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Diffstat (limited to 'arch/powerpc/platforms/powernv/smp.c')
-rw-r--r--arch/powerpc/platforms/powernv/smp.c62
1 files changed, 56 insertions, 6 deletions
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c
index 6a3ecca5b72..88c9459c3e0 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -71,18 +71,68 @@ int pnv_smp_kick_cpu(int nr)
BUG_ON(nr < 0 || nr >= NR_CPUS);
- /* On OPAL v2 the CPU are still spinning inside OPAL itself,
- * get them back now
+ /*
+ * If we already started or OPALv2 is not supported, we just
+ * kick the CPU via the PACA
*/
- if (!paca[nr].cpu_start && firmware_has_feature(FW_FEATURE_OPALv2)) {
- pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n", nr, pcpu);
- rc = opal_start_cpu(pcpu, start_here);
+ if (paca[nr].cpu_start || !firmware_has_feature(FW_FEATURE_OPALv2))
+ goto kick;
+
+ /*
+ * At this point, the CPU can either be spinning on the way in
+ * from kexec or be inside OPAL waiting to be started for the
+ * first time. OPAL v3 allows us to query OPAL to know if it
+ * has the CPUs, so we do that
+ */
+ if (firmware_has_feature(FW_FEATURE_OPALv3)) {
+ uint8_t status;
+
+ rc = opal_query_cpu_status(pcpu, &status);
if (rc != OPAL_SUCCESS) {
- pr_warn("OPAL Error %ld starting CPU %d\n",
+ pr_warn("OPAL Error %ld querying CPU %d state\n",
rc, nr);
return -ENODEV;
}
+
+ /*
+ * Already started, just kick it, probably coming from
+ * kexec and spinning
+ */
+ if (status == OPAL_THREAD_STARTED)
+ goto kick;
+
+ /*
+ * Available/inactive, let's kick it
+ */
+ if (status == OPAL_THREAD_INACTIVE) {
+ pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n",
+ nr, pcpu);
+ rc = opal_start_cpu(pcpu, start_here);
+ if (rc != OPAL_SUCCESS) {
+ pr_warn("OPAL Error %ld starting CPU %d\n",
+ rc, nr);
+ return -ENODEV;
+ }
+ } else {
+ /*
+ * An unavailable CPU (or any other unknown status)
+ * shouldn't be started. It should also
+ * not be in the possible map but currently it can
+ * happen
+ */
+ pr_devel("OPAL: CPU %d (HW 0x%x) is unavailable"
+ " (status %d)...\n", nr, pcpu, status);
+ return -ENODEV;
+ }
+ } else {
+ /*
+ * On OPAL v2, we just kick it and hope for the best,
+ * we must not test the error from opal_start_cpu() or
+ * we would fail to get CPUs from kexec.
+ */
+ opal_start_cpu(pcpu, start_here);
}
+ kick:
return smp_generic_kick_cpu(nr);
}