FreeBSD/Linux Kernel Cross Reference
sys/dev/pci/pci_pci.c

     /*-
      * Copyright (c) 1994,1995 Stefan Esser, Wolfgang StanglMeier
      * Copyright (c) 2000 Michael Smith <msmith@freebsd.org>
      * Copyright (c) 2000 BSDi
      * 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. The name of the author may not be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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: releng/11.2/sys/dev/pci/pci_pci.c 331722 2018-03-29 02:50:57Z eadler $");
    
    /*
     * PCI:PCI bridge support.
     */
    
    #include "opt_pci.h"
    
    #include <sys/param.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/malloc.h>
    #include <sys/module.h>
    #include <sys/rman.h>
    #include <sys/sysctl.h>
    #include <sys/systm.h>
    #include <sys/taskqueue.h>
    
    #include <dev/pci/pcivar.h>
    #include <dev/pci/pcireg.h>
    #include <dev/pci/pci_private.h>
    #include <dev/pci/pcib_private.h>
    
    #include "pcib_if.h"
    
    static int              pcib_probe(device_t dev);
    static int              pcib_suspend(device_t dev);
    static int              pcib_resume(device_t dev);
    static int              pcib_power_for_sleep(device_t pcib, device_t dev,
                                int *pstate);
    static int              pcib_ari_get_id(device_t pcib, device_t dev,
        enum pci_id_type type, uintptr_t *id);
    static uint32_t         pcib_read_config(device_t dev, u_int b, u_int s,
        u_int f, u_int reg, int width);
    static void             pcib_write_config(device_t dev, u_int b, u_int s,
        u_int f, u_int reg, uint32_t val, int width);
    static int              pcib_ari_maxslots(device_t dev);
    static int              pcib_ari_maxfuncs(device_t dev);
    static int              pcib_try_enable_ari(device_t pcib, device_t dev);
    static int              pcib_ari_enabled(device_t pcib);
    static void             pcib_ari_decode_rid(device_t pcib, uint16_t rid,
                                int *bus, int *slot, int *func);
    #ifdef PCI_HP
    static void             pcib_pcie_ab_timeout(void *arg);
    static void             pcib_pcie_cc_timeout(void *arg);
    static void             pcib_pcie_dll_timeout(void *arg);
    #endif
    
    static device_method_t pcib_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,             pcib_probe),
        DEVMETHOD(device_attach,            pcib_attach),
        DEVMETHOD(device_detach,            pcib_detach),
        DEVMETHOD(device_shutdown,          bus_generic_shutdown),
        DEVMETHOD(device_suspend,           pcib_suspend),
        DEVMETHOD(device_resume,            pcib_resume),
    
        /* Bus interface */
        DEVMETHOD(bus_child_present,        pcib_child_present),
        DEVMETHOD(bus_read_ivar,            pcib_read_ivar),
        DEVMETHOD(bus_write_ivar,           pcib_write_ivar),
        DEVMETHOD(bus_alloc_resource,       pcib_alloc_resource),
    #ifdef NEW_PCIB
        DEVMETHOD(bus_adjust_resource,      pcib_adjust_resource),
        DEVMETHOD(bus_release_resource,     pcib_release_resource),
    #else
        DEVMETHOD(bus_adjust_resource,      bus_generic_adjust_resource),
        DEVMETHOD(bus_release_resource,     bus_generic_release_resource),
   #endif
       DEVMETHOD(bus_activate_resource,    bus_generic_activate_resource),
       DEVMETHOD(bus_deactivate_resource,  bus_generic_deactivate_resource),
       DEVMETHOD(bus_setup_intr,           bus_generic_setup_intr),
       DEVMETHOD(bus_teardown_intr,        bus_generic_teardown_intr),
   
       /* pcib interface */
       DEVMETHOD(pcib_maxslots,            pcib_ari_maxslots),
       DEVMETHOD(pcib_maxfuncs,            pcib_ari_maxfuncs),
       DEVMETHOD(pcib_read_config,         pcib_read_config),
       DEVMETHOD(pcib_write_config,        pcib_write_config),
       DEVMETHOD(pcib_route_interrupt,     pcib_route_interrupt),
       DEVMETHOD(pcib_alloc_msi,           pcib_alloc_msi),
       DEVMETHOD(pcib_release_msi,         pcib_release_msi),
       DEVMETHOD(pcib_alloc_msix,          pcib_alloc_msix),
       DEVMETHOD(pcib_release_msix,        pcib_release_msix),
       DEVMETHOD(pcib_map_msi,             pcib_map_msi),
       DEVMETHOD(pcib_power_for_sleep,     pcib_power_for_sleep),
       DEVMETHOD(pcib_get_id,              pcib_ari_get_id),
       DEVMETHOD(pcib_try_enable_ari,      pcib_try_enable_ari),
       DEVMETHOD(pcib_ari_enabled,         pcib_ari_enabled),
       DEVMETHOD(pcib_decode_rid,          pcib_ari_decode_rid),
   
       DEVMETHOD_END
   };
   
   static devclass_t pcib_devclass;
   
   DEFINE_CLASS_0(pcib, pcib_driver, pcib_methods, sizeof(struct pcib_softc));
   DRIVER_MODULE(pcib, pci, pcib_driver, pcib_devclass, NULL, NULL);
   
   #if defined(NEW_PCIB) || defined(PCI_HP)
   SYSCTL_DECL(_hw_pci);
   #endif
   
   #ifdef NEW_PCIB
   static int pci_clear_pcib;
   SYSCTL_INT(_hw_pci, OID_AUTO, clear_pcib, CTLFLAG_RDTUN, &pci_clear_pcib, 0,
       "Clear firmware-assigned resources for PCI-PCI bridge I/O windows.");
   
   /*
    * Is a resource from a child device sub-allocated from one of our
    * resource managers?
    */
   static int
   pcib_is_resource_managed(struct pcib_softc *sc, int type, struct resource *r)
   {
   
           switch (type) {
   #ifdef PCI_RES_BUS
           case PCI_RES_BUS:
                   return (rman_is_region_manager(r, &sc->bus.rman));
   #endif
           case SYS_RES_IOPORT:
                   return (rman_is_region_manager(r, &sc->io.rman));
           case SYS_RES_MEMORY:
                   /* Prefetchable resources may live in either memory rman. */
                   if (rman_get_flags(r) & RF_PREFETCHABLE &&
                       rman_is_region_manager(r, &sc->pmem.rman))
                           return (1);
                   return (rman_is_region_manager(r, &sc->mem.rman));
           }
           return (0);
   }
   
   static int
   pcib_is_window_open(struct pcib_window *pw)
   {
   
           return (pw->valid && pw->base < pw->limit);
   }
   
   /*
    * XXX: If RF_ACTIVE did not also imply allocating a bus space tag and
    * handle for the resource, we could pass RF_ACTIVE up to the PCI bus
    * when allocating the resource windows and rely on the PCI bus driver
    * to do this for us.
    */
   static void
   pcib_activate_window(struct pcib_softc *sc, int type)
   {
   
           PCI_ENABLE_IO(device_get_parent(sc->dev), sc->dev, type);
   }
   
   static void
   pcib_write_windows(struct pcib_softc *sc, int mask)
   {
           device_t dev;
           uint32_t val;
   
           dev = sc->dev;
           if (sc->io.valid && mask & WIN_IO) {
                   val = pci_read_config(dev, PCIR_IOBASEL_1, 1);
                   if ((val & PCIM_BRIO_MASK) == PCIM_BRIO_32) {
                           pci_write_config(dev, PCIR_IOBASEH_1,
                               sc->io.base >> 16, 2);
                           pci_write_config(dev, PCIR_IOLIMITH_1,
                               sc->io.limit >> 16, 2);
                   }
                   pci_write_config(dev, PCIR_IOBASEL_1, sc->io.base >> 8, 1);
                   pci_write_config(dev, PCIR_IOLIMITL_1, sc->io.limit >> 8, 1);
           }
   
           if (mask & WIN_MEM) {
                   pci_write_config(dev, PCIR_MEMBASE_1, sc->mem.base >> 16, 2);
                   pci_write_config(dev, PCIR_MEMLIMIT_1, sc->mem.limit >> 16, 2);
           }
   
           if (sc->pmem.valid && mask & WIN_PMEM) {
                   val = pci_read_config(dev, PCIR_PMBASEL_1, 2);
                   if ((val & PCIM_BRPM_MASK) == PCIM_BRPM_64) {
                           pci_write_config(dev, PCIR_PMBASEH_1,
                               sc->pmem.base >> 32, 4);
                           pci_write_config(dev, PCIR_PMLIMITH_1,
                               sc->pmem.limit >> 32, 4);
                   }
                   pci_write_config(dev, PCIR_PMBASEL_1, sc->pmem.base >> 16, 2);
                   pci_write_config(dev, PCIR_PMLIMITL_1, sc->pmem.limit >> 16, 2);
           }
   }
   
   /*
    * This is used to reject I/O port allocations that conflict with an
    * ISA alias range.
    */
   static int
   pcib_is_isa_range(struct pcib_softc *sc, rman_res_t start, rman_res_t end,
       rman_res_t count)
   {
           rman_res_t next_alias;
   
           if (!(sc->bridgectl & PCIB_BCR_ISA_ENABLE))
                   return (0);
   
           /* Only check fixed ranges for overlap. */
           if (start + count - 1 != end)
                   return (0);
   
           /* ISA aliases are only in the lower 64KB of I/O space. */
           if (start >= 65536)
                   return (0);
   
           /* Check for overlap with 0x000 - 0x0ff as a special case. */
           if (start < 0x100)
                   goto alias;
   
           /*
            * If the start address is an alias, the range is an alias.
            * Otherwise, compute the start of the next alias range and
            * check if it is before the end of the candidate range.
            */
           if ((start & 0x300) != 0)
                   goto alias;
           next_alias = (start & ~0x3fful) | 0x100;
           if (next_alias <= end)
                   goto alias;
           return (0);
   
   alias:
           if (bootverbose)
                   device_printf(sc->dev,
                       "I/O range %#jx-%#jx overlaps with an ISA alias\n", start,
                       end);
           return (1);
   }
   
   static void
   pcib_add_window_resources(struct pcib_window *w, struct resource **res,
       int count)
   {
           struct resource **newarray;
           int error, i;
   
           newarray = malloc(sizeof(struct resource *) * (w->count + count),
               M_DEVBUF, M_WAITOK);
           if (w->res != NULL)
                   bcopy(w->res, newarray, sizeof(struct resource *) * w->count);
           bcopy(res, newarray + w->count, sizeof(struct resource *) * count);
           free(w->res, M_DEVBUF);
           w->res = newarray;
           w->count += count;
   
           for (i = 0; i < count; i++) {
                   error = rman_manage_region(&w->rman, rman_get_start(res[i]),
                       rman_get_end(res[i]));
                   if (error)
                           panic("Failed to add resource to rman");
           }
   }
   
   typedef void (nonisa_callback)(rman_res_t start, rman_res_t end, void *arg);
   
   static void
   pcib_walk_nonisa_ranges(rman_res_t start, rman_res_t end, nonisa_callback *cb,
       void *arg)
   {
           rman_res_t next_end;
   
           /*
            * If start is within an ISA alias range, move up to the start
            * of the next non-alias range.  As a special case, addresses
            * in the range 0x000 - 0x0ff should also be skipped since
            * those are used for various system I/O devices in ISA
            * systems.
            */
           if (start <= 65535) {
                   if (start < 0x100 || (start & 0x300) != 0) {
                           start &= ~0x3ff;
                           start += 0x400;
                   }
           }
   
           /* ISA aliases are only in the lower 64KB of I/O space. */
           while (start <= MIN(end, 65535)) {
                   next_end = MIN(start | 0xff, end);
                   cb(start, next_end, arg);
                   start += 0x400;
           }
   
           if (start <= end)
                   cb(start, end, arg);
   }
   
   static void
   count_ranges(rman_res_t start, rman_res_t end, void *arg)
   {
           int *countp;
   
           countp = arg;
           (*countp)++;
   }
   
   struct alloc_state {
           struct resource **res;
           struct pcib_softc *sc;
           int count, error;
   };
   
   static void
   alloc_ranges(rman_res_t start, rman_res_t end, void *arg)
   {
           struct alloc_state *as;
           struct pcib_window *w;
           int rid;
   
           as = arg;
           if (as->error != 0)
                   return;
   
           w = &as->sc->io;
           rid = w->reg;
           if (bootverbose)
                   device_printf(as->sc->dev,
                       "allocating non-ISA range %#jx-%#jx\n", start, end);
           as->res[as->count] = bus_alloc_resource(as->sc->dev, SYS_RES_IOPORT,
               &rid, start, end, end - start + 1, 0);
           if (as->res[as->count] == NULL)
                   as->error = ENXIO;
           else
                   as->count++;
   }
   
   static int
   pcib_alloc_nonisa_ranges(struct pcib_softc *sc, rman_res_t start, rman_res_t end)
   {
           struct alloc_state as;
           int i, new_count;
   
           /* First, see how many ranges we need. */
           new_count = 0;
           pcib_walk_nonisa_ranges(start, end, count_ranges, &new_count);
   
           /* Second, allocate the ranges. */
           as.res = malloc(sizeof(struct resource *) * new_count, M_DEVBUF,
               M_WAITOK);
           as.sc = sc;
           as.count = 0;
           as.error = 0;
           pcib_walk_nonisa_ranges(start, end, alloc_ranges, &as);
           if (as.error != 0) {
                   for (i = 0; i < as.count; i++)
                           bus_release_resource(sc->dev, SYS_RES_IOPORT,
                               sc->io.reg, as.res[i]);
                   free(as.res, M_DEVBUF);
                   return (as.error);
           }
           KASSERT(as.count == new_count, ("%s: count mismatch", __func__));
   
           /* Third, add the ranges to the window. */
           pcib_add_window_resources(&sc->io, as.res, as.count);
           free(as.res, M_DEVBUF);
           return (0);
   }
   
   static void
   pcib_alloc_window(struct pcib_softc *sc, struct pcib_window *w, int type,
       int flags, pci_addr_t max_address)
   {
           struct resource *res;
           char buf[64];
           int error, rid;
   
           if (max_address != (rman_res_t)max_address)
                   max_address = ~0;
           w->rman.rm_start = 0;
           w->rman.rm_end = max_address;
           w->rman.rm_type = RMAN_ARRAY;
           snprintf(buf, sizeof(buf), "%s %s window",
               device_get_nameunit(sc->dev), w->name);
           w->rman.rm_descr = strdup(buf, M_DEVBUF);
           error = rman_init(&w->rman);
           if (error)
                   panic("Failed to initialize %s %s rman",
                       device_get_nameunit(sc->dev), w->name);
   
           if (!pcib_is_window_open(w))
                   return;
   
           if (w->base > max_address || w->limit > max_address) {
                   device_printf(sc->dev,
                       "initial %s window has too many bits, ignoring\n", w->name);
                   return;
           }
           if (type == SYS_RES_IOPORT && sc->bridgectl & PCIB_BCR_ISA_ENABLE)
                   (void)pcib_alloc_nonisa_ranges(sc, w->base, w->limit);
           else {
                   rid = w->reg;
                   res = bus_alloc_resource(sc->dev, type, &rid, w->base, w->limit,
                       w->limit - w->base + 1, flags);
                   if (res != NULL)
                           pcib_add_window_resources(w, &res, 1);
           }
           if (w->res == NULL) {
                   device_printf(sc->dev,
                       "failed to allocate initial %s window: %#jx-%#jx\n",
                       w->name, (uintmax_t)w->base, (uintmax_t)w->limit);
                   w->base = max_address;
                   w->limit = 0;
                   pcib_write_windows(sc, w->mask);
                   return;
           }
           pcib_activate_window(sc, type);
   }
   
   /*
    * Initialize I/O windows.
    */
   static void
   pcib_probe_windows(struct pcib_softc *sc)
   {
           pci_addr_t max;
           device_t dev;
           uint32_t val;
   
           dev = sc->dev;
   
           if (pci_clear_pcib) {
                   pcib_bridge_init(dev);
           }
   
           /* Determine if the I/O port window is implemented. */
           val = pci_read_config(dev, PCIR_IOBASEL_1, 1);
           if (val == 0) {
                   /*
                    * If 'val' is zero, then only 16-bits of I/O space
                    * are supported.
                    */
                   pci_write_config(dev, PCIR_IOBASEL_1, 0xff, 1);
                   if (pci_read_config(dev, PCIR_IOBASEL_1, 1) != 0) {
                           sc->io.valid = 1;
                           pci_write_config(dev, PCIR_IOBASEL_1, 0, 1);
                   }
           } else
                   sc->io.valid = 1;
   
           /* Read the existing I/O port window. */
           if (sc->io.valid) {
                   sc->io.reg = PCIR_IOBASEL_1;
                   sc->io.step = 12;
                   sc->io.mask = WIN_IO;
                   sc->io.name = "I/O port";
                   if ((val & PCIM_BRIO_MASK) == PCIM_BRIO_32) {
                           sc->io.base = PCI_PPBIOBASE(
                               pci_read_config(dev, PCIR_IOBASEH_1, 2), val);
                           sc->io.limit = PCI_PPBIOLIMIT(
                               pci_read_config(dev, PCIR_IOLIMITH_1, 2),
                               pci_read_config(dev, PCIR_IOLIMITL_1, 1));
                           max = 0xffffffff;
                   } else {
                           sc->io.base = PCI_PPBIOBASE(0, val);
                           sc->io.limit = PCI_PPBIOLIMIT(0,
                               pci_read_config(dev, PCIR_IOLIMITL_1, 1));
                           max = 0xffff;
                   }
                   pcib_alloc_window(sc, &sc->io, SYS_RES_IOPORT, 0, max);
           }
   
           /* Read the existing memory window. */
           sc->mem.valid = 1;
           sc->mem.reg = PCIR_MEMBASE_1;
           sc->mem.step = 20;
           sc->mem.mask = WIN_MEM;
           sc->mem.name = "memory";
           sc->mem.base = PCI_PPBMEMBASE(0,
               pci_read_config(dev, PCIR_MEMBASE_1, 2));
           sc->mem.limit = PCI_PPBMEMLIMIT(0,
               pci_read_config(dev, PCIR_MEMLIMIT_1, 2));
           pcib_alloc_window(sc, &sc->mem, SYS_RES_MEMORY, 0, 0xffffffff);
   
           /* Determine if the prefetchable memory window is implemented. */
           val = pci_read_config(dev, PCIR_PMBASEL_1, 2);
           if (val == 0) {
                   /*
                    * If 'val' is zero, then only 32-bits of memory space
                    * are supported.
                    */
                   pci_write_config(dev, PCIR_PMBASEL_1, 0xffff, 2);
                   if (pci_read_config(dev, PCIR_PMBASEL_1, 2) != 0) {
                           sc->pmem.valid = 1;
                           pci_write_config(dev, PCIR_PMBASEL_1, 0, 2);
                   }
           } else
                   sc->pmem.valid = 1;
   
           /* Read the existing prefetchable memory window. */
           if (sc->pmem.valid) {
                   sc->pmem.reg = PCIR_PMBASEL_1;
                   sc->pmem.step = 20;
                   sc->pmem.mask = WIN_PMEM;
                   sc->pmem.name = "prefetch";
                   if ((val & PCIM_BRPM_MASK) == PCIM_BRPM_64) {
                           sc->pmem.base = PCI_PPBMEMBASE(
                               pci_read_config(dev, PCIR_PMBASEH_1, 4), val);
                           sc->pmem.limit = PCI_PPBMEMLIMIT(
                               pci_read_config(dev, PCIR_PMLIMITH_1, 4),
                               pci_read_config(dev, PCIR_PMLIMITL_1, 2));
                           max = 0xffffffffffffffff;
                   } else {
                           sc->pmem.base = PCI_PPBMEMBASE(0, val);
                           sc->pmem.limit = PCI_PPBMEMLIMIT(0,
                               pci_read_config(dev, PCIR_PMLIMITL_1, 2));
                           max = 0xffffffff;
                   }
                   pcib_alloc_window(sc, &sc->pmem, SYS_RES_MEMORY,
                       RF_PREFETCHABLE, max);
           }
   }
   
   static void
   pcib_release_window(struct pcib_softc *sc, struct pcib_window *w, int type)
   {
           device_t dev;
           int error, i;
   
           if (!w->valid)
                   return;
   
           dev = sc->dev;
           error = rman_fini(&w->rman);
           if (error) {
                   device_printf(dev, "failed to release %s rman\n", w->name);
                   return;
           }
           free(__DECONST(char *, w->rman.rm_descr), M_DEVBUF);
   
           for (i = 0; i < w->count; i++) {
                   error = bus_free_resource(dev, type, w->res[i]);
                   if (error)
                           device_printf(dev,
                               "failed to release %s resource: %d\n", w->name,
                               error);
           }
           free(w->res, M_DEVBUF);
   }
   
   static void
   pcib_free_windows(struct pcib_softc *sc)
   {
   
           pcib_release_window(sc, &sc->pmem, SYS_RES_MEMORY);
           pcib_release_window(sc, &sc->mem, SYS_RES_MEMORY);
           pcib_release_window(sc, &sc->io, SYS_RES_IOPORT);
   }
   
   #ifdef PCI_RES_BUS
   /*
    * Allocate a suitable secondary bus for this bridge if needed and
    * initialize the resource manager for the secondary bus range.  Note
    * that the minimum count is a desired value and this may allocate a
    * smaller range.
    */
   void
   pcib_setup_secbus(device_t dev, struct pcib_secbus *bus, int min_count)
   {
           char buf[64];
           int error, rid, sec_reg;
   
           switch (pci_read_config(dev, PCIR_HDRTYPE, 1) & PCIM_HDRTYPE) {
           case PCIM_HDRTYPE_BRIDGE:
                   sec_reg = PCIR_SECBUS_1;
                   bus->sub_reg = PCIR_SUBBUS_1;
                   break;
           case PCIM_HDRTYPE_CARDBUS:
                   sec_reg = PCIR_SECBUS_2;
                   bus->sub_reg = PCIR_SUBBUS_2;
                   break;
           default:
                   panic("not a PCI bridge");
           }
           bus->sec = pci_read_config(dev, sec_reg, 1);
           bus->sub = pci_read_config(dev, bus->sub_reg, 1);
           bus->dev = dev;
           bus->rman.rm_start = 0;
           bus->rman.rm_end = PCI_BUSMAX;
           bus->rman.rm_type = RMAN_ARRAY;
           snprintf(buf, sizeof(buf), "%s bus numbers", device_get_nameunit(dev));
           bus->rman.rm_descr = strdup(buf, M_DEVBUF);
           error = rman_init(&bus->rman);
           if (error)
                   panic("Failed to initialize %s bus number rman",
                       device_get_nameunit(dev));
   
           /*
            * Allocate a bus range.  This will return an existing bus range
            * if one exists, or a new bus range if one does not.
            */
           rid = 0;
           bus->res = bus_alloc_resource_anywhere(dev, PCI_RES_BUS, &rid,
               min_count, 0);
           if (bus->res == NULL) {
                   /*
                    * Fall back to just allocating a range of a single bus
                    * number.
                    */
                   bus->res = bus_alloc_resource_anywhere(dev, PCI_RES_BUS, &rid,
                       1, 0);
           } else if (rman_get_size(bus->res) < min_count)
                   /*
                    * Attempt to grow the existing range to satisfy the
                    * minimum desired count.
                    */
                   (void)bus_adjust_resource(dev, PCI_RES_BUS, bus->res,
                       rman_get_start(bus->res), rman_get_start(bus->res) +
                       min_count - 1);
   
           /*
            * Add the initial resource to the rman.
            */
           if (bus->res != NULL) {
                   error = rman_manage_region(&bus->rman, rman_get_start(bus->res),
                       rman_get_end(bus->res));
                   if (error)
                           panic("Failed to add resource to rman");
                   bus->sec = rman_get_start(bus->res);
                   bus->sub = rman_get_end(bus->res);
           }
   }
   
   void
   pcib_free_secbus(device_t dev, struct pcib_secbus *bus)
   {
           int error;
   
           error = rman_fini(&bus->rman);
           if (error) {
                   device_printf(dev, "failed to release bus number rman\n");
                   return;
           }
           free(__DECONST(char *, bus->rman.rm_descr), M_DEVBUF);
   
           error = bus_free_resource(dev, PCI_RES_BUS, bus->res);
           if (error)
                   device_printf(dev,
                       "failed to release bus numbers resource: %d\n", error);
   }
   
   static struct resource *
   pcib_suballoc_bus(struct pcib_secbus *bus, device_t child, int *rid,
       rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
   {
           struct resource *res;
   
           res = rman_reserve_resource(&bus->rman, start, end, count, flags,
               child);
           if (res == NULL)
                   return (NULL);
   
           if (bootverbose)
                   device_printf(bus->dev,
                       "allocated bus range (%ju-%ju) for rid %d of %s\n",
                       rman_get_start(res), rman_get_end(res), *rid,
                       pcib_child_name(child));
           rman_set_rid(res, *rid);
           return (res);
   }
   
   /*
    * Attempt to grow the secondary bus range.  This is much simpler than
    * for I/O windows as the range can only be grown by increasing
    * subbus.
    */
   static int
   pcib_grow_subbus(struct pcib_secbus *bus, rman_res_t new_end)
   {
           rman_res_t old_end;
           int error;
   
           old_end = rman_get_end(bus->res);
           KASSERT(new_end > old_end, ("attempt to shrink subbus"));
           error = bus_adjust_resource(bus->dev, PCI_RES_BUS, bus->res,
               rman_get_start(bus->res), new_end);
           if (error)
                   return (error);
           if (bootverbose)
                   device_printf(bus->dev, "grew bus range to %ju-%ju\n",
                       rman_get_start(bus->res), rman_get_end(bus->res));
           error = rman_manage_region(&bus->rman, old_end + 1,
               rman_get_end(bus->res));
           if (error)
                   panic("Failed to add resource to rman");
           bus->sub = rman_get_end(bus->res);
           pci_write_config(bus->dev, bus->sub_reg, bus->sub, 1);
           return (0);
   }
   
   struct resource *
   pcib_alloc_subbus(struct pcib_secbus *bus, device_t child, int *rid,
       rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
   {
           struct resource *res;
           rman_res_t start_free, end_free, new_end;
   
           /*
            * First, see if the request can be satisified by the existing
            * bus range.
            */
           res = pcib_suballoc_bus(bus, child, rid, start, end, count, flags);
           if (res != NULL)
                   return (res);
   
           /*
            * Figure out a range to grow the bus range.  First, find the
            * first bus number after the last allocated bus in the rman and
            * enforce that as a minimum starting point for the range.
            */
           if (rman_last_free_region(&bus->rman, &start_free, &end_free) != 0 ||
               end_free != bus->sub)
                   start_free = bus->sub + 1;
           if (start_free < start)
                   start_free = start;
           new_end = start_free + count - 1;
   
           /*
            * See if this new range would satisfy the request if it
            * succeeds.
            */
           if (new_end > end)
                   return (NULL);
   
           /* Finally, attempt to grow the existing resource. */
           if (bootverbose) {
                   device_printf(bus->dev,
                       "attempting to grow bus range for %ju buses\n", count);
                   printf("\tback candidate range: %ju-%ju\n", start_free,
                       new_end);
           }
           if (pcib_grow_subbus(bus, new_end) == 0)
                   return (pcib_suballoc_bus(bus, child, rid, start, end, count,
                       flags));
           return (NULL);
   }
   #endif
   
   #else
   
   /*
    * Is the prefetch window open (eg, can we allocate memory in it?)
    */
   static int
   pcib_is_prefetch_open(struct pcib_softc *sc)
   {
           return (sc->pmembase > 0 && sc->pmembase < sc->pmemlimit);
   }
   
   /*
    * Is the nonprefetch window open (eg, can we allocate memory in it?)
    */
   static int
   pcib_is_nonprefetch_open(struct pcib_softc *sc)
   {
           return (sc->membase > 0 && sc->membase < sc->memlimit);
   }
   
   /*
    * Is the io window open (eg, can we allocate ports in it?)
    */
   static int
   pcib_is_io_open(struct pcib_softc *sc)
   {
           return (sc->iobase > 0 && sc->iobase < sc->iolimit);
   }
   
   /*
    * Get current I/O decode.
    */
   static void
   pcib_get_io_decode(struct pcib_softc *sc)
   {
           device_t        dev;
           uint32_t        iolow;
   
           dev = sc->dev;
   
           iolow = pci_read_config(dev, PCIR_IOBASEL_1, 1);
           if ((iolow & PCIM_BRIO_MASK) == PCIM_BRIO_32)
                   sc->iobase = PCI_PPBIOBASE(
                       pci_read_config(dev, PCIR_IOBASEH_1, 2), iolow);
           else
                   sc->iobase = PCI_PPBIOBASE(0, iolow);
   
           iolow = pci_read_config(dev, PCIR_IOLIMITL_1, 1);
           if ((iolow & PCIM_BRIO_MASK) == PCIM_BRIO_32)
                   sc->iolimit = PCI_PPBIOLIMIT(
                       pci_read_config(dev, PCIR_IOLIMITH_1, 2), iolow);
           else
                   sc->iolimit = PCI_PPBIOLIMIT(0, iolow);
   }
   
   /*
    * Get current memory decode.
    */
   static void
   pcib_get_mem_decode(struct pcib_softc *sc)
   {
           device_t        dev;
           pci_addr_t      pmemlow;
   
           dev = sc->dev;
   
           sc->membase = PCI_PPBMEMBASE(0,
               pci_read_config(dev, PCIR_MEMBASE_1, 2));
           sc->memlimit = PCI_PPBMEMLIMIT(0,
               pci_read_config(dev, PCIR_MEMLIMIT_1, 2));
   
           pmemlow = pci_read_config(dev, PCIR_PMBASEL_1, 2);
           if ((pmemlow & PCIM_BRPM_MASK) == PCIM_BRPM_64)
                   sc->pmembase = PCI_PPBMEMBASE(
                       pci_read_config(dev, PCIR_PMBASEH_1, 4), pmemlow);
           else
                   sc->pmembase = PCI_PPBMEMBASE(0, pmemlow);
   
           pmemlow = pci_read_config(dev, PCIR_PMLIMITL_1, 2);
           if ((pmemlow & PCIM_BRPM_MASK) == PCIM_BRPM_64)
                   sc->pmemlimit = PCI_PPBMEMLIMIT(
                       pci_read_config(dev, PCIR_PMLIMITH_1, 4), pmemlow);
           else
                   sc->pmemlimit = PCI_PPBMEMLIMIT(0, pmemlow);
   }
   
   /*
    * Restore previous I/O decode.
    */
   static void
   pcib_set_io_decode(struct pcib_softc *sc)
   {
           device_t        dev;
           uint32_t        iohi;
   
           dev = sc->dev;
   
           iohi = sc->iobase >> 16;
           if (iohi > 0)
                   pci_write_config(dev, PCIR_IOBASEH_1, iohi, 2);
           pci_write_config(dev, PCIR_IOBASEL_1, sc->iobase >> 8, 1);
   
           iohi = sc->iolimit >> 16;
           if (iohi > 0)
                   pci_write_config(dev, PCIR_IOLIMITH_1, iohi, 2);
           pci_write_config(dev, PCIR_IOLIMITL_1, sc->iolimit >> 8, 1);
   }
   
   /*
    * Restore previous memory decode.
    */
   static void
   pcib_set_mem_decode(struct pcib_softc *sc)
   {
           device_t        dev;
           pci_addr_t      pmemhi;
   
           dev = sc->dev;
   
           pci_write_config(dev, PCIR_MEMBASE_1, sc->membase >> 16, 2);
           pci_write_config(dev, PCIR_MEMLIMIT_1, sc->memlimit >> 16, 2);
   
           pmemhi = sc->pmembase >> 32;
           if (pmemhi > 0)
                   pci_write_config(dev, PCIR_PMBASEH_1, pmemhi, 4);
           pci_write_config(dev, PCIR_PMBASEL_1, sc->pmembase >> 16, 2);
   
           pmemhi = sc->pmemlimit >> 32;
           if (pmemhi > 0)
                   pci_write_config(dev, PCIR_PMLIMITH_1, pmemhi, 4);
           pci_write_config(dev, PCIR_PMLIMITL_1, sc->pmemlimit >> 16, 2);
   }
   #endif
   
   #ifdef PCI_HP
   /*
    * PCI-express HotPlug support.
    */
   static int pci_enable_pcie_hp = 1;
   SYSCTL_INT(_hw_pci, OID_AUTO, enable_pcie_hp, CTLFLAG_RDTUN,
       &pci_enable_pcie_hp, 0,
       "Enable support for native PCI-express HotPlug.");
   
   static void
   pcib_probe_hotplug(struct pcib_softc *sc)
   {
           device_t dev;
           uint32_t link_cap;
           uint16_t link_sta, slot_sta;
   
           if (!pci_enable_pcie_hp)
                   return;
   
           dev = sc->dev;
           if (pci_find_cap(dev, PCIY_EXPRESS, NULL) != 0)
                   return;
   
           if (!(pcie_read_config(dev, PCIER_FLAGS, 2) & PCIEM_FLAGS_SLOT))
                   return;
   
           sc->pcie_slot_cap = pcie_read_config(dev, PCIER_SLOT_CAP, 4);
   
           if ((sc->pcie_slot_cap & PCIEM_SLOT_CAP_HPC) == 0)
                   return;
           link_cap = pcie_read_config(dev, PCIER_LINK_CAP, 4);
           if ((link_cap & PCIEM_LINK_CAP_DL_ACTIVE) == 0)
                   return;
   
           /*
            * Some devices report that they have an MRL when they actually
            * do not.  Since they always report that the MRL is open, child
            * devices would be ignored.  Try to detect these devices and
            * ignore their claim of HotPlug support.
            *
            * If there is an open MRL but the Data Link Layer is active,
            * the MRL is not real.
            */
           if ((sc->pcie_slot_cap & PCIEM_SLOT_CAP_MRLSP) != 0) {
                   link_sta = pcie_read_config(dev, PCIER_LINK_STA, 2);
                   slot_sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);
                   if ((slot_sta & PCIEM_SLOT_STA_MRLSS) != 0 &&
                       (link_sta & PCIEM_LINK_STA_DL_ACTIVE) != 0) {
                           return;
                   }
           }
   
           sc->flags |= PCIB_HOTPLUG;
   }
   
   /*
    * Send a HotPlug command to the slot control register.  If this slot
    * uses command completion interrupts and a previous command is still
    * in progress, then the command is dropped.  Once the previous
    * command completes or times out, pcib_pcie_hotplug_update() will be
    * invoked to post a new command based on the slot's state at that
    * time.
    */
   static void
   pcib_pcie_hotplug_command(struct pcib_softc *sc, uint16_t val, uint16_t mask)
   {
           device_t dev;
           uint16_t ctl, new;
   
           dev = sc->dev;
   
           if (sc->flags & PCIB_HOTPLUG_CMD_PENDING)
                   return;
   
           ctl = pcie_read_config(dev, PCIER_SLOT_CTL, 2);
           new = (ctl & ~mask) | val;
           if (new == ctl)
                   return;
           if (bootverbose)
                   device_printf(dev, "HotPlug command: %04x -> %04x\n", ctl, new);
           pcie_write_config(dev, PCIER_SLOT_CTL, new, 2);
           if (!(sc->pcie_slot_cap & PCIEM_SLOT_CAP_NCCS) &&
               (ctl & new) & PCIEM_SLOT_CTL_CCIE) {
                   sc->flags |= PCIB_HOTPLUG_CMD_PENDING;
                   if (!cold)
                           callout_reset(&sc->pcie_cc_timer, hz,
                               pcib_pcie_cc_timeout, sc);
           }
   }
   
   static void
   pcib_pcie_hotplug_command_completed(struct pcib_softc *sc)
  {
          device_t dev;
  
          dev = sc->dev;
  
          if (bootverbose)
                  device_printf(dev, "Command Completed\n");
          if (!(sc->flags & PCIB_HOTPLUG_CMD_PENDING))
                  return;
          callout_stop(&sc->pcie_cc_timer);
          sc->flags &= ~PCIB_HOTPLUG_CMD_PENDING;
          wakeup(sc);
  }
  
  /*
   * Returns true if a card is fully inserted from the user's
   * perspective.  It may not yet be ready for access, but the driver
   * can now start enabling access if necessary.
   */
  static bool
  pcib_hotplug_inserted(struct pcib_softc *sc)
  {
  
          /* Pretend the card isn't present if a detach is forced. */
          if (sc->flags & PCIB_DETACHING)
                  return (false);
  
          /* Card must be present in the slot. */
          if ((sc->pcie_slot_sta & PCIEM_SLOT_STA_PDS) == 0)
                  return (false);
  
          /* A power fault implicitly turns off power to the slot. */
          if (sc->pcie_slot_sta & PCIEM_SLOT_STA_PFD)
                  return (false);
  
          /* If the MRL is disengaged, the slot is powered off. */
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_MRLSP &&
              (sc->pcie_slot_sta & PCIEM_SLOT_STA_MRLSS) != 0)
                  return (false);
  
          return (true);
  }
  
  /*
   * Returns -1 if the card is fully inserted, powered, and ready for
   * access.  Otherwise, returns 0.
   */
  static int
  pcib_hotplug_present(struct pcib_softc *sc)
  {
  
          /* Card must be inserted. */
          if (!pcib_hotplug_inserted(sc))
                  return (0);
  
          /*
           * Require the Electromechanical Interlock to be engaged if
           * present.
           */
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_EIP &&
              (sc->pcie_slot_sta & PCIEM_SLOT_STA_EIS) == 0)
                  return (0);
  
          /* Require the Data Link Layer to be active. */
          if (!(sc->pcie_link_sta & PCIEM_LINK_STA_DL_ACTIVE))
                  return (0);
  
          return (-1);
  }
  
  static void
  pcib_pcie_hotplug_update(struct pcib_softc *sc, uint16_t val, uint16_t mask,
      bool schedule_task)
  {
          bool card_inserted, ei_engaged;
  
          /* Clear DETACHING if Presence Detect has cleared. */
          if ((sc->pcie_slot_sta & (PCIEM_SLOT_STA_PDC | PCIEM_SLOT_STA_PDS)) ==
              PCIEM_SLOT_STA_PDC)
                  sc->flags &= ~PCIB_DETACHING;
  
          card_inserted = pcib_hotplug_inserted(sc);
  
          /* Turn the power indicator on if a card is inserted. */
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_PIP) {
                  mask |= PCIEM_SLOT_CTL_PIC;
                  if (card_inserted)
                          val |= PCIEM_SLOT_CTL_PI_ON;
                  else if (sc->flags & PCIB_DETACH_PENDING)
                          val |= PCIEM_SLOT_CTL_PI_BLINK;
                  else
                          val |= PCIEM_SLOT_CTL_PI_OFF;
          }
  
          /* Turn the power on via the Power Controller if a card is inserted. */
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_PCP) {
                  mask |= PCIEM_SLOT_CTL_PCC;
                  if (card_inserted)
                          val |= PCIEM_SLOT_CTL_PC_ON;
                  else
                          val |= PCIEM_SLOT_CTL_PC_OFF;
          }
  
          /*
           * If a card is inserted, enable the Electromechanical
           * Interlock.  If a card is not inserted (or we are in the
           * process of detaching), disable the Electromechanical
           * Interlock.
           */
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_EIP) {
                  mask |= PCIEM_SLOT_CTL_EIC;
                  ei_engaged = (sc->pcie_slot_sta & PCIEM_SLOT_STA_EIS) != 0;
                  if (card_inserted != ei_engaged)
                          val |= PCIEM_SLOT_CTL_EIC;
          }
  
          /*
           * Start a timer to see if the Data Link Layer times out.
           * Note that we only start the timer if Presence Detect or MRL Sensor
           * changed on this interrupt.  Stop any scheduled timer if
           * the Data Link Layer is active.
           */
          if (card_inserted &&
              !(sc->pcie_link_sta & PCIEM_LINK_STA_DL_ACTIVE) &&
              sc->pcie_slot_sta &
              (PCIEM_SLOT_STA_MRLSC | PCIEM_SLOT_STA_PDC)) {
                  if (cold)
                          device_printf(sc->dev,
                              "Data Link Layer inactive\n");
                  else
                          callout_reset(&sc->pcie_dll_timer, hz,
                              pcib_pcie_dll_timeout, sc);
          } else if (sc->pcie_link_sta & PCIEM_LINK_STA_DL_ACTIVE)
                  callout_stop(&sc->pcie_dll_timer);
  
          pcib_pcie_hotplug_command(sc, val, mask);
  
          /*
           * During attach the child "pci" device is added synchronously;
           * otherwise, the task is scheduled to manage the child
           * device.
           */
          if (schedule_task &&
              (pcib_hotplug_present(sc) != 0) != (sc->child != NULL))
                  taskqueue_enqueue(taskqueue_thread, &sc->pcie_hp_task);
  }
  
  static void
  pcib_pcie_intr(void *arg)
  {
          struct pcib_softc *sc;
          device_t dev;
  
          sc = arg;
          dev = sc->dev;
          sc->pcie_slot_sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);
  
          /* Clear the events just reported. */
          pcie_write_config(dev, PCIER_SLOT_STA, sc->pcie_slot_sta, 2);
  
          if (bootverbose)
                  device_printf(dev, "HotPlug interrupt: %#x\n",
                      sc->pcie_slot_sta);
  
          if (sc->pcie_slot_sta & PCIEM_SLOT_STA_ABP) {
                  if (sc->flags & PCIB_DETACH_PENDING) {  
                          device_printf(dev,
                              "Attention Button Pressed: Detach Cancelled\n");
                          sc->flags &= ~PCIB_DETACH_PENDING;
                          callout_stop(&sc->pcie_ab_timer);
                  } else {
                          device_printf(dev,
                      "Attention Button Pressed: Detaching in 5 seconds\n");
                          sc->flags |= PCIB_DETACH_PENDING;
                          callout_reset(&sc->pcie_ab_timer, 5 * hz,
                              pcib_pcie_ab_timeout, sc);
                  }
          }
          if (sc->pcie_slot_sta & PCIEM_SLOT_STA_PFD)
                  device_printf(dev, "Power Fault Detected\n");
          if (sc->pcie_slot_sta & PCIEM_SLOT_STA_MRLSC)
                  device_printf(dev, "MRL Sensor Changed to %s\n",
                      sc->pcie_slot_sta & PCIEM_SLOT_STA_MRLSS ? "open" :
                      "closed");
          if (bootverbose && sc->pcie_slot_sta & PCIEM_SLOT_STA_PDC)
                  device_printf(dev, "Presence Detect Changed to %s\n",
                      sc->pcie_slot_sta & PCIEM_SLOT_STA_PDS ? "card present" :
                      "empty");
          if (sc->pcie_slot_sta & PCIEM_SLOT_STA_CC)
                  pcib_pcie_hotplug_command_completed(sc);
          if (sc->pcie_slot_sta & PCIEM_SLOT_STA_DLLSC) {
                  sc->pcie_link_sta = pcie_read_config(dev, PCIER_LINK_STA, 2);
                  if (bootverbose)
                          device_printf(dev,
                              "Data Link Layer State Changed to %s\n",
                              sc->pcie_link_sta & PCIEM_LINK_STA_DL_ACTIVE ?
                              "active" : "inactive");
          }
  
          pcib_pcie_hotplug_update(sc, 0, 0, true);
  }
  
  static void
  pcib_pcie_hotplug_task(void *context, int pending)
  {
          struct pcib_softc *sc;
          device_t dev;
  
          sc = context;
          mtx_lock(&Giant);
          dev = sc->dev;
          if (pcib_hotplug_present(sc) != 0) {
                  if (sc->child == NULL) {
                          sc->child = device_add_child(dev, "pci", -1);
                          bus_generic_attach(dev);
                  }
          } else {
                  if (sc->child != NULL) {
                          if (device_delete_child(dev, sc->child) == 0)
                                  sc->child = NULL;
                  }
          }
          mtx_unlock(&Giant);
  }
  
  static void
  pcib_pcie_ab_timeout(void *arg)
  {
          struct pcib_softc *sc;
          device_t dev;
  
          sc = arg;
          dev = sc->dev;
          mtx_assert(&Giant, MA_OWNED);
          if (sc->flags & PCIB_DETACH_PENDING) {
                  sc->flags |= PCIB_DETACHING;
                  sc->flags &= ~PCIB_DETACH_PENDING;
                  pcib_pcie_hotplug_update(sc, 0, 0, true);
          }
  }
  
  static void
  pcib_pcie_cc_timeout(void *arg)
  {
          struct pcib_softc *sc;
          device_t dev;
          uint16_t sta;
  
          sc = arg;
          dev = sc->dev;
          mtx_assert(&Giant, MA_OWNED);
          sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);
          if (!(sta & PCIEM_SLOT_STA_CC)) {
                  device_printf(dev,
                      "HotPlug Command Timed Out - forcing detach\n");
                  sc->flags &= ~(PCIB_HOTPLUG_CMD_PENDING | PCIB_DETACH_PENDING);
                  sc->flags |= PCIB_DETACHING;
                  pcib_pcie_hotplug_update(sc, 0, 0, true);
          } else {
                  device_printf(dev,
              "Missed HotPlug interrupt waiting for Command Completion\n");
                  pcib_pcie_intr(sc);
          }
  }
  
  static void
  pcib_pcie_dll_timeout(void *arg)
  {
          struct pcib_softc *sc;
          device_t dev;
          uint16_t sta;
  
          sc = arg;
          dev = sc->dev;
          mtx_assert(&Giant, MA_OWNED);
          sta = pcie_read_config(dev, PCIER_LINK_STA, 2);
          if (!(sta & PCIEM_LINK_STA_DL_ACTIVE)) {
                  device_printf(dev,
                      "Timed out waiting for Data Link Layer Active\n");
                  sc->flags |= PCIB_DETACHING;
                  pcib_pcie_hotplug_update(sc, 0, 0, true);
          } else if (sta != sc->pcie_link_sta) {
                  device_printf(dev,
                      "Missed HotPlug interrupt waiting for DLL Active\n");
                  pcib_pcie_intr(sc);
          }
  }
  
  static int
  pcib_alloc_pcie_irq(struct pcib_softc *sc)
  {
          device_t dev;
          int count, error, rid;
  
          rid = -1;
          dev = sc->dev;
  
          /*
           * For simplicity, only use MSI-X if there is a single message.
           * To support a device with multiple messages we would have to
           * use remap intr if the MSI number is not 0.
           */
          count = pci_msix_count(dev);
          if (count == 1) {
                  error = pci_alloc_msix(dev, &count);
                  if (error == 0)
                          rid = 1;
          }
  
          if (rid < 0 && pci_msi_count(dev) > 0) {
                  count = 1;
                  error = pci_alloc_msi(dev, &count);
                  if (error == 0)
                          rid = 1;
          }
  
          if (rid < 0)
                  rid = 0;
  
          sc->pcie_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
              RF_ACTIVE);
          if (sc->pcie_irq == NULL) {
                  device_printf(dev,
                      "Failed to allocate interrupt for PCI-e events\n");
                  if (rid > 0)
                          pci_release_msi(dev);
                  return (ENXIO);
          }
  
          error = bus_setup_intr(dev, sc->pcie_irq, INTR_TYPE_MISC,
              NULL, pcib_pcie_intr, sc, &sc->pcie_ihand);
          if (error) {
                  device_printf(dev, "Failed to setup PCI-e interrupt handler\n");
                  bus_release_resource(dev, SYS_RES_IRQ, rid, sc->pcie_irq);
                  if (rid > 0)
                          pci_release_msi(dev);
                  return (error);
          }
          return (0);
  }
  
  static int
  pcib_release_pcie_irq(struct pcib_softc *sc)
  {
          device_t dev;
          int error;
  
          dev = sc->dev;
          error = bus_teardown_intr(dev, sc->pcie_irq, sc->pcie_ihand);
          if (error)
                  return (error);
          error = bus_free_resource(dev, SYS_RES_IRQ, sc->pcie_irq);
          if (error)
                  return (error);
          return (pci_release_msi(dev));
  }
  
  static void
  pcib_setup_hotplug(struct pcib_softc *sc)
  {
          device_t dev;
          uint16_t mask, val;
  
          dev = sc->dev;
          callout_init(&sc->pcie_ab_timer, 0);
          callout_init(&sc->pcie_cc_timer, 0);
          callout_init(&sc->pcie_dll_timer, 0);
          TASK_INIT(&sc->pcie_hp_task, 0, pcib_pcie_hotplug_task, sc);
  
          /* Allocate IRQ. */
          if (pcib_alloc_pcie_irq(sc) != 0)
                  return;
  
          sc->pcie_link_sta = pcie_read_config(dev, PCIER_LINK_STA, 2);
          sc->pcie_slot_sta = pcie_read_config(dev, PCIER_SLOT_STA, 2);
  
          /* Clear any events previously pending. */
          pcie_write_config(dev, PCIER_SLOT_STA, sc->pcie_slot_sta, 2);
  
          /* Enable HotPlug events. */
          mask = PCIEM_SLOT_CTL_DLLSCE | PCIEM_SLOT_CTL_HPIE |
              PCIEM_SLOT_CTL_CCIE | PCIEM_SLOT_CTL_PDCE | PCIEM_SLOT_CTL_MRLSCE |
              PCIEM_SLOT_CTL_PFDE | PCIEM_SLOT_CTL_ABPE;
          val = PCIEM_SLOT_CTL_DLLSCE | PCIEM_SLOT_CTL_HPIE | PCIEM_SLOT_CTL_PDCE;
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_APB)
                  val |= PCIEM_SLOT_CTL_ABPE;
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_PCP)
                  val |= PCIEM_SLOT_CTL_PFDE;
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_MRLSP)
                  val |= PCIEM_SLOT_CTL_MRLSCE;
          if (!(sc->pcie_slot_cap & PCIEM_SLOT_CAP_NCCS))
                  val |= PCIEM_SLOT_CTL_CCIE;
  
          /* Turn the attention indicator off. */
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_AIP) {
                  mask |= PCIEM_SLOT_CTL_AIC;
                  val |= PCIEM_SLOT_CTL_AI_OFF;
          }
  
          pcib_pcie_hotplug_update(sc, val, mask, false);
  }
  
  static int
  pcib_detach_hotplug(struct pcib_softc *sc)
  {
          uint16_t mask, val;
          int error;
  
          /* Disable the card in the slot and force it to detach. */
          if (sc->flags & PCIB_DETACH_PENDING) {
                  sc->flags &= ~PCIB_DETACH_PENDING;
                  callout_stop(&sc->pcie_ab_timer);
          }
          sc->flags |= PCIB_DETACHING;
  
          if (sc->flags & PCIB_HOTPLUG_CMD_PENDING) {
                  callout_stop(&sc->pcie_cc_timer);
                  tsleep(sc, 0, "hpcmd", hz);
                  sc->flags &= ~PCIB_HOTPLUG_CMD_PENDING;
          }
  
          /* Disable HotPlug events. */
          mask = PCIEM_SLOT_CTL_DLLSCE | PCIEM_SLOT_CTL_HPIE |
              PCIEM_SLOT_CTL_CCIE | PCIEM_SLOT_CTL_PDCE | PCIEM_SLOT_CTL_MRLSCE |
              PCIEM_SLOT_CTL_PFDE | PCIEM_SLOT_CTL_ABPE;
          val = 0;
  
          /* Turn the attention indicator off. */
          if (sc->pcie_slot_cap & PCIEM_SLOT_CAP_AIP) {
                  mask |= PCIEM_SLOT_CTL_AIC;
                  val |= PCIEM_SLOT_CTL_AI_OFF;
          }
  
          pcib_pcie_hotplug_update(sc, val, mask, false);
          
          error = pcib_release_pcie_irq(sc);
          if (error)
                  return (error);
          taskqueue_drain(taskqueue_thread, &sc->pcie_hp_task);
          callout_drain(&sc->pcie_ab_timer);
          callout_drain(&sc->pcie_cc_timer);
          callout_drain(&sc->pcie_dll_timer);
          return (0);
  }
  #endif
  
  /*
   * Get current bridge configuration.
   */
  static void
  pcib_cfg_save(struct pcib_softc *sc)
  {
  #ifndef NEW_PCIB
          device_t        dev;
          uint16_t command;
  
          dev = sc->dev;
  
          command = pci_read_config(dev, PCIR_COMMAND, 2);
          if (command & PCIM_CMD_PORTEN)
                  pcib_get_io_decode(sc);
          if (command & PCIM_CMD_MEMEN)
                  pcib_get_mem_decode(sc);
  #endif
  }
  
  /*
   * Restore previous bridge configuration.
   */
  static void
  pcib_cfg_restore(struct pcib_softc *sc)
  {
          device_t        dev;
  #ifndef NEW_PCIB
          uint16_t command;
  #endif
          dev = sc->dev;
  
  #ifdef NEW_PCIB
          pcib_write_windows(sc, WIN_IO | WIN_MEM | WIN_PMEM);
  #else
          command = pci_read_config(dev, PCIR_COMMAND, 2);
          if (command & PCIM_CMD_PORTEN)
                  pcib_set_io_decode(sc);
          if (command & PCIM_CMD_MEMEN)
                  pcib_set_mem_decode(sc);
  #endif
  }
  
  /*
   * Generic device interface
   */
  static int
  pcib_probe(device_t dev)
  {
      if ((pci_get_class(dev) == PCIC_BRIDGE) &&
          (pci_get_subclass(dev) == PCIS_BRIDGE_PCI)) {
          device_set_desc(dev, "PCI-PCI bridge");
          return(-10000);
      }
      return(ENXIO);
  }
  
  void
  pcib_attach_common(device_t dev)
  {
      struct pcib_softc   *sc;
      struct sysctl_ctx_list *sctx;
      struct sysctl_oid   *soid;
      int comma;
  
      sc = device_get_softc(dev);
      sc->dev = dev;
  
      /*
       * Get current bridge configuration.
       */
      sc->domain = pci_get_domain(dev);
  #if !(defined(NEW_PCIB) && defined(PCI_RES_BUS))
      sc->bus.sec = pci_read_config(dev, PCIR_SECBUS_1, 1);
      sc->bus.sub = pci_read_config(dev, PCIR_SUBBUS_1, 1);
  #endif
      sc->bridgectl = pci_read_config(dev, PCIR_BRIDGECTL_1, 2);
      pcib_cfg_save(sc);
  
      /*
       * The primary bus register should always be the bus of the
       * parent.
       */
      sc->pribus = pci_get_bus(dev);
      pci_write_config(dev, PCIR_PRIBUS_1, sc->pribus, 1);
  
      /*
       * Setup sysctl reporting nodes
       */
      sctx = device_get_sysctl_ctx(dev);
      soid = device_get_sysctl_tree(dev);
      SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "domain",
        CTLFLAG_RD, &sc->domain, 0, "Domain number");
      SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "pribus",
        CTLFLAG_RD, &sc->pribus, 0, "Primary bus number");
      SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "secbus",
        CTLFLAG_RD, &sc->bus.sec, 0, "Secondary bus number");
      SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "subbus",
        CTLFLAG_RD, &sc->bus.sub, 0, "Subordinate bus number");
  
      /*
       * Quirk handling.
       */
      switch (pci_get_devid(dev)) {
  #if !(defined(NEW_PCIB) && defined(PCI_RES_BUS))
      case 0x12258086:            /* Intel 82454KX/GX (Orion) */
          {
              uint8_t     supbus;
  
              supbus = pci_read_config(dev, 0x41, 1);
              if (supbus != 0xff) {
                  sc->bus.sec = supbus + 1;
                  sc->bus.sub = supbus + 1;
              }
              break;
          }
  #endif
  
      /*
       * The i82380FB mobile docking controller is a PCI-PCI bridge,
       * and it is a subtractive bridge.  However, the ProgIf is wrong
       * so the normal setting of PCIB_SUBTRACTIVE bit doesn't
       * happen.  There are also Toshiba and Cavium ThunderX bridges
       * that behave this way.
       */
      case 0xa002177d:            /* Cavium ThunderX */
      case 0x124b8086:            /* Intel 82380FB Mobile */
      case 0x060513d7:            /* Toshiba ???? */
          sc->flags |= PCIB_SUBTRACTIVE;
          break;
  
  #if !(defined(NEW_PCIB) && defined(PCI_RES_BUS))
      /* Compaq R3000 BIOS sets wrong subordinate bus number. */
      case 0x00dd10de:
          {
              char *cp;
  
              if ((cp = kern_getenv("smbios.planar.maker")) == NULL)
                  break;
              if (strncmp(cp, "Compal", 6) != 0) {
                  freeenv(cp);
                  break;
              }
              freeenv(cp);
              if ((cp = kern_getenv("smbios.planar.product")) == NULL)
                  break;
              if (strncmp(cp, "08A0", 4) != 0) {
                  freeenv(cp);
                  break;
              }
              freeenv(cp);
              if (sc->bus.sub < 0xa) {
                  pci_write_config(dev, PCIR_SUBBUS_1, 0xa, 1);
                  sc->bus.sub = pci_read_config(dev, PCIR_SUBBUS_1, 1);
              }
              break;
          }
  #endif
      }
  
      if (pci_msi_device_blacklisted(dev))
          sc->flags |= PCIB_DISABLE_MSI;
  
      if (pci_msix_device_blacklisted(dev))
          sc->flags |= PCIB_DISABLE_MSIX;
  
      /*
       * Intel 815, 845 and other chipsets say they are PCI-PCI bridges,
       * but have a ProgIF of 0x80.  The 82801 family (AA, AB, BAM/CAM,
       * BA/CA/DB and E) PCI bridges are HUB-PCI bridges, in Intelese.
       * This means they act as if they were subtractively decoding
       * bridges and pass all transactions.  Mark them and real ProgIf 1
       * parts as subtractive.
       */
      if ((pci_get_devid(dev) & 0xff00ffff) == 0x24008086 ||
        pci_read_config(dev, PCIR_PROGIF, 1) == PCIP_BRIDGE_PCI_SUBTRACTIVE)
          sc->flags |= PCIB_SUBTRACTIVE;
  
  #ifdef PCI_HP
      pcib_probe_hotplug(sc);
  #endif
  #ifdef NEW_PCIB
  #ifdef PCI_RES_BUS
      pcib_setup_secbus(dev, &sc->bus, 1);
  #endif
      pcib_probe_windows(sc);
  #endif
  #ifdef PCI_HP
      if (sc->flags & PCIB_HOTPLUG)
              pcib_setup_hotplug(sc);
  #endif
      if (bootverbose) {
          device_printf(dev, "  domain            %d\n", sc->domain);
          device_printf(dev, "  secondary bus     %d\n", sc->bus.sec);
          device_printf(dev, "  subordinate bus   %d\n", sc->bus.sub);
  #ifdef NEW_PCIB
          if (pcib_is_window_open(&sc->io))
              device_printf(dev, "  I/O decode        0x%jx-0x%jx\n",
                (uintmax_t)sc->io.base, (uintmax_t)sc->io.limit);
          if (pcib_is_window_open(&sc->mem))
              device_printf(dev, "  memory decode     0x%jx-0x%jx\n",
                (uintmax_t)sc->mem.base, (uintmax_t)sc->mem.limit);
          if (pcib_is_window_open(&sc->pmem))
              device_printf(dev, "  prefetched decode 0x%jx-0x%jx\n",
                (uintmax_t)sc->pmem.base, (uintmax_t)sc->pmem.limit);
  #else
          if (pcib_is_io_open(sc))
              device_printf(dev, "  I/O decode        0x%x-0x%x\n",
                sc->iobase, sc->iolimit);
          if (pcib_is_nonprefetch_open(sc))
              device_printf(dev, "  memory decode     0x%jx-0x%jx\n",
                (uintmax_t)sc->membase, (uintmax_t)sc->memlimit);
          if (pcib_is_prefetch_open(sc))
              device_printf(dev, "  prefetched decode 0x%jx-0x%jx\n",
                (uintmax_t)sc->pmembase, (uintmax_t)sc->pmemlimit);
  #endif
          if (sc->bridgectl & (PCIB_BCR_ISA_ENABLE | PCIB_BCR_VGA_ENABLE) ||
              sc->flags & PCIB_SUBTRACTIVE) {
                  device_printf(dev, "  special decode    ");
                  comma = 0;
                  if (sc->bridgectl & PCIB_BCR_ISA_ENABLE) {
                          printf("ISA");
                          comma = 1;
                  }
                  if (sc->bridgectl & PCIB_BCR_VGA_ENABLE) {
                          printf("%sVGA", comma ? ", " : "");
                          comma = 1;
                  }
                  if (sc->flags & PCIB_SUBTRACTIVE)
                          printf("%ssubtractive", comma ? ", " : "");
                  printf("\n");
          }
      }
  
      /*
       * Always enable busmastering on bridges so that transactions
       * initiated on the secondary bus are passed through to the
       * primary bus.
       */
      pci_enable_busmaster(dev);
  }
  
  #ifdef PCI_HP
  static int
  pcib_present(struct pcib_softc *sc)
  {
  
          if (sc->flags & PCIB_HOTPLUG)
                  return (pcib_hotplug_present(sc) != 0);
          return (1);
  }
  #endif
  
  int
  pcib_attach_child(device_t dev)
  {
          struct pcib_softc *sc;
  
          sc = device_get_softc(dev);
          if (sc->bus.sec == 0) {
                  /* no secondary bus; we should have fixed this */
                  return(0);
          }
  
  #ifdef PCI_HP
          if (!pcib_present(sc)) {
                  /* An empty HotPlug slot, so don't add a PCI bus yet. */
                  return (0);
          }
  #endif
  
          sc->child = device_add_child(dev, "pci", -1);
          return (bus_generic_attach(dev));
  }
  
  int
  pcib_attach(device_t dev)
  {
  
      pcib_attach_common(dev);
      return (pcib_attach_child(dev));
  }
  
  int
  pcib_detach(device_t dev)
  {
  #if defined(PCI_HP) || defined(NEW_PCIB)
          struct pcib_softc *sc;
  #endif
          int error;
  
  #if defined(PCI_HP) || defined(NEW_PCIB)
          sc = device_get_softc(dev);
  #endif
          error = bus_generic_detach(dev);
          if (error)
                  return (error);
  #ifdef PCI_HP
          if (sc->flags & PCIB_HOTPLUG) {
                  error = pcib_detach_hotplug(sc);
                  if (error)
                          return (error);
          }
  #endif
          error = device_delete_children(dev);
          if (error)
                  return (error);
  #ifdef NEW_PCIB
          pcib_free_windows(sc);
  #ifdef PCI_RES_BUS
          pcib_free_secbus(dev, &sc->bus);
  #endif
  #endif
          return (0);
  }
  
  int
  pcib_suspend(device_t dev)
  {
  
          pcib_cfg_save(device_get_softc(dev));
          return (bus_generic_suspend(dev));
  }
  
  int
  pcib_resume(device_t dev)
  {
  
          pcib_cfg_restore(device_get_softc(dev));
          return (bus_generic_resume(dev));
  }
  
  void
  pcib_bridge_init(device_t dev)
  {
          pci_write_config(dev, PCIR_IOBASEL_1, 0xff, 1);
          pci_write_config(dev, PCIR_IOBASEH_1, 0xffff, 2);
          pci_write_config(dev, PCIR_IOLIMITL_1, 0, 1);
          pci_write_config(dev, PCIR_IOLIMITH_1, 0, 2);
          pci_write_config(dev, PCIR_MEMBASE_1, 0xffff, 2);
          pci_write_config(dev, PCIR_MEMLIMIT_1, 0, 2);
          pci_write_config(dev, PCIR_PMBASEL_1, 0xffff, 2);
          pci_write_config(dev, PCIR_PMBASEH_1, 0xffffffff, 4);
          pci_write_config(dev, PCIR_PMLIMITL_1, 0, 2);
          pci_write_config(dev, PCIR_PMLIMITH_1, 0, 4);
  }
  
  int
  pcib_child_present(device_t dev, device_t child)
  {
  #ifdef PCI_HP
          struct pcib_softc *sc = device_get_softc(dev);
          int retval;
  
          retval = bus_child_present(dev);
          if (retval != 0 && sc->flags & PCIB_HOTPLUG)
                  retval = pcib_hotplug_present(sc);
          return (retval);
  #else
          return (bus_child_present(dev));
  #endif
  }
  
  int
  pcib_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
  {
      struct pcib_softc   *sc = device_get_softc(dev);
  
      switch (which) {
      case PCIB_IVAR_DOMAIN:
          *result = sc->domain;
          return(0);
      case PCIB_IVAR_BUS:
          *result = sc->bus.sec;
          return(0);
      }
      return(ENOENT);
  }
  
  int
  pcib_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
  {
  
      switch (which) {
      case PCIB_IVAR_DOMAIN:
          return(EINVAL);
      case PCIB_IVAR_BUS:
          return(EINVAL);
      }
      return(ENOENT);
  }
  
  #ifdef NEW_PCIB
  /*
   * Attempt to allocate a resource from the existing resources assigned
   * to a window.
   */
  static struct resource *
  pcib_suballoc_resource(struct pcib_softc *sc, struct pcib_window *w,
      device_t child, int type, int *rid, rman_res_t start, rman_res_t end,
      rman_res_t count, u_int flags)
  {
          struct resource *res;
  
          if (!pcib_is_window_open(w))
                  return (NULL);
  
          res = rman_reserve_resource(&w->rman, start, end, count,
              flags & ~RF_ACTIVE, child);
          if (res == NULL)
                  return (NULL);
  
          if (bootverbose)
                  device_printf(sc->dev,
                      "allocated %s range (%#jx-%#jx) for rid %x of %s\n",
                      w->name, rman_get_start(res), rman_get_end(res), *rid,
                      pcib_child_name(child));
          rman_set_rid(res, *rid);
  
          /*
           * If the resource should be active, pass that request up the
           * tree.  This assumes the parent drivers can handle
           * activating sub-allocated resources.
           */
          if (flags & RF_ACTIVE) {
                  if (bus_activate_resource(child, type, *rid, res) != 0) {
                          rman_release_resource(res);
                          return (NULL);
                  }
          }
  
          return (res);
  }
  
  /* Allocate a fresh resource range for an unconfigured window. */
  static int
  pcib_alloc_new_window(struct pcib_softc *sc, struct pcib_window *w, int type,
      rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
  {
          struct resource *res;
          rman_res_t base, limit, wmask;
          int rid;
  
          /*
           * If this is an I/O window on a bridge with ISA enable set
           * and the start address is below 64k, then try to allocate an
           * initial window of 0x1000 bytes long starting at address
           * 0xf000 and walking down.  Note that if the original request
           * was larger than the non-aliased range size of 0x100 our
           * caller would have raised the start address up to 64k
           * already.
           */
          if (type == SYS_RES_IOPORT && sc->bridgectl & PCIB_BCR_ISA_ENABLE &&
              start < 65536) {
                  for (base = 0xf000; (long)base >= 0; base -= 0x1000) {
                          limit = base + 0xfff;
  
                          /*
                           * Skip ranges that wouldn't work for the
                           * original request.  Note that the actual
                           * window that overlaps are the non-alias
                           * ranges within [base, limit], so this isn't
                           * quite a simple comparison.
                           */
                          if (start + count > limit - 0x400)
                                  continue;
                          if (base == 0) {
                                  /*
                                   * The first open region for the window at
                                   * 0 is 0x400-0x4ff.
                                   */
                                  if (end - count + 1 < 0x400)
                                          continue;
                          } else {
                                  if (end - count + 1 < base)
                                          continue;
                          }
  
                          if (pcib_alloc_nonisa_ranges(sc, base, limit) == 0) {
                                  w->base = base;
                                  w->limit = limit;
                                  return (0);
                          }
                  }
                  return (ENOSPC);
          }
  
          wmask = ((rman_res_t)1 << w->step) - 1;
          if (RF_ALIGNMENT(flags) < w->step) {
                  flags &= ~RF_ALIGNMENT_MASK;
                  flags |= RF_ALIGNMENT_LOG2(w->step);
          }
          start &= ~wmask;
          end |= wmask;
          count = roundup2(count, (rman_res_t)1 << w->step);
          rid = w->reg;
          res = bus_alloc_resource(sc->dev, type, &rid, start, end, count,
              flags & ~RF_ACTIVE);
          if (res == NULL)
                  return (ENOSPC);
          pcib_add_window_resources(w, &res, 1);
          pcib_activate_window(sc, type);
          w->base = rman_get_start(res);
          w->limit = rman_get_end(res);
          return (0);
  }
  
  /* Try to expand an existing window to the requested base and limit. */
  static int
  pcib_expand_window(struct pcib_softc *sc, struct pcib_window *w, int type,
      rman_res_t base, rman_res_t limit)
  {
          struct resource *res;
          int error, i, force_64k_base;
  
          KASSERT(base <= w->base && limit >= w->limit,
              ("attempting to shrink window"));
  
          /*
           * XXX: pcib_grow_window() doesn't try to do this anyway and
           * the error handling for all the edge cases would be tedious.
           */
          KASSERT(limit == w->limit || base == w->base,
              ("attempting to grow both ends of a window"));
  
          /*
           * Yet more special handling for requests to expand an I/O
           * window behind an ISA-enabled bridge.  Since I/O windows
           * have to grow in 0x1000 increments and the end of the 0xffff
           * range is an alias, growing a window below 64k will always
           * result in allocating new resources and never adjusting an
           * existing resource.
           */
          if (type == SYS_RES_IOPORT && sc->bridgectl & PCIB_BCR_ISA_ENABLE &&
              (limit <= 65535 || (base <= 65535 && base != w->base))) {
                  KASSERT(limit == w->limit || limit <= 65535,
                      ("attempting to grow both ends across 64k ISA alias"));
  
                  if (base != w->base)
                          error = pcib_alloc_nonisa_ranges(sc, base, w->base - 1);
                  else
                          error = pcib_alloc_nonisa_ranges(sc, w->limit + 1,
                              limit);
                  if (error == 0) {
                          w->base = base;
                          w->limit = limit;
                  }
                  return (error);
          }
  
          /*
           * Find the existing resource to adjust.  Usually there is only one,
           * but for an ISA-enabled bridge we might be growing the I/O window
           * above 64k and need to find the existing resource that maps all
           * of the area above 64k.
           */
          for (i = 0; i < w->count; i++) {
                  if (rman_get_end(w->res[i]) == w->limit)
                          break;
          }
          KASSERT(i != w->count, ("did not find existing resource"));
          res = w->res[i];
  
          /*
           * Usually the resource we found should match the window's
           * existing range.  The one exception is the ISA-enabled case
           * mentioned above in which case the resource should start at
           * 64k.
           */
          if (type == SYS_RES_IOPORT && sc->bridgectl & PCIB_BCR_ISA_ENABLE &&
              w->base <= 65535) {
                  KASSERT(rman_get_start(res) == 65536,
                      ("existing resource mismatch"));
                  force_64k_base = 1;
          } else {
                  KASSERT(w->base == rman_get_start(res),
                      ("existing resource mismatch"));
                  force_64k_base = 0;
          }
  
          error = bus_adjust_resource(sc->dev, type, res, force_64k_base ?
              rman_get_start(res) : base, limit);
          if (error)
                  return (error);
  
          /* Add the newly allocated region to the resource manager. */
          if (w->base != base) {
                  error = rman_manage_region(&w->rman, base, w->base - 1);
                  w->base = base;
          } else {
                  error = rman_manage_region(&w->rman, w->limit + 1, limit);
                  w->limit = limit;
          }
          if (error) {
                  if (bootverbose)
                          device_printf(sc->dev,
                              "failed to expand %s resource manager\n", w->name);
                  (void)bus_adjust_resource(sc->dev, type, res, force_64k_base ?
                      rman_get_start(res) : w->base, w->limit);
          }
          return (error);
  }
  
  /*
   * Attempt to grow a window to make room for a given resource request.
   */
  static int
  pcib_grow_window(struct pcib_softc *sc, struct pcib_window *w, int type,
      rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
  {
          rman_res_t align, start_free, end_free, front, back, wmask;
          int error;
  
          /*
           * Clamp the desired resource range to the maximum address
           * this window supports.  Reject impossible requests.
           *
           * For I/O port requests behind a bridge with the ISA enable
           * bit set, force large allocations to start above 64k.
           */
          if (!w->valid)
                  return (EINVAL);
          if (sc->bridgectl & PCIB_BCR_ISA_ENABLE && count > 0x100 &&
              start < 65536)
                  start = 65536;
          if (end > w->rman.rm_end)
                  end = w->rman.rm_end;
          if (start + count - 1 > end || start + count < start)
                  return (EINVAL);
          wmask = ((rman_res_t)1 << w->step) - 1;
  
          /*
           * If there is no resource at all, just try to allocate enough
           * aligned space for this resource.
           */
          if (w->res == NULL) {
                  error = pcib_alloc_new_window(sc, w, type, start, end, count,
                      flags);
                  if (error) {
                          if (bootverbose)
                                  device_printf(sc->dev,
                      "failed to allocate initial %s window (%#jx-%#jx,%#jx)\n",
                                      w->name, start, end, count);
                          return (error);
                  }
                  if (bootverbose)
                          device_printf(sc->dev,
                              "allocated initial %s window of %#jx-%#jx\n",
                              w->name, (uintmax_t)w->base, (uintmax_t)w->limit);
                  goto updatewin;
          }
  
          /*
           * See if growing the window would help.  Compute the minimum
           * amount of address space needed on both the front and back
           * ends of the existing window to satisfy the allocation.
           *
           * For each end, build a candidate region adjusting for the
           * required alignment, etc.  If there is a free region at the
           * edge of the window, grow from the inner edge of the free
           * region.  Otherwise grow from the window boundary.
           *
           * Growing an I/O window below 64k for a bridge with the ISA
           * enable bit doesn't require any special magic as the step
           * size of an I/O window (1k) always includes multiple
           * non-alias ranges when it is grown in either direction.
           *
           * XXX: Special case: if w->res is completely empty and the
           * request size is larger than w->res, we should find the
           * optimal aligned buffer containing w->res and allocate that.
           */
          if (bootverbose)
                  device_printf(sc->dev,
                      "attempting to grow %s window for (%#jx-%#jx,%#jx)\n",
                      w->name, start, end, count);
          align = (rman_res_t)1 << RF_ALIGNMENT(flags);
          if (start < w->base) {
                  if (rman_first_free_region(&w->rman, &start_free, &end_free) !=
                      0 || start_free != w->base)
                          end_free = w->base;
                  if (end_free > end)
                          end_free = end + 1;
  
                  /* Move end_free down until it is properly aligned. */
                  end_free &= ~(align - 1);
                  end_free--;
                  front = end_free - (count - 1);
  
                  /*
                   * The resource would now be allocated at (front,
                   * end_free).  Ensure that fits in the (start, end)
                   * bounds.  end_free is checked above.  If 'front' is
                   * ok, ensure it is properly aligned for this window.
                   * Also check for underflow.
                   */
                  if (front >= start && front <= end_free) {
                          if (bootverbose)
                                  printf("\tfront candidate range: %#jx-%#jx\n",
                                      front, end_free);
                          front &= ~wmask;
                          front = w->base - front;
                  } else
                          front = 0;
          } else
                  front = 0;
          if (end > w->limit) {
                  if (rman_last_free_region(&w->rman, &start_free, &end_free) !=
                      0 || end_free != w->limit)
                          start_free = w->limit + 1;
                  if (start_free < start)
                          start_free = start;
  
                  /* Move start_free up until it is properly aligned. */
                  start_free = roundup2(start_free, align);
                  back = start_free + count - 1;
  
                  /*
                   * The resource would now be allocated at (start_free,
                   * back).  Ensure that fits in the (start, end)
                   * bounds.  start_free is checked above.  If 'back' is
                   * ok, ensure it is properly aligned for this window.
                   * Also check for overflow.
                   */
                  if (back <= end && start_free <= back) {
                          if (bootverbose)
                                  printf("\tback candidate range: %#jx-%#jx\n",
                                      start_free, back);
                          back |= wmask;
                          back -= w->limit;
                  } else
                          back = 0;
          } else
                  back = 0;
  
          /*
           * Try to allocate the smallest needed region first.
           * If that fails, fall back to the other region.
           */
          error = ENOSPC;
          while (front != 0 || back != 0) {
                  if (front != 0 && (front <= back || back == 0)) {
                          error = pcib_expand_window(sc, w, type, w->base - front,
                              w->limit);
                          if (error == 0)
                                  break;
                          front = 0;
                  } else {
                          error = pcib_expand_window(sc, w, type, w->base,
                              w->limit + back);
                          if (error == 0)
                                  break;
                          back = 0;
                  }
          }
  
          if (error)
                  return (error);
          if (bootverbose)
                  device_printf(sc->dev, "grew %s window to %#jx-%#jx\n",
                      w->name, (uintmax_t)w->base, (uintmax_t)w->limit);
  
  updatewin:
          /* Write the new window. */
          KASSERT((w->base & wmask) == 0, ("start address is not aligned"));
          KASSERT((w->limit & wmask) == wmask, ("end address is not aligned"));
          pcib_write_windows(sc, w->mask);
          return (0);
  }
  
  /*
   * We have to trap resource allocation requests and ensure that the bridge
   * is set up to, or capable of handling them.
   */
  struct resource *
  pcib_alloc_resource(device_t dev, device_t child, int type, int *rid,
      rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
  {
          struct pcib_softc *sc;
          struct resource *r;
  
          sc = device_get_softc(dev);
  
          /*
           * VGA resources are decoded iff the VGA enable bit is set in
           * the bridge control register.  VGA resources do not fall into
           * the resource windows and are passed up to the parent.
           */
          if ((type == SYS_RES_IOPORT && pci_is_vga_ioport_range(start, end)) ||
              (type == SYS_RES_MEMORY && pci_is_vga_memory_range(start, end))) {
                  if (sc->bridgectl & PCIB_BCR_VGA_ENABLE)
                          return (bus_generic_alloc_resource(dev, child, type,
                              rid, start, end, count, flags));
                  else
                          return (NULL);
          }
  
          switch (type) {
  #ifdef PCI_RES_BUS
          case PCI_RES_BUS:
                  return (pcib_alloc_subbus(&sc->bus, child, rid, start, end,
                      count, flags));
  #endif
          case SYS_RES_IOPORT:
                  if (pcib_is_isa_range(sc, start, end, count))
                          return (NULL);
                  r = pcib_suballoc_resource(sc, &sc->io, child, type, rid, start,
                      end, count, flags);
                  if (r != NULL || (sc->flags & PCIB_SUBTRACTIVE) != 0)
                          break;
                  if (pcib_grow_window(sc, &sc->io, type, start, end, count,
                      flags) == 0)
                          r = pcib_suballoc_resource(sc, &sc->io, child, type,
                              rid, start, end, count, flags);
                  break;
          case SYS_RES_MEMORY:
                  /*
                   * For prefetchable resources, prefer the prefetchable
                   * memory window, but fall back to the regular memory
                   * window if that fails.  Try both windows before
                   * attempting to grow a window in case the firmware
                   * has used a range in the regular memory window to
                   * map a prefetchable BAR.
                   */
                  if (flags & RF_PREFETCHABLE) {
                          r = pcib_suballoc_resource(sc, &sc->pmem, child, type,
                              rid, start, end, count, flags);
                          if (r != NULL)
                                  break;
                  }
                  r = pcib_suballoc_resource(sc, &sc->mem, child, type, rid,
                      start, end, count, flags);
                  if (r != NULL || (sc->flags & PCIB_SUBTRACTIVE) != 0)
                          break;
                  if (flags & RF_PREFETCHABLE) {
                          if (pcib_grow_window(sc, &sc->pmem, type, start, end,
                              count, flags) == 0) {
                                  r = pcib_suballoc_resource(sc, &sc->pmem, child,
                                      type, rid, start, end, count, flags);
                                  if (r != NULL)
                                          break;
                          }
                  }
                  if (pcib_grow_window(sc, &sc->mem, type, start, end, count,
                      flags & ~RF_PREFETCHABLE) == 0)
                          r = pcib_suballoc_resource(sc, &sc->mem, child, type,
                              rid, start, end, count, flags);
                  break;
          default:
                  return (bus_generic_alloc_resource(dev, child, type, rid,
                      start, end, count, flags));
          }
  
          /*
           * If attempts to suballocate from the window fail but this is a
           * subtractive bridge, pass the request up the tree.
           */
          if (sc->flags & PCIB_SUBTRACTIVE && r == NULL)
                  return (bus_generic_alloc_resource(dev, child, type, rid,
                      start, end, count, flags));
          return (r);
  }
  
  int
  pcib_adjust_resource(device_t bus, device_t child, int type, struct resource *r,
      rman_res_t start, rman_res_t end)
  {
          struct pcib_softc *sc;
  
          sc = device_get_softc(bus);
          if (pcib_is_resource_managed(sc, type, r))
                  return (rman_adjust_resource(r, start, end));
          return (bus_generic_adjust_resource(bus, child, type, r, start, end));
  }
  
  int
  pcib_release_resource(device_t dev, device_t child, int type, int rid,
      struct resource *r)
  {
          struct pcib_softc *sc;
          int error;
  
          sc = device_get_softc(dev);
          if (pcib_is_resource_managed(sc, type, r)) {
                  if (rman_get_flags(r) & RF_ACTIVE) {
                          error = bus_deactivate_resource(child, type, rid, r);
                          if (error)
                                  return (error);
                  }
                  return (rman_release_resource(r));
          }
          return (bus_generic_release_resource(dev, child, type, rid, r));
  }
  #else
  /*
   * We have to trap resource allocation requests and ensure that the bridge
   * is set up to, or capable of handling them.
   */
  struct resource *
  pcib_alloc_resource(device_t dev, device_t child, int type, int *rid,
      rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
  {
          struct pcib_softc       *sc = device_get_softc(dev);
          const char *name, *suffix;
          int ok;
  
          /*
           * Fail the allocation for this range if it's not supported.
           */
          name = device_get_nameunit(child);
          if (name == NULL) {
                  name = "";
                  suffix = "";
          } else
                  suffix = " ";
          switch (type) {
          case SYS_RES_IOPORT:
                  ok = 0;
                  if (!pcib_is_io_open(sc))
                          break;
                  ok = (start >= sc->iobase && end <= sc->iolimit);
  
                  /*
                   * Make sure we allow access to VGA I/O addresses when the
                   * bridge has the "VGA Enable" bit set.
                   */
                  if (!ok && pci_is_vga_ioport_range(start, end))
                          ok = (sc->bridgectl & PCIB_BCR_VGA_ENABLE) ? 1 : 0;
  
                  if ((sc->flags & PCIB_SUBTRACTIVE) == 0) {
                          if (!ok) {
                                  if (start < sc->iobase)
                                          start = sc->iobase;
                                  if (end > sc->iolimit)
                                          end = sc->iolimit;
                                  if (start < end)
                                          ok = 1;
                          }
                  } else {
                          ok = 1;
  #if 0
                          /*
                           * If we overlap with the subtractive range, then
                           * pick the upper range to use.
                           */
                          if (start < sc->iolimit && end > sc->iobase)
                                  start = sc->iolimit + 1;
  #endif
                  }
                  if (end < start) {
                          device_printf(dev, "ioport: end (%jx) < start (%jx)\n",
                              end, start);
                          start = 0;
                          end = 0;
                          ok = 0;
                  }
                  if (!ok) {
                          device_printf(dev, "%s%srequested unsupported I/O "
                              "range 0x%jx-0x%jx (decoding 0x%x-0x%x)\n",
                              name, suffix, start, end, sc->iobase, sc->iolimit);
                          return (NULL);
                  }
                  if (bootverbose)
                          device_printf(dev,
                              "%s%srequested I/O range 0x%jx-0x%jx: in range\n",
                              name, suffix, start, end);
                  break;
  
          case SYS_RES_MEMORY:
                  ok = 0;
                  if (pcib_is_nonprefetch_open(sc))
                          ok = ok || (start >= sc->membase && end <= sc->memlimit);
                  if (pcib_is_prefetch_open(sc))
                          ok = ok || (start >= sc->pmembase && end <= sc->pmemlimit);
  
                  /*
                   * Make sure we allow access to VGA memory addresses when the
                   * bridge has the "VGA Enable" bit set.
                   */
                  if (!ok && pci_is_vga_memory_range(start, end))
                          ok = (sc->bridgectl & PCIB_BCR_VGA_ENABLE) ? 1 : 0;
  
                  if ((sc->flags & PCIB_SUBTRACTIVE) == 0) {
                          if (!ok) {
                                  ok = 1;
                                  if (flags & RF_PREFETCHABLE) {
                                          if (pcib_is_prefetch_open(sc)) {
                                                  if (start < sc->pmembase)
                                                          start = sc->pmembase;
                                                  if (end > sc->pmemlimit)
                                                          end = sc->pmemlimit;
                                          } else {
                                                  ok = 0;
                                          }
                                  } else {        /* non-prefetchable */
                                          if (pcib_is_nonprefetch_open(sc)) {
                                                  if (start < sc->membase)
                                                          start = sc->membase;
                                                  if (end > sc->memlimit)
                                                          end = sc->memlimit;
                                          } else {
                                                  ok = 0;
                                          }
                                  }
                          }
                  } else if (!ok) {
                          ok = 1; /* subtractive bridge: always ok */
  #if 0
                          if (pcib_is_nonprefetch_open(sc)) {
                                  if (start < sc->memlimit && end > sc->membase)
                                          start = sc->memlimit + 1;
                          }
                          if (pcib_is_prefetch_open(sc)) {
                                  if (start < sc->pmemlimit && end > sc->pmembase)
                                          start = sc->pmemlimit + 1;
                          }
  #endif
                  }
                  if (end < start) {
                          device_printf(dev, "memory: end (%jx) < start (%jx)\n",
                              end, start);
                          start = 0;
                          end = 0;
                          ok = 0;
                  }
                  if (!ok && bootverbose)
                          device_printf(dev,
                              "%s%srequested unsupported memory range %#jx-%#jx "
                              "(decoding %#jx-%#jx, %#jx-%#jx)\n",
                              name, suffix, start, end,
                              (uintmax_t)sc->membase, (uintmax_t)sc->memlimit,
                              (uintmax_t)sc->pmembase, (uintmax_t)sc->pmemlimit);
                  if (!ok)
                          return (NULL);
                  if (bootverbose)
                          device_printf(dev,"%s%srequested memory range "
                              "0x%jx-0x%jx: good\n",
                              name, suffix, start, end);
                  break;
  
          default:
                  break;
          }
          /*
           * Bridge is OK decoding this resource, so pass it up.
           */
          return (bus_generic_alloc_resource(dev, child, type, rid, start, end,
              count, flags));
  }
  #endif
  
  /*
   * If ARI is enabled on this downstream port, translate the function number
   * to the non-ARI slot/function.  The downstream port will convert it back in
   * hardware.  If ARI is not enabled slot and func are not modified.
   */
  static __inline void
  pcib_xlate_ari(device_t pcib, int bus, int *slot, int *func)
  {
          struct pcib_softc *sc;
          int ari_func;
  
          sc = device_get_softc(pcib);
          ari_func = *func;
  
          if (sc->flags & PCIB_ENABLE_ARI) {
                  KASSERT(*slot == 0,
                      ("Non-zero slot number with ARI enabled!"));
                  *slot = PCIE_ARI_SLOT(ari_func);
                  *func = PCIE_ARI_FUNC(ari_func);
          }
  }
  
  
  static void
  pcib_enable_ari(struct pcib_softc *sc, uint32_t pcie_pos)
  {
          uint32_t ctl2;
  
          ctl2 = pci_read_config(sc->dev, pcie_pos + PCIER_DEVICE_CTL2, 4);
          ctl2 |= PCIEM_CTL2_ARI;
          pci_write_config(sc->dev, pcie_pos + PCIER_DEVICE_CTL2, ctl2, 4);
  
          sc->flags |= PCIB_ENABLE_ARI;
  }
  
  /*
   * PCIB interface.
   */
  int
  pcib_maxslots(device_t dev)
  {
          return (PCI_SLOTMAX);
  }
  
  static int
  pcib_ari_maxslots(device_t dev)
  {
          struct pcib_softc *sc;
  
          sc = device_get_softc(dev);
  
          if (sc->flags & PCIB_ENABLE_ARI)
                  return (PCIE_ARI_SLOTMAX);
          else
                  return (PCI_SLOTMAX);
  }
  
  static int
  pcib_ari_maxfuncs(device_t dev)
  {
          struct pcib_softc *sc;
  
          sc = device_get_softc(dev);
  
          if (sc->flags & PCIB_ENABLE_ARI)
                  return (PCIE_ARI_FUNCMAX);
          else
                  return (PCI_FUNCMAX);
  }
  
  static void
  pcib_ari_decode_rid(device_t pcib, uint16_t rid, int *bus, int *slot,
      int *func)
  {
          struct pcib_softc *sc;
  
          sc = device_get_softc(pcib);
  
          *bus = PCI_RID2BUS(rid);
          if (sc->flags & PCIB_ENABLE_ARI) {
                  *slot = PCIE_ARI_RID2SLOT(rid);
                  *func = PCIE_ARI_RID2FUNC(rid);
          } else {
                  *slot = PCI_RID2SLOT(rid);
                  *func = PCI_RID2FUNC(rid);
          }
  }
  
  /*
   * Since we are a child of a PCI bus, its parent must support the pcib interface.
   */
  static uint32_t
  pcib_read_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, int width)
  {
  #ifdef PCI_HP
          struct pcib_softc *sc;
  
          sc = device_get_softc(dev);
          if (!pcib_present(sc)) {
                  switch (width) {
                  case 2:
                          return (0xffff);
                  case 1:
                          return (0xff);
                  default:
                          return (0xffffffff);
                  }
          }
  #endif
          pcib_xlate_ari(dev, b, &s, &f);
          return(PCIB_READ_CONFIG(device_get_parent(device_get_parent(dev)), b, s,
              f, reg, width));
  }
  
  static void
  pcib_write_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, uint32_t val, int width)
  {
  #ifdef PCI_HP
          struct pcib_softc *sc;
  
          sc = device_get_softc(dev);
          if (!pcib_present(sc))
                  return;
  #endif
          pcib_xlate_ari(dev, b, &s, &f);
          PCIB_WRITE_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f,
              reg, val, width);
  }
  
  /*
   * Route an interrupt across a PCI bridge.
   */
  int
  pcib_route_interrupt(device_t pcib, device_t dev, int pin)
  {
      device_t    bus;
      int         parent_intpin;
      int         intnum;
  
      /*
       *
       * The PCI standard defines a swizzle of the child-side device/intpin to
       * the parent-side intpin as follows.
       *
       * device = device on child bus
       * child_intpin = intpin on child bus slot (0-3)
       * parent_intpin = intpin on parent bus slot (0-3)
       *
       * parent_intpin = (device + child_intpin) % 4
       */
      parent_intpin = (pci_get_slot(dev) + (pin - 1)) % 4;
  
      /*
       * Our parent is a PCI bus.  Its parent must export the pcib interface
       * which includes the ability to route interrupts.
       */
      bus = device_get_parent(pcib);
      intnum = PCIB_ROUTE_INTERRUPT(device_get_parent(bus), pcib, parent_intpin + 1);
      if (PCI_INTERRUPT_VALID(intnum) && bootverbose) {
          device_printf(pcib, "slot %d INT%c is routed to irq %d\n",
              pci_get_slot(dev), 'A' + pin - 1, intnum);
      }
      return(intnum);
  }
  
  /* Pass request to alloc MSI/MSI-X messages up to the parent bridge. */
  int
  pcib_alloc_msi(device_t pcib, device_t dev, int count, int maxcount, int *irqs)
  {
          struct pcib_softc *sc = device_get_softc(pcib);
          device_t bus;
  
          if (sc->flags & PCIB_DISABLE_MSI)
                  return (ENXIO);
          bus = device_get_parent(pcib);
          return (PCIB_ALLOC_MSI(device_get_parent(bus), dev, count, maxcount,
              irqs));
  }
  
  /* Pass request to release MSI/MSI-X messages up to the parent bridge. */
  int
  pcib_release_msi(device_t pcib, device_t dev, int count, int *irqs)
  {
          device_t bus;
  
          bus = device_get_parent(pcib);
          return (PCIB_RELEASE_MSI(device_get_parent(bus), dev, count, irqs));
  }
  
  /* Pass request to alloc an MSI-X message up to the parent bridge. */
  int
  pcib_alloc_msix(device_t pcib, device_t dev, int *irq)
  {
          struct pcib_softc *sc = device_get_softc(pcib);
          device_t bus;
  
          if (sc->flags & PCIB_DISABLE_MSIX)
                  return (ENXIO);
          bus = device_get_parent(pcib);
          return (PCIB_ALLOC_MSIX(device_get_parent(bus), dev, irq));
  }
  
  /* Pass request to release an MSI-X message up to the parent bridge. */
  int
  pcib_release_msix(device_t pcib, device_t dev, int irq)
  {
          device_t bus;
  
          bus = device_get_parent(pcib);
          return (PCIB_RELEASE_MSIX(device_get_parent(bus), dev, irq));
  }
  
  /* Pass request to map MSI/MSI-X message up to parent bridge. */
  int
  pcib_map_msi(device_t pcib, device_t dev, int irq, uint64_t *addr,
      uint32_t *data)
  {
          device_t bus;
          int error;
  
          bus = device_get_parent(pcib);
          error = PCIB_MAP_MSI(device_get_parent(bus), dev, irq, addr, data);
          if (error)
                  return (error);
  
          pci_ht_map_msi(pcib, *addr);
          return (0);
  }
  
  /* Pass request for device power state up to parent bridge. */
  int
  pcib_power_for_sleep(device_t pcib, device_t dev, int *pstate)
  {
          device_t bus;
  
          bus = device_get_parent(pcib);
          return (PCIB_POWER_FOR_SLEEP(bus, dev, pstate));
  }
  
  static int
  pcib_ari_enabled(device_t pcib)
  {
          struct pcib_softc *sc;
  
          sc = device_get_softc(pcib);
  
          return ((sc->flags & PCIB_ENABLE_ARI) != 0);
  }
  
  static int
  pcib_ari_get_id(device_t pcib, device_t dev, enum pci_id_type type,
      uintptr_t *id)
  {
          struct pcib_softc *sc;
          device_t bus_dev;
          uint8_t bus, slot, func;
  
          if (type != PCI_ID_RID) {
                  bus_dev = device_get_parent(pcib);
                  return (PCIB_GET_ID(device_get_parent(bus_dev), dev, type, id));
          }
  
          sc = device_get_softc(pcib);
  
          if (sc->flags & PCIB_ENABLE_ARI) {
                  bus = pci_get_bus(dev);
                  func = pci_get_function(dev);
  
                  *id = (PCI_ARI_RID(bus, func));
          } else {
                  bus = pci_get_bus(dev);
                  slot = pci_get_slot(dev);
                  func = pci_get_function(dev);
  
                  *id = (PCI_RID(bus, slot, func));
          }
  
          return (0);
  }
  
  /*
   * Check that the downstream port (pcib) and the endpoint device (dev) both
   * support ARI.  If so, enable it and return 0, otherwise return an error.
   */
  static int
  pcib_try_enable_ari(device_t pcib, device_t dev)
  {
          struct pcib_softc *sc;
          int error;
          uint32_t cap2;
          int ari_cap_off;
          uint32_t ari_ver;
          uint32_t pcie_pos;
  
          sc = device_get_softc(pcib);
  
          /*
           * ARI is controlled in a register in the PCIe capability structure.
           * If the downstream port does not have the PCIe capability structure
           * then it does not support ARI.
           */
          error = pci_find_cap(pcib, PCIY_EXPRESS, &pcie_pos);
          if (error != 0)
                  return (ENODEV);
  
          /* Check that the PCIe port advertises ARI support. */
          cap2 = pci_read_config(pcib, pcie_pos + PCIER_DEVICE_CAP2, 4);
          if (!(cap2 & PCIEM_CAP2_ARI))
                  return (ENODEV);
  
          /*
           * Check that the endpoint device advertises ARI support via the ARI
           * extended capability structure.
           */
          error = pci_find_extcap(dev, PCIZ_ARI, &ari_cap_off);
          if (error != 0)
                  return (ENODEV);
  
          /*
           * Finally, check that the endpoint device supports the same version
           * of ARI that we do.
           */
          ari_ver = pci_read_config(dev, ari_cap_off, 4);
          if (PCI_EXTCAP_VER(ari_ver) != PCIB_SUPPORTED_ARI_VER) {
                  if (bootverbose)
                          device_printf(pcib,
                              "Unsupported version of ARI (%d) detected\n",
                              PCI_EXTCAP_VER(ari_ver));
  
                  return (ENXIO);
          }
  
          pcib_enable_ari(sc, pcie_pos);
  
          return (0);
  }

Cache object: 5f1a3be11f049a0abf3f1479fcca0770