Improvements mostly from John Dyson, with a little bit from me.
* Removed pmap_is_wired * added extra cli/sti protection in idle (swtch.s) * slight code improvement in trap.c * added lots of comments * improved paging and other algorithms in VM system
This commit is contained in:
dg
parent
eab8c19a7a
commit
c5c5295745
@ -33,7 +33,7 @@
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $Id: swtch.s,v 1.1 1993/11/13 02:25:06 davidg Exp $
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* $Id: swtch.s,v 1.2 1994/01/14 16:23:40 davidg Exp $
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*/
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#include "npx.h" /* for NNPX */
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@ -146,8 +146,10 @@ Idle:
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ALIGN_TEXT
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idle_loop:
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call _spl0
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cli
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cmpl $0,_whichqs
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jne sw1
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sti
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hlt /* wait for interrupt */
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jmp idle_loop
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@ -35,7 +35,7 @@
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* SUCH DAMAGE.
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*
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* from: @(#)pmap.c 7.7 (Berkeley) 5/12/91
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* $Id$
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* $Id: pmap.c,v 1.12 1994/01/14 16:23:37 davidg Exp $
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*/
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/*
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@ -310,6 +310,7 @@ pmap_use_pt(pmap, va, use)
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{
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vm_offset_t pt, pa;
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pv_entry_t pv;
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vm_page_t m;
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if (va >= VM_MAX_ADDRESS)
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return;
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@ -323,32 +324,14 @@ pmap_use_pt(pmap, va, use)
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return;
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pv = pa_to_pvh(pa);
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m = PHYS_TO_VM_PAGE(pa);
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if (use) {
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pv->pv_wire++;
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} else if (pv->pv_wire > 0) {
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pv->pv_wire--;
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vm_page_wire(m);
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} else {
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printf("attempt to decrement wire count below 0: %d\n", pv->pv_wire);
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vm_page_unwire(m);
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}
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}
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/*
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* see if a page is pmap_wired
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*/
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inline int
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pmap_pt_is_used(pa)
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vm_offset_t pa;
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{
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pv_entry_t pv;
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int s;
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if (!pmap_is_managed(pa))
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return 0;
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pv = pa_to_pvh(pa);
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return pv->pv_wire;
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}
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/* [ macro again?, should I force kstack into user map here? -wfj ] */
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void
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pmap_activate(pmap, pcbp)
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@ -834,13 +817,10 @@ pmap_remove_entry(pmap, pv, va)
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if (pmap == pv->pv_pmap && va == pv->pv_va) {
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npv = pv->pv_next;
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if (npv) {
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wired = pv->pv_wire;
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*pv = *npv;
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pv->pv_wire = wired;
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free_pv_entry(npv);
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} else {
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pv->pv_pmap = NULL;
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pv->pv_wire = 0;
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}
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} else {
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for (npv = pv->pv_next; npv; npv = npv->pv_next) {
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@ -1030,9 +1010,6 @@ pmap_remove_all(pa)
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splx(s);
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}
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if (pv->pv_wire != 0)
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panic("pmap_remove_all, wire count != 0\n");
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tlbflush();
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}
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@ -1084,6 +1061,9 @@ pmap_protect(pmap, sva, eva, prot)
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pte = ptp + i386_btop(va);
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/*
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* scan for a non-empty pte
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*/
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{
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int found=0;
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int svap = pte - ptp;
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@ -1218,7 +1198,6 @@ pmap_enter(pmap, va, pa, prot, wired)
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pv->pv_va = va;
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pv->pv_pmap = pmap;
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pv->pv_next = NULL;
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pv->pv_wire = 0;
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}
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/*
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* There is at least one other VA mapping this page.
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@ -1256,8 +1235,23 @@ pmap_enter(pmap, va, pa, prot, wired)
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* Now validate mapping with desired protection/wiring.
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*/
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npte = (pa & PG_FRAME) | pte_prot(pmap, prot) | PG_V;
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/*
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* When forking (copy-on-write, etc):
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* A process will turn off write permissions for any of its writable
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* pages. If the data (object) is only referred to by one process, the
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* processes map is modified directly as opposed to using the
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* object manipulation routine. When using pmap_protect, the
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* modified bits are not kept in the vm_page_t data structure.
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* Therefore, when using pmap_enter in vm_fault to bring back
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* writability of a page, there has been no memory of the
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* modified or referenced bits except at the pte level.
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* this clause supports the carryover of the modified and
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* used (referenced) bits.
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*/
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if (pa == opa)
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npte |= *(int *)pte & (PG_M|PG_U);
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if (wired)
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npte |= PG_W;
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if (va < UPT_MIN_ADDRESS)
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@ -1636,19 +1630,6 @@ pmap_is_referenced(pa)
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return(pmap_testbit(pa, PG_U));
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}
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/*
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* pmap_is_pageable:
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*
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* Return whether or not the pmap system needs a page wired for its purposes
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*/
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boolean_t
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pmap_is_wired(pa)
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vm_offset_t pa;
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{
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return pmap_pt_is_used(pa)?1:0;
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}
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/*
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* pmap_is_modified:
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*
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@ -33,7 +33,7 @@
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $Id: swtch.s,v 1.1 1993/11/13 02:25:06 davidg Exp $
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* $Id: swtch.s,v 1.2 1994/01/14 16:23:40 davidg Exp $
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*/
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#include "npx.h" /* for NNPX */
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@ -146,8 +146,10 @@ Idle:
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ALIGN_TEXT
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idle_loop:
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call _spl0
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cli
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cmpl $0,_whichqs
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jne sw1
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sti
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hlt /* wait for interrupt */
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jmp idle_loop
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@ -34,7 +34,7 @@
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* SUCH DAMAGE.
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*
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* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
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* $Id: trap.c,v 1.13 1994/01/03 07:55:24 davidg Exp $
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* $Id: trap.c,v 1.14 1994/01/14 16:23:41 davidg Exp $
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*/
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/*
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@ -390,10 +390,10 @@ trap(frame)
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/* check if page table is mapped, if not, fault it first */
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#define pde_v(v) (PTD[((v)>>PD_SHIFT)&1023].pd_v)
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{
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vm_offset_t v = trunc_page(vtopte(va));
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if (map != kernel_map) {
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vm_offset_t pa;
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vm_offset_t v = (vm_offset_t) vtopte(va);
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/* Fault the pte only if needed: */
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*(volatile char *)v += 0;
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@ -401,16 +401,21 @@ trap(frame)
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/* Get the physical address: */
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pa = pmap_extract(vm_map_pmap(map), v);
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/* And wire the page at system vm level: */
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/* And wire the pte page at system vm level: */
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vm_page_wire(PHYS_TO_VM_PAGE(pa));
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/* Fault in the user page: */
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rv = vm_fault(map, va, ftype, FALSE);
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/* Unwire the pte page */
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/* Unwire the pte page: */
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vm_page_unwire(PHYS_TO_VM_PAGE(pa));
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} else {
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/*
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* Since we know that kernel virtual address addresses
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* always have pte pages mapped, we just have to fault
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* the page.
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*/
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rv = vm_fault(map, va, ftype, FALSE);
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}
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@ -606,10 +611,19 @@ int trapwrite(addr)
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{
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vm_offset_t v;
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v = trunc_page(vtopte(va));
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/*
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* wire the pte page
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*/
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if (va < USRSTACK) {
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vm_map_pageable(&vm->vm_map, v, round_page(v+1), FALSE);
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}
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/*
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* fault the data page
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*/
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rv = vm_fault(&vm->vm_map, va, VM_PROT_READ|VM_PROT_WRITE, FALSE);
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/*
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* unwire the pte page
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*/
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if (va < USRSTACK) {
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vm_map_pageable(&vm->vm_map, v, round_page(v+1), TRUE);
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}
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@ -35,7 +35,7 @@
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* SUCH DAMAGE.
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*
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* from: @(#)pmap.c 7.7 (Berkeley) 5/12/91
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* $Id$
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* $Id: pmap.c,v 1.12 1994/01/14 16:23:37 davidg Exp $
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*/
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/*
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@ -310,6 +310,7 @@ pmap_use_pt(pmap, va, use)
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{
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vm_offset_t pt, pa;
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pv_entry_t pv;
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vm_page_t m;
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if (va >= VM_MAX_ADDRESS)
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return;
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@ -323,32 +324,14 @@ pmap_use_pt(pmap, va, use)
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return;
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pv = pa_to_pvh(pa);
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m = PHYS_TO_VM_PAGE(pa);
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if (use) {
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pv->pv_wire++;
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} else if (pv->pv_wire > 0) {
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pv->pv_wire--;
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vm_page_wire(m);
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} else {
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printf("attempt to decrement wire count below 0: %d\n", pv->pv_wire);
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vm_page_unwire(m);
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}
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}
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/*
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* see if a page is pmap_wired
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*/
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inline int
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pmap_pt_is_used(pa)
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vm_offset_t pa;
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{
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pv_entry_t pv;
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int s;
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if (!pmap_is_managed(pa))
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return 0;
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pv = pa_to_pvh(pa);
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return pv->pv_wire;
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}
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/* [ macro again?, should I force kstack into user map here? -wfj ] */
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void
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pmap_activate(pmap, pcbp)
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@ -834,13 +817,10 @@ pmap_remove_entry(pmap, pv, va)
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if (pmap == pv->pv_pmap && va == pv->pv_va) {
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npv = pv->pv_next;
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if (npv) {
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wired = pv->pv_wire;
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*pv = *npv;
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pv->pv_wire = wired;
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free_pv_entry(npv);
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} else {
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pv->pv_pmap = NULL;
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pv->pv_wire = 0;
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}
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} else {
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for (npv = pv->pv_next; npv; npv = npv->pv_next) {
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@ -1030,9 +1010,6 @@ pmap_remove_all(pa)
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splx(s);
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}
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if (pv->pv_wire != 0)
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panic("pmap_remove_all, wire count != 0\n");
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tlbflush();
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}
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@ -1084,6 +1061,9 @@ pmap_protect(pmap, sva, eva, prot)
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pte = ptp + i386_btop(va);
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/*
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* scan for a non-empty pte
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*/
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{
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int found=0;
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int svap = pte - ptp;
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@ -1218,7 +1198,6 @@ pmap_enter(pmap, va, pa, prot, wired)
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pv->pv_va = va;
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pv->pv_pmap = pmap;
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pv->pv_next = NULL;
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pv->pv_wire = 0;
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}
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/*
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* There is at least one other VA mapping this page.
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@ -1256,8 +1235,23 @@ pmap_enter(pmap, va, pa, prot, wired)
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* Now validate mapping with desired protection/wiring.
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*/
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npte = (pa & PG_FRAME) | pte_prot(pmap, prot) | PG_V;
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/*
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* When forking (copy-on-write, etc):
|
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* A process will turn off write permissions for any of its writable
|
||||
* pages. If the data (object) is only referred to by one process, the
|
||||
* processes map is modified directly as opposed to using the
|
||||
* object manipulation routine. When using pmap_protect, the
|
||||
* modified bits are not kept in the vm_page_t data structure.
|
||||
* Therefore, when using pmap_enter in vm_fault to bring back
|
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* writability of a page, there has been no memory of the
|
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* modified or referenced bits except at the pte level.
|
||||
* this clause supports the carryover of the modified and
|
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* used (referenced) bits.
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*/
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if (pa == opa)
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npte |= *(int *)pte & (PG_M|PG_U);
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if (wired)
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npte |= PG_W;
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if (va < UPT_MIN_ADDRESS)
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@ -1636,19 +1630,6 @@ pmap_is_referenced(pa)
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return(pmap_testbit(pa, PG_U));
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}
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/*
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* pmap_is_pageable:
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*
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* Return whether or not the pmap system needs a page wired for its purposes
|
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*/
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boolean_t
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pmap_is_wired(pa)
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vm_offset_t pa;
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{
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return pmap_pt_is_used(pa)?1:0;
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}
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/*
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* pmap_is_modified:
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*
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@ -33,7 +33,7 @@
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||||
* SUCH DAMAGE.
|
||||
*
|
||||
* $Id: swtch.s,v 1.1 1993/11/13 02:25:06 davidg Exp $
|
||||
* $Id: swtch.s,v 1.2 1994/01/14 16:23:40 davidg Exp $
|
||||
*/
|
||||
|
||||
#include "npx.h" /* for NNPX */
|
||||
@ -146,8 +146,10 @@ Idle:
|
||||
ALIGN_TEXT
|
||||
idle_loop:
|
||||
call _spl0
|
||||
cli
|
||||
cmpl $0,_whichqs
|
||||
jne sw1
|
||||
sti
|
||||
hlt /* wait for interrupt */
|
||||
jmp idle_loop
|
||||
|
||||
|
||||
@ -34,7 +34,7 @@
|
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* SUCH DAMAGE.
|
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*
|
||||
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
|
||||
* $Id: trap.c,v 1.13 1994/01/03 07:55:24 davidg Exp $
|
||||
* $Id: trap.c,v 1.14 1994/01/14 16:23:41 davidg Exp $
|
||||
*/
|
||||
|
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/*
|
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@ -390,10 +390,10 @@ trap(frame)
|
||||
/* check if page table is mapped, if not, fault it first */
|
||||
#define pde_v(v) (PTD[((v)>>PD_SHIFT)&1023].pd_v)
|
||||
{
|
||||
vm_offset_t v = trunc_page(vtopte(va));
|
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|
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if (map != kernel_map) {
|
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vm_offset_t pa;
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vm_offset_t v = (vm_offset_t) vtopte(va);
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|
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/* Fault the pte only if needed: */
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*(volatile char *)v += 0;
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@ -401,16 +401,21 @@ trap(frame)
|
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/* Get the physical address: */
|
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pa = pmap_extract(vm_map_pmap(map), v);
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/* And wire the page at system vm level: */
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/* And wire the pte page at system vm level: */
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vm_page_wire(PHYS_TO_VM_PAGE(pa));
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/* Fault in the user page: */
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rv = vm_fault(map, va, ftype, FALSE);
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/* Unwire the pte page */
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/* Unwire the pte page: */
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vm_page_unwire(PHYS_TO_VM_PAGE(pa));
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} else {
|
||||
/*
|
||||
* Since we know that kernel virtual address addresses
|
||||
* always have pte pages mapped, we just have to fault
|
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* the page.
|
||||
*/
|
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rv = vm_fault(map, va, ftype, FALSE);
|
||||
}
|
||||
|
||||
@ -606,10 +611,19 @@ int trapwrite(addr)
|
||||
{
|
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vm_offset_t v;
|
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v = trunc_page(vtopte(va));
|
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/*
|
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* wire the pte page
|
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*/
|
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if (va < USRSTACK) {
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vm_map_pageable(&vm->vm_map, v, round_page(v+1), FALSE);
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}
|
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/*
|
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* fault the data page
|
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*/
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rv = vm_fault(&vm->vm_map, va, VM_PROT_READ|VM_PROT_WRITE, FALSE);
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/*
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* unwire the pte page
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*/
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if (va < USRSTACK) {
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vm_map_pageable(&vm->vm_map, v, round_page(v+1), TRUE);
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}
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|
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@ -34,7 +34,7 @@
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* SUCH DAMAGE.
|
||||
*
|
||||
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
|
||||
* $Id: trap.c,v 1.13 1994/01/03 07:55:24 davidg Exp $
|
||||
* $Id: trap.c,v 1.14 1994/01/14 16:23:41 davidg Exp $
|
||||
*/
|
||||
|
||||
/*
|
||||
@ -390,10 +390,10 @@ trap(frame)
|
||||
/* check if page table is mapped, if not, fault it first */
|
||||
#define pde_v(v) (PTD[((v)>>PD_SHIFT)&1023].pd_v)
|
||||
{
|
||||
vm_offset_t v = trunc_page(vtopte(va));
|
||||
|
||||
if (map != kernel_map) {
|
||||
vm_offset_t pa;
|
||||
vm_offset_t v = (vm_offset_t) vtopte(va);
|
||||
|
||||
/* Fault the pte only if needed: */
|
||||
*(volatile char *)v += 0;
|
||||
@ -401,16 +401,21 @@ trap(frame)
|
||||
/* Get the physical address: */
|
||||
pa = pmap_extract(vm_map_pmap(map), v);
|
||||
|
||||
/* And wire the page at system vm level: */
|
||||
/* And wire the pte page at system vm level: */
|
||||
vm_page_wire(PHYS_TO_VM_PAGE(pa));
|
||||
|
||||
/* Fault in the user page: */
|
||||
rv = vm_fault(map, va, ftype, FALSE);
|
||||
|
||||
/* Unwire the pte page */
|
||||
/* Unwire the pte page: */
|
||||
vm_page_unwire(PHYS_TO_VM_PAGE(pa));
|
||||
|
||||
} else {
|
||||
/*
|
||||
* Since we know that kernel virtual address addresses
|
||||
* always have pte pages mapped, we just have to fault
|
||||
* the page.
|
||||
*/
|
||||
rv = vm_fault(map, va, ftype, FALSE);
|
||||
}
|
||||
|
||||
@ -606,10 +611,19 @@ int trapwrite(addr)
|
||||
{
|
||||
vm_offset_t v;
|
||||
v = trunc_page(vtopte(va));
|
||||
/*
|
||||
* wire the pte page
|
||||
*/
|
||||
if (va < USRSTACK) {
|
||||
vm_map_pageable(&vm->vm_map, v, round_page(v+1), FALSE);
|
||||
}
|
||||
/*
|
||||
* fault the data page
|
||||
*/
|
||||
rv = vm_fault(&vm->vm_map, va, VM_PROT_READ|VM_PROT_WRITE, FALSE);
|
||||
/*
|
||||
* unwire the pte page
|
||||
*/
|
||||
if (va < USRSTACK) {
|
||||
vm_map_pageable(&vm->vm_map, v, round_page(v+1), TRUE);
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user