freebsd-dev/sys/dev/virtio/mmio/virtio_mmio_fdt.c
Jessica Clarke be79a2c60f virtio_mmio: Fix V1 device probing spec conformance (section 4.2.3.1.1)
We must check MagicValue not just Version before anything else, and then
we must check DeviceID and immediately abort if zero (and this must not
be an error).

Do all this when probing rather than at the start of attaching as that's
where this belongs, and provides a clear boundary between the device
detection and device initialisation parts of the specified driver
initialisation process. This also means we don't create empty device
instances for placeholder devices, reducing clutter on systems that
pre-allocate a large number, such as QEMU's AArch64 virt machine (which
provides 32).

Reviewed by:	bryanv
Differential Revision:	https://reviews.freebsd.org/D28070
2021-01-21 01:05:21 +00:00

147 lines
3.9 KiB
C

/*-
* Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
* Copyright (c) 2014 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by SRI International and the University of
* Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
* ("CTSRD"), as part of the DARPA CRASH research programme.
*
* Portions of this software were developed by Andrew Turner
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY 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.
*/
/*
* VirtIO MMIO interface.
* This driver is heavily based on VirtIO PCI interface driver.
*/
/*
* FDT example:
* virtio_block@1000 {
* compatible = "virtio,mmio";
* reg = <0x1000 0x100>;
* interrupts = <63>;
* interrupt-parent = <&GIC>;
* };
*/
#include "opt_platform.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/virtio/mmio/virtio_mmio.h>
static int vtmmio_fdt_probe(device_t);
static int vtmmio_fdt_attach(device_t);
static device_method_t vtmmio_fdt_methods[] = {
/* Device interface. */
DEVMETHOD(device_probe, vtmmio_fdt_probe),
DEVMETHOD(device_attach, vtmmio_fdt_attach),
DEVMETHOD_END
};
DEFINE_CLASS_1(virtio_mmio, vtmmio_fdt_driver, vtmmio_fdt_methods,
sizeof(struct vtmmio_softc), vtmmio_driver);
static devclass_t vtmmio_fdt_devclass;
DRIVER_MODULE(virtio_mmio, simplebus, vtmmio_fdt_driver, vtmmio_fdt_devclass,
0, 0);
DRIVER_MODULE(virtio_mmio, ofwbus, vtmmio_fdt_driver, vtmmio_fdt_devclass, 0,0);
MODULE_DEPEND(virtio_mmio, simplebus, 1, 1, 1);
MODULE_DEPEND(virtio_mmio, virtio, 1, 1, 1);
static int
vtmmio_fdt_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "virtio,mmio"))
return (ENXIO);
return (vtmmio_probe(dev));
}
static int
vtmmio_setup_platform(device_t dev, struct vtmmio_softc *sc)
{
phandle_t platform_node;
struct fdt_ic *ic;
phandle_t xref;
phandle_t node;
sc->platform = NULL;
if ((node = ofw_bus_get_node(dev)) == -1)
return (ENXIO);
if (OF_searchencprop(node, "platform", &xref,
sizeof(xref)) == -1) {
return (ENXIO);
}
platform_node = OF_node_from_xref(xref);
SLIST_FOREACH(ic, &fdt_ic_list_head, fdt_ics) {
if (ic->iph == platform_node) {
sc->platform = ic->dev;
break;
}
}
if (sc->platform == NULL) {
/* No platform-specific device. Ignore it. */
}
return (0);
}
static int
vtmmio_fdt_attach(device_t dev)
{
struct vtmmio_softc *sc;
sc = device_get_softc(dev);
vtmmio_setup_platform(dev, sc);
return (vtmmio_attach(dev));
}