From: Conor Dooley <[email protected]>
The default implementation of store_cpu_topology() was derived from the
arm64 implementation, but with the mpidr bits removed. Extract the mpidr
bits from the arch implementation to the callsites & use the generic
version.
Signed-off-by: Conor Dooley <[email protected]>
---
arch/arm64/kernel/smp.c | 16 +++++++++++++--
arch/arm64/kernel/topology.c | 40 ------------------------------------
2 files changed, 14 insertions(+), 42 deletions(-)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 62ed361a4376..9e8acaa4c2f7 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -234,7 +234,12 @@ asmlinkage notrace void secondary_start_kernel(void)
* Log the CPU info before it is marked online and might get read.
*/
cpuinfo_store_cpu();
- store_cpu_topology(cpu);
+
+ /*
+ * Uniprocessor systems can rely on default topology values
+ */
+ if (!(mpidr & MPIDR_UP_BITMASK))
+ store_cpu_topology(cpu);
/*
* Enable GIC and timers.
@@ -719,6 +724,7 @@ void __init smp_init_cpus(void)
void __init smp_prepare_cpus(unsigned int max_cpus)
{
const struct cpu_operations *ops;
+ u64 mpidr;
int err;
unsigned int cpu;
unsigned int this_cpu;
@@ -726,7 +732,13 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
init_cpu_topology();
this_cpu = smp_processor_id();
- store_cpu_topology(this_cpu);
+ mpidr = read_cpuid_mpidr();
+
+ /*
+ * Uniprocessor systems can rely on default topology values
+ */
+ if (!(mpidr & MPIDR_UP_BITMASK))
+ store_cpu_topology(this_cpu);
numa_store_cpu_info(this_cpu);
numa_add_cpu(this_cpu);
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c
index 869ffc4d4484..7889a00f5487 100644
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -22,46 +22,6 @@
#include <asm/cputype.h>
#include <asm/topology.h>
-void store_cpu_topology(unsigned int cpuid)
-{
- struct cpu_topology *cpuid_topo = &cpu_topology[cpuid];
- u64 mpidr;
-
- if (cpuid_topo->package_id != -1)
- goto topology_populated;
-
- mpidr = read_cpuid_mpidr();
-
- /* Uniprocessor systems can rely on default topology values */
- if (mpidr & MPIDR_UP_BITMASK)
- return;
-
- /*
- * This would be the place to create cpu topology based on MPIDR.
- *
- * However, it cannot be trusted to depict the actual topology; some
- * pieces of the architecture enforce an artificial cap on Aff0 values
- * (e.g. GICv3's ICC_SGI1R_EL1 limits it to 15), leading to an
- * artificial cycling of Aff1, Aff2 and Aff3 values. IOW, these end up
- * having absolutely no relationship to the actual underlying system
- * topology, and cannot be reasonably used as core / package ID.
- *
- * If the MT bit is set, Aff0 *could* be used to define a thread ID, but
- * we still wouldn't be able to obtain a sane core ID. This means we
- * need to entirely ignore MPIDR for any topology deduction.
- */
- cpuid_topo->thread_id = -1;
- cpuid_topo->core_id = cpuid;
- cpuid_topo->package_id = cpu_to_node(cpuid);
-
- pr_debug("CPU%u: cluster %d core %d thread %d mpidr %#016llx\n",
- cpuid, cpuid_topo->package_id, cpuid_topo->core_id,
- cpuid_topo->thread_id, mpidr);
-
-topology_populated:
- update_siblings_masks(cpuid);
-}
-
#ifdef CONFIG_ACPI
static bool __init acpi_cpu_is_threaded(int cpu)
{
--
2.37.0