xref: /freebsd-11-stable/sys/dev/pci/pci_subr.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.
 *
 *	$FreeBSD: head/sys/dev/pci/pci_pci.c 69783 2000-12-08 22:11:23Z msmith $
 */

/*
 * PCI:PCI bridge support.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>

#include <machine/resource.h>

#include <pci/pcivar.h>
#include <pci/pcireg.h>

#include "pcib_if.h"

/*
 * Bridge-specific data.
 */
struct pcib_softc
{
    device_t	dev;
    u_int8_t	secbus;		/* secondary bus number */
    u_int8_t	subbus;		/* subordinate bus number */
    pci_addr_t	pmembase;	/* base address of prefetchable memory */
    pci_addr_t	pmemlimit;	/* topmost address of prefetchable memory */
    u_int32_t	membase;	/* base address of memory window */
    u_int32_t	memlimit;	/* topmost address of memory window */
    u_int32_t	iobase;		/* base address of port window */
    u_int32_t	iolimit;	/* topmost address of port window */
    u_int16_t	secstat;	/* secondary bus status register */
    u_int16_t	bridgectl;	/* bridge control register */
    u_int8_t	seclat;		/* secondary bus latency timer */
};

static int		pcib_probe(device_t dev);
static int		pcib_attach(device_t dev);
static int		pcib_read_ivar(device_t dev, device_t child, int which, uintptr_t *result);
static int		pcib_write_ivar(device_t dev, device_t child, int which, uintptr_t value);
static struct resource *pcib_alloc_resource(device_t dev, device_t child, int type, int *rid,
					    u_long start, u_long end, u_long count, u_int flags);
static int		pcib_maxslots(device_t dev);
static u_int32_t	pcib_read_config(device_t dev, int b, int s, int f, int reg, int width);
static void		pcib_write_config(device_t dev, int b, int s, int f, int reg, u_int32_t val, int width);
static int		pcib_route_interrupt(device_t pcib, device_t dev, int pin);

static device_method_t pcib_methods[] = {
    /* Device interface */
    DEVMETHOD(device_probe,		pcib_probe),
    DEVMETHOD(device_attach,		pcib_attach),
    DEVMETHOD(device_shutdown,		bus_generic_shutdown),
    DEVMETHOD(device_suspend,		bus_generic_suspend),
    DEVMETHOD(device_resume,		bus_generic_resume),

    /* Bus interface */
    DEVMETHOD(bus_print_child,		bus_generic_print_child),
    DEVMETHOD(bus_read_ivar,		pcib_read_ivar),
    DEVMETHOD(bus_write_ivar,		pcib_write_ivar),
    DEVMETHOD(bus_alloc_resource,	pcib_alloc_resource),
    DEVMETHOD(bus_release_resource,	bus_generic_release_resource),
    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_maxslots),
    DEVMETHOD(pcib_read_config,		pcib_read_config),
    DEVMETHOD(pcib_write_config,	pcib_write_config),
    DEVMETHOD(pcib_route_interrupt,	pcib_route_interrupt),

    { 0, 0 }
};

static driver_t pcib_driver = {
    "pcib",
    pcib_methods,
    sizeof(struct pcib_softc),
};

static devclass_t pcib_devclass;

DRIVER_MODULE(pcib, pci, pcib_driver, pcib_devclass, 0, 0);

/*
 * 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);
}

static int
pcib_attach(device_t dev)
{
    struct pcib_softc	*sc;
    device_t		pcib, child;
    int			b, s, f;

    sc = device_get_softc(dev);
    sc->dev = dev;
    pcib = device_get_parent(dev);
    b = pci_get_bus(dev);
    s = pci_get_slot(dev);
    f = pci_get_function(dev);

    sc->secbus    = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_SECBUS_1, 1);
    sc->subbus    = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_SUBBUS_1, 1);
    sc->secstat   = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_SECSTAT_1, 2);
    sc->bridgectl = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_BRIDGECTL_1, 2);
    sc->seclat    = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_SECLAT_1, 1);
    sc->iobase    = PCI_PPBIOBASE(PCIB_READ_CONFIG(pcib, b, s, f, PCIR_IOBASEH_1, 2),
				  PCIB_READ_CONFIG(pcib, b, s, f, PCIR_IOBASEL_1, 1));
    sc->iolimit   = PCI_PPBIOLIMIT(PCIB_READ_CONFIG(pcib, b, s, f, PCIR_IOLIMITH_1, 2),
				   PCIB_READ_CONFIG(pcib, b, s, f, PCIR_IOLIMITL_1, 1));
    sc->membase   = PCI_PPBMEMBASE(0, PCIB_READ_CONFIG(pcib, b, s, f, PCIR_MEMBASE_1, 2));
    sc->memlimit  = PCI_PPBMEMLIMIT(0, PCIB_READ_CONFIG(pcib, b, s, f, PCIR_MEMLIMIT_1, 2));
    sc->pmembase  = PCI_PPBMEMBASE((pci_addr_t)PCIB_READ_CONFIG(pcib, b, s, f, PCIR_PMBASEH_1, 4),
				   PCIB_READ_CONFIG(pcib, b, s, f, PCIR_PMBASEL_1, 2));
    sc->pmemlimit = PCI_PPBMEMLIMIT((pci_addr_t)PCIB_READ_CONFIG(pcib, b, s, f,PCIR_PMLIMITH_1, 4),
				    PCIB_READ_CONFIG(pcib, b, s, f, PCIR_PMLIMITL_1, 2));

    if (bootverbose) {
	device_printf(dev, "  secondary bus     %d\n", sc->secbus);
	device_printf(dev, "  subordinate bus   %d\n", sc->subbus);
	device_printf(dev, "  I/O decode        0x%x-0x%x\n", sc->iobase, sc->iolimit);
	device_printf(dev, "  memory decode     0x%x-0x%x\n", sc->membase, sc->memlimit);
	device_printf(dev, "  prefetched decode 0x%x-0x%x\n", sc->pmembase, sc->pmemlimit);
    }

    /*
     * XXX If the secondary bus number is zero, we should assign a bus number
     *     since the BIOS hasn't, then initialise the bridge.
     */

    /*
     * XXX If the subordinate bus number is less than the secondary bus number,
     *     we should pick a better value.  One sensible alternative would be to
     *     pick 255; the only tradeoff here is that configuration transactions
     *     would be more widely routed than absolutely necessary.
     */

    if (sc->secbus != 0) {
	child = device_add_child(dev, "pci", -1);
	if (child != NULL)
	    return(bus_generic_attach(dev));
    }

    /* no secondary bus; we should have fixed this */
    return(0);
}

static 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_BUS:
	*result = sc->secbus;
	return(0);
    }
    return(ENOENT);
}

static int
pcib_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
{
    struct pcib_softc	*sc = device_get_softc(dev);

    switch (which) {
    case PCIB_IVAR_BUS:
	sc->secbus = value;
	break;
    }
    return(ENOENT);
}

/*
 * We have to trap resource allocation requests and ensure that the bridge
 * is set up to, or capable of handling them.
 */
static struct resource *
pcib_alloc_resource(device_t dev, device_t child, int type, int *rid,
		    u_long start, u_long end, u_long count, u_int flags)
{
    struct pcib_softc	*sc = device_get_softc(dev);

    /*
     * If this is a "default" allocation against this rid, we can't work
     * out where it's coming from (we should actually never see these) so we
     * just have to punt.
     */
    if ((start == 0) && (end == ~0)) {
	device_printf(dev, "can't decode default resource id %d for %s%d, bypassing\n",
		      *rid, device_get_name(child), device_get_unit(child));
    } else {
	/*
	 * Fail the allocation for this range if it's not supported.
	 *
	 * XXX we should probably just fix up the bridge decode and soldier on.
	 */
	switch (type) {
	case SYS_RES_IOPORT:
	    if ((start < sc->iobase) || (end > sc->iolimit)) {
		device_printf(dev, "device %s%d requested unsupported I/O range 0x%lx-0x%lx"
			      " (decoding 0x%x-0x%x)\n",
			      device_get_name(child), device_get_unit(child), start, end,
			      sc->iobase, sc->iolimit);
		return(NULL);
	    }
	    break;

	    /*
	     * XXX will have to decide whether the device making the request is asking
	     *     for prefetchable memory or not.  If it's coming from another bridge
	     *     down the line, do we assume not, or ask the bridge to pass in another
	     *     flag as the request bubbles up?
	     */
	case SYS_RES_MEMORY:
	    if (((start < sc->membase) || (end > sc->memlimit)) &&
		((start < sc->pmembase) || (end > sc->pmemlimit))) {
		device_printf(dev, "device %s%d requested unsupported memory range 0x%lx-0x%lx"
			      " (decoding 0x%x-0x%x, 0x%x-0x%x)\n",
			      device_get_name(child), device_get_unit(child), start, end,
			      sc->membase, sc->memlimit, sc->pmembase, sc->pmemlimit);
		return(NULL);
	    }
	default:
	}
    }
    device_printf(sc->dev, "resource request type %d 0x%lx-0x%lx decodes OK\n",
		  type, start, end);
    /*
     * Bridge is OK decoding this resource, so pass it up.
     */
    return(bus_generic_alloc_resource(dev, child, type, rid, start, end, count, flags));
}

/*
 * PCIB interface.
 */
static int
pcib_maxslots(device_t dev)
{
    return(31);
}

/*
 * Since we are a child of a PCI bus, its parent must support the pcib interface.
 */
static u_int32_t
pcib_read_config(device_t dev, int b, int s, int f, int reg, int width)
{
    return(PCIB_READ_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, width));
}

static void
pcib_write_config(device_t dev, int b, int s, int f, int reg, u_int32_t val, int width)
{
    PCIB_WRITE_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, val, width);
}

/*
 * Route an interrupt across a PCI bridge.
 */
static 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(pcib) + (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);
    device_printf(pcib, "routed slot %d INT%c to irq %d\n", pci_get_slot(dev),
		  'A' + pin - 1, intnum);
    return(intnum);
}