[PATCH v9 7/7] acpi: Provide the interface to validate the proc_id

[Dou Liyang]

When we want to identify whether the proc_id is unreasonable or not, we
can call the "acpi_processor_validate_proc_id" function. It will search
in the duplicate IDs. If we find the proc_id in the IDs, we return true
to the call function. Conversely, the false represents available.

When we establish all possible cpuid <-> nodeid mapping to handle the
cpu hotplugs, we will use the proc_id from ACPI table.

We do validation when we get the proc_id. If the result is true, we
will stop the mapping.

Signed-off-by: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>
---
 drivers/acpi/acpi_processor.c | 16 ++++++++++++++++
 drivers/acpi/processor_core.c |  4 ++++
 include/linux/acpi.h          |  3 +++
 3 files changed, 23 insertions(+)

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 346fbfc..ae6dae9 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -659,6 +659,22 @@ static void acpi_processor_duplication_valiate(void)
 						NULL, NULL, NULL);
 }
 
+bool acpi_processor_validate_proc_id(int proc_id)
+{
+	int i;
+
+	/*
+	 * compare the proc_id with duplicate IDs, if the proc_id is already
+	 * in the duplicate IDs, return true, otherwise, return false.
+	 */
+	for (i = 0; i < nr_duplicate_ids; i++) {
+		if (duplicate_processor_ids[i] == proc_id)
+			return true;
+	}
+
+	return false;
+}
+
 void __init acpi_processor_init(void)
 {
 	acpi_processor_duplication_valiate();
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index b44675b..97adffb 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -282,6 +282,10 @@ static bool map_processor(acpi_handle handle, phys_cpuid_t *phys_id, int *cpuid)
 		if (ACPI_FAILURE(status))
 			return false;
 		acpi_id = object.processor.proc_id;
+
+		/* validate the acpi_id */
+		if(acpi_processor_validate_proc_id(acpi_id))
+			return false;
 		break;
 	case ACPI_TYPE_DEVICE:
 		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 53b3014..94ceae1 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -254,6 +254,9 @@ static inline bool invalid_phys_cpuid(phys_cpuid_t phys_id)
 	return phys_id == PHYS_CPUID_INVALID;
 }
 
+/*validate the processor object's proc_id*/
+bool acpi_processor_validate_proc_id(int proc_id);
+
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 /* Arch dependent functions for cpu hotplug support */
 int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu);
-- 
2.5.5