Author: markj
Date: Tue Nov 20 16:35:53 2018
New Revision: 340680
URL: https://svnweb.freebsd.org/changeset/base/340680
Log:
MFC r340678:
Handle kernel superpage mappings in pmap_remove_l2().
Modified:
stable/12/sys/arm64/arm64/pmap.c
Directory Properties:
stable/12/ (props changed)
Modified: stable/12/sys/arm64/arm64/pmap.c
==============================================================================
--- stable/12/sys/arm64/arm64/pmap.c Tue Nov 20 15:14:30 2018
(r340679)
+++ stable/12/sys/arm64/arm64/pmap.c Tue Nov 20 16:35:53 2018
(r340680)
@@ -2382,8 +2382,40 @@ pmap_pv_insert_l2(pmap_t pmap, vm_offset_t va, pd_entr
return (true);
}
+static void
+pmap_remove_kernel_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t va)
+{
+ pt_entry_t newl2, oldl2;
+ vm_page_t ml3;
+ vm_paddr_t ml3pa;
+
+ KASSERT(!VIRT_IN_DMAP(va), ("removing direct mapping of %#lx", va));
+ KASSERT(pmap == kernel_pmap, ("pmap %p is not kernel_pmap", pmap));
+ PMAP_LOCK_ASSERT(pmap, MA_OWNED);
+
+ ml3 = pmap_remove_pt_page(pmap, va);
+ if (ml3 == NULL)
+ panic("pmap_remove_kernel_l2: Missing pt page");
+
+ ml3pa = VM_PAGE_TO_PHYS(ml3);
+ newl2 = ml3pa | L2_TABLE;
+
+ /*
+ * Initialize the page table page.
+ */
+ pagezero((void *)PHYS_TO_DMAP(ml3pa));
+
+ /*
+ * Demote the mapping. The caller must have already invalidated the
+ * mapping (i.e., the "break" in break-before-make).
+ */
+ oldl2 = pmap_load_store(l2, newl2);
+ KASSERT(oldl2 == 0, ("%s: found existing mapping at %p: %#lx",
+ __func__, l2, oldl2));
+}
+
/*
- * pmap_remove_l2: do the things to unmap a level 2 superpage in a process
+ * pmap_remove_l2: Do the things to unmap a level 2 superpage.
*/
static int
pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva,
@@ -2419,16 +2451,18 @@ pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_
vm_page_aflag_clear(m, PGA_WRITEABLE);
}
}
- KASSERT(pmap != kernel_pmap,
- ("Attempting to remove an l2 kernel page"));
- ml3 = pmap_remove_pt_page(pmap, sva);
- if (ml3 != NULL) {
- pmap_resident_count_dec(pmap, 1);
- KASSERT(ml3->wire_count == NL3PG,
- ("pmap_remove_l2: l3 page wire count error"));
- ml3->wire_count = 1;
- vm_page_unwire_noq(ml3);
- pmap_add_delayed_free_list(ml3, free, FALSE);
+ if (pmap == kernel_pmap) {
+ pmap_remove_kernel_l2(pmap, l2, sva);
+ } else {
+ ml3 = pmap_remove_pt_page(pmap, sva);
+ if (ml3 != NULL) {
+ pmap_resident_count_dec(pmap, 1);
+ KASSERT(ml3->wire_count == NL3PG,
+ ("pmap_remove_l2: l3 page wire count error"));
+ ml3->wire_count = 1;
+ vm_page_unwire_noq(ml3);
+ pmap_add_delayed_free_list(ml3, free, FALSE);
+ }
}
return (pmap_unuse_pt(pmap, sva, l1e, free));
}
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