FreeBSD/Linux Kernel Cross Reference
sys/dev/ofw/openfirm.c

     /*      $NetBSD: Locore.c,v 1.7 2000/08/20 07:04:59 tsubai Exp $        */
     
     /*-
      * SPDX-License-Identifier: BSD-4-Clause
      *
      * Copyright (C) 1995, 1996 Wolfgang Solfrank.
      * Copyright (C) 1995, 1996 TooLs GmbH.
      * All rights reserved.
      *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by TooLs GmbH.
     * 4. The name of TooLs GmbH may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    /*-
     * Copyright (C) 2000 Benno Rice.
     * All rights reserved.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_platform.h"
    
    #include <sys/param.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/mutex.h>
    #include <sys/queue.h>
    #include <sys/systm.h>
    #include <sys/endian.h>
    
    #include <machine/stdarg.h>
    
    #include <dev/ofw/ofwvar.h>
    #include <dev/ofw/openfirm.h>
    
    #include "ofw_if.h"
    
    static void OF_putchar(int c, void *arg);
    
    MALLOC_DEFINE(M_OFWPROP, "openfirm", "Open Firmware properties");
    
    static ihandle_t stdout;
    
    static ofw_def_t        *ofw_def_impl = NULL;
    static ofw_t            ofw_obj;
    static struct ofw_kobj  ofw_kernel_obj;
    static struct kobj_ops  ofw_kernel_kops;
    
    struct xrefinfo {
            phandle_t       xref;
            phandle_t       node;
            device_t        dev;
            SLIST_ENTRY(xrefinfo) next_entry;
    };
    
    static SLIST_HEAD(, xrefinfo) xreflist = SLIST_HEAD_INITIALIZER(xreflist);
   static struct mtx xreflist_lock;
   static boolean_t xref_init_done;
   
   #define FIND_BY_XREF    0
   #define FIND_BY_NODE    1
   #define FIND_BY_DEV     2
   
   /*
    * xref-phandle-device lookup helper routines.
    *
    * As soon as we are able to use malloc(), walk the node tree and build a list
    * of info that cross-references node handles, xref handles, and device_t
    * instances.  This list exists primarily to allow association of a device_t
    * with an xref handle, but it is also used to speed up translation between xref
    * and node handles.  Before malloc() is available we have to recursively search
    * the node tree each time we want to translate between a node and xref handle.
    * Afterwards we can do the translations by searching this much shorter list.
    */
   static void
   xrefinfo_create(phandle_t node)
   {
           struct xrefinfo * xi;
           phandle_t child, xref;
   
           /*
            * Recursively descend from parent, looking for nodes with a property
            * named either "phandle", "ibm,phandle", or "linux,phandle".  For each
            * such node found create an entry in the xreflist.
            */
           for (child = OF_child(node); child != 0; child = OF_peer(child)) {
                   xrefinfo_create(child);
                   if (OF_getencprop(child, "phandle", &xref, sizeof(xref)) ==
                       -1 && OF_getencprop(child, "ibm,phandle", &xref,
                       sizeof(xref)) == -1 && OF_getencprop(child,
                       "linux,phandle", &xref, sizeof(xref)) == -1)
                           continue;
                   xi = malloc(sizeof(*xi), M_OFWPROP, M_WAITOK | M_ZERO);
                   xi->node = child;
                   xi->xref = xref;
                   SLIST_INSERT_HEAD(&xreflist, xi, next_entry);
           }
   }
   
   static void
   xrefinfo_init(void *unsed)
   {
   
           /*
            * There is no locking during this init because it runs much earlier
            * than any of the clients/consumers of the xref list data, but we do
            * initialize the mutex that will be used for access later.
            */
           mtx_init(&xreflist_lock, "OF xreflist lock", NULL, MTX_DEF);
           xrefinfo_create(OF_peer(0));
           xref_init_done = true;
   }
   SYSINIT(xrefinfo, SI_SUB_KMEM, SI_ORDER_ANY, xrefinfo_init, NULL);
   
   static struct xrefinfo *
   xrefinfo_find(uintptr_t key, int find_by)
   {
           struct xrefinfo *rv, *xi;
   
           rv = NULL;
           mtx_lock(&xreflist_lock);
           SLIST_FOREACH(xi, &xreflist, next_entry) {
                   if ((find_by == FIND_BY_XREF && (phandle_t)key == xi->xref) ||
                       (find_by == FIND_BY_NODE && (phandle_t)key == xi->node) ||
                       (find_by == FIND_BY_DEV && key == (uintptr_t)xi->dev)) {
                           rv = xi;
                           break;
                   }
           }
           mtx_unlock(&xreflist_lock);
           return (rv);
   }
   
   static struct xrefinfo *
   xrefinfo_add(phandle_t node, phandle_t xref, device_t dev)
   {
           struct xrefinfo *xi;
   
           xi = malloc(sizeof(*xi), M_OFWPROP, M_WAITOK);
           xi->node = node;
           xi->xref = xref;
           xi->dev  = dev;
           mtx_lock(&xreflist_lock);
           SLIST_INSERT_HEAD(&xreflist, xi, next_entry);
           mtx_unlock(&xreflist_lock);
           return (xi);
   }
   
   /*
    * OFW install routines.  Highest priority wins, equal priority also
    * overrides allowing last-set to win.
    */
   SET_DECLARE(ofw_set, ofw_def_t);
   
   boolean_t
   OF_install(char *name, int prio)
   {
           ofw_def_t *ofwp, **ofwpp;
           static int curr_prio = 0;
   
           /* Allow OF layer to be uninstalled */
           if (name == NULL) {
                   ofw_def_impl = NULL;
                   return (FALSE);
           }
   
           /*
            * Try and locate the OFW kobj corresponding to the name.
            */
           SET_FOREACH(ofwpp, ofw_set) {
                   ofwp = *ofwpp;
   
                   if (ofwp->name &&
                       !strcmp(ofwp->name, name) &&
                       prio >= curr_prio) {
                           curr_prio = prio;
                           ofw_def_impl = ofwp;
                           return (TRUE);
                   }
           }
   
           return (FALSE);
   }
   
   /* Initializer */
   int
   OF_init(void *cookie)
   {
           phandle_t chosen;
           int rv;
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           ofw_obj = &ofw_kernel_obj;
           /*
            * Take care of compiling the selected class, and
            * then statically initialize the OFW object.
            */
           kobj_class_compile_static(ofw_def_impl, &ofw_kernel_kops);
           kobj_init_static((kobj_t)ofw_obj, ofw_def_impl);
   
           rv = OFW_INIT(ofw_obj, cookie);
   
           if ((chosen = OF_finddevice("/chosen")) != -1)
                   if (OF_getencprop(chosen, "stdout", &stdout,
                       sizeof(stdout)) == -1)
                           stdout = -1;
   
           return (rv);
   }
   
   static void
   OF_putchar(int c, void *arg __unused)
   {
           char cbuf;
   
           if (c == '\n') {
                   cbuf = '\r';
                   OF_write(stdout, &cbuf, 1);
           }
   
           cbuf = c;
           OF_write(stdout, &cbuf, 1);
   }
   
   void
   OF_printf(const char *fmt, ...)
   {
           va_list va;
   
           va_start(va, fmt);
           (void)kvprintf(fmt, OF_putchar, NULL, 10, va);
           va_end(va);
   }
   
   /*
    * Generic functions
    */
   
   /* Test to see if a service exists. */
   int
   OF_test(const char *name)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_TEST(ofw_obj, name));
   }
   
   int
   OF_interpret(const char *cmd, int nreturns, ...)
   {
           va_list ap;
           cell_t slots[16];
           int i = 0;
           int status;
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           status = OFW_INTERPRET(ofw_obj, cmd, nreturns, slots);
           if (status == -1)
                   return (status);
   
           va_start(ap, nreturns);
           while (i < nreturns)
                   *va_arg(ap, cell_t *) = slots[i++];
           va_end(ap);
   
           return (status);
   }
   
   /*
    * Device tree functions
    */
   
   /* Return the next sibling of this node or 0. */
   phandle_t
   OF_peer(phandle_t node)
   {
   
           if (ofw_def_impl == NULL)
                   return (0);
   
           return (OFW_PEER(ofw_obj, node));
   }
   
   /* Return the first child of this node or 0. */
   phandle_t
   OF_child(phandle_t node)
   {
   
           if (ofw_def_impl == NULL)
                   return (0);
   
           return (OFW_CHILD(ofw_obj, node));
   }
   
   /* Return the parent of this node or 0. */
   phandle_t
   OF_parent(phandle_t node)
   {
   
           if (ofw_def_impl == NULL)
                   return (0);
   
           return (OFW_PARENT(ofw_obj, node));
   }
   
   /* Return the package handle that corresponds to an instance handle. */
   phandle_t
   OF_instance_to_package(ihandle_t instance)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_INSTANCE_TO_PACKAGE(ofw_obj, instance));
   }
   
   /* Get the length of a property of a package. */
   ssize_t
   OF_getproplen(phandle_t package, const char *propname)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_GETPROPLEN(ofw_obj, package, propname));
   }
   
   /* Check existence of a property of a package. */
   int
   OF_hasprop(phandle_t package, const char *propname)
   {
   
           return (OF_getproplen(package, propname) >= 0 ? 1 : 0);
   }
   
   /* Get the value of a property of a package. */
   ssize_t
   OF_getprop(phandle_t package, const char *propname, void *buf, size_t buflen)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_GETPROP(ofw_obj, package, propname, buf, buflen));
   }
   
   ssize_t
   OF_getencprop(phandle_t node, const char *propname, pcell_t *buf, size_t len)
   {
           ssize_t retval;
           int i;
   
           KASSERT(len % 4 == 0, ("Need a multiple of 4 bytes"));
   
           retval = OF_getprop(node, propname, buf, len);
           if (retval <= 0)
                   return (retval);
   
           for (i = 0; i < len/4; i++)
                   buf[i] = be32toh(buf[i]);
   
           return (retval);
   }
   
   /*
    * Recursively search the node and its parent for the given property, working
    * downward from the node to the device tree root.  Returns the value of the
    * first match.
    */
   ssize_t
   OF_searchprop(phandle_t node, const char *propname, void *buf, size_t len)
   {
           ssize_t rv;
   
           for (; node != 0; node = OF_parent(node))
                   if ((rv = OF_getprop(node, propname, buf, len)) != -1)
                           return (rv);
           return (-1);
   }
   
   ssize_t
   OF_searchencprop(phandle_t node, const char *propname, pcell_t *buf, size_t len)
   {
           ssize_t rv;
   
           for (; node != 0; node = OF_parent(node))
                   if ((rv = OF_getencprop(node, propname, buf, len)) != -1)
                           return (rv);
           return (-1);
   }
   
   /*
    * Store the value of a property of a package into newly allocated memory
    * (using the M_OFWPROP malloc pool and M_WAITOK).
    */
   ssize_t
   OF_getprop_alloc(phandle_t package, const char *propname, void **buf)
   {
           int len;
   
           *buf = NULL;
           if ((len = OF_getproplen(package, propname)) == -1)
                   return (-1);
   
           if (len > 0) {
                   *buf = malloc(len, M_OFWPROP, M_WAITOK);
                   if (OF_getprop(package, propname, *buf, len) == -1) {
                           free(*buf, M_OFWPROP);
                           *buf = NULL;
                           return (-1);
                   }
           }
           return (len);
   }
   
   /*
    * Store the value of a property of a package into newly allocated memory
    * (using the M_OFWPROP malloc pool and M_WAITOK).  elsz is the size of a
    * single element, the number of elements is return in number.
    */
   ssize_t
   OF_getprop_alloc_multi(phandle_t package, const char *propname, int elsz, void **buf)
   {
           int len;
   
           *buf = NULL;
           if ((len = OF_getproplen(package, propname)) == -1 ||
               len % elsz != 0)
                   return (-1);
   
           if (len > 0) {
                   *buf = malloc(len, M_OFWPROP, M_WAITOK);
                   if (OF_getprop(package, propname, *buf, len) == -1) {
                           free(*buf, M_OFWPROP);
                           *buf = NULL;
                           return (-1);
                   }
           }
           return (len / elsz);
   }
   
   ssize_t
   OF_getencprop_alloc(phandle_t package, const char *name, void **buf)
   {
           ssize_t ret;
   
           ret = OF_getencprop_alloc_multi(package, name, sizeof(pcell_t),
               buf);
           if (ret < 0)
                   return (ret);
           else
                   return (ret * sizeof(pcell_t));
   }
   
   ssize_t
   OF_getencprop_alloc_multi(phandle_t package, const char *name, int elsz,
       void **buf)
   {
           ssize_t retval;
           pcell_t *cell;
           int i;
   
           retval = OF_getprop_alloc_multi(package, name, elsz, buf);
           if (retval == -1)
                   return (-1);
   
           cell = *buf;
           for (i = 0; i < retval * elsz / 4; i++)
                   cell[i] = be32toh(cell[i]);
   
           return (retval);
   }
   
   /* Free buffer allocated by OF_getencprop_alloc or OF_getprop_alloc */
   void OF_prop_free(void *buf)
   {
   
           free(buf, M_OFWPROP);
   }
   
   /* Get the next property of a package. */
   int
   OF_nextprop(phandle_t package, const char *previous, char *buf, size_t size)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_NEXTPROP(ofw_obj, package, previous, buf, size));
   }
   
   /* Set the value of a property of a package. */
   int
   OF_setprop(phandle_t package, const char *propname, const void *buf, size_t len)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_SETPROP(ofw_obj, package, propname, buf,len));
   }
   
   /* Convert a device specifier to a fully qualified pathname. */
   ssize_t
   OF_canon(const char *device, char *buf, size_t len)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_CANON(ofw_obj, device, buf, len));
   }
   
   /* Return a package handle for the specified device. */
   phandle_t
   OF_finddevice(const char *device)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_FINDDEVICE(ofw_obj, device));
   }
   
   /* Return the fully qualified pathname corresponding to an instance. */
   ssize_t
   OF_instance_to_path(ihandle_t instance, char *buf, size_t len)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_INSTANCE_TO_PATH(ofw_obj, instance, buf, len));
   }
   
   /* Return the fully qualified pathname corresponding to a package. */
   ssize_t
   OF_package_to_path(phandle_t package, char *buf, size_t len)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_PACKAGE_TO_PATH(ofw_obj, package, buf, len));
   }
   
   /* Look up effective phandle (see FDT/PAPR spec) */
   static phandle_t
   OF_child_xref_phandle(phandle_t parent, phandle_t xref)
   {
           phandle_t child, rxref;
   
           /*
            * Recursively descend from parent, looking for a node with a property
            * named either "phandle", "ibm,phandle", or "linux,phandle" that
            * matches the xref we are looking for.
            */
   
           for (child = OF_child(parent); child != 0; child = OF_peer(child)) {
                   rxref = OF_child_xref_phandle(child, xref);
                   if (rxref != -1)
                           return (rxref);
   
                   if (OF_getencprop(child, "phandle", &rxref, sizeof(rxref)) ==
                       -1 && OF_getencprop(child, "ibm,phandle", &rxref,
                       sizeof(rxref)) == -1 && OF_getencprop(child,
                       "linux,phandle", &rxref, sizeof(rxref)) == -1)
                           continue;
   
                   if (rxref == xref)
                           return (child);
           }
   
           return (-1);
   }
   
   phandle_t
   OF_node_from_xref(phandle_t xref)
   {
           struct xrefinfo *xi;
           phandle_t node;
   
           if (xref_init_done) {
                   if ((xi = xrefinfo_find(xref, FIND_BY_XREF)) == NULL)
                           return (xref);
                   return (xi->node);
           }
   
           if ((node = OF_child_xref_phandle(OF_peer(0), xref)) == -1)
                   return (xref);
           return (node);
   }
   
   phandle_t
   OF_xref_from_node(phandle_t node)
   {
           struct xrefinfo *xi;
           phandle_t xref;
   
           if (xref_init_done) {
                   if ((xi = xrefinfo_find(node, FIND_BY_NODE)) == NULL)
                           return (node);
                   return (xi->xref);
           }
   
           if (OF_getencprop(node, "phandle", &xref, sizeof(xref)) == -1 &&
               OF_getencprop(node, "ibm,phandle", &xref, sizeof(xref)) == -1 &&
               OF_getencprop(node, "linux,phandle", &xref, sizeof(xref)) == -1)
                   return (node);
           return (xref);
   }
   
   device_t
   OF_device_from_xref(phandle_t xref)
   {
           struct xrefinfo *xi;
   
           if (xref_init_done) {
                   if ((xi = xrefinfo_find(xref, FIND_BY_XREF)) == NULL)
                           return (NULL);
                   return (xi->dev);
           }
           panic("Attempt to find device before xreflist_init");
   }
   
   phandle_t
   OF_xref_from_device(device_t dev)
   {
           struct xrefinfo *xi;
   
           if (xref_init_done) {
                   if ((xi = xrefinfo_find((uintptr_t)dev, FIND_BY_DEV)) == NULL)
                           return (0);
                   return (xi->xref);
           }
           panic("Attempt to find xref before xreflist_init");
   }
   
   int
   OF_device_register_xref(phandle_t xref, device_t dev)
   {
           struct xrefinfo *xi;
   
           /*
            * If the given xref handle doesn't already exist in the list then we
            * add a list entry.  In theory this can only happen on a system where
            * nodes don't contain phandle properties and xref and node handles are
            * synonymous, so the xref handle is added as the node handle as well.
            */
           if (xref_init_done) {
                   if ((xi = xrefinfo_find(xref, FIND_BY_XREF)) == NULL)
                           xrefinfo_add(xref, xref, dev);
                   else 
                           xi->dev = dev;
                   return (0);
           }
           panic("Attempt to register device before xreflist_init");
   }
   
   /*  Call the method in the scope of a given instance. */
   int
   OF_call_method(const char *method, ihandle_t instance, int nargs, int nreturns,
       ...)
   {
           va_list ap;
           cell_t args_n_results[12];
           int n, status;
   
           if (nargs > 6 || ofw_def_impl == NULL)
                   return (-1);
           va_start(ap, nreturns);
           for (n = 0; n < nargs; n++)
                   args_n_results[n] = va_arg(ap, cell_t);
   
           status = OFW_CALL_METHOD(ofw_obj, instance, method, nargs, nreturns,
               args_n_results);
           if (status != 0)
                   return (status);
   
           for (; n < nargs + nreturns; n++)
                   *va_arg(ap, cell_t *) = args_n_results[n];
           va_end(ap);
           return (0);
   }
   
   /*
    * Device I/O functions
    */
   
   /* Open an instance for a device. */
   ihandle_t
   OF_open(const char *device)
   {
   
           if (ofw_def_impl == NULL)
                   return (0);
   
           return (OFW_OPEN(ofw_obj, device));
   }
   
   /* Close an instance. */
   void
   OF_close(ihandle_t instance)
   {
   
           if (ofw_def_impl == NULL)
                   return;
   
           OFW_CLOSE(ofw_obj, instance);
   }
   
   /* Read from an instance. */
   ssize_t
   OF_read(ihandle_t instance, void *addr, size_t len)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_READ(ofw_obj, instance, addr, len));
   }
   
   /* Write to an instance. */
   ssize_t
   OF_write(ihandle_t instance, const void *addr, size_t len)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_WRITE(ofw_obj, instance, addr, len));
   }
   
   /* Seek to a position. */
   int
   OF_seek(ihandle_t instance, uint64_t pos)
   {
   
           if (ofw_def_impl == NULL)
                   return (-1);
   
           return (OFW_SEEK(ofw_obj, instance, pos));
   }
   
   /*
    * Memory functions
    */
   
   /* Claim an area of memory. */
   void *
   OF_claim(void *virt, size_t size, u_int align)
   {
   
           if (ofw_def_impl == NULL)
                   return ((void *)-1);
   
           return (OFW_CLAIM(ofw_obj, virt, size, align));
   }
   
   /* Release an area of memory. */
   void
   OF_release(void *virt, size_t size)
   {
   
           if (ofw_def_impl == NULL)
                   return;
   
           OFW_RELEASE(ofw_obj, virt, size);
   }
   
   /*
    * Control transfer functions
    */
   
   /* Suspend and drop back to the Open Firmware interface. */
   void
   OF_enter(void)
   {
   
           if (ofw_def_impl == NULL)
                   return;
   
           OFW_ENTER(ofw_obj);
   }
   
   /* Shut down and drop back to the Open Firmware interface. */
   void
   OF_exit(void)
   {
   
           if (ofw_def_impl == NULL)
                   panic("OF_exit: Open Firmware not available");
   
           /* Should not return */
           OFW_EXIT(ofw_obj);
   
           for (;;)                        /* just in case */
                   ;
   }

Cache object: 72463f9b94b9d7726e45d0d33b245efa