From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 31320391508; Tue, 17 Mar 2026 21:21:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773782483; cv=none; b=Eh3s+/lcpsTbjKprBNjUNylsNkUpsQm9je6XOg+0fHhzLswjQJGgUsPIbOQQSZ6OEd6fsBqB9+GZoMOjlg5WQfKyJnKc/s+m7cje0fHdXyK5KNd4PDRJttefhfcwWs+RlpujNNFjFdYF/Rl0wWYTLqldnbmkMOtu44w5+6y1hKg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773782483; c=relaxed/simple; bh=PJs3oxRB8lT0Tg8YppcpewTxR0d/WbnMS5j5WICltOg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=miyVFySsCGqtX8vU7IMOJdC4COUqE1Flex64DOlz26Mn3uCQb+Q6bLlwujkluoTzqqPOXyFHBMDC9J3NFrxH6Z/Nt2O14PsfBhhXYCZUwnHq7h/EaH6WjFpGTQyOF42Tpydyy3zkjc4WmY57E92s3d2sK6OSbMLlaV8E2+LBTX8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1E1F81477; Tue, 17 Mar 2026 14:21:14 -0700 (PDT) Received: from [172.27.42.179] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5E1313F73B; Tue, 17 Mar 2026 14:21:15 -0700 (PDT) Message-ID: <48f70869-6628-46ec-9ab1-cb3fefa99ba2@arm.com> Date: Tue, 17 Mar 2026 16:21:14 -0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 1/3] ACPI: Refactor get_acpi_id_for_cpu() to acpi_get_cpu_uid() on non-x86 To: Chengwen Feng , Bjorn Helgaas , Catalin Marinas , Will Deacon , "Rafael J . Wysocki" Cc: Jonathan Corbet , Shuah Khan , Huacai Chen , WANG Xuerui , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Juergen Gross , Sohil Mehta , Ilkka Koskinen , Robin Murphy , James Clark , Besar Wicaksono , Ma Ke , Wei Huang , Andy Gospodarek , Somnath Kotur , kees@kernel.org, punit.agrawal@oss.qualcomm.com, guohanjun@huawei.com, suzuki.poulose@arm.com, ryan.roberts@arm.com, chenl311@chinatelecom.cn, masahiroy@kernel.org, wangyuquan1236@phytium.com.cn, anshuman.khandual@arm.com, heinrich.schuchardt@canonical.com, Eric.VanTassell@amd.com, jonathan.cameron@huawei.com, wangzhou1@hisilicon.com, wanghuiqiang@huawei.com, liuyonglong@huawei.com, linux-pci@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, linux-perf-users@vger.kernel.org, stable@vger.kernel.org References: <20260313022144.40942-1-fengchengwen@huawei.com> <20260313022144.40942-2-fengchengwen@huawei.com> Content-Language: en-US From: Jeremy Linton In-Reply-To: <20260313022144.40942-2-fengchengwen@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi, On 3/12/26 9:21 PM, Chengwen Feng wrote: > Unify CPU ACPI ID retrieval interface across architectures by > refactoring get_acpi_id_for_cpu() to acpi_get_cpu_uid() on > arm64/riscv/loongarch: > - Add input parameter validation > - Adjust interface to int acpi_get_cpu_uid(unsigned int cpu, u32 *uid) > (old: u32 get_acpi_id_for_cpu(unsigned int cpu), no input check) > > This refactoring (not a pure rename) enhances interface robustness while > preparing for consistent ACPI Processor UID retrieval across all > ACPI-enabled platforms. Valid inputs retain original behavior. > > 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. I moved get_cpu_for_acpi_id() into arm64/kernel/acpi.c, and granted didn't test a wide range of configs, but i'm not seeing the circular dependency, what is causing that? > > Cc: stable@vger.kernel.org > Signed-off-by: Chengwen Feng > Reviewed-by: Jonathan Cameron > --- > arch/arm64/include/asm/acpi.h | 16 +--------- > arch/arm64/kernel/acpi.c | 16 ++++++++++ > arch/arm64/kernel/acpi_numa.c | 14 +++++++++ > 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 ++++-- > drivers/acpi/pptt.c | 50 ++++++++++++++++++++++-------- > drivers/acpi/riscv/rhct.c | 7 ++++- > drivers/perf/arm_cspmu/arm_cspmu.c | 6 ++-- > include/linux/acpi.h | 13 ++++++++ > 12 files changed, 122 insertions(+), 43 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..f3866606fc46 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; I think this should be cpu_possible() because we have a number of for_each_possible() calls that end up in here and AFAIK nr_cpu_ids can be more restrictive than the possible list.> + > + gicc = acpi_cpu_get_madt_gicc(cpu); > + if (!gicc) > + return -ENODEV; So, on arm64, I didn't think it was possible to have a logical cpu lookup that didn't map to a gicc uid, because the logical core couldn't exist otherwise and (AFAIK) we don't have holes in the possible cpu mask. Once you know the logical core is less than nr_cpu_ids it must have a MADT mapping. So check this is redundant too, no? But, if its possible to call this with an invalid logical cpu then we probably want to know that, so nr_cpu_ids/cpu_possible() check should have pr_warn_once() because there is a bug somewhere, particularly from all the pptt calls below where I guess there is an implication there is an ID mismatch between the MADT and the PPTT or simply that the user has clamped max cpus less than the for_each_possible() calls in the pptt/etc code. > + > + *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..41d1e46a4338 100644 > --- a/arch/arm64/kernel/acpi_numa.c > +++ b/arch/arm64/kernel/acpi_numa.c > @@ -34,6 +34,20 @@ 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 ret; > + > + for (int cpu = 0; cpu < nr_cpu_ids; cpu++) { > + ret = acpi_get_cpu_uid(cpu, &cpu_uid); This change is redundant, no? Your walking a limited list of possible CPUs that have GICC entries and checking to see if one of the known logical cores has a matching ACPI id. AKA you can't have an invalid logical core here, so the previous call must have a valid acpi id. But at the same time so was the acpi_cpu_get_madt_gicc() check in there before, which was probably left over from when the tables were being mapped rather than cached. > + if (ret == 0 && uid == cpu_uid) > + return cpu; > + } > + > + return -EINVAL; > +} > + I didn't actually manage to hit the case here that keeps this from compiling cleanly in acpi.c above if its placed immediately following acpi_get_cpu_uid(). IMHO, these two functions are kept close to each other since they are so conceptually related. > 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..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/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; > 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