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Handle kernel superpage mappings in pmap_remove_l2().

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PR:		233088
Reviewed by:	alc, andrew, kib
Tested by:	sbruno
MFC after:	3 days
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D17981
This commit is contained in:
Mark Johnston 2018-11-20 15:12:37 +00:00
parent 737037f6c0
commit cafcdfd00f
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=340678
1 changed files with 45 additions and 11 deletions
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56
sys/arm64/arm64/pmap.c
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@ -2382,8 +2382,40 @@ 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, 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_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));
}