Adapt tlb flush calls following arm64/pmap.c

1. in pmap_enter() no need to call tlb_flush_page() if we don't actually
insert a pted
2. all callers of pmap_pte_remove() already call tlb_flush_page()

This seems to result in some performance improvement (18mn -> 17mn15)
while building libc on a Hifive Unmatched).  Also zap whitespace and
useless comments to further reduce the diff with arm64/pmap.c

ok kettenis@

diff --git a/sys/arch/riscv64/riscv64/pmap.c b/sys/arch/riscv64/riscv64/pmap.c
index 148314d..25d1fda 100644 (file)
--- a/sys/arch/riscv64/riscv64/pmap.c
+++ b/sys/arch/riscv64/riscv64/pmap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: pmap.c,v 1.32 2023/09/03 00:15:46 jca Exp $   */
+/*     $OpenBSD: pmap.c,v 1.33 2023/09/03 00:23:25 jca Exp $   */
 
 /*
  * Copyright (c) 2019-2020 Brian Bamsch <bbamsch@google.com>
@@ -577,10 +577,9 @@ pmap_enter(pmap_t pm, vaddr_t va, paddr_t pa, vm_prot_t prot, int flags)
         */
        if (flags & (PROT_READ|PROT_WRITE|PROT_EXEC|PMAP_WIRED)) {
                pmap_pte_insert(pted);
+               tlb_flush_page(pm, va & ~PAGE_MASK);
        }
 
-       tlb_flush_page(pm, va & ~PAGE_MASK);
-
        error = 0;
 out:
        pmap_unlock(pm);
@@ -629,7 +628,6 @@ pmap_remove_pted(pmap_t pm, struct pte_desc *pted)
        }
 
        pmap_pte_remove(pted, pm != pmap_kernel());
-
        tlb_flush_page(pm, pted->pted_va & ~PAGE_MASK);
 
        if (pted->pted_va & PTED_VA_EXEC_M) {
@@ -686,7 +684,6 @@ _pmap_kenter_pa(vaddr_t va, paddr_t pa, vm_prot_t prot, int flags, int cache)
         * so map the page!
         */
        pmap_pte_insert(pted);
-
        tlb_flush_page(pm, va & ~PAGE_MASK);
 
        pg = PHYS_TO_VM_PAGE(pa);
@@ -734,7 +731,6 @@ pmap_kremove_pg(vaddr_t va)
         * or that the mapping is not present in the hash table.
         */
        pmap_pte_remove(pted, 0);
-
        tlb_flush_page(pm, pted->pted_va & ~PAGE_MASK);
 
        if (pted->pted_va & PTED_VA_EXEC_M)
@@ -1495,10 +1491,7 @@ pmap_page_ro(pmap_t pm, vaddr_t va, vm_prot_t prot)
                pted->pted_pte &= ~PROT_EXEC;
        }
        pmap_pte_update(pted, pl3);
-
        tlb_flush_page(pm, pted->pted_va & ~PAGE_MASK);
-
-       return;
 }
 
 /*
@@ -1655,8 +1648,6 @@ pmap_pte_remove(struct pte_desc *pted, int remove_pted)
        vp3->l3[VP_IDX3(pted->pted_va)] = 0;
        if (remove_pted)
                vp3->vp[VP_IDX3(pted->pted_va)] = NULL;
-
-       tlb_flush_page(pm, pted->pted_va);
 }
 
 /*
@@ -1758,8 +1749,6 @@ pmap_fault_fixup(pmap_t pm, vaddr_t va, vm_prot_t ftype)
 
        /* We actually made a change, so flush it and sync. */
        pmap_pte_update(pted, pl3);
-
-       /* Flush tlb. */
        tlb_flush_page(pm, va & ~PAGE_MASK);
 
        retcode = 1;