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[src/trunk]: src/sys/arch/x86/x86 Simplify pmap_sync_pv: just pass a pa, and ...



details:   https://anonhg.NetBSD.org/src/rev/8805c080f462
branches:  trunk
changeset: 447582:8805c080f462
user:      maxv <maxv%NetBSD.org@localhost>
date:      Thu Jan 17 14:24:51 2019 +0000

description:
Simplify pmap_sync_pv: just pass a pa, and build the pte inside.

diffstat:

 sys/arch/x86/x86/pmap.c |  54 +++++++++++++++++++-----------------------------
 1 files changed, 21 insertions(+), 33 deletions(-)

diffs (192 lines):

diff -r 094564f1eff5 -r 8805c080f462 sys/arch/x86/x86/pmap.c
--- a/sys/arch/x86/x86/pmap.c   Thu Jan 17 13:51:25 2019 +0000
+++ b/sys/arch/x86/x86/pmap.c   Thu Jan 17 14:24:51 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.315 2018/12/17 07:10:07 maxv Exp $  */
+/*     $NetBSD: pmap.c,v 1.316 2019/01/17 14:24:51 maxv Exp $  */
 
 /*
  * Copyright (c) 2008, 2010, 2016, 2017 The NetBSD Foundation, Inc.
@@ -130,7 +130,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.315 2018/12/17 07:10:07 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.316 2019/01/17 14:24:51 maxv Exp $");
 
 #include "opt_user_ldt.h"
 #include "opt_lockdebug.h"
@@ -3579,8 +3579,7 @@
  * => issues tlb shootdowns if necessary.
  */
 static int
-pmap_sync_pv(struct pv_pte *pvpte, pt_entry_t expect, int clearbits,
-    pt_entry_t *optep)
+pmap_sync_pv(struct pv_pte *pvpte, paddr_t pa, int clearbits, pt_entry_t *optep)
 {
        struct pmap *pmap;
        struct vm_page *ptp;
@@ -3588,16 +3587,16 @@
        pt_entry_t *ptep;
        pt_entry_t opte;
        pt_entry_t npte;
+       pt_entry_t expect;
        bool need_shootdown;
 
+       expect = pmap_pa2pte(pa) | PG_V;
        ptp = pvpte->pte_ptp;
        va = pvpte->pte_va;
        KASSERT(ptp == NULL || ptp->uobject != NULL);
        KASSERT(ptp == NULL || ptp_va2o(va, 1) == ptp->offset);
        pmap = ptp_to_pmap(ptp);
 
-       KASSERT((expect & ~(PG_FRAME | PG_V)) == 0);
-       KASSERT((expect & PG_V) != 0);
        KASSERT(clearbits == ~0 || (clearbits & ~(PG_M | PG_U | PG_RW)) == 0);
        KASSERT(kpreempt_disabled());
 
@@ -3608,16 +3607,14 @@
                KASSERT((opte & (PG_U | PG_V)) != PG_U);
                KASSERT(opte == 0 || (opte & PG_V) != 0);
                if ((opte & (PG_FRAME | PG_V)) != expect) {
-
                        /*
-                        * we lost a race with a V->P operation like
-                        * pmap_remove().  wait for the competitor
+                        * We lost a race with a V->P operation like
+                        * pmap_remove().  Wait for the competitor
                         * reflecting pte bits into mp_attrs.
                         *
-                        * issue a redundant TLB shootdown so that
+                        * Issue a redundant TLB shootdown so that
                         * we can wait for its completion.
                         */
-
                        pmap_unmap_pte();
                        if (clearbits != 0) {
                                pmap_tlb_shootdown(pmap, va,
@@ -3628,30 +3625,26 @@
                }
 
                /*
-                * check if there's anything to do on this pte.
+                * Check if there's anything to do on this PTE.
                 */
-
                if ((opte & clearbits) == 0) {
                        need_shootdown = false;
                        break;
                }
 
                /*
-                * we need a shootdown if the pte is cached. (PG_U)
-                *
-                * ...unless we are clearing only the PG_RW bit and
-                * it isn't cached as RW. (PG_M)
+                * We need a shootdown if the PTE is cached (PG_U) ...
+                * ... Unless we are clearing only the PG_RW bit and
+                * it isn't cached as RW (PG_M).
                 */
-
                need_shootdown = (opte & PG_U) != 0 &&
                    !(clearbits == PG_RW && (opte & PG_M) == 0);
 
                npte = opte & ~clearbits;
 
                /*
-                * if we need a shootdown anyway, clear PG_U and PG_M.
+                * If we need a shootdown anyway, clear PG_U and PG_M.
                 */
-
                if (need_shootdown) {
                        npte &= ~(PG_U | PG_M);
                }
@@ -3675,10 +3668,8 @@
        struct pv_pte *pvpte;
        struct pv_entry *killlist = NULL;
        struct vm_page *ptp;
-       pt_entry_t expect;
        int count;
 
-       expect = pmap_pa2pte(pa) | PG_V;
        count = SPINLOCK_BACKOFF_MIN;
        kpreempt_disable();
 startover:
@@ -3690,17 +3681,16 @@
                int error;
 
                /*
-                * add a reference to the pmap before clearing the pte.
-                * otherwise the pmap can disappear behind us.
+                * Add a reference to the pmap before clearing the pte.
+                * Otherwise the pmap can disappear behind us.
                 */
-
                ptp = pvpte->pte_ptp;
                pmap = ptp_to_pmap(ptp);
                if (ptp != NULL) {
                        pmap_reference(pmap);
                }
 
-               error = pmap_sync_pv(pvpte, expect, ~0, &opte);
+               error = pmap_sync_pv(pvpte, pa, ~0, &opte);
                if (error == EAGAIN) {
                        int hold_count;
                        KERNEL_UNLOCK_ALL(curlwp, &hold_count);
@@ -3716,7 +3706,7 @@
                va = pvpte->pte_va;
                pve = pmap_remove_pv(pp, ptp, va);
 
-               /* update the PTP reference count.  free if last reference. */
+               /* Update the PTP reference count. Free if last reference. */
                if (ptp != NULL) {
                        struct pmap *pmap2;
                        pt_entry_t *ptes;
@@ -3798,8 +3788,8 @@
 {
        struct pmap_page *pp;
        struct pv_pte *pvpte;
-       pt_entry_t expect;
        u_int result;
+       paddr_t pa;
 
        KASSERT(uvm_page_locked_p(pg));
 
@@ -3807,7 +3797,7 @@
        if ((pp->pp_attrs & testbits) != 0) {
                return true;
        }
-       expect = pmap_pa2pte(VM_PAGE_TO_PHYS(pg)) | PG_V;
+       pa = VM_PAGE_TO_PHYS(pg);
        kpreempt_disable();
        for (pvpte = pv_pte_first(pp); pvpte; pvpte = pv_pte_next(pp, pvpte)) {
                pt_entry_t opte;
@@ -3816,7 +3806,7 @@
                if ((pp->pp_attrs & testbits) != 0) {
                        break;
                }
-               error = pmap_sync_pv(pvpte, expect, 0, &opte);
+               error = pmap_sync_pv(pvpte, pa, 0, &opte);
                if (error == 0) {
                        pp->pp_attrs |= opte;
                }
@@ -3837,10 +3827,8 @@
 {
        struct pv_pte *pvpte;
        u_int result;
-       pt_entry_t expect;
        int count;
 
-       expect = pmap_pa2pte(pa) | PG_V;
        count = SPINLOCK_BACKOFF_MIN;
        kpreempt_disable();
 startover:
@@ -3848,7 +3836,7 @@
                pt_entry_t opte;
                int error;
 
-               error = pmap_sync_pv(pvpte, expect, clearbits, &opte);
+               error = pmap_sync_pv(pvpte, pa, clearbits, &opte);
                if (error == EAGAIN) {
                        int hold_count;
                        KERNEL_UNLOCK_ALL(curlwp, &hold_count);



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