arm64: topology: enable ACPI/PPTT based CPU topology

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.

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>
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Jeremy Linton 2018-05-11 18:58:05 -05:00 committed by Catalin Marinas
parent 868abc0768
commit 2f0a5d107e

View File

@ -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();
}