(dev_stop_paging): New function.

(pager_dropweak): New function.
(pager_port_type): Deleted var.
(pager_port_bucket, pager_port_class): New vars.
(dev_get_memory_object): Moved here from dev.c.  Also, call init_dev_pager if
  necessary.
(service_paging_requests): New function.
(init_dev_pager): New function.

1 files changed, 127 insertions, 5 deletions

diff --git a/devio/devpager.c b/devio/devpager.c
index ab3da34a..9d6e4abb 100644
--- a/devio/devpager.c
+++ b/devio/devpager.c
@@ -24,15 +24,10 @@
 #include <assert.h>
 
 #include "dev.h"
-#include "ptypes.h"
 
 /* ---------------------------------------------------------------- */
 /* Pager library callbacks; see <hurd/pager.h> for more info.  */
 
-/* This will be the type used in calls to allocate_port by the pager system.
- */
-int pager_port_type = PT_MEMOBJ;
-
 /* For pager PAGER, read one page from offset PAGE.  Set *BUF to be the
    address of the page, and set *WRITE_LOCK if the page must be provided
    read-only.  The only permissable error returns are EIO, EDQUOT, and
@@ -150,3 +145,130 @@ void
 pager_clear_user_data(struct user_pager_info *upi)
 {
 }
+
+/* ---------------------------------------------------------------- */
+
+/* A top-level function for the paging thread that just services paging
+   requests.  */
+static void
+service_paging_requests (any_t arg)
+{
+  struct dev *dev = (struct dev *)arg;
+  for (;;)
+    ports_manage_port_operations_multithread (dev->pager_port_bucket,
+					      pager_demuxer,
+					      1000 * 30, 1000 * 60 * 5,
+					      1, MACH_PORT_NULL);
+}
+
+/* Initialize paging for this device.  */
+static void
+init_dev_paging (struct dev *dev)
+{
+  dev->pager_port_bucket = ports_create_bucket ();
+
+  /* Make a thread to service paging requests.  */
+  cthread_detach (cthread_fork ((cthread_fn_t)service_paging_requests,
+				(any_t)dev));
+}
+
+void
+pager_dropweak (struct user_pager_info *upi __attribute__ ((unused)))
+{
+}
+
+/* ---------------------------------------------------------------- */
+
+/* Try to stop all paging activity on DEV, returning true if we were
+   successful.  If NOSYNC is true, then we won't write back any (kernel)
+   cached pages to the device.  */
+int
+dev_stop_paging (struct dev *dev, int nosync)
+{
+  int success = 1;		/* Initially assume success.  */
+
+  io_state_lock(&dev->io_state);
+
+  if (dev->pager != NULL)
+    {
+      int num_pagers = ports_count_bucket (dev->pager_port_bucket);
+      if (num_pagers > 0 && !nosync)
+	{
+	  error_t block_cache (void *arg)
+	    {
+	      struct pager *p = arg;
+	      pager_change_attributes (p, 0, MEMORY_OBJECT_COPY_DELAY, 1);
+	      return 0;
+	    }
+	  error_t enable_cache (void *arg)
+	    {
+	      struct pager *p = arg;
+	      pager_change_attributes (p, 1, MEMORY_OBJECT_COPY_DELAY, 0);
+	      return 0;
+	    }
+
+	  /* Loop through the pagers and turn off caching one by one,
+	     synchronously.  That should cause termination of each pager. */
+	  ports_bucket_iterate (dev->pager_port_bucket, block_cache);
+      
+	  /* Give it a second; the kernel doesn't actually shutdown
+	     immediately.  XXX */
+	  sleep (1);
+      
+	  num_pagers = ports_count_bucket (dev->pager_port_bucket);
+	  if (num_pagers > 0)
+	    /* Darn, there are actual honest users.  Turn caching back on,
+	       and return failure. */
+	    {
+	      ports_bucket_iterate (dev->pager_port_bucket, enable_cache);
+	      success = 0;
+	    }
+	}
+
+      if (success && !nosync)
+	/* shutdown the pager on DEV.  If NOSYNC is set, we don't bother, for
+	   fear that this may result in I/O.  In this case we've disabled
+	   rpcs on the pager's ports, so this will result in hanging...  What
+	   do we do??? XXXX */
+	pager_shutdown (dev->pager);
+    }
+
+  if (success)
+    dev->pager = NULL;
+
+  io_state_lock(&dev->io_state);
+
+  return success;
+}
+
+/* ---------------------------------------------------------------- */
+
+/* Returns in MEMOBJ the port for a memory object backed by the storage on
+   DEV.  Returns 0 or the error code if an error occurred.  */
+error_t
+dev_get_memory_object(struct dev *dev, memory_object_t *memobj)
+{
+  if (dev_is(dev, DEV_SERIAL))
+    return ENODEV;
+
+  io_state_lock(&dev->io_state);
+  if (dev->pager_port_bucket == NULL)
+    init_dev_paging (dev);
+  if (dev->pager == NULL)
+    dev->pager =
+      pager_create((struct user_pager_info *)dev, dev->pager_port_bucket,
+		   1, MEMORY_OBJECT_COPY_DELAY);
+  io_state_unlock(&dev->io_state);
+
+  if (dev->pager == NULL)
+    return ENODEV;		/* XXX ??? */
+
+  *memobj = pager_get_port(dev->pager);
+  if (*memobj != MACH_PORT_NULL)
+    return
+      mach_port_insert_right(mach_task_self(),
+			     *memobj, *memobj,
+			     MACH_MSG_TYPE_MAKE_SEND);
+
+  return 0;
+}