[PATCH v6 2/3] x86: Implement acpi_get_cpu_uid()

[Chengwen Feng <fengchengwen@xxxxxxxxxx>]

Add acpi_get_cpu_uid() implementation for x86, replacing the existing
cpu_acpi_id() function. This completes the unified ACPI Processor UID
retrieval interface across all ACPI-enabled architectures.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Chengwen Feng <fengchengwen@xxxxxxxxxx>
---
 arch/x86/include/asm/cpu.h   |  1 -
 arch/x86/include/asm/smp.h   |  1 -
 arch/x86/kernel/cpu/common.c | 15 +++++++++++++++
 arch/x86/xen/enlighten_hvm.c |  5 +++--
 include/linux/acpi.h         |  2 --
 5 files changed, 18 insertions(+), 6 deletions(-)

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/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 1c3261cae40c..3081557542c7 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -28,6 +28,7 @@
 #include <linux/stackprotector.h>
 #include <linux/utsname.h>
 #include <linux/efi.h>
+#include <linux/acpi.h>
 
 #include <asm/alternative.h>
 #include <asm/cmdline.h>
@@ -57,6 +58,7 @@
 #include <asm/asm.h>
 #include <asm/bugs.h>
 #include <asm/cpu.h>
+#include <asm/smp.h>
 #include <asm/mce.h>
 #include <asm/msr.h>
 #include <asm/cacheinfo.h>
@@ -2643,3 +2645,16 @@ void __init arch_cpu_finalize_init(void)
         */
        mem_encrypt_init();
 }
+
+int acpi_get_cpu_uid(unsigned int cpu, u32 *uid)
+{
+       if (cpu >= nr_cpu_ids)
+               return -EINVAL;
+#ifndef CONFIG_SMP
+       *uid = 0;
+#else
+       *uid = per_cpu(x86_cpu_to_acpiid, cpu);
+#endif
+       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);
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 035094a55f18..90a1fdcb7eb9 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -324,7 +324,6 @@ 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)
@@ -335,7 +334,6 @@ acpi_handle acpi_get_processor_handle(int cpu);
  *         -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);
-- 
2.17.1