+
+ boolean_t page_queues_locked = FALSE;
+#define __VM_PAGE_LOCKSPIN_QUEUES_IF_NEEDED() \
+MACRO_BEGIN \
+ if (! page_queues_locked) { \
+ page_queues_locked = TRUE; \
+ vm_page_lockspin_queues(); \
+ } \
+MACRO_END
+#define __VM_PAGE_UNLOCK_QUEUES_IF_NEEDED() \
+MACRO_BEGIN \
+ if (page_queues_locked) { \
+ page_queues_locked = FALSE; \
+ vm_page_unlock_queues(); \
+ } \
+MACRO_END
+
+ /*
+ * Hold queues lock to manipulate
+ * the page queues. Change wiring
+ * case is obvious.
+ */
+ assert(m->compressor || m->object != compressor_object);
+ if (m->compressor) {
+ /*
+ * Compressor pages are neither wired
+ * nor pageable and should never change.
+ */
+ assert(m->object == compressor_object);
+ } else if (change_wiring) {
+ __VM_PAGE_LOCKSPIN_QUEUES_IF_NEEDED();
+
+ if (wired) {
+ if (kr == KERN_SUCCESS) {
+ vm_page_wire(m);
+ }
+ } else {
+ vm_page_unwire(m, TRUE);
+ }
+ /* we keep the page queues lock, if we need it later */
+
+ } else {
+ if (kr != KERN_SUCCESS) {
+ __VM_PAGE_LOCKSPIN_QUEUES_IF_NEEDED();
+ vm_page_deactivate(m);
+ /* we keep the page queues lock, if we need it later */
+ } else if (((!m->active && !m->inactive) ||
+ m->clean_queue ||
+ no_cache) &&
+ !VM_PAGE_WIRED(m) && !m->throttled) {
+
+ if (vm_page_local_q &&
+ !no_cache &&
+ (*type_of_fault == DBG_COW_FAULT ||
+ *type_of_fault == DBG_ZERO_FILL_FAULT) ) {
+ struct vpl *lq;
+ uint32_t lid;
+
+ __VM_PAGE_UNLOCK_QUEUES_IF_NEEDED();
+ vm_object_lock_assert_exclusive(m->object);
+
+ /*
+ * we got a local queue to stuff this
+ * new page on...
+ * its safe to manipulate local and
+ * local_id at this point since we're
+ * behind an exclusive object lock and
+ * the page is not on any global queue.
+ *
+ * we'll use the current cpu number to
+ * select the queue note that we don't
+ * need to disable preemption... we're
+ * going to behind the local queue's
+ * lock to do the real work
+ */
+ lid = cpu_number();
+
+ lq = &vm_page_local_q[lid].vpl_un.vpl;
+
+ VPL_LOCK(&lq->vpl_lock);
+
+ queue_enter(&lq->vpl_queue, m,
+ vm_page_t, pageq);
+ m->local = TRUE;
+ m->local_id = lid;
+ lq->vpl_count++;
+
+ if (m->object->internal)
+ lq->vpl_internal_count++;
+ else
+ lq->vpl_external_count++;
+
+ VPL_UNLOCK(&lq->vpl_lock);
+
+ if (lq->vpl_count > vm_page_local_q_soft_limit)
+ {
+ /*
+ * we're beyond the soft limit
+ * for the local queue
+ * vm_page_reactivate_local will
+ * 'try' to take the global page
+ * queue lock... if it can't
+ * that's ok... we'll let the
+ * queue continue to grow up
+ * to the hard limit... at that
+ * point we'll wait for the
+ * lock... once we've got the
+ * lock, we'll transfer all of
+ * the pages from the local
+ * queue to the global active
+ * queue
+ */
+ vm_page_reactivate_local(lid, FALSE, FALSE);
+ }
+ } else {
+
+ __VM_PAGE_LOCKSPIN_QUEUES_IF_NEEDED();
+
+ /*
+ * test again now that we hold the
+ * page queue lock
+ */
+ if (!VM_PAGE_WIRED(m)) {
+ if (m->clean_queue) {
+ VM_PAGE_QUEUES_REMOVE(m);
+
+ vm_pageout_cleaned_reactivated++;
+ vm_pageout_cleaned_fault_reactivated++;
+ }
+
+ if ((!m->active &&
+ !m->inactive) ||
+ no_cache) {
+ /*
+ * If this is a no_cache mapping
+ * and the page has never been
+ * mapped before or was
+ * previously a no_cache page,
+ * then we want to leave pages
+ * in the speculative state so
+ * that they can be readily
+ * recycled if free memory runs
+ * low. Otherwise the page is
+ * activated as normal.
+ */
+
+ if (no_cache &&
+ (!previously_pmapped ||
+ m->no_cache)) {
+ m->no_cache = TRUE;
+
+ if (!m->speculative)
+ vm_page_speculate(m, FALSE);
+
+ } else if (!m->active &&
+ !m->inactive) {
+
+ vm_page_activate(m);
+ }
+ }
+ }
+ /* we keep the page queues lock, if we need it later */
+ }
+ }
+ }
+
+ if ((prot & VM_PROT_EXECUTE) &&
+ ! m->xpmapped) {
+
+ __VM_PAGE_LOCKSPIN_QUEUES_IF_NEEDED();
+
+ /*
+ * xpmapped is protected by the page queues lock
+ * so it matters not that we might only hold the
+ * object lock in the shared state
+ */
+
+ if (! m->xpmapped) {
+
+ m->xpmapped = TRUE;
+ __VM_PAGE_UNLOCK_QUEUES_IF_NEEDED();
+
+ if ((COMPRESSED_PAGER_IS_ACTIVE || DEFAULT_FREEZER_COMPRESSED_PAGER_IS_ACTIVE) &&
+ m->object->internal &&
+ m->object->pager != NULL) {
+ /*
+ * This page could have been
+ * uncompressed by the
+ * compressor pager and its
+ * contents might be only in
+ * the data cache.
+ * Since it's being mapped for
+ * "execute" for the fist time,
+ * make sure the icache is in
+ * sync.
+ */
+ pmap_sync_page_data_phys(m->phys_page);
+ }
+
+ }
+ }
+ /* we're done with the page queues lock, if we ever took it */
+ __VM_PAGE_UNLOCK_QUEUES_IF_NEEDED();
+
+
+ /* If we have a KERN_SUCCESS from the previous checks, we either have
+ * a good page, or a tainted page that has been accepted by the process.
+ * In both cases the page will be entered into the pmap.
+ * If the page is writeable, we need to disconnect it from other pmaps
+ * now so those processes can take note.
+ */
+ if (kr == KERN_SUCCESS) {
+ /*
+ * NOTE: we may only hold the vm_object lock SHARED
+ * at this point, but the update of pmapped is ok
+ * since this is the ONLY bit updated behind the SHARED
+ * lock... however, we need to figure out how to do an atomic
+ * update on a bit field to make this less fragile... right
+ * now I don't know how to coerce 'C' to give me the offset info
+ * that's needed for an AtomicCompareAndSwap
+ */
+ m->pmapped = TRUE;
+ if(vm_page_is_slideable(m)) {
+ boolean_t was_busy = m->busy;
+
+ vm_object_lock_assert_exclusive(m->object);
+
+ m->busy = TRUE;
+ kr = vm_page_slide(m, 0);
+ assert(m->busy);
+ if(!was_busy) {
+ PAGE_WAKEUP_DONE(m);
+ }
+ if (kr != KERN_SUCCESS) {
+ /*
+ * This page has not been slid correctly,
+ * do not do the pmap_enter() !
+ * Let vm_fault_enter() return the error
+ * so the caller can fail the fault.
+ */
+ goto after_the_pmap_enter;
+ }
+ }
+
+ if (fault_type & VM_PROT_WRITE) {
+
+ if (m->wpmapped == FALSE) {
+ vm_object_lock_assert_exclusive(m->object);
+
+ m->wpmapped = TRUE;
+ }
+ if (must_disconnect) {
+ /*
+ * We can only get here
+ * because of the CSE logic
+ */
+ assert(cs_enforcement_enabled);
+ pmap_disconnect(m->phys_page);
+ /*
+ * If we are faulting for a write, we can clear
+ * the execute bit - that will ensure the page is
+ * checked again before being executable, which
+ * protects against a map switch.
+ * This only happens the first time the page
+ * gets tainted, so we won't get stuck here
+ * to make an already writeable page executable.
+ */
+ if (!cs_bypass){
+ prot &= ~VM_PROT_EXECUTE;
+ }
+ }
+ }
+
+ /* Prevent a deadlock by not
+ * holding the object lock if we need to wait for a page in
+ * pmap_enter() - <rdar://problem/7138958> */
+ PMAP_ENTER_OPTIONS(pmap, vaddr, m, prot, fault_type, 0,
+ wired, PMAP_OPTIONS_NOWAIT, pe_result);
+
+ if(pe_result == KERN_RESOURCE_SHORTAGE) {
+
+ if (need_retry) {
+ /*
+ * this will be non-null in the case where we hold the lock
+ * on the top-object in this chain... we can't just drop
+ * the lock on the object we're inserting the page into
+ * and recall the PMAP_ENTER since we can still cause
+ * a deadlock if one of the critical paths tries to
+ * acquire the lock on the top-object and we're blocked
+ * in PMAP_ENTER waiting for memory... our only recourse
+ * is to deal with it at a higher level where we can
+ * drop both locks.
+ */
+ *need_retry = TRUE;
+ vm_pmap_enter_retried++;
+ goto after_the_pmap_enter;
+ }
+ /* The nonblocking version of pmap_enter did not succeed.
+ * and we don't need to drop other locks and retry
+ * at the level above us, so
+ * use the blocking version instead. Requires marking
+ * the page busy and unlocking the object */
+ boolean_t was_busy = m->busy;
+
+ vm_object_lock_assert_exclusive(m->object);
+
+ m->busy = TRUE;
+ vm_object_unlock(m->object);
+
+ PMAP_ENTER(pmap, vaddr, m, prot, fault_type, 0, wired);
+
+ /* Take the object lock again. */
+ vm_object_lock(m->object);
+
+ /* If the page was busy, someone else will wake it up.
+ * Otherwise, we have to do it now. */
+ assert(m->busy);
+ if(!was_busy) {
+ PAGE_WAKEUP_DONE(m);
+ }
+ vm_pmap_enter_blocked++;
+ }
+ }
+
+after_the_pmap_enter:
+ return kr;
projects / apple / xnu.git / blobdiff