+ /* No lockless fast path .. yet */
+ spin_lock(&context_lock);
+
+#ifndef DEBUG_STEAL_ONLY
+ pr_debug("[%d] activating context for mm @%p, active=%d, id=%d\n",
+ cpu, next, next->context.active, next->context.id);
+#endif
+
+#ifdef CONFIG_SMP
+ /* Mark us active and the previous one not anymore */
+ next->context.active++;
+ if (prev) {
+ WARN_ON(prev->context.active < 1);
+ prev->context.active--;
+ }
+#endif /* CONFIG_SMP */
+
+ /* If we already have a valid assigned context, skip all that */
+ id = next->context.id;
+ if (likely(id != MMU_NO_CONTEXT))
+ goto ctxt_ok;
+
+ /* We really don't have a context, let's try to acquire one */
+ id = next_context;
+ if (id > LAST_CONTEXT)
+ id = FIRST_CONTEXT;
+ map = context_map;
+
+ /* No more free contexts, let's try to steal one */
+ if (nr_free_contexts == 0) {
+#ifdef CONFIG_SMP
+ if (num_online_cpus() > 1) {
+ id = steal_context_smp(id);
+ goto stolen;
+ }
+#endif /* CONFIG_SMP */
+ id = steal_context_up(id);
+ goto stolen;
+ }
+ nr_free_contexts--;
+
+ /* We know there's at least one free context, try to find it */
+ while (__test_and_set_bit(id, map)) {
+ id = find_next_zero_bit(map, LAST_CONTEXT+1, id);
+ if (id > LAST_CONTEXT)
+ id = FIRST_CONTEXT;
+ }
+ stolen:
+ next_context = id + 1;
+ context_mm[id] = next;
+ next->context.id = id;
+
+#ifndef DEBUG_STEAL_ONLY
+ pr_debug("[%d] picked up new id %d, nrf is now %d\n",
+ cpu, id, nr_free_contexts);
+#endif
+
+ context_check_map();
+ ctxt_ok:
+
+ /* If that context got marked stale on this CPU, then flush the
+ * local TLB for it and unmark it before we use it
+ */
+ if (test_bit(id, stale_map[cpu])) {
+ pr_debug("[%d] flushing stale context %d for mm @%p !\n",
+ cpu, id, next);
+ local_flush_tlb_mm(next);
+
+ /* XXX This clear should ultimately be part of local_flush_tlb_mm */
+ __clear_bit(id, stale_map[cpu]);
+ }
+
+ /* Flick the MMU and release lock */
+ set_context(id, next->pgd);
+ spin_unlock(&context_lock);