diff mbox series

[v9,10/12] arm64: topology: enable ACPI/PPTT based CPU topology

Message ID 20180511235807.30834-11-jeremy.linton@arm.com
State Accepted
Commit 2f0a5d107e1fd6250a3a0469892a6c47a8ca933b
Headers show
Series [v9,01/12] drivers: base: cacheinfo: move cache_setup_of_node() | expand

Commit Message

Jeremy Linton May 11, 2018, 11:58 p.m. UTC 
Propagate the topology information from the PPTT tree to the
cpu_topology array. We can get the thread id and core_id by assuming
certain levels of the PPTT tree correspond to those concepts.
The package_id is flagged in the tree and can be found by calling
find_acpi_cpu_topology_package() which terminates
its search when it finds an ACPI node flagged as the physical
package. If the tree doesn't contain enough levels to represent
all of the requested levels then the root node will be returned
for all subsequent levels.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>

Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Tested-by: Vijaya Kumar K <vkilari@codeaurora.org>

Tested-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>

Tested-by: Tomasz Nowicki <Tomasz.Nowicki@cavium.com>

Acked-by: Sudeep Holla <sudeep.holla@arm.com>

Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Acked-by: Morten Rasmussen <morten.rasmussen@arm.com>

---
 arch/arm64/kernel/topology.c | 45 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

-- 
2.13.6
diff mbox series

Patch

diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index dc18b1e53194..047d98e68502 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -11,6 +11,7 @@ 
  * for more details.
  */
 
+#include <linux/acpi.h>
 #include <linux/arch_topology.h>
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
@@ -22,6 +23,7 @@ 
 #include <linux/sched.h>
 #include <linux/sched/topology.h>
 #include <linux/slab.h>
+#include <linux/smp.h>
 #include <linux/string.h>
 
 #include <asm/cpu.h>
@@ -296,6 +298,45 @@  static void __init reset_cpu_topology(void)
 	}
 }
 
+#ifdef CONFIG_ACPI
+/*
+ * Propagate the topology information of the processor_topology_node tree to the
+ * cpu_topology array.
+ */
+static int __init parse_acpi_topology(void)
+{
+	bool is_threaded;
+	int cpu, topology_id;
+
+	is_threaded = read_cpuid_mpidr() & MPIDR_MT_BITMASK;
+
+	for_each_possible_cpu(cpu) {
+		topology_id = find_acpi_cpu_topology(cpu, 0);
+		if (topology_id < 0)
+			return topology_id;
+
+		if (is_threaded) {
+			cpu_topology[cpu].thread_id = topology_id;
+			topology_id = find_acpi_cpu_topology(cpu, 1);
+			cpu_topology[cpu].core_id   = topology_id;
+		} else {
+			cpu_topology[cpu].thread_id  = -1;
+			cpu_topology[cpu].core_id    = topology_id;
+		}
+		topology_id = find_acpi_cpu_topology_package(cpu);
+		cpu_topology[cpu].package_id = topology_id;
+	}
+
+	return 0;
+}
+
+#else
+static inline int __init parse_acpi_topology(void)
+{
+	return -EINVAL;
+}
+#endif
+
 void __init init_cpu_topology(void)
 {
 	reset_cpu_topology();
@@ -304,6 +345,8 @@  void __init init_cpu_topology(void)
 	 * Discard anything that was parsed if we hit an error so we
 	 * don't use partial information.
 	 */
-	if (of_have_populated_dt() && parse_dt_topology())
+	if (!acpi_disabled && parse_acpi_topology())
+		reset_cpu_topology();
+	else if (of_have_populated_dt() && parse_dt_topology())
 		reset_cpu_topology();
 }