git: 6f6a166eaf5e - main - arm64: Use page_to_pvh() when the vm_page_t is known

Alan Cox alc at FreeBSD.org
Mon Jun 21 22:27:09 UTC 2021


The branch main has been updated by alc:

URL: https://cgit.FreeBSD.org/src/commit/?id=6f6a166eaf5e59dedb761ea6152417433a841e3b

commit 6f6a166eaf5e59dedb761ea6152417433a841e3b
Author:     Alan Cox <alc at FreeBSD.org>
AuthorDate: 2021-06-21 07:45:21 +0000
Commit:     Alan Cox <alc at FreeBSD.org>
CommitDate: 2021-06-21 22:25:06 +0000

    arm64: Use page_to_pvh() when the vm_page_t is known
    
    When support for a sparse pv_table was added, the implementation of
    pa_to_pvh() changed from a simple constant-time calculation to iterating
    over the array vm_phys_segs[].  To mitigate this issue, an alternative
    function, page_to_pvh(), was introduced that still runs in constant time
    but requires the vm_page_t to be known.  However, three cases where the
    vm_page_t is known were not converted to page_to_pvh().  This change
    converts those three cases.
    
    Reviewed by:    kib, markj
    MFC after:      1 week
    Differential Revision:  https://reviews.freebsd.org/D30832
---
 sys/arm64/arm64/pmap.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index ffc83be852bd..5f321be98528 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -3474,7 +3474,7 @@ pmap_pv_promote_l2(pmap_t pmap, vm_offset_t va, vm_paddr_t pa,
 	va = va & ~L2_OFFSET;
 	pv = pmap_pvh_remove(&m->md, pmap, va);
 	KASSERT(pv != NULL, ("pmap_pv_promote_l2: pv not found"));
-	pvh = pa_to_pvh(pa);
+	pvh = page_to_pvh(m);
 	TAILQ_INSERT_TAIL(&pvh->pv_list, pv, pv_next);
 	pvh->pv_gen++;
 	/* Free the remaining NPTEPG - 1 pv entries. */
@@ -3896,7 +3896,7 @@ havel3:
 			if ((om->a.flags & PGA_WRITEABLE) != 0 &&
 			    TAILQ_EMPTY(&om->md.pv_list) &&
 			    ((om->flags & PG_FICTITIOUS) != 0 ||
-			    TAILQ_EMPTY(&pa_to_pvh(opa)->pv_list)))
+			    TAILQ_EMPTY(&page_to_pvh(om)->pv_list)))
 				vm_page_aflag_clear(om, PGA_WRITEABLE);
 		} else {
 			KASSERT((orig_l3 & ATTR_AF) != 0,
@@ -5000,7 +5000,7 @@ pmap_remove_pages(pmap_t pmap)
 				case 1:
 					pmap_resident_count_dec(pmap,
 					    L2_SIZE / PAGE_SIZE);
-					pvh = pa_to_pvh(tpte & ~ATTR_MASK);
+					pvh = page_to_pvh(m);
 					TAILQ_REMOVE(&pvh->pv_list, pv,pv_next);
 					pvh->pv_gen++;
 					if (TAILQ_EMPTY(&pvh->pv_list)) {


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