[PATCH v2 7/7] x86, acpi, cpu-hotplug: Set persistent cpuid <-> nodeid mapping when booting.

[Tang Chen <tangchen@cn.fujitsu.com>]

From: Gu Zheng <guz.fnst@cn.fujitsu.com>

This patch finishes step4 mentioned in previous patch 4.

There are four mappings in the kernel:
1. nodeid (logical node id)   <->   pxm
2. apicid (physical cpu id)   <->   nodeid
3. cpuid (logical cpu id)     <->   apicid
4. cpuid (logical cpu id)     <->   nodeid

1. pxm (proximity domain) is provided by ACPI firmware in SRAT, and nodeid <-> pxm
   mapping is setup at boot time. This mapping is persistent, won't change.

2. apicid <-> nodeid mapping is setup using info in 1. The mapping is setup at boot
   time and CPU hotadd time, and cleared at CPU hotremove time. This mapping is also
   persistent.

3. cpuid <-> apicid mapping is setup at boot time and CPU hotadd time. cpuid is
   allocated, lower ids first, and released at CPU hotremove time, reused for other
   hotadded CPUs. So this mapping is not persistent.

4. cpuid <-> nodeid mapping is also setup at boot time and CPU hotadd time, and
   cleared at CPU hotremove time. As a result of 3, this mapping is not persistent.

So, in order to setup persistent cpuid <-> nodeid mapping for all possible CPUs,
we should:
1. Setup cpuid <-> apicid mapping for all possible CPUs, which has been done in patch 4.
2. Setup cpuid <-> nodeid mapping for all possible CPUs.

This patch set the persistent cpuid <-> nodeid mapping for all enabled/disabled
processors at boot time via an additional acpi namespace walk for processors.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
---
 arch/ia64/kernel/acpi.c       |  2 +-
 arch/x86/kernel/acpi/boot.c   |  2 +-
 drivers/acpi/bus.c            |  3 ++
 drivers/acpi/processor_core.c | 65 +++++++++++++++++++++++++++++++++++++++++++
 include/linux/acpi.h          |  2 ++
 5 files changed, 72 insertions(+), 2 deletions(-)

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index b1698bc..7db5563 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -796,7 +796,7 @@ int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi)
  *  ACPI based hotplug CPU support
  */
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
-static int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
+int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
 {
 #ifdef CONFIG_ACPI_NUMA
 	/*
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index bcc85b2..b9a1aa1 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -695,7 +695,7 @@ static void __init acpi_set_irq_model_ioapic(void)
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 #include <acpi/processor.h>
 
-static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
+void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
 {
 #ifdef CONFIG_ACPI_NUMA
 	int nid;
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 513e7230e..fd03885 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -700,6 +700,9 @@ static int __init acpi_init(void)
 	acpi_debugfs_init();
 	acpi_sleep_proc_init();
 	acpi_wakeup_device_init();
+#ifdef CONFIG_ACPI_HOTPLUG_CPU
+	acpi_set_processor_mapping();
+#endif
 	return 0;
 }
 
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 824b98b..45580ff 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -261,6 +261,71 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 }
 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 
+#ifdef CONFIG_ACPI_HOTPLUG_CPU
+static bool map_processor(acpi_handle handle, int *phys_id, int *cpuid)
+{
+	int type;
+	u32 acpi_id;
+	acpi_status status;
+	acpi_object_type acpi_type;
+	unsigned long long tmp;
+	union acpi_object object = { 0 };
+	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
+
+	status = acpi_get_type(handle, &acpi_type);
+	if (ACPI_FAILURE(status))
+		return false;
+
+	switch (acpi_type) {
+	case ACPI_TYPE_PROCESSOR:
+		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
+		if (ACPI_FAILURE(status))
+			return false;
+		acpi_id = object.processor.proc_id;
+		break;
+	case ACPI_TYPE_DEVICE:
+		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
+		if (ACPI_FAILURE(status))
+			return false;
+		acpi_id = tmp;
+		break;
+	default:
+		return false;
+	}
+
+	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
+
+	*phys_id = __acpi_get_phys_id(handle, type, acpi_id, false);
+	*cpuid = acpi_map_cpuid(*phys_id, acpi_id);
+	if (*cpuid == -1)
+		return false;
+
+	return true;
+}
+
+static acpi_status __init
+set_processor_node_mapping(acpi_handle handle, u32 lvl, void *context,
+			   void **rv)
+{
+	u32 apic_id;
+	int cpu_id;
+
+	if (!map_processor(handle, &apic_id, &cpu_id))
+		return AE_ERROR;
+
+	acpi_map_cpu2node(handle, cpu_id, apic_id);
+	return AE_OK;
+}
+
+void __init acpi_set_processor_mapping(void)
+{
+	/* Set persistent cpu <-> node mapping for all processors. */
+	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
+			    ACPI_UINT32_MAX, set_processor_node_mapping,
+			    NULL, NULL, NULL);
+}
+#endif
+
 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
 static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,
 			 u64 *phys_addr, int *ioapic_id)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index d2445fa..7a78830 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -185,6 +185,8 @@ static inline bool invalid_phys_cpuid(phys_cpuid_t phys_id)
 /* Arch dependent functions for cpu hotplug support */
 int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu);
 int acpi_unmap_cpu(int cpu);
+void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid);
+void __init acpi_set_processor_mapping(void);
 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 
 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
-- 
1.9.3

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