@@ -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>
@@ -300,6 +302,47 @@ 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)
+{
+ u64 is_threaded;
+ int cpu;
+ int 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;
+ topology_id = find_acpi_cpu_topology_package(cpu);
+ cpu_topology[cpu].physical_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].physical_id = topology_id;
+ }
+ }
+ return 0;
+}
+
+#else
+static int __init parse_acpi_topology(void)
+{
+ /*ACPI kernels should be built with PPTT support*/
+ return -EINVAL;
+}
+#endif
void __init init_cpu_topology(void)
{
@@ -309,6 +352,8 @@ 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();
}
@@ -43,6 +43,8 @@
if (nr_cpus_node(node))
int arch_update_cpu_topology(void);
+int find_acpi_cpu_topology(unsigned int cpu, int level);
+int find_acpi_cpu_topology_package(unsigned int cpu);
/* Conform to ACPI 2.0 SLIT distance definitions */
#define LOCAL_DISTANCE 10
Propagate the topology information from the PPTT tree to the cpu_topology array. We can get the thread id, core_id and cluster_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> --- arch/arm64/kernel/topology.c | 47 +++++++++++++++++++++++++++++++++++++++++++- include/linux/topology.h | 2 ++ 2 files changed, 48 insertions(+), 1 deletion(-) -- 2.13.5