diff options
Diffstat (limited to 'arch/mips/kernel/mips-cm.c')
| -rw-r--r-- | arch/mips/kernel/mips-cm.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/mips/kernel/mips-cm.c b/arch/mips/kernel/mips-cm.c index 3a115fab5573..3eb2cfb893e1 100644 --- a/arch/mips/kernel/mips-cm.c +++ b/arch/mips/kernel/mips-cm.c @@ -512,3 +512,40 @@ void mips_cm_error_report(void) /* reprime cause register */ write_gcr_error_cause(cm_error); } + +unsigned int mips_cps_first_online_in_cluster(void) +{ + unsigned int local_cl; + int i; + + local_cl = cpu_cluster(¤t_cpu_data); + + /* + * We rely upon knowledge that CPUs are numbered sequentially by + * cluster - ie. CPUs 0..X will be in cluster 0, CPUs X+1..Y in cluster + * 1, CPUs Y+1..Z in cluster 2 etc. This means that CPUs in the same + * cluster will immediately precede or follow one another. + * + * First we scan backwards, until we find an online CPU in the cluster + * or we move on to another cluster. + */ + for (i = smp_processor_id() - 1; i >= 0; i--) { + if (cpu_cluster(&cpu_data[i]) != local_cl) + break; + if (!cpu_online(i)) + continue; + return false; + } + + /* Then do the same for higher numbered CPUs */ + for (i = smp_processor_id() + 1; i < nr_cpu_ids; i++) { + if (cpu_cluster(&cpu_data[i]) != local_cl) + break; + if (!cpu_online(i)) + continue; + return false; + } + + /* We found no online CPUs in the local cluster */ + return true; +} |