git: 0c188c06c627 - main - arm64: replace pa_to_pvh() with page_to_pvh() in pmap_remove_l2()

[Alan Cox]

The branch main has been updated by alc:

URL: https://cgit.FreeBSD.org/src/commit/?id=0c188c06c627b5de30eeeeb7cde00d071a80ecfa

commit 0c188c06c627b5de30eeeeb7cde00d071a80ecfa
Author:     Alan Cox <alc at FreeBSD.org>
AuthorDate: 2021-06-23 19:14:31 +0000
Commit:     Alan Cox <alc at FreeBSD.org>
CommitDate: 2021-06-24 03:35:46 +0000

    arm64: replace pa_to_pvh() with page_to_pvh() in pmap_remove_l2()
    
    Revise pmap_remove_l2() to use the constant-time function page_to_pvh()
    instead of the linear-time function pa_to_pvh().
    
    Reviewed by:    kib, markj
    MFC after:      1 week
    Differential Revision:  https://reviews.freebsd.org/D30876
---
 sys/arm64/arm64/pmap.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c
index 7def96bca70b..bc3d4fd6446b 100644
--- a/sys/arm64/arm64/pmap.c
+++ b/sys/arm64/arm64/pmap.c
@@ -2834,8 +2834,7 @@ pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva,
 {
 	struct md_page *pvh;
 	pt_entry_t old_l2;
-	vm_offset_t eva, va;
-	vm_page_t m, ml3;
+	vm_page_t m, ml3, mt;
 
 	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
 	KASSERT((sva & L2_OFFSET) == 0, ("pmap_remove_l2: sva is not aligned"));
@@ -2853,19 +2852,18 @@ pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva,
 		pmap->pm_stats.wired_count -= L2_SIZE / PAGE_SIZE;
 	pmap_resident_count_dec(pmap, L2_SIZE / PAGE_SIZE);
 	if (old_l2 & ATTR_SW_MANAGED) {
+		m = PHYS_TO_VM_PAGE(old_l2 & ~ATTR_MASK);
+		pvh = page_to_pvh(m);
 		CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, old_l2 & ~ATTR_MASK);
-		pvh = pa_to_pvh(old_l2 & ~ATTR_MASK);
 		pmap_pvh_free(pvh, pmap, sva);
-		eva = sva + L2_SIZE;
-		for (va = sva, m = PHYS_TO_VM_PAGE(old_l2 & ~ATTR_MASK);
-		    va < eva; va += PAGE_SIZE, m++) {
+		for (mt = m; mt < &m[L2_SIZE / PAGE_SIZE]; mt++) {
 			if (pmap_pte_dirty(pmap, old_l2))
-				vm_page_dirty(m);
+				vm_page_dirty(mt);
 			if (old_l2 & ATTR_AF)
-				vm_page_aflag_set(m, PGA_REFERENCED);
-			if (TAILQ_EMPTY(&m->md.pv_list) &&
+				vm_page_aflag_set(mt, PGA_REFERENCED);
+			if (TAILQ_EMPTY(&mt->md.pv_list) &&
 			    TAILQ_EMPTY(&pvh->pv_list))
-				vm_page_aflag_clear(m, PGA_WRITEABLE);
+				vm_page_aflag_clear(mt, PGA_WRITEABLE);
 		}
 	}
 	if (pmap == kernel_pmap) {