Simplify the way we handle TLB flushes. Since ARMv7 effectively has a

unified TLB there is not much point in optimizing TLB flushing for pages
that have never been executable.  The only difference is a flush of the
branch predictor and even that isn't necessary anymore on all but the oldest
Cortex cores.

ok patrick@

diff --git a/sys/arch/arm/arm/pmap7.c b/sys/arch/arm/arm/pmap7.c
index bc6ef2d..a837ce1 100644 (file)
--- a/sys/arch/arm/arm/pmap7.c
+++ b/sys/arch/arm/arm/pmap7.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: pmap7.c,v 1.31 2016/07/31 22:27:07 kettenis Exp $     */
+/*     $OpenBSD: pmap7.c,v 1.32 2016/08/03 11:52:43 kettenis Exp $     */
 /*     $NetBSD: pmap.c,v 1.147 2004/01/18 13:03:50 scw Exp $   */
 
 /*
@@ -1028,12 +1028,8 @@ pmap_clearbit(struct vm_page *pg, u_int maskbits)
                        *ptep = npte;
                        PTE_SYNC(ptep);
                        /* Flush the TLB entry if a current pmap. */
-                       if (l2pte_valid(opte)) {
-                               if (PV_BEEN_EXECD(oflags))
-                                       pmap_tlb_flushID_SE(pm, pv->pv_va);
-                               else
-                                       pmap_tlb_flushD_SE(pm, pv->pv_va);
-                       }
+                       if (l2pte_valid(opte))
+                               pmap_tlb_flushID_SE(pm, pv->pv_va);
                }
 
                NPDEBUG(PDB_BITS,
@@ -1281,7 +1277,6 @@ pmap_enter(pmap_t pm, vaddr_t va, paddr_t pa, vm_prot_t prot, int flags)
        ptep = &l2b->l2b_kva[l2pte_index(va)];
        opte = *ptep;
        npte = pa;
-       oflags = 0;
 
        if (opte != 0) {        /* not l2pte_valid!!! MIOD */
                /*
@@ -1367,7 +1362,6 @@ pmap_enter(pmap_t pm, vaddr_t va, paddr_t pa, vm_prot_t prot, int flags)
                                 * must remove it from the PV list
                                 */
                                pve = pmap_remove_pv(opg, pm, va);
-                               oflags = pve->pv_flags;
                        } else
                        if ((pve = pool_get(&pmap_pv_pool, PR_NOWAIT)) == NULL){
                                if ((flags & PMAP_CANFAIL) == 0)
@@ -1397,8 +1391,6 @@ pmap_enter(pmap_t pm, vaddr_t va, paddr_t pa, vm_prot_t prot, int flags)
                         * at this address.
                         */
                        pve = pmap_remove_pv(opg, pm, va);
-                       oflags = pve->pv_flags;
-
                        pool_put(&pmap_pv_pool, pve);
                }
        }
@@ -1449,12 +1441,8 @@ pmap_enter(pmap_t pm, vaddr_t va, paddr_t pa, vm_prot_t prot, int flags)
                        }
                }
 
-               if (l2pte_valid(opte)) {
-                       if (PV_BEEN_EXECD(oflags))
-                               pmap_tlb_flushID_SE(pm, va);
-                       else
-                               pmap_tlb_flushD_SE(pm, va);
-               }
+               if (l2pte_valid(opte))
+                       pmap_tlb_flushID_SE(pm, va);
        }
 
        /*
@@ -1480,7 +1468,7 @@ pmap_remove(pmap_t pm, vaddr_t sva, vaddr_t eva)
        struct l2_bucket *l2b;
        vaddr_t next_bucket;
        pt_entry_t *ptep;
-       u_int mappings, is_exec;
+       u_int mappings;
 
        NPDEBUG(PDB_REMOVE, printf("pmap_remove: pmap=%p sva=%08lx eva=%08lx\n",
            pm, sva, eva));
@@ -1520,7 +1508,6 @@ pmap_remove(pmap_t pm, vaddr_t sva, vaddr_t eva)
 
                        pm->pm_stats.resident_count--;
                        pa = l2pte_pa(pte);
-                       is_exec = 0;
 
                        /*
                         * Update flags. In a number of circumstances,
@@ -1531,10 +1518,8 @@ pmap_remove(pmap_t pm, vaddr_t sva, vaddr_t eva)
                        if (pg != NULL) {
                                struct pv_entry *pve;
                                pve = pmap_remove_pv(pg, pm, sva);
-                               if (pve != NULL) {
-                                       is_exec = PV_BEEN_EXECD(pve->pv_flags);
+                               if (pve != NULL)
                                        pool_put(&pmap_pv_pool, pve);
-                               }
                        }
 
                        /*
@@ -1547,12 +1532,8 @@ pmap_remove(pmap_t pm, vaddr_t sva, vaddr_t eva)
 
                        *ptep = L2_TYPE_INV;
                        PTE_SYNC(ptep);
-                       if (l2pte_valid(pte)) {
-                               if (is_exec)
-                                       pmap_tlb_flushID_SE(pm, sva);
-                               else
-                                       pmap_tlb_flushD_SE(pm, sva);
-                       }
+                       if (l2pte_valid(pte))
+                               pmap_tlb_flushID_SE(pm, sva);
 
                        sva += PAGE_SIZE;
                        ptep++;
@@ -1801,12 +1782,8 @@ NPDEBUG(PDB_PROTECT, printf("\n"));
 
                                if (flush >= 0) {
                                        flush++;
-                                       if (l2pte_valid(opte)) {
-                                               if (PV_BEEN_EXECD(f))
-                                                       cpu_tlb_flushID_SE(sva);
-                                               else
-                                                       cpu_tlb_flushD_SE(sva);
-                                       }
+                                       if (l2pte_valid(opte))
+                                               cpu_tlb_flushID_SE(sva);
                                } else
                                        flags |= f;
                        }
@@ -1816,12 +1793,9 @@ NPDEBUG(PDB_PROTECT, printf("\n"));
                }
        }
 
-       if (flush < 0) {
-               if (PV_BEEN_EXECD(flags))
-                       pmap_tlb_flushID(pm);
-               else
-                       pmap_tlb_flushD(pm);
-       }
+       if (flush < 0)
+               pmap_tlb_flushID(pm);
+
 NPDEBUG(PDB_PROTECT, printf("\n"));
 }