Initial source

1 files changed, 1820 insertions, 0 deletions

diff --git a/device/ds_routines.c b/device/ds_routines.c
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+++ b/device/ds_routines.c
@@ -0,0 +1,1820 @@
+/* 
+ * Mach Operating System
+ * Copyright (c) 1993,1991,1990,1989 Carnegie Mellon University
+ * All Rights Reserved.
+ * 
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ * 
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ * 
+ * Carnegie Mellon requests users of this software to return to
+ * 
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ * 
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
+/*
+ *	Author: David B. Golub, Carnegie Mellon University
+ *	Date: 	3/89
+ */
+
+#include <norma_device.h>
+
+#include <mach/boolean.h>
+#include <mach/kern_return.h>
+#include <mach/mig_errors.h>
+#include <mach/port.h>
+#include <mach/vm_param.h>
+#include <mach/notify.h>
+#include <machine/machspl.h>		/* spl definitions */
+
+#include <ipc/ipc_port.h>
+#include <ipc/ipc_space.h>
+
+#include <kern/ast.h>
+#include <kern/counters.h>
+#include <kern/queue.h>
+#include <kern/zalloc.h>
+#include <kern/thread.h>
+#include <kern/task.h>
+#include <kern/sched_prim.h>
+
+#include <vm/memory_object.h>
+#include <vm/vm_map.h>
+#include <vm/vm_kern.h>
+
+#include <device/device_types.h>
+#include <device/dev_hdr.h>
+#include <device/conf.h>
+#include <device/io_req.h>
+#include <device/ds_routines.h>
+#include <device/net_status.h>
+#include <device/device_port.h>
+#include "device_reply.h"
+
+#include <machine/machspl.h>
+
+#ifdef i386
+#include <i386at/device_emul.h>
+#endif
+
+#ifdef i386
+ipc_port_t
+mach_convert_device_to_port (void *d)
+{
+  ipc_port_t port;
+  mach_device_t device = d;
+
+  if (! device)
+    return IP_NULL;
+  device_lock(device);
+  if (device->state == DEV_STATE_OPEN)
+    port = ipc_port_make_send(device->port);
+  else
+    port = IP_NULL;
+  device_unlock(device);
+  mach_device_deallocate(device);
+  return port;
+}
+#endif /* i386 */
+
+#ifdef i386
+static io_return_t
+device_open(reply_port, reply_port_type, mode, name, device_p)
+#else
+io_return_t
+ds_device_open(open_port, reply_port, reply_port_type,
+	       mode, name, device_p)
+	ipc_port_t	open_port;
+#endif
+	ipc_port_t	reply_port;
+	mach_msg_type_name_t reply_port_type;
+	dev_mode_t	mode;
+	char *		name;
+	device_t	*device_p;	/* out */
+{
+	register mach_device_t	device;
+	register kern_return_t	result;
+	register io_req_t	ior;
+	char			namebuf[64];
+	ipc_port_t		notify;
+
+#ifndef i386
+	/*
+	 * Open must be called on the master device port.
+	 */
+	if (open_port != master_device_port)
+	    return (D_INVALID_OPERATION);
+
+	/*
+	 * There must be a reply port.
+	 */
+	if (!IP_VALID(reply_port)) {
+	    printf("ds_* invalid reply port\n");
+	    Debugger("ds_* reply_port");
+	    return (MIG_NO_REPLY);	/* no sense in doing anything */
+	}
+
+#if	NORMA_DEVICE
+	/*
+	 * Map global device name to <node> + local device name.
+	 */
+	if (name[0] != '<') {
+		extern char *dev_forward_name();
+
+		name = dev_forward_name(name, namebuf, sizeof(namebuf));
+	}
+	/*
+	 * Look for explicit node specifier, e.g., <2>sd0a.
+	 * If found, then forward request to correct device server.
+	 * If not found, then remove '<n>' and process locally.
+	 *
+	 * XXX should handle send-right reply_port as well as send-once XXX
+	 */
+	if (name[0] == '<') {
+		char *n;
+		int node = 0;
+
+		for (n = &name[1]; *n != '>'; n++) {
+			if (*n >= '0' && *n <= '9') {
+				node = 10 * node + (*n - '0');
+			} else {
+				return (D_NO_SUCH_DEVICE);
+			}
+		}
+		if (node == node_self()) {
+			name = &n[1];	/* skip trailing '>' */
+		} else {
+			forward_device_open_send(remote_device(node),
+						 reply_port, mode, name);
+			return (MIG_NO_REPLY);
+		}
+	}
+#endif	NORMA_DEVICE
+#endif	/* ! i386 */
+
+	/*
+	 * Find the device.
+	 */
+	device = device_lookup(name);
+	if (device == MACH_DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+
+	/*
+	 * If the device is being opened or closed,
+	 * wait for that operation to finish.
+	 */
+	device_lock(device);
+	while (device->state == DEV_STATE_OPENING ||
+		device->state == DEV_STATE_CLOSING) {
+	    device->io_wait = TRUE;
+	    thread_sleep((event_t)device, simple_lock_addr(device->lock), TRUE);
+	    device_lock(device);
+	}
+
+	/*
+	 * If the device is already open, increment the open count
+	 * and return.
+	 */
+	if (device->state == DEV_STATE_OPEN) {
+
+	    if (device->flag & D_EXCL_OPEN) {
+		/*
+		 * Cannot open a second time.
+		 */
+		device_unlock(device);
+		mach_device_deallocate(device);
+		return (D_ALREADY_OPEN);
+	    }
+
+	    device->open_count++;
+	    device_unlock(device);
+#ifdef i386
+	    *device_p = &device->dev;
+#else
+	    *device_p = device;
+#endif
+	    return (D_SUCCESS);
+	    /*
+	     * Return deallocates device reference while acquiring
+	     * port.
+	     */
+	}
+
+	/*
+	 * Allocate the device port and register the device before
+	 * opening it.
+	 */
+	device->state = DEV_STATE_OPENING;
+	device_unlock(device);
+
+	/*
+	 * Allocate port, keeping a reference for it.
+	 */
+	device->port = ipc_port_alloc_kernel();
+	if (device->port == IP_NULL) {
+	    device_lock(device);
+	    device->state = DEV_STATE_INIT;
+	    device->port = IP_NULL;
+	    if (device->io_wait) {
+		device->io_wait = FALSE;
+		thread_wakeup((event_t)device);
+	    }
+	    device_unlock(device);
+	    mach_device_deallocate(device);
+	    return (KERN_RESOURCE_SHORTAGE);
+	}
+
+	dev_port_enter(device);
+
+	/*
+	 * Request no-senders notifications on device port.
+	 */
+	notify = ipc_port_make_sonce(device->port);
+	ip_lock(device->port);
+	ipc_port_nsrequest(device->port, 1, notify, &notify);
+	assert(notify == IP_NULL);
+
+	/*
+	 * Open the device.
+	 */
+	io_req_alloc(ior, 0);
+
+	ior->io_device	= device;
+	ior->io_unit	= device->dev_number;
+	ior->io_op	= IO_OPEN | IO_CALL;
+	ior->io_mode	= mode;
+	ior->io_error	= 0;
+	ior->io_done	= ds_open_done;
+	ior->io_reply_port = reply_port;
+	ior->io_reply_port_type = reply_port_type;
+
+	result = (*device->dev_ops->d_open)(device->dev_number, (int)mode, ior);
+	if (result == D_IO_QUEUED)
+	    return (MIG_NO_REPLY);
+
+	/*
+	 * Return result via ds_open_done.
+	 */
+	ior->io_error = result;
+	(void) ds_open_done(ior);
+
+	io_req_free(ior);
+
+	return (MIG_NO_REPLY);	/* reply already sent */
+}
+
+boolean_t
+ds_open_done(ior)
+	register io_req_t	ior;
+{
+	kern_return_t		result;
+	register mach_device_t	device;
+
+	device = ior->io_device;
+	result = ior->io_error;
+
+	if (result != D_SUCCESS) {
+	    /*
+	     * Open failed.  Deallocate port and device.
+	     */
+	    dev_port_remove(device);
+	    ipc_port_dealloc_kernel(device->port);
+	    device->port = IP_NULL;
+
+	    device_lock(device);
+	    device->state = DEV_STATE_INIT;
+	    if (device->io_wait) {
+		device->io_wait = FALSE;
+		thread_wakeup((event_t)device);
+	    }
+	    device_unlock(device);
+
+	    mach_device_deallocate(device);
+	    device = MACH_DEVICE_NULL;
+	}
+	else {
+	    /*
+	     * Open succeeded.
+	     */
+	    device_lock(device);
+	    device->state = DEV_STATE_OPEN;
+	    device->open_count = 1;
+	    if (device->io_wait) {
+		device->io_wait = FALSE;
+		thread_wakeup((event_t)device);
+	    }
+	    device_unlock(device);
+
+	    /* donate device reference to get port */
+	}
+	/*
+	 * Must explicitly convert device to port, since
+	 * device_reply interface is built as 'user' side
+	 * (thus cannot get translation).
+	 */
+	if (IP_VALID(ior->io_reply_port)) {
+		(void) ds_device_open_reply(ior->io_reply_port,
+					    ior->io_reply_port_type,
+					    result,
+#ifdef i386
+					    (mach_convert_device_to_port
+					     (device)));
+#else
+					    convert_device_to_port(device));
+#endif
+	} else
+		mach_device_deallocate(device);
+
+	return (TRUE);
+}
+
+#ifdef i386
+static io_return_t
+device_close(device)
+#else
+io_return_t
+ds_device_close(device)
+#endif
+	register mach_device_t	device;
+{
+#ifndef i386
+	if (device == DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+#endif
+
+	device_lock(device);
+
+	/*
+	 * If device will remain open, do nothing.
+	 */
+	if (--device->open_count > 0) {
+	    device_unlock(device);
+	    return (D_SUCCESS);
+	}
+
+	/*
+	 * If device is being closed, do nothing.
+	 */
+	if (device->state == DEV_STATE_CLOSING) {
+	    device_unlock(device);
+	    return (D_SUCCESS);
+	}
+
+	/*
+	 * Mark device as closing, to prevent new IO.
+	 * Outstanding IO will still be in progress.
+	 */
+	device->state = DEV_STATE_CLOSING;
+	device_unlock(device);
+
+	/*
+	 * ? wait for IO to end ?
+	 *   only if device wants to
+	 */
+
+	/*
+	 * Remove the device-port association.
+	 */
+	dev_port_remove(device);
+	ipc_port_dealloc_kernel(device->port);
+
+	/*
+	 * Close the device
+	 */
+	(*device->dev_ops->d_close)(device->dev_number);
+
+	/*
+	 * Finally mark it closed.  If someone else is trying
+	 * to open it, the open can now proceed.
+	 */
+	device_lock(device);
+	device->state = DEV_STATE_INIT;
+	if (device->io_wait) {
+	    device->io_wait = FALSE;
+	    thread_wakeup((event_t)device);
+	}
+	device_unlock(device);
+
+	return (D_SUCCESS);
+}
+
+/*
+ * Write to a device.
+ */
+#ifdef i386
+static io_return_t
+device_write(d, reply_port, reply_port_type, mode, recnum,
+	     data, data_count, bytes_written)
+	void *d;
+#else
+io_return_t
+ds_device_write(device, reply_port, reply_port_type, mode, recnum,
+		data, data_count, bytes_written)
+	register mach_device_t	device;
+#endif
+	ipc_port_t		reply_port;
+	mach_msg_type_name_t	reply_port_type;
+	dev_mode_t		mode;
+	recnum_t		recnum;
+	io_buf_ptr_t		data;
+	unsigned int		data_count;
+	int			*bytes_written;	/* out */
+{
+#ifdef i386
+	register mach_device_t	device = d;
+#endif
+	register io_req_t	ior;
+	register io_return_t	result;
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+	    return (D_NO_SUCH_DEVICE);
+
+#ifndef i386
+	if (data == 0)
+	   return (D_INVALID_SIZE);
+#endif
+
+	/*
+	 * XXX Need logic to reject ridiculously big requests.
+	 */
+
+	/* XXX note that a CLOSE may proceed at any point */
+
+	/*
+	 * Package the write request for the device driver
+	 */
+	io_req_alloc(ior, data_count);
+
+	ior->io_device		= device;
+	ior->io_unit		= device->dev_number;
+	ior->io_op		= IO_WRITE | IO_CALL;
+	ior->io_mode		= mode;
+	ior->io_recnum		= recnum;
+	ior->io_data		= data;
+	ior->io_count		= data_count;
+	ior->io_total		= data_count;
+	ior->io_alloc_size	= 0;
+	ior->io_residual	= 0;
+	ior->io_error		= 0;
+	ior->io_done		= ds_write_done;
+	ior->io_reply_port	= reply_port;
+	ior->io_reply_port_type	= reply_port_type;
+	ior->io_copy		= VM_MAP_COPY_NULL;
+
+	/*
+	 * The ior keeps an extra reference for the device.
+	 */
+	mach_device_reference(device);
+
+	/*
+	 * And do the write ...
+	 *
+	 * device_write_dealoc returns false if there's more
+	 * to do; it has updated the ior appropriately and expects
+	 * its caller to reinvoke it on the device.
+	 */
+
+	do {
+
+		result = (*device->dev_ops->d_write)(device->dev_number, ior);
+
+		/*
+		 * If the IO was queued, delay reply until it is finished.
+		 */
+		if (result == D_IO_QUEUED)
+		    return (MIG_NO_REPLY);
+
+		/*
+		 * Discard the local mapping of the data.
+		 */
+
+	} while (!device_write_dealloc(ior));
+
+	/*
+	 * Return the number of bytes actually written.
+	 */
+	*bytes_written = ior->io_total - ior->io_residual;
+
+	/*
+	 * Remove the extra reference.
+	 */
+	mach_device_deallocate(device);
+
+	io_req_free(ior);
+	return (result);
+}
+
+/*
+ * Write to a device, but memory is in message.
+ */
+#ifdef i386
+static io_return_t
+device_write_inband(d, reply_port, reply_port_type, mode, recnum,
+		    data, data_count, bytes_written)
+	void *d;
+#else
+io_return_t
+ds_device_write_inband(device, reply_port, reply_port_type, mode, recnum,
+		       data, data_count, bytes_written)
+	register mach_device_t	device;
+#endif
+	ipc_port_t		reply_port;
+	mach_msg_type_name_t	reply_port_type;
+	dev_mode_t		mode;
+	recnum_t		recnum;
+	io_buf_ptr_inband_t	data;
+	unsigned int		data_count;
+	int			*bytes_written; /* out */
+{
+#ifdef i386
+	register mach_device_t	device = d;
+#endif
+	register io_req_t	ior;
+	register io_return_t	result;
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+	    return (D_NO_SUCH_DEVICE);
+
+#ifndef i386
+	if (data == 0)
+	   return (D_INVALID_SIZE);
+#endif
+
+	/* XXX note that a CLOSE may proceed at any point */
+
+	/*
+	 * Package the write request for the device driver.
+	 */
+	io_req_alloc(ior, 0);
+
+	ior->io_device		= device;
+	ior->io_unit		= device->dev_number;
+	ior->io_op		= IO_WRITE | IO_CALL | IO_INBAND;
+	ior->io_mode		= mode;
+	ior->io_recnum		= recnum;
+	ior->io_data		= data;
+	ior->io_count		= data_count;
+	ior->io_total		= data_count;
+	ior->io_alloc_size	= 0;
+	ior->io_residual	= 0;
+	ior->io_error		= 0;
+	ior->io_done		= ds_write_done;
+	ior->io_reply_port	= reply_port;
+	ior->io_reply_port_type = reply_port_type;
+
+	/*
+	 * The ior keeps an extra reference for the device.
+	 */
+	mach_device_reference(device);
+
+	/*
+	 * And do the write.
+	 */
+	result = (*device->dev_ops->d_write)(device->dev_number, ior);
+
+	/*
+	 * If the IO was queued, delay reply until it is finished.
+	 */
+	if (result == D_IO_QUEUED)
+	    return (MIG_NO_REPLY);
+
+	/*
+	 * Return the number of bytes actually written.
+	 */
+	*bytes_written = ior->io_total - ior->io_residual;
+
+	/*
+	 * Remove the extra reference.
+	 */
+	mach_device_deallocate(device);
+
+	io_req_free(ior);
+	return (result);
+}
+
+/*
+ * Wire down incoming memory to give to device.
+ */
+kern_return_t
+device_write_get(ior, wait)
+	register io_req_t	ior;
+	boolean_t		*wait;
+{
+	vm_map_copy_t		io_copy;
+	vm_offset_t		new_addr;
+	register kern_return_t	result;
+	int			bsize;
+	vm_size_t		min_size;
+
+	/*
+	 * By default, caller does not have to wait.
+	 */
+	*wait = FALSE;
+
+	/*
+	 * Nothing to do if no data.
+	 */
+	if (ior->io_count == 0)
+	    return (KERN_SUCCESS);
+
+	/*
+	 * Loaned iors already have valid data.
+	 */
+	if (ior->io_op & IO_LOANED)
+	    return (KERN_SUCCESS);
+
+	/*
+	 * Inband case.
+	 */
+	if (ior->io_op & IO_INBAND) {
+	    assert(ior->io_count <= sizeof (io_buf_ptr_inband_t));
+	    new_addr = zalloc(io_inband_zone);
+	    bcopy((void*)ior->io_data, (void*)new_addr, ior->io_count);
+	    ior->io_data = (io_buf_ptr_t)new_addr;
+	    ior->io_alloc_size = sizeof (io_buf_ptr_inband_t);
+
+	    return (KERN_SUCCESS);
+	}
+
+	/*
+	 *	Figure out how much data to move this time.  If the device
+	 *	won't return a block size, then we have to do the whole
+	 *	request in one shot (ditto if this is a block fragment),
+	 *	otherwise, move at least one block's worth.
+	 */
+	result = (*ior->io_device->dev_ops->d_dev_info)(
+					ior->io_device->dev_number,
+					D_INFO_BLOCK_SIZE,
+					&bsize);
+
+	if (result != KERN_SUCCESS || ior->io_count < (vm_size_t) bsize)
+		min_size = (vm_size_t) ior->io_count;
+	else
+		min_size = (vm_size_t) bsize;
+
+	/*
+	 *	Map the pages from this page list into memory.
+	 *	io_data records location of data.
+	 *	io_alloc_size is the vm size of the region to deallocate.
+	 */
+	io_copy = (vm_map_copy_t) ior->io_data;
+	result = kmem_io_map_copyout(device_io_map,
+			(vm_offset_t*)&ior->io_data, &new_addr,
+		        &ior->io_alloc_size, io_copy, min_size);
+	if (result != KERN_SUCCESS)
+	    return (result);
+
+	if ((ior->io_data + ior->io_count) > 
+	    (((char *)new_addr) + ior->io_alloc_size)) {
+
+		/*
+		 *	Operation has to be split.  Reset io_count for how
+		 *	much we can do this time.
+		 */
+		assert(vm_map_copy_has_cont(io_copy));
+		assert(ior->io_count == io_copy->size);
+		ior->io_count = ior->io_alloc_size -
+			(ior->io_data - ((char *)new_addr));
+
+		/*
+		 *	Caller must wait synchronously.
+		 */
+		ior->io_op &= ~IO_CALL;
+		*wait = TRUE;		
+	}
+
+	ior->io_copy = io_copy;			/* vm_map_copy to discard */
+	return (KERN_SUCCESS);
+}
+
+/*
+ * Clean up memory allocated for IO.
+ */
+boolean_t
+device_write_dealloc(ior)
+	register io_req_t	ior;
+{
+	vm_map_copy_t	new_copy = VM_MAP_COPY_NULL;
+	register
+	vm_map_copy_t	io_copy;
+	kern_return_t	result;
+	vm_offset_t	size_to_do;
+	int		bsize;	
+
+	if (ior->io_alloc_size == 0)
+	    return (TRUE);
+
+	/*
+	 * Inband case.
+	 */
+	if (ior->io_op & IO_INBAND) {
+	    zfree(io_inband_zone, (vm_offset_t)ior->io_data);
+
+	    return (TRUE);
+	}
+	
+	if ((io_copy = ior->io_copy) == VM_MAP_COPY_NULL)
+	    return (TRUE);
+
+	/*
+	 *	To prevent a possible deadlock with the default pager,
+	 *	we have to release space in the device_io_map before
+	 *	we allocate any memory.  (Which vm_map_copy_invoke_cont
+	 *	might do.)  See the discussion in ds_init.
+	 */
+
+	kmem_io_map_deallocate(device_io_map,
+		     	 trunc_page(ior->io_data),
+			(vm_size_t) ior->io_alloc_size);
+
+	if (vm_map_copy_has_cont(io_copy)) {
+
+		/*
+		 *	Remember how much is left, then 
+		 *	invoke or abort the continuation.
+		 */
+		size_to_do = io_copy->size - ior->io_count;
+		if (ior->io_error == 0) {
+			vm_map_copy_invoke_cont(io_copy, &new_copy, &result);
+		}
+		else {
+			vm_map_copy_abort_cont(io_copy);
+			result = KERN_FAILURE;
+		}
+
+		if (result == KERN_SUCCESS && new_copy != VM_MAP_COPY_NULL) {
+			register int	res;
+
+			/*
+			 *	We have a new continuation, reset the ior to
+			 *	represent the remainder of the request.  Must
+			 *	adjust the recnum because drivers assume
+			 *	that the residual is zero.
+			 */
+			ior->io_op &= ~IO_DONE;
+			ior->io_op |= IO_CALL;
+
+			res = (*ior->io_device->dev_ops->d_dev_info)(
+					ior->io_device->dev_number,
+					D_INFO_BLOCK_SIZE,
+					&bsize);
+
+			if (res != D_SUCCESS)
+				panic("device_write_dealloc: No block size");
+			
+			ior->io_recnum += ior->io_count/bsize;
+			ior->io_count = new_copy->size;
+		}
+		else {
+
+			/*
+			 *	No continuation.  Add amount we didn't get
+			 *	to into residual.
+			 */
+			ior->io_residual += size_to_do;
+		}
+	}
+
+	/*
+	 *	Clean up the state for the IO that just completed.
+	 */
+        vm_map_copy_discard(ior->io_copy);
+	ior->io_copy = VM_MAP_COPY_NULL;
+	ior->io_data = (char *) new_copy;
+
+	/*
+	 *	Return FALSE if there's more IO to do.
+	 */
+
+	return(new_copy == VM_MAP_COPY_NULL);
+}
+
+/*
+ * Send write completion message to client, and discard the data.
+ */
+boolean_t
+ds_write_done(ior)
+	register io_req_t	ior;
+{
+	/*
+	 *	device_write_dealloc discards the data that has been
+	 *	written, but may decide that there is more to write.
+	 */
+	while (!device_write_dealloc(ior)) {
+		register io_return_t	result;
+		register mach_device_t	device;
+
+		/*
+		 *     More IO to do -- invoke it.
+		 */
+		device = ior->io_device;
+		result = (*device->dev_ops->d_write)(device->dev_number, ior);
+
+		/*
+		 * If the IO was queued, return FALSE -- not done yet.
+		 */
+		if (result == D_IO_QUEUED)
+		    return (FALSE);
+	}
+
+	/*
+	 *	Now the write is really complete.  Send reply.
+	 */
+
+	if (IP_VALID(ior->io_reply_port)) {
+	    (void) (*((ior->io_op & IO_INBAND) ?
+		      ds_device_write_reply_inband :
+		      ds_device_write_reply))(ior->io_reply_port,
+					      ior->io_reply_port_type,
+					      ior->io_error,
+					      (int) (ior->io_total -
+						     ior->io_residual));
+	}
+	mach_device_deallocate(ior->io_device);
+
+	return (TRUE);
+}
+
+/*
+ * Read from a device.
+ */
+#ifdef i386
+static io_return_t
+device_read(d, reply_port, reply_port_type, mode, recnum,
+	    bytes_wanted, data, data_count)
+	void *d;
+#else
+io_return_t
+ds_device_read(device, reply_port, reply_port_type, mode, recnum,
+	       bytes_wanted, data, data_count)
+	register mach_device_t	device;
+#endif
+	ipc_port_t		reply_port;
+	mach_msg_type_name_t	reply_port_type;
+	dev_mode_t		mode;
+	recnum_t		recnum;
+	int			bytes_wanted;
+	io_buf_ptr_t		*data;		/* out */
+	unsigned int		*data_count;	/* out */
+{
+#ifdef i386
+	register mach_device_t	device = d;
+#endif
+	register io_req_t	ior;
+	register io_return_t	result;
+
+#ifdef lint
+	*data = *data;
+	*data_count = *data_count;
+#endif lint
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+	    return (D_NO_SUCH_DEVICE);
+
+	/* XXX note that a CLOSE may proceed at any point */
+
+	/*
+	 * There must be a reply port.
+	 */
+	if (!IP_VALID(reply_port)) {
+	    printf("ds_* invalid reply port\n");
+	    Debugger("ds_* reply_port");
+	    return (MIG_NO_REPLY);	/* no sense in doing anything */
+	}
+
+	/*
+	 * Package the read request for the device driver
+	 */
+	io_req_alloc(ior, 0);
+
+	ior->io_device		= device;
+	ior->io_unit		= device->dev_number;
+	ior->io_op		= IO_READ | IO_CALL;
+	ior->io_mode		= mode;
+	ior->io_recnum		= recnum;
+	ior->io_data		= 0;		/* driver must allocate data */
+	ior->io_count		= bytes_wanted;
+	ior->io_alloc_size	= 0;		/* no data allocated yet */
+	ior->io_residual	= 0;
+	ior->io_error		= 0;
+	ior->io_done		= ds_read_done;
+	ior->io_reply_port	= reply_port;
+	ior->io_reply_port_type	= reply_port_type;
+
+	/*
+	 * The ior keeps an extra reference for the device.
+	 */
+	mach_device_reference(device);
+
+	/*
+	 * And do the read.
+	 */
+	result = (*device->dev_ops->d_read)(device->dev_number, ior);
+
+	/*
+	 * If the IO was queued, delay reply until it is finished.
+	 */
+	if (result == D_IO_QUEUED)
+	    return (MIG_NO_REPLY);
+
+	/*
+	 * Return result via ds_read_done.
+	 */
+	ior->io_error = result;
+	(void) ds_read_done(ior);
+	io_req_free(ior);
+
+	return (MIG_NO_REPLY);	/* reply has already been sent. */
+}
+
+/*
+ * Read from a device, but return the data 'inband.'
+ */
+#ifdef i386
+static io_return_t
+device_read_inband(d, reply_port, reply_port_type, mode, recnum,
+		   bytes_wanted, data, data_count)
+	void *d;
+#else
+io_return_t
+ds_device_read_inband(device, reply_port, reply_port_type, mode, recnum,
+		      bytes_wanted, data, data_count)
+	register mach_device_t	device;
+#endif
+	ipc_port_t		reply_port;
+	mach_msg_type_name_t	reply_port_type;
+	dev_mode_t		mode;
+	recnum_t		recnum;
+	int			bytes_wanted;
+	char			*data;		/* pointer to OUT array */
+	unsigned int		*data_count;	/* out */
+{
+#ifdef i386
+	register mach_device_t	device = d;
+#endif
+	register io_req_t	ior;
+	register io_return_t	result;
+
+#ifdef lint
+	*data = *data;
+	*data_count = *data_count;
+#endif lint
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+	    return (D_NO_SUCH_DEVICE);
+
+	/* XXX note that a CLOSE may proceed at any point */
+
+	/*
+	 * There must be a reply port.
+	 */
+	if (!IP_VALID(reply_port)) {
+	    printf("ds_* invalid reply port\n");
+	    Debugger("ds_* reply_port");
+	    return (MIG_NO_REPLY);	/* no sense in doing anything */
+	}
+
+	/*
+	 * Package the read for the device driver
+	 */
+	io_req_alloc(ior, 0);
+
+	ior->io_device		= device;
+	ior->io_unit		= device->dev_number;
+	ior->io_op		= IO_READ | IO_CALL | IO_INBAND;
+	ior->io_mode		= mode;
+	ior->io_recnum		= recnum;
+	ior->io_data		= 0;		/* driver must allocate data */
+	ior->io_count		= 
+	    ((bytes_wanted < sizeof(io_buf_ptr_inband_t)) ?
+		bytes_wanted : sizeof(io_buf_ptr_inband_t));
+	ior->io_alloc_size	= 0;		/* no data allocated yet */
+	ior->io_residual	= 0;
+	ior->io_error		= 0;
+	ior->io_done		= ds_read_done;
+	ior->io_reply_port	= reply_port;
+	ior->io_reply_port_type	= reply_port_type;
+
+	/*
+	 * The ior keeps an extra reference for the device.
+	 */
+	mach_device_reference(device);
+
+	/*
+	 * Do the read.
+	 */
+	result = (*device->dev_ops->d_read)(device->dev_number, ior);
+
+	/*
+	 * If the io was queued, delay reply until it is finished.
+	 */
+	if (result == D_IO_QUEUED)
+	    return (MIG_NO_REPLY);
+
+	/*
+	 * Return result, via ds_read_done.
+	 */
+	ior->io_error = result;
+	(void) ds_read_done(ior);
+	io_req_free(ior);
+
+	return (MIG_NO_REPLY);	/* reply has already been sent. */
+}
+
+
+/*
+ * Allocate wired-down memory for device read.
+ */
+kern_return_t device_read_alloc(ior, size)
+	register io_req_t	ior;
+	register vm_size_t	size;
+{
+	vm_offset_t		addr;
+	kern_return_t		kr;
+
+	/*
+	 * Nothing to do if no data.
+	 */
+	if (ior->io_count == 0)
+	    return (KERN_SUCCESS);
+
+	if (ior->io_op & IO_INBAND) {
+	    ior->io_data = (io_buf_ptr_t) zalloc(io_inband_zone);
+	    ior->io_alloc_size = sizeof(io_buf_ptr_inband_t);
+	} else {
+	    size = round_page(size);
+	    kr = kmem_alloc(kernel_map, &addr, size);
+	    if (kr != KERN_SUCCESS)
+		return (kr);
+
+	    ior->io_data = (io_buf_ptr_t) addr;
+	    ior->io_alloc_size = size;
+	}
+
+	return (KERN_SUCCESS);
+}
+
+boolean_t ds_read_done(ior)
+	io_req_t	ior;
+{
+	vm_offset_t		start_data, end_data;
+	vm_offset_t		start_sent, end_sent;
+	register vm_size_t	size_read;
+
+	if (ior->io_error)
+	    size_read = 0;
+	else
+	    size_read = ior->io_count - ior->io_residual;
+
+	start_data  = (vm_offset_t)ior->io_data;
+	end_data    = start_data + size_read;
+
+	start_sent  = (ior->io_op & IO_INBAND) ? start_data :
+						trunc_page(start_data);
+	end_sent    = (ior->io_op & IO_INBAND) ? 
+		start_data + ior->io_alloc_size : round_page(end_data);
+
+	/*
+	 * Zero memory that the device did not fill.
+	 */
+	if (start_sent < start_data)
+	    bzero((char *)start_sent, start_data - start_sent);
+	if (end_sent > end_data)
+	    bzero((char *)end_data, end_sent - end_data);
+
+
+	/*
+	 * Touch the data being returned, to mark it dirty.
+	 * If the pages were filled by DMA, the pmap module
+	 * may think that they are clean.
+	 */
+	{
+	    register vm_offset_t	touch;
+	    register int		c;
+
+	    for (touch = start_sent; touch < end_sent; touch += PAGE_SIZE) {
+		c = *(char *)touch;
+		*(char *)touch = c;
+	    }
+	}
+
+	/*
+	 * Send the data to the reply port - this
+	 * unwires and deallocates it.
+	 */
+	if (ior->io_op & IO_INBAND) {
+	    (void)ds_device_read_reply_inband(ior->io_reply_port,
+					      ior->io_reply_port_type,
+					      ior->io_error,
+					      (char *) start_data,
+					      size_read);
+	} else {
+	    vm_map_copy_t copy;
+	    kern_return_t kr;
+
+	    kr = vm_map_copyin_page_list(kernel_map, start_data,
+						 size_read, TRUE, TRUE,
+						 &copy, FALSE);
+
+	    if (kr != KERN_SUCCESS)
+		panic("read_done: vm_map_copyin_page_list failed");
+
+	    (void)ds_device_read_reply(ior->io_reply_port,
+				       ior->io_reply_port_type,
+				       ior->io_error,
+				       (char *) copy,
+				       size_read);
+	}
+
+	/*
+	 * Free any memory that was allocated but not sent.
+	 */
+	if (ior->io_count != 0) {
+	    if (ior->io_op & IO_INBAND) {
+		if (ior->io_alloc_size > 0)
+		    zfree(io_inband_zone, (vm_offset_t)ior->io_data);
+	    } else {
+		register vm_offset_t	end_alloc;
+
+		end_alloc = start_sent + round_page(ior->io_alloc_size);
+		if (end_alloc > end_sent)
+		    (void) vm_deallocate(kernel_map,
+					 end_sent,
+					 end_alloc - end_sent);
+	    }
+	}
+
+	mach_device_deallocate(ior->io_device);
+
+	return (TRUE);
+}
+
+#ifdef i386
+static io_return_t
+device_set_status(d, flavor, status, status_count)
+	void *d;
+#else
+io_return_t
+ds_device_set_status(device, flavor, status, status_count)
+	register mach_device_t	device;
+#endif
+	dev_flavor_t		flavor;
+	dev_status_t		status;
+	mach_msg_type_number_t	status_count;
+{
+#ifdef i386
+	register mach_device_t device = d;
+#endif
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+	    return (D_NO_SUCH_DEVICE);
+
+	/* XXX note that a CLOSE may proceed at any point */
+
+	return ((*device->dev_ops->d_setstat)(device->dev_number,
+					      flavor,
+					      status,
+					      status_count));
+}
+
+#ifdef i386
+io_return_t
+mach_device_get_status(d, flavor, status, status_count)
+	void *d;
+#else
+io_return_t
+ds_device_get_status(device, flavor, status, status_count)
+	register mach_device_t	device;
+#endif
+	dev_flavor_t		flavor;
+	dev_status_t		status;		/* pointer to OUT array */
+	mach_msg_type_number_t	*status_count;	/* out */
+{
+#ifdef i386
+	register mach_device_t	device = d;
+#endif
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+	    return (D_NO_SUCH_DEVICE);
+
+	/* XXX note that a CLOSE may proceed at any point */
+
+	return ((*device->dev_ops->d_getstat)(device->dev_number,
+					      flavor,
+					      status,
+					      status_count));
+}
+
+#ifdef i386
+static io_return_t
+device_set_filter(d, receive_port, priority, filter, filter_count)
+	void *d;
+#else
+io_return_t
+ds_device_set_filter(device, receive_port, priority, filter, filter_count)
+	register mach_device_t	device;
+#endif
+	ipc_port_t		receive_port;
+	int			priority;
+	filter_t		filter[];	/* pointer to IN array */
+	unsigned int		filter_count;
+{
+#ifdef i386
+	register mach_device_t	device = d;
+#endif
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+	    return (D_NO_SUCH_DEVICE);
+
+	/* XXX note that a CLOSE may proceed at any point */
+
+	/*
+	 * Request is absurd if no receive port is specified.
+	 */
+	if (!IP_VALID(receive_port))
+	    return (D_INVALID_OPERATION);
+
+	return ((*device->dev_ops->d_async_in)(device->dev_number,
+					       receive_port,
+					       priority,
+					       filter,
+					       filter_count));
+}
+
+#ifdef i386
+static io_return_t
+device_map(d, protection, offset, size, pager, unmap)
+	void *d;
+#else
+io_return_t
+ds_device_map(device, protection, offset, size, pager, unmap)
+	register mach_device_t	device;
+#endif
+	vm_prot_t		protection;
+	vm_offset_t		offset;
+	vm_size_t		size;
+	ipc_port_t		*pager;	/* out */
+	boolean_t		unmap;	/* ? */
+{
+#ifdef i386
+	register mach_device_t device = d;
+#endif
+
+#ifdef	lint
+	unmap = unmap;
+#endif	lint
+	if (protection & ~VM_PROT_ALL)
+		return (KERN_INVALID_ARGUMENT);
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+	    return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+	    return (D_NO_SUCH_DEVICE);
+
+	/* XXX note that a CLOSE may proceed at any point */
+
+	return (device_pager_setup(device, protection, offset, size,
+				    (mach_port_t*)pager));
+}
+
+/*
+ * Doesn't do anything (yet).
+ */
+#ifdef i386
+static void
+#else
+void
+#endif
+ds_no_senders(notification)
+	mach_no_senders_notification_t *notification;
+{
+	printf("ds_no_senders called! device_port=0x%x count=%d\n",
+	       notification->not_header.msgh_remote_port,
+	       notification->not_count);
+}
+
+#ifndef i386
+boolean_t
+ds_notify(msg)
+	mach_msg_header_t *msg;
+{
+	switch (msg->msgh_id) {
+		case MACH_NOTIFY_NO_SENDERS:
+		ds_no_senders((mach_no_senders_notification_t *) msg);
+		return TRUE;
+
+		default:
+		printf("ds_notify: strange notification %d\n", msg->msgh_id);
+		return FALSE;
+	}
+}
+#endif
+
+queue_head_t		io_done_list;
+decl_simple_lock_data(,	io_done_list_lock)
+
+#define	splio	splsched	/* XXX must block ALL io devices */
+
+void iodone(ior)
+	register io_req_t	ior;
+{
+	register spl_t	s;
+
+	/*
+	 * If this ior was loaned to us, return it directly.
+	 */
+	if (ior->io_op & IO_LOANED) {
+		(*ior->io_done)(ior);
+		return;
+	}
+	/*
+	 * If !IO_CALL, some thread is waiting for this.  Must lock
+	 * structure to interlock correctly with iowait().  Else can
+	 * toss on queue for io_done thread to call completion.
+	 */
+	s = splio();
+	if ((ior->io_op & IO_CALL) == 0) {
+	    ior_lock(ior);
+	    ior->io_op |= IO_DONE;
+	    ior->io_op &= ~IO_WANTED;
+	    ior_unlock(ior);
+	    thread_wakeup((event_t)ior);
+	} else {
+	    ior->io_op |= IO_DONE;
+	    simple_lock(&io_done_list_lock);
+	    enqueue_tail(&io_done_list, (queue_entry_t)ior);
+	    thread_wakeup((event_t)&io_done_list);
+	    simple_unlock(&io_done_list_lock);
+	}
+	splx(s);
+}
+
+void io_done_thread_continue()
+{
+	for (;;) {
+	    register spl_t	s;
+	    register io_req_t	ior;
+
+#if defined (i386) && defined (LINUX_DEV)
+	    free_skbuffs ();
+#endif
+	    s = splio();
+	    simple_lock(&io_done_list_lock);
+	    while ((ior = (io_req_t)dequeue_head(&io_done_list)) != 0) {
+		simple_unlock(&io_done_list_lock);
+		(void) splx(s);
+
+		if ((*ior->io_done)(ior)) {
+		    /*
+		     * IO done - free io_req_elt
+		     */
+		    io_req_free(ior);
+		}
+		/* else routine has re-queued it somewhere */
+
+		s = splio();
+		simple_lock(&io_done_list_lock);
+	    }
+
+	    assert_wait(&io_done_list, FALSE);
+	    simple_unlock(&io_done_list_lock);
+	    (void) splx(s);
+	    counter(c_io_done_thread_block++);
+	    thread_block(io_done_thread_continue);
+	}
+}
+
+void io_done_thread()
+{
+	/*
+	 * Set thread privileges and highest priority.
+	 */
+	current_thread()->vm_privilege = TRUE;
+	stack_privilege(current_thread());
+	thread_set_own_priority(0);
+
+	io_done_thread_continue();
+	/*NOTREACHED*/
+}
+
+#define	DEVICE_IO_MAP_SIZE	(2 * 1024 * 1024)
+
+extern void ds_trap_init(void);		/* forward */
+
+void ds_init()
+{
+	vm_offset_t	device_io_min, device_io_max;
+
+	queue_init(&io_done_list);
+	simple_lock_init(&io_done_list_lock);
+
+	device_io_map = kmem_suballoc(kernel_map,
+				      &device_io_min,
+				      &device_io_max,
+				      DEVICE_IO_MAP_SIZE,
+				      FALSE);
+	/*
+	 *	If the kernel receives many device_write requests, the
+	 *	device_io_map might run out of space.  To prevent
+	 *	device_write_get from failing in this case, we enable
+	 *	wait_for_space on the map.  This causes kmem_io_map_copyout
+	 *	to block until there is sufficient space.
+	 *	(XXX Large writes may be starved by small writes.)
+	 *
+	 *	There is a potential deadlock problem with this solution,
+	 *	if a device_write from the default pager has to wait
+	 *	for the completion of a device_write which needs to wait
+	 *	for memory allocation.  Hence, once device_write_get
+	 *	allocates space in device_io_map, no blocking memory
+	 *	allocations should happen until device_write_dealloc
+	 *	frees the space.  (XXX A large write might starve
+	 *	a small write from the default pager.)
+	 */
+	device_io_map->wait_for_space = TRUE;
+
+	io_inband_zone = zinit(sizeof(io_buf_ptr_inband_t),
+			    1000 * sizeof(io_buf_ptr_inband_t),
+			    10 * sizeof(io_buf_ptr_inband_t),
+			    FALSE,
+			    "io inband read buffers");
+
+	ds_trap_init();
+}
+
+void iowait(ior)
+    io_req_t ior;
+{
+    spl_t s;
+
+    s = splio();
+    ior_lock(ior);
+    while ((ior->io_op&IO_DONE)==0) {
+	assert_wait((event_t)ior, FALSE);
+	ior_unlock(ior);
+	thread_block((void (*)()) 0);
+        ior_lock(ior);
+    }
+    ior_unlock(ior);
+    splx(s);
+}
+
+
+/*
+ * Device trap support.
+ */
+
+/*
+ * Memory Management
+ *
+ * This currently has a single pool of 2k wired buffers
+ * since we only handle writes to an ethernet device.
+ * Should be more general.
+ */
+#define IOTRAP_REQSIZE 2048
+
+zone_t io_trap_zone;
+
+/*
+ * Initialization.  Called from ds_init().
+ */
+void
+ds_trap_init(void)
+{
+	io_trap_zone = zinit(IOTRAP_REQSIZE,
+			     256 * IOTRAP_REQSIZE,
+			     16 * IOTRAP_REQSIZE,
+			     FALSE,
+			     "wired device trap buffers");
+}
+
+/*
+ * Allocate an io_req_t.
+ * Currently zalloc's from io_trap_zone.
+ *
+ * Could have lists of different size zones.
+ * Could call a device-specific routine.
+ */
+io_req_t
+ds_trap_req_alloc(mach_device_t device, vm_size_t data_size)
+{
+	return (io_req_t) zalloc(io_trap_zone);
+}
+
+/*
+ * Called by iodone to release ior.
+ */
+boolean_t
+ds_trap_write_done(io_req_t ior)
+{
+	register mach_device_t dev;
+
+	dev = ior->io_device;
+
+	/*
+	 * Should look at reply port and maybe send a message.
+	 */
+	zfree(io_trap_zone, ior);
+	
+	/*
+	 * Give up device reference from ds_write_trap.
+	 */
+	mach_device_deallocate(dev);
+	return TRUE;
+}
+
+/*
+ * Like device_write except that data is in user space.
+ */
+#ifdef i386
+static io_return_t
+device_write_trap (void *d, dev_mode_t mode,
+		   recnum_t recnum, vm_offset_t data, vm_size_t data_count)
+#else
+io_return_t
+ds_device_write_trap(device_t		device,
+		     dev_mode_t		mode,
+		     recnum_t		recnum,
+		     vm_offset_t	data,
+		     vm_size_t		data_count)
+#endif
+{
+#ifdef i386
+	mach_device_t device = d;
+#endif
+	io_req_t ior;
+	io_return_t result;
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+		return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+		return (D_NO_SUCH_DEVICE);
+ 
+	/* XXX note that a CLOSE may proceed at any point */
+ 
+	/*
+	 * Get a buffer to hold the ioreq.
+	 */
+	ior = ds_trap_req_alloc(device, data_count);
+ 
+	/*
+	 * Package the write request for the device driver.
+	 */
+
+	ior->io_device          = device;
+	ior->io_unit            = device->dev_number;
+	ior->io_op              = IO_WRITE | IO_CALL | IO_LOANED;
+	ior->io_mode            = mode;
+	ior->io_recnum          = recnum;
+	ior->io_data            = (io_buf_ptr_t)
+		(vm_offset_t)ior + sizeof(struct io_req);
+	ior->io_count           = data_count;
+	ior->io_total           = data_count;
+	ior->io_alloc_size      = 0;
+	ior->io_residual        = 0;
+	ior->io_error           = 0;
+	ior->io_done            = ds_trap_write_done;
+	ior->io_reply_port      = IP_NULL;	/* XXX */
+	ior->io_reply_port_type = 0;		/* XXX */
+
+	/*
+	 * Copy the data from user space.
+	 */
+	if (data_count > 0)
+		copyin((char *)data, (char *)ior->io_data, data_count);
+ 
+	/*
+	 * The ior keeps an extra reference for the device.
+	 */
+	mach_device_reference(device);
+ 
+	/*
+	 * And do the write.
+	 */
+	result = (*device->dev_ops->d_write)(device->dev_number, ior);
+ 
+	/*
+	 * If the IO was queued, delay reply until it is finished.
+	 */
+	if (result == D_IO_QUEUED)
+		return (MIG_NO_REPLY);
+ 
+	/*
+	 * Remove the extra reference.
+	 */
+	mach_device_deallocate(device);
+ 
+	zfree(io_trap_zone, ior);
+	return (result);
+}
+
+#ifdef i386
+static io_return_t
+device_writev_trap (void *d, dev_mode_t mode,
+		    recnum_t recnum, io_buf_vec_t *iovec, vm_size_t iocount)
+#else
+io_return_t
+ds_device_writev_trap(device_t		device,
+		      dev_mode_t	mode,
+		      recnum_t		recnum,
+		      io_buf_vec_t	*iovec,
+		      vm_size_t		iocount)
+#endif
+{
+#ifdef i386
+	mach_device_t device = d;
+#endif
+	io_req_t ior;
+	io_return_t result;
+	io_buf_vec_t	stack_iovec[16]; /* XXX */
+	vm_size_t data_count;
+	int i;
+
+#ifndef i386
+	/*
+	 * Refuse if device is dead or not completely open.
+	 */
+	if (device == DEVICE_NULL)
+		return (D_NO_SUCH_DEVICE);
+#endif
+
+	if (device->state != DEV_STATE_OPEN)
+		return (D_NO_SUCH_DEVICE);
+ 
+	/* XXX note that a CLOSE may proceed at any point */
+ 
+	/*
+	 * Copyin user addresses.
+	 */
+	if (iocount > 16)
+		return KERN_INVALID_VALUE; /* lame */
+	copyin((char *)iovec,
+	       (char *)stack_iovec,
+	       iocount * sizeof(io_buf_vec_t));
+	for (data_count = 0, i = 0; i < iocount; i++)
+		data_count += stack_iovec[i].count;
+
+	/*
+	 * Get a buffer to hold the ioreq.
+	 */
+	ior = ds_trap_req_alloc(device, data_count);
+ 
+	/*
+	 * Package the write request for the device driver.
+	 */
+
+	ior->io_device          = device;
+	ior->io_unit            = device->dev_number;
+	ior->io_op              = IO_WRITE | IO_CALL | IO_LOANED;
+	ior->io_mode            = mode;
+	ior->io_recnum          = recnum;
+	ior->io_data            = (io_buf_ptr_t)
+		(vm_offset_t)ior + sizeof(struct io_req);
+	ior->io_count           = data_count;
+	ior->io_total           = data_count;
+	ior->io_alloc_size      = 0;
+	ior->io_residual        = 0;
+	ior->io_error           = 0;
+	ior->io_done            = ds_trap_write_done;
+	ior->io_reply_port      = IP_NULL;	/* XXX */
+	ior->io_reply_port_type = 0;		/* XXX */
+
+	/*
+	 * Copy the data from user space.
+	 */
+	if (data_count > 0) {
+		vm_offset_t p;
+
+		p = (vm_offset_t) ior->io_data;
+		for (i = 0; i < iocount; i++) {
+			copyin((char *) stack_iovec[i].data,
+			       (char *) p,
+			       stack_iovec[i].count);
+			p += stack_iovec[i].count;
+		}
+	}
+ 
+	/*
+	 * The ior keeps an extra reference for the device.
+	 */
+	mach_device_reference(device);
+ 
+	/*
+	 * And do the write.
+	 */
+	result = (*device->dev_ops->d_write)(device->dev_number, ior);
+ 
+	/*
+	 * If the IO was queued, delay reply until it is finished.
+	 */
+	if (result == D_IO_QUEUED)
+		return (MIG_NO_REPLY);
+ 
+	/*
+	 * Remove the extra reference.
+	 */
+	mach_device_deallocate(device);
+ 
+	zfree(io_trap_zone, ior);
+	return (result);
+}
+
+#ifdef i386
+struct device_emulation_ops mach_device_emulation_ops =
+{
+  mach_device_reference,
+  mach_device_deallocate,
+  mach_convert_device_to_port,
+  device_open,
+  device_close,
+  device_write,
+  device_write_inband,
+  device_read,
+  device_read_inband,
+  device_set_status,
+  mach_device_get_status,
+  device_set_filter,
+  device_map,
+  ds_no_senders,
+  device_write_trap,
+  device_writev_trap
+};
+#endif