h            |  4 +--
 18 files changed, 158 insertions(+), 57 deletions(-)

-- 
2.17.1

[PATCH v10 1/8] arm64: acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval

[Chengwen Feng]

As a step towards unifying the interface for retrieving ACPI CPU UID
across architectures, introduce a new function acpi_get_cpu_uid() for
arm64. While at it, add input validation to make the code more robust.

Reimplement get_cpu_for_acpi_id() based on acpi_get_cpu_uid() for
consistency, and move its implementation next to the new function for
code coherence.

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 | 14 ++------------
 arch/arm64/kernel/acpi.c      | 30 ++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index c07a58b96329..2219a3301e72 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -118,18 +118,8 @@ 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 acpi_get_cpu_uid(unsigned int cpu, u32 *uid);
+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..24b9d934be54 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -458,3 +458,33 @@ 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)
+		return -ENODEV;
+
+	*uid = gicc->uid;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_get_cpu_uid);
+
+int get_cpu_for_acpi_id(u32 uid)
+{
+	u32 cpu_uid;
+	int ret;
+
+	for (int 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;
+}
-- 
2.17.1

[PATCH v10 2/8] LoongArch: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval

[Chengwen Feng]

As a step towards unifying the interface for retrieving ACPI CPU UID
across architectures, introduce a new function acpi_get_cpu_uid() for
loongarch. While at it, add input validation to make the code more
robust.

Cc: stable@vger.kernel.org
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/loongarch/include/asm/acpi.h | 1 +
 arch/loongarch/kernel/acpi.c      | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/arch/loongarch/include/asm/acpi.h b/arch/loongarch/include/asm/acpi.h
index 7376840fa9f7..8bb101b4557e 100644
--- a/arch/loongarch/include/asm/acpi.h
+++ b/arch/loongarch/include/asm/acpi.h
@@ -44,6 +44,7 @@ static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
 {
 	return acpi_core_pic[cpu_logical_map(cpu)].processor_id;
 }
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid);
 
 #endif /* !CONFIG_ACPI */
 
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);
-- 
2.17.1

[PATCH v10 3/8] RISC-V: ACPI: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval

[Chengwen Feng]

As a step towards unifying the interface for retrieving ACPI CPU UID
across architectures, introduce a new function acpi_get_cpu_uid() for
riscv. While at it, add input validation to make the code more robust.

And also update acpi_numa.c and rhct.c to use the new interface instead
of the legacy get_acpi_id_for_cpu().

Cc: stable@vger.kernel.org
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 arch/riscv/include/asm/acpi.h |  1 +
 arch/riscv/kernel/acpi.c      | 16 ++++++++++++++++
 arch/riscv/kernel/acpi_numa.c |  9 ++++++---
 drivers/acpi/riscv/rhct.c     |  7 ++++++-
 4 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h
index 6e13695120bc..f3520cc85af3 100644
--- a/arch/riscv/include/asm/acpi.h
+++ b/arch/riscv/include/asm/acpi.h
@@ -65,6 +65,7 @@ static inline u32 get_acpi_id_for_cpu(int cpu)
 {
 	return acpi_cpu_get_madt_rintc(cpu)->uid;
 }
+int acpi_get_cpu_uid(unsigned int cpu, u32 *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..322ea92aa39f 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)
+		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..6a2d4289f806 100644
--- a/arch/riscv/kernel/acpi_numa.c
+++ b/arch/riscv/kernel/acpi_numa.c
@@ -37,11 +37,14 @@ static int __init acpi_numa_get_nid(unsigned int cpu)
 
 static inline int get_cpu_for_acpi_id(u32 uid)
 {
-	int cpu;
+	u32 cpu_uid;
+	int ret;
 
-	for (cpu = 0; cpu < nr_cpu_ids; cpu++)
-		if (uid == get_acpi_id_for_cpu(cpu))
+	for (int 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/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)
-- 
2.17.1

[PATCH v10 4/8] x86/acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval

[Chengwen Feng]

As a step towards unifying the interface for retrieving ACPI CPU UID
across architectures, introduce a new function acpi_get_cpu_uid() for
x86. While at it, add input validation to make the code more robust.

Update Xen-related code to use acpi_get_cpu_uid() instead of the legacy
cpu_acpi_id() function, and remove the now-unused cpu_acpi_id() to clean
up redundant code.

Cc: stable@vger.kernel.org
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/include/asm/acpi.h  |  2 ++
 arch/x86/include/asm/cpu.h   |  1 -
 arch/x86/include/asm/smp.h   |  1 -
 arch/x86/kernel/acpi/boot.c  | 20 ++++++++++++++++++++
 arch/x86/xen/enlighten_hvm.c |  5 +++--
 5 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index a03aa6f999d1..92b5c27c4fea 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -157,6 +157,8 @@ static inline bool acpi_has_cpu_in_madt(void)
 	return !!acpi_lapic;
 }
 
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid);
+
 #define ACPI_HAVE_ARCH_SET_ROOT_POINTER
 static __always_inline void acpi_arch_set_root_pointer(u64 addr)
 {
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index ad235dda1ded..57a0786dfd75 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -11,7 +11,6 @@
 
 #ifndef CONFIG_SMP
 #define cpu_physical_id(cpu)			boot_cpu_physical_apicid
-#define cpu_acpi_id(cpu)			0
 #endif /* CONFIG_SMP */
 
 #ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 84951572ab81..05d1d479b4cf 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -130,7 +130,6 @@ __visible void smp_call_function_interrupt(struct pt_regs *regs);
 __visible void smp_call_function_single_interrupt(struct pt_regs *r);
 
 #define cpu_physical_id(cpu)	per_cpu(x86_cpu_to_apicid, cpu)
-#define cpu_acpi_id(cpu)	per_cpu(x86_cpu_to_acpiid, cpu)
 
 /*
  * This function is needed by all SMP systems. It must _always_ be valid
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index a3f2fb1fea1b..ceba24f65ae3 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1848,3 +1848,23 @@ void __iomem * (*acpi_os_ioremap)(acpi_physical_address phys, acpi_size size) =
 	x86_acpi_os_ioremap;
 EXPORT_SYMBOL_GPL(acpi_os_ioremap);
 #endif
+
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid)
+{
+	u32 acpi_id;
+
+	if (cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+#ifdef CONFIG_SMP
+	acpi_id = per_cpu(x86_cpu_to_acpiid, cpu);
+	if (acpi_id == CPU_ACPIID_INVALID)
+		return -ENODEV;
+#else
+	acpi_id = 0;
+#endif
+
+	*uid = acpi_id;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_get_cpu_uid);
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index fe57ff85d004..2f9fa27e5a3c 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -151,6 +151,7 @@ static void xen_hvm_crash_shutdown(struct pt_regs *regs)
 
 static int xen_cpu_up_prepare_hvm(unsigned int cpu)
 {
+	u32 cpu_uid;
 	int rc = 0;
 
 	/*
@@ -161,8 +162,8 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu)
 	 */
 	xen_uninit_lock_cpu(cpu);
 
-	if (cpu_acpi_id(cpu) != CPU_ACPIID_INVALID)
-		per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
+	if (acpi_get_cpu_uid(cpu, &cpu_uid) == 0)
+		per_cpu(xen_vcpu_id, cpu) = cpu_uid;
 	else
 		per_cpu(xen_vcpu_id, cpu) = cpu;
 	xen_vcpu_setup(cpu);
-- 
2.17.1

[PATCH v10 5/8] ACPI: Centralize acpi_get_cpu_uid() declaration in include/linux/acpi.h

[Chengwen Feng]

Centralize acpi_get_cpu_uid() in include/linux/acpi.h (global scope) and
remove arch-specific declarations from arm64/loongarch/riscv/x86
asm/acpi.h. This unifies the interface across architectures and
simplifies maintenance by eliminating duplicate prototypes.

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     |  1 -
 arch/loongarch/include/asm/acpi.h |  1 -
 arch/riscv/include/asm/acpi.h     |  1 -
 arch/x86/include/asm/acpi.h       |  2 --
 include/linux/acpi.h              | 11 +++++++++++
 5 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index 2219a3301e72..bdb0ecf95b5c 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -118,7 +118,6 @@ static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
 {
 	return	acpi_cpu_get_madt_gicc(cpu)->uid;
 }
-int acpi_get_cpu_uid(unsigned int cpu, u32 *uid);
 int get_cpu_for_acpi_id(u32 uid);
 
 static inline void arch_fix_phys_package_id(int num, u32 slot) { }
diff --git a/arch/loongarch/include/asm/acpi.h b/arch/loongarch/include/asm/acpi.h
index 8bb101b4557e..7376840fa9f7 100644
--- a/arch/loongarch/include/asm/acpi.h
+++ b/arch/loongarch/include/asm/acpi.h
@@ -44,7 +44,6 @@ static inline u32 get_acpi_id_for_cpu(unsigned int cpu)
 {
 	return acpi_core_pic[cpu_logical_map(cpu)].processor_id;
 }
-int acpi_get_cpu_uid(unsigned int cpu, u32 *uid);
 
 #endif /* !CONFIG_ACPI */
 
diff --git a/arch/riscv/include/asm/acpi.h b/arch/riscv/include/asm/acpi.h
index f3520cc85af3..6e13695120bc 100644
--- a/arch/riscv/include/asm/acpi.h
+++ b/arch/riscv/include/asm/acpi.h
@@ -65,7 +65,6 @@ static inline u32 get_acpi_id_for_cpu(int cpu)
 {
 	return acpi_cpu_get_madt_rintc(cpu)->uid;
 }
-int acpi_get_cpu_uid(unsigned int cpu, u32 *uid);
 
 int acpi_get_riscv_isa(struct acpi_table_header *table,
 		       unsigned int cpu, const char **isa);
diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index 92b5c27c4fea..a03aa6f999d1 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -157,8 +157,6 @@ static inline bool acpi_has_cpu_in_madt(void)
 	return !!acpi_lapic;
 }
 
-int acpi_get_cpu_uid(unsigned int cpu, u32 *uid);
-
 #define ACPI_HAVE_ARCH_SET_ROOT_POINTER
 static __always_inline void acpi_arch_set_root_pointer(u64 addr)
 {
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 4d2f0bed7a06..74a73f0e5944 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -324,6 +324,17 @@ int acpi_unmap_cpu(int cpu);
 
 acpi_handle acpi_get_processor_handle(int cpu);
 
+/**
+ * acpi_get_cpu_uid() - Get ACPI Processor UID of from MADT table
+ * @cpu: Logical CPU number (0-based)
+ * @uid: Pointer to store ACPI Processor UID
+ *
+ * Return: 0 on success (ACPI Processor ID stored in *uid);
+ *         -EINVAL if CPU number is invalid or out of range;
+ *         -ENODEV if ACPI Processor UID for the CPU is not found.
+ */
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid);
+
 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
 int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr);
 #endif
-- 
2.17.1

[PATCH v10 6/8] perf: arm_cspmu: Switch to acpi_get_cpu_uid() from get_acpi_id_for_cpu()

[Chengwen Feng]

Update arm_cspmu to use acpi_get_cpu_uid() instead of
get_acpi_id_for_cpu(), aligning with unified ACPI CPU UID interface.

No functional changes are introduced by this switch (valid inputs retain
original behavior).

Cc: stable@vger.kernel.org
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
---
 drivers/perf/arm_cspmu/arm_cspmu.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

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;
 			}
-- 
2.17.1

[PATCH v10 7/8] ACPI: PPTT: Use acpi_get_cpu_uid() and remove get_acpi_id_for_cpu()

[Chengwen Feng]

Update acpi/pptt.c to use acpi_get_cpu_uid() and remove unused
get_acpi_id_for_cpu() from arm64/loongarch/riscv, completing PPTT's
migration to the unified ACPI CPU UID interface

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     |  4 ---
 arch/loongarch/include/asm/acpi.h |  5 ----
 arch/riscv/include/asm/acpi.h     |  4 ---
 drivers/acpi/pptt.c               | 50 +++++++++++++++++++++++--------
 4 files changed, 37 insertions(+), 26 deletions(-)

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index bdb0ecf95b5c..8a54ca6ba602 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -114,10 +114,6 @@ 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;
-}
 int get_cpu_for_acpi_id(u32 uid);
 
 static inline void arch_fix_phys_package_id(int num, u32 slot) { }
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/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/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index de5f8c018333..7bd5bc1f225a 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 +682,9 @@ 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 +793,9 @@ 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 +811,9 @@ 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 +888,9 @@ 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 +984,13 @@ 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 +1051,13 @@ 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;
-- 
2.17.1

[PATCH v10 8/8] PCI/TPH: Pass ACPI Processor UID to Cache Locality _DSM

[Chengwen Feng]

pcie_tph_get_cpu_st() uses the Query Cache Locality Features _DSM [1]
to retrieve the TPH Steering Tag for memory associated with the CPU
identified by its "cpu_uid" parameter, a Linux logical CPU ID.

The _DSM requires an ACPI Processor UID, which pcie_tph_get_cpu_st()
previously assumed was the same as the Linux logical CPU ID. This is
true on x86 but not on arm64, so pcie_tph_get_cpu_st() returned the
wrong Steering Tag, resulting in incorrect TPH functionality on arm64.

Convert the Linux logical CPU ID to the ACPI Processor UID with
acpi_get_cpu_uid() before passing it to the _DSM. Additionally, rename
the pcie_tph_get_cpu_st() parameter from "cpu_uid" to "cpu" to reflect
that it represents a logical CPU ID (not an ACPI Processor UID).

[1] According to ECN_TPH-ST_Revision_20200924
    (https://members.pcisig.com/wg/PCI-SIG/document/15470), the input
    is defined as: "If the target is a processor, then this field
    represents the ACPI Processor UID of the processor as specified in
    the MADT. If the target is a processor container, then this field
    represents the ACPI Processor UID of the processor container as
    specified in the PPTT."

Fixes: d2e8a34876ce ("PCI/TPH: Add Steering Tag support")
Cc: stable@vger.kernel.org
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
---
 Documentation/PCI/tph.rst |  4 ++--
 drivers/pci/tph.c         | 16 +++++++++++-----
 include/linux/pci-tph.h   |  4 ++--
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/Documentation/PCI/tph.rst b/Documentation/PCI/tph.rst
index e8993be64fd6..b6cf22b9bd90 100644
--- a/Documentation/PCI/tph.rst
+++ b/Documentation/PCI/tph.rst
@@ -79,10 +79,10 @@ To retrieve a Steering Tag for a target memory associated with a specific
 CPU, use the following function::
 
   int pcie_tph_get_cpu_st(struct pci_dev *pdev, enum tph_mem_type type,
-                          unsigned int cpu_uid, u16 *tag);
+                          unsigned int cpu, u16 *tag);
 
 The `type` argument is used to specify the memory type, either volatile
-or persistent, of the target memory. The `cpu_uid` argument specifies the
+or persistent, of the target memory. The `cpu` argument specifies the
 CPU where the memory is associated to.
 
 After the ST value is retrieved, the device driver can use the following
diff --git a/drivers/pci/tph.c b/drivers/pci/tph.c
index ca4f97be7538..b67c9ad14bda 100644
--- a/drivers/pci/tph.c
+++ b/drivers/pci/tph.c
@@ -236,21 +236,27 @@ static int write_tag_to_st_table(struct pci_dev *pdev, int index, u16 tag)
  * with a specific CPU
  * @pdev: PCI device
  * @mem_type: target memory type (volatile or persistent RAM)
- * @cpu_uid: associated CPU id
+ * @cpu: associated CPU id
  * @tag: Steering Tag to be returned
  *
  * Return the Steering Tag for a target memory that is associated with a
- * specific CPU as indicated by cpu_uid.
+ * specific CPU as indicated by cpu.
  *
  * Return: 0 if success, otherwise negative value (-errno)
  */
 int pcie_tph_get_cpu_st(struct pci_dev *pdev, enum tph_mem_type mem_type,
-			unsigned int cpu_uid, u16 *tag)
+			unsigned int cpu, u16 *tag)
 {
 #ifdef CONFIG_ACPI
 	struct pci_dev *rp;
 	acpi_handle rp_acpi_handle;
 	union st_info info;
+	u32 cpu_uid;
+	int ret;
+
+	ret = acpi_get_cpu_uid(cpu, &cpu_uid);
+	if (ret != 0)
+		return ret;
 
 	rp = pcie_find_root_port(pdev);
 	if (!rp || !rp->bus || !rp->bus->bridge)
@@ -265,9 +271,9 @@ int pcie_tph_get_cpu_st(struct pci_dev *pdev, enum tph_mem_type mem_type,
 
 	*tag = tph_extract_tag(mem_type, pdev->tph_req_type, &info);
 
-	pci_dbg(pdev, "get steering tag: mem_type=%s, cpu_uid=%d, tag=%#04x\n",
+	pci_dbg(pdev, "get steering tag: mem_type=%s, cpu=%d, tag=%#04x\n",
 		(mem_type == TPH_MEM_TYPE_VM) ? "volatile" : "persistent",
-		cpu_uid, *tag);
+		cpu, *tag);
 
 	return 0;
 #else
diff --git a/include/linux/pci-tph.h b/include/linux/pci-tph.h
index ba28140ce670..be68cd17f2f8 100644
--- a/include/linux/pci-tph.h
+++ b/include/linux/pci-tph.h
@@ -25,7 +25,7 @@ int pcie_tph_set_st_entry(struct pci_dev *pdev,
 			  unsigned int index, u16 tag);
 int pcie_tph_get_cpu_st(struct pci_dev *dev,
 			enum tph_mem_type mem_type,
-			unsigned int cpu_uid, u16 *tag);
+			unsigned int cpu, u16 *tag);
 void pcie_disable_tph(struct pci_dev *pdev);
 int pcie_enable_tph(struct pci_dev *pdev, int mode);
 u16 pcie_tph_get_st_table_size(struct pci_dev *pdev);
@@ -36,7 +36,7 @@ static inline int pcie_tph_set_st_entry(struct pci_dev *pdev,
 { return -EINVAL; }
 static inline int pcie_tph_get_cpu_st(struct pci_dev *dev,
 				      enum tph_mem_type mem_type,
-				      unsigned int cpu_uid, u16 *tag)
+				      unsigned int cpu, u16 *tag)
 { return -EINVAL; }
 static inline void pcie_disable_tph(struct pci_dev *pdev) { }
 static inline int pcie_enable_tph(struct pci_dev *pdev, int mode)
-- 
2.17.1

Re: [PATCH v10 0/8] ACPI: Unify CPU UID interface and fix ARM64 TPH steer-tag issue

[Rafael J. Wysocki]

On Fri, Mar 20, 2026 at 4:17 AM Chengwen Feng <fengchengwen@huawei.com> wrote:
>
> This patchset unifies ACPI Processor UID retrieval across
> arm64/loongarch/riscv/x86 via acpi_get_cpu_uid() (with input validation)
> and fixes ARM64 CPU steer-tag retrieval failure in PCI/TPH:
>
> 1-4: Add acpi_get_cpu_uid() for arm64/loongarch/riscv/x86 (update
>      respective users)
> 5: Centralize acpi_get_cpu_uid() declaration in include/linux/acpi.h
> 6: Clean up perf/arm_cspmu
> 7: Clean up ACPI/PPTT and remove unused get_acpi_id_for_cpu()
> 8: Pass ACPI Processor UID to Cache Locality _DSM
>
> The interface refactor ensures consistent CPU UID retrieval across
> architectures (no functional changes for valid inputs) and provides the
> unified interface required for the ARM64 TPH fix.
>
> ---
> Changes in v10:
> - Refine commit header&log according to Punit's and Bjorn's review
> - Split perf/arm_cspmu as a separate commit which address Punit's
>   review
>
> Changes in v9:
> - Address Bjorn's review: split commits to each platform so that make
>   them easy to review
>
> Changes in v8:
> - Moving arm64's get_cpu_for_acpi_id() to kernel/acpi.c which address
>   Jeremy's review
>
> Chengwen Feng (8):
>   arm64: acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
>   LoongArch: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
>   RISC-V: ACPI: Add acpi_get_cpu_uid() for unified ACPI CPU UID
>     retrieval
>   x86/acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
>   ACPI: Centralize acpi_get_cpu_uid() declaration in
>     include/linux/acpi.h
>   perf: arm_cspmu: Switch to acpi_get_cpu_uid() from
>     get_acpi_id_for_cpu()
>   ACPI: PPTT: Use acpi_get_cpu_uid() and remove get_acpi_id_for_cpu()
>   PCI/TPH: Pass ACPI Processor UID to Cache Locality _DSM
>
>  Documentation/PCI/tph.rst          |  4 +--
>  arch/arm64/include/asm/acpi.h      | 17 +---------
>  arch/arm64/kernel/acpi.c           | 30 ++++++++++++++++++
>  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      |  9 ++++--
>  arch/x86/include/asm/cpu.h         |  1 -
>  arch/x86/include/asm/smp.h         |  1 -
>  arch/x86/kernel/acpi/boot.c        | 20 ++++++++++++
>  arch/x86/xen/enlighten_hvm.c       |  5 +--
>  drivers/acpi/pptt.c                | 50 ++++++++++++++++++++++--------
>  drivers/acpi/riscv/rhct.c          |  7 ++++-
>  drivers/pci/tph.c                  | 16 +++++++---
>  drivers/perf/arm_cspmu/arm_cspmu.c |  6 ++--
>  include/linux/acpi.h               | 11 +++++++
>  include/linux/pci-tph.h            |  4 +--
>  18 files changed, 158 insertions(+), 57 deletions(-)
>
> --

It doesn't look like anyone has a particular heartburn related to this
series, so I could apply it in principle, but I'd appreciate some ACKs
from arch maintainers.

Why don't you resend it with all of the tags collected so far (and
please add x86@kernel.org to the CC list)?

Re: [PATCH v10 0/8] ACPI: Unify CPU UID interface and fix ARM64 TPH steer-tag issue

[fengchengwen]

On 3/31/2026 8:24 PM, Rafael J. Wysocki wrote:
> On Fri, Mar 20, 2026 at 4:17 AM Chengwen Feng <fengchengwen@huawei.com> wrote:
>>
>> This patchset unifies ACPI Processor UID retrieval across
>> arm64/loongarch/riscv/x86 via acpi_get_cpu_uid() (with input validation)
>> and fixes ARM64 CPU steer-tag retrieval failure in PCI/TPH:
>>
>> 1-4: Add acpi_get_cpu_uid() for arm64/loongarch/riscv/x86 (update
>>      respective users)
>> 5: Centralize acpi_get_cpu_uid() declaration in include/linux/acpi.h
>> 6: Clean up perf/arm_cspmu
>> 7: Clean up ACPI/PPTT and remove unused get_acpi_id_for_cpu()
>> 8: Pass ACPI Processor UID to Cache Locality _DSM
>>
>> The interface refactor ensures consistent CPU UID retrieval across
>> architectures (no functional changes for valid inputs) and provides the
>> unified interface required for the ARM64 TPH fix.
>>
>> ---
>> Changes in v10:
>> - Refine commit header&log according to Punit's and Bjorn's review
>> - Split perf/arm_cspmu as a separate commit which address Punit's
>>   review
>>
>> Changes in v9:
>> - Address Bjorn's review: split commits to each platform so that make
>>   them easy to review
>>
>> Changes in v8:
>> - Moving arm64's get_cpu_for_acpi_id() to kernel/acpi.c which address
>>   Jeremy's review
>>
>> Chengwen Feng (8):
>>   arm64: acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
>>   LoongArch: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
>>   RISC-V: ACPI: Add acpi_get_cpu_uid() for unified ACPI CPU UID
>>     retrieval
>>   x86/acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
>>   ACPI: Centralize acpi_get_cpu_uid() declaration in
>>     include/linux/acpi.h
>>   perf: arm_cspmu: Switch to acpi_get_cpu_uid() from
>>     get_acpi_id_for_cpu()
>>   ACPI: PPTT: Use acpi_get_cpu_uid() and remove get_acpi_id_for_cpu()
>>   PCI/TPH: Pass ACPI Processor UID to Cache Locality _DSM
>>
>>  Documentation/PCI/tph.rst          |  4 +--
>>  arch/arm64/include/asm/acpi.h      | 17 +---------
>>  arch/arm64/kernel/acpi.c           | 30 ++++++++++++++++++
>>  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      |  9 ++++--
>>  arch/x86/include/asm/cpu.h         |  1 -
>>  arch/x86/include/asm/smp.h         |  1 -
>>  arch/x86/kernel/acpi/boot.c        | 20 ++++++++++++
>>  arch/x86/xen/enlighten_hvm.c       |  5 +--
>>  drivers/acpi/pptt.c                | 50 ++++++++++++++++++++++--------
>>  drivers/acpi/riscv/rhct.c          |  7 ++++-
>>  drivers/pci/tph.c                  | 16 +++++++---
>>  drivers/perf/arm_cspmu/arm_cspmu.c |  6 ++--
>>  include/linux/acpi.h               | 11 +++++++
>>  include/linux/pci-tph.h            |  4 +--
>>  18 files changed, 158 insertions(+), 57 deletions(-)
>>
>> --
> 
> It doesn't look like anyone has a particular heartburn related to this
> series, so I could apply it in principle, but I'd appreciate some ACKs
> from arch maintainers.
> 
> Why don't you resend it with all of the tags collected so far (and
> please add x86@kernel.org to the CC list)?

done for resend v10 which with all the review/ack tag, add add x86@kernel.org to CC list

Thanks

Re: [PATCH v10 0/8] ACPI: Unify CPU UID interface and fix ARM64 TPH steer-tag issue

[Catalin Marinas]

On Fri, Mar 20, 2026 at 11:17:29AM +0800, Chengwen Feng wrote:
> This patchset unifies ACPI Processor UID retrieval across
> arm64/loongarch/riscv/x86 via acpi_get_cpu_uid() (with input validation)
> and fixes ARM64 CPU steer-tag retrieval failure in PCI/TPH:
> 
> 1-4: Add acpi_get_cpu_uid() for arm64/loongarch/riscv/x86 (update
>      respective users)
> 5: Centralize acpi_get_cpu_uid() declaration in include/linux/acpi.h
> 6: Clean up perf/arm_cspmu
> 7: Clean up ACPI/PPTT and remove unused get_acpi_id_for_cpu()
> 8: Pass ACPI Processor UID to Cache Locality _DSM
> 
> The interface refactor ensures consistent CPU UID retrieval across
> architectures (no functional changes for valid inputs) and provides the
> unified interface required for the ARM64 TPH fix.
> 
> ---
> Changes in v10:
> - Refine commit header&log according to Punit's and Bjorn's review
> - Split perf/arm_cspmu as a separate commit which address Punit's
>   review
> 
> Changes in v9:
> - Address Bjorn's review: split commits to each platform so that make
>   them easy to review
> 
> Changes in v8:
> - Moving arm64's get_cpu_for_acpi_id() to kernel/acpi.c which address
>   Jeremy's review
> 
> Chengwen Feng (8):
>   arm64: acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
>   LoongArch: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
>   RISC-V: ACPI: Add acpi_get_cpu_uid() for unified ACPI CPU UID
>     retrieval
>   x86/acpi: Add acpi_get_cpu_uid() for unified ACPI CPU UID retrieval
>   ACPI: Centralize acpi_get_cpu_uid() declaration in
>     include/linux/acpi.h
>   perf: arm_cspmu: Switch to acpi_get_cpu_uid() from
>     get_acpi_id_for_cpu()
>   ACPI: PPTT: Use acpi_get_cpu_uid() and remove get_acpi_id_for_cpu()
>   PCI/TPH: Pass ACPI Processor UID to Cache Locality _DSM
> 
>  Documentation/PCI/tph.rst          |  4 +--
>  arch/arm64/include/asm/acpi.h      | 17 +---------
>  arch/arm64/kernel/acpi.c           | 30 ++++++++++++++++++

For the arm64 bits:

Acked-by: Catalin Marinas <catalin.marinas@arm.com>