[src/yamt-km]: src/sys/arch/i386/i386 - simplify pvpage allocation.

[yamt <yamt%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6a6a78b496a4
branches:  yamt-km
changeset: 573297:6a6a78b496a4
user:      yamt <yamt%NetBSD.org@localhost>
date:      Wed Jan 26 09:20:45 2005 +0000

description:
- simplify pvpage allocation.
- assert that pmap_enter is never called before pmap_init.

diffstat:

 sys/arch/i386/i386/pmap.c |  77 +++++++++++-----------------------------------
 1 files changed, 19 insertions(+), 58 deletions(-)

diffs (154 lines):

diff -r 4043bfb96d2c -r 6a6a78b496a4 sys/arch/i386/i386/pmap.c
--- a/sys/arch/i386/i386/pmap.c Wed Jan 26 08:33:14 2005 +0000
+++ b/sys/arch/i386/i386/pmap.c Wed Jan 26 09:20:45 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: pmap.c,v 1.180.4.1 2005/01/25 13:01:08 yamt Exp $      */
+/*     $NetBSD: pmap.c,v 1.180.4.2 2005/01/26 09:20:45 yamt Exp $      */
 
 /*
  *
@@ -60,7 +60,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.180.4.1 2005/01/25 13:01:08 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.180.4.2 2005/01/26 09:20:45 yamt Exp $");
 
 #include "opt_cputype.h"
 #include "opt_user_ldt.h"
@@ -379,7 +379,6 @@
 static struct pv_pagelist pv_freepages;        /* list of pv_pages with free entrys */
 static struct pv_pagelist pv_unusedpgs; /* list of unused pv_pages */
 static int pv_nfpvents;                        /* # of free pv entries */
-static vaddr_t pv_cachedva;            /* cached VA for later use */
 
 #define PVE_LOWAT (PVE_PER_PVPAGE / 2) /* free pv_entry low water mark */
 #define PVE_HIWAT (PVE_LOWAT + (PVE_PER_PVPAGE * 2))
@@ -1148,7 +1147,6 @@
 {
        int i;
 
-       pv_cachedva = 0;   /* a VA we have allocated but not used yet */
        pv_nfpvents = 0;
 
        pj_page = (void *)uvm_km_alloc(kernel_map, PAGE_SIZE, 0, UVM_KMF_WIRED);
@@ -1254,7 +1252,6 @@
        struct pmap *pmap;
        int mode;
 {
-       struct vm_page *pg;
        struct pv_page *pvpage;
        struct pv_entry *pv;
        int s;
@@ -1280,38 +1277,17 @@
        }
 
        /*
-        *  see if we've got a cached unmapped VA that we can map a page in.
-        * if not, try to allocate one.
-        */
-
-       if (pv_cachedva == 0) {
-               s = splvm();   /* must protect kmem_map with splvm! */
-               pv_cachedva = uvm_km_alloc(kmem_map, PAGE_SIZE, 0,
-                   UVM_KMF_TRYLOCK|UVM_KMF_VAONLY);
-               splx(s);
-               if (pv_cachedva == 0) {
-                       return (NULL);
-               }
-       }
-
-       pg = uvm_pagealloc(NULL, pv_cachedva - vm_map_min(kernel_map), NULL,
-           UVM_PGA_USERESERVE);
-       if (pg == NULL)
-               return (NULL);
-       pg->flags &= ~PG_BUSY;  /* never busy */
-
-       /*
-        * add a mapping for our new pv_page and free its entrys (save one!)
-        *
         * NOTE: If we are allocating a PV page for the kernel pmap, the
         * pmap is already locked!  (...but entering the mapping is safe...)
         */
 
-       pmap_kenter_pa(pv_cachedva, VM_PAGE_TO_PHYS(pg),
-           VM_PROT_READ | VM_PROT_WRITE);
-       pmap_update(pmap_kernel());
-       pvpage = (struct pv_page *) pv_cachedva;
-       pv_cachedva = 0;
+       s = splvm();   /* must protect kmem_map with splvm! */
+       pvpage = (struct pv_page *)uvm_km_alloc(kmem_map, PAGE_SIZE, 0,
+           UVM_KMF_TRYLOCK|UVM_KMF_NOWAIT|UVM_KMF_WIRED);
+       splx(s);
+       if (pvpage == NULL)
+               return NULL;
+
        return (pmap_add_pvpage(pvpage, mode != ALLOCPV_NONEED));
 }
 
@@ -1447,40 +1423,23 @@
  *
  * => assume caller is holding the pvalloc_lock and that
  *     there is a page on the pv_unusedpgs list
- * => if we can't get a lock on the kmem_map we try again later
  */
 
 static void
 pmap_free_pvpage()
 {
        int s;
-       struct vm_map *map;
-       struct vm_map_entry *dead_entries;
        struct pv_page *pvp;
 
-       s = splvm(); /* protect kmem_map */
-
        pvp = TAILQ_FIRST(&pv_unusedpgs);
-
-       map = kmem_map;
-       if (vm_map_lock_try(map)) {
-
-               /* remove pvp from pv_unusedpgs */
-               TAILQ_REMOVE(&pv_unusedpgs, pvp, pvinfo.pvpi_list);
-
-               /* unmap the page */
-               dead_entries = NULL;
-               uvm_unmap_remove(map, (vaddr_t)pvp, ((vaddr_t)pvp) + PAGE_SIZE,
-                   &dead_entries, NULL, 0);
-               vm_map_unlock(map);
-
-               if (dead_entries != NULL)
-                       uvm_unmap_detach(dead_entries, 0);
-
-               pv_nfpvents -= PVE_PER_PVPAGE;  /* update free count */
-       }
-
+       /* remove pvp from pv_unusedpgs */
+       TAILQ_REMOVE(&pv_unusedpgs, pvp, pvinfo.pvpi_list);
+
+       s = splvm();
+       uvm_km_free(kmem_map, (vaddr_t)pvp, PAGE_SIZE, UVM_KMF_WIRED);
        splx(s);
+
+       pv_nfpvents -= PVE_PER_PVPAGE;  /* update free count */
 }
 
 /*
@@ -3259,6 +3218,8 @@
        int error;
        boolean_t wired = (flags & PMAP_WIRED) != 0;
 
+       KASSERT(pmap_initialized);
+
 #ifdef DIAGNOSTIC
        /* sanity check: totally out of range? */
        if (va >= VM_MAX_KERNEL_ADDRESS)
@@ -3367,7 +3328,7 @@
        }
 
        pg = PHYS_TO_VM_PAGE(pa);
-       if (pmap_initialized && pg != NULL) {
+       if (pg != NULL) {
                /* This is a managed page */
                npte |= PG_PVLIST;
                mdpg = &pg->mdpage;