Attachment 199188 Details for Bug 233088 – proposed patch

[patch] proposed patch

pmap_remove_l2.diff (text/plain), 2.31 KB, created by Mark Johnston on 2018-11-13 01:00:19 UTC

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Creator: Mark Johnston

Created: 2018-11-13 01:00:19 UTC

Size: 2.31 KB

patch

obsolete

>diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
>index 1e8f61fa1a5e..9c4e88793656 100644
>--- a/sys/arm64/arm64/pmap.c
>+++ b/sys/arm64/arm64/pmap.c
>@@ -532,7 +532,7 @@ CTASSERT(L1_BLOCK == L2_BLOCK);
> 
> /*
>  * Checks if the page is dirty. We currently lack proper tracking of this on
>- * arm64 so for now assume is a page mapped as rw was accessed it is.
>+ * arm64 so for now assume if a page mapped as rw was accessed it is dirty.
>  */
> static inline int
> pmap_page_dirty(pt_entry_t pte)
>@@ -2382,6 +2382,35 @@ pmap_pv_insert_l2(pmap_t pmap, vm_offset_t va, pd_entry_t l2e, u_int flags,
> 	return (true);
> }
> 
>+static void
>+pmap_remove_kernel_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t va)
>+{
>+	pt_entry_t newl2;
>+	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 | ATTR_DEFAULT | ATTR_IDX(ml3->md.pv_memattr) | L2_TABLE;
>+
>+	/*
>+	 * Initialize the page table page.
>+	 */
>+	pagezero((void *)PHYS_TO_DMAP(ml3pa));
>+
>+	/*
>+	 * Demote the mapping.
>+	 */
>+	(void)pmap_load_store(l2, newl2);
>+}
>+
> /*
>  * pmap_remove_l2: do the things to unmap a level 2 superpage in a process
>  */
>@@ -2419,16 +2448,18 @@ pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva,
> 				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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Attachments on bug 233088: 199094 | 199188 | 199259