diff options
Diffstat (limited to 'arch/arm64/kernel/topology.c')
| -rw-r--r-- | arch/arm64/kernel/topology.c | 47 |
1 files changed, 33 insertions, 14 deletions
diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 43514f90591..b6ee26b0939 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -20,6 +20,7 @@ #include <linux/of.h> #include <linux/sched.h> +#include <asm/cputype.h> #include <asm/topology.h> static int __init get_cpu_for_node(struct device_node *node) @@ -188,13 +189,9 @@ static int __init parse_dt_topology(void) * Check that all cores are in the topology; the SMP code will * only mark cores described in the DT as possible. */ - for_each_possible_cpu(cpu) { - if (cpu_topology[cpu].cluster_id == -1) { - pr_err("CPU%d: No topology information specified\n", - cpu); + for_each_possible_cpu(cpu) + if (cpu_topology[cpu].cluster_id == -1) ret = -EINVAL; - } - } out_map: of_node_put(map); @@ -219,14 +216,6 @@ static void update_siblings_masks(unsigned int cpuid) struct cpu_topology *cpu_topo, *cpuid_topo = &cpu_topology[cpuid]; int cpu; - if (cpuid_topo->cluster_id == -1) { - /* - * DT does not contain topology information for this cpu. - */ - pr_debug("CPU%u: No topology information configured\n", cpuid); - return; - } - /* update core and thread sibling masks */ for_each_possible_cpu(cpu) { cpu_topo = &cpu_topology[cpu]; @@ -249,6 +238,36 @@ static void update_siblings_masks(unsigned int cpuid) void store_cpu_topology(unsigned int cpuid) { + struct cpu_topology *cpuid_topo = &cpu_topology[cpuid]; + u64 mpidr; + + if (cpuid_topo->cluster_id != -1) + goto topology_populated; + + mpidr = read_cpuid_mpidr(); + + /* Uniprocessor systems can rely on default topology values */ + if (mpidr & MPIDR_UP_BITMASK) + return; + + /* Create cpu topology mapping based on MPIDR. */ + if (mpidr & MPIDR_MT_BITMASK) { + /* Multiprocessor system : Multi-threads per core */ + cpuid_topo->thread_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 1); + cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 2); + } else { + /* Multiprocessor system : Single-thread per core */ + cpuid_topo->thread_id = -1; + cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cpuid_topo->cluster_id = MPIDR_AFFINITY_LEVEL(mpidr, 1); + } + + pr_debug("CPU%u: cluster %d core %d thread %d mpidr %#016llx\n", + cpuid, cpuid_topo->cluster_id, cpuid_topo->core_id, + cpuid_topo->thread_id, mpidr); + +topology_populated: update_siblings_masks(cpuid); } |