Allow sbld allocation to fail when PMAP_CANFAIL.

pool_get in powerpc64's pmap might fail when uvm_km_pages.free == 0.
This might cause KASSERT(slbd) to panic 'kernel diagnostic assertion
"sbld" failed'.  Remove this KASSERT and add a check for PMAP_CANFAIL.
pmap_enter calls without PMAP_CANFAIL might still panic.

ok mpi@ jca@

diff --git a/sys/arch/powerpc64/powerpc64/pmap.c b/sys/arch/powerpc64/powerpc64/pmap.c
index 53c2bad..9034952 100644 (file)
--- a/sys/arch/powerpc64/powerpc64/pmap.c
+++ b/sys/arch/powerpc64/powerpc64/pmap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: pmap.c,v 1.61 2024/04/03 19:30:59 gkoehler Exp $ */
+/*     $OpenBSD: pmap.c,v 1.62 2024/06/04 17:31:59 gkoehler Exp $ */
 
 /*
  * Copyright (c) 2015 Martin Pieuchot
@@ -602,7 +602,11 @@ pmap_vp_enter(pmap_t pm, vaddr_t va, struct pte_desc *pted, int flags)
        slbd = pmap_slbd_lookup(pm, va);
        if (slbd == NULL) {
                slbd = pmap_slbd_alloc(pm, va);
-               KASSERT(slbd);
+               if (slbd == NULL) {
+                       if ((flags & PMAP_CANFAIL) == 0)
+                               panic("%s: unable to allocate slbd", __func__);
+                       return ENOMEM;
+               }
        }
 
        vp1 = slbd->slbd_vp;