freebsd-skq/sys/x86/xen/xenpv.c

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/*
* Copyright (c) 2014 Roger Pau Monné <roger.pau@citrix.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY 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("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/pcpu.h>
#include <sys/rman.h>
#include <sys/smp.h>
#include <sys/limits.h>
#include <sys/vmmeter.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_param.h>
#include <vm/vm_phys.h>
#include <xen/xen-os.h>
#include <xen/gnttab.h>
#include "xenmem_if.h"
/*
* Allocate unused physical memory above 4GB in order to map memory
* from foreign domains. We use memory starting at 4GB in order to
* prevent clashes with MMIO/ACPI regions.
*
* Since this is not possible on i386 just use any available memory
* chunk and hope we don't clash with anything else.
*/
#ifdef __amd64__
#define LOW_MEM_LIMIT 0x100000000ul
#else
#define LOW_MEM_LIMIT 0
#endif
static devclass_t xenpv_devclass;
static void
xenpv_identify(driver_t *driver, device_t parent)
{
if (!xen_domain())
return;
/* Make sure there's only one xenpv device. */
if (devclass_get_device(xenpv_devclass, 0))
return;
/*
* The xenpv bus should be the last to attach in order
* to properly detect if an ISA bus has already been added.
*/
if (BUS_ADD_CHILD(parent, UINT_MAX, "xenpv", 0) == NULL)
panic("Unable to attach xenpv bus.");
}
static int
xenpv_probe(device_t dev)
{
device_set_desc(dev, "Xen PV bus");
return (BUS_PROBE_NOWILDCARD);
}
static int
xenpv_attach(device_t dev)
{
int error;
/*
* Let our child drivers identify any child devices that they
* can find. Once that is done attach any devices that we
* found.
*/
error = bus_generic_probe(dev);
if (error)
return (error);
error = bus_generic_attach(dev);
return (error);
}
static struct resource *
xenpv_alloc_physmem(device_t dev, device_t child, int *res_id, size_t size)
{
struct resource *res;
vm_paddr_t phys_addr;
int error;
res = bus_alloc_resource(child, SYS_RES_MEMORY, res_id, LOW_MEM_LIMIT,
~0, size, RF_ACTIVE);
if (res == NULL)
return (NULL);
phys_addr = rman_get_start(res);
error = vm_phys_fictitious_reg_range(phys_addr, phys_addr + size,
VM_MEMATTR_DEFAULT);
if (error) {
bus_release_resource(child, SYS_RES_MEMORY, *res_id, res);
return (NULL);
}
return (res);
}
static int
xenpv_free_physmem(device_t dev, device_t child, int res_id, struct resource *res)
{
vm_paddr_t phys_addr;
size_t size;
phys_addr = rman_get_start(res);
size = rman_get_size(res);
vm_phys_fictitious_unreg_range(phys_addr, phys_addr + size);
return (bus_release_resource(child, SYS_RES_MEMORY, res_id, res));
}
static device_method_t xenpv_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, xenpv_identify),
DEVMETHOD(device_probe, xenpv_probe),
DEVMETHOD(device_attach, xenpv_attach),
DEVMETHOD(device_suspend, bus_generic_suspend),
DEVMETHOD(device_resume, bus_generic_resume),
/* Bus interface */
DEVMETHOD(bus_add_child, bus_generic_add_child),
DEVMETHOD(bus_alloc_resource, bus_generic_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),
/* Interface to allocate memory for foreign mappings */
DEVMETHOD(xenmem_alloc, xenpv_alloc_physmem),
DEVMETHOD(xenmem_free, xenpv_free_physmem),
DEVMETHOD_END
};
static driver_t xenpv_driver = {
"xenpv",
xenpv_methods,
0,
};
DRIVER_MODULE(xenpv, nexus, xenpv_driver, xenpv_devclass, 0, 0);
struct resource *
xenmem_alloc(device_t dev, int *res_id, size_t size)
{
device_t parent;
parent = device_get_parent(dev);
if (parent == NULL)
return (NULL);
return (XENMEM_ALLOC(parent, dev, res_id, size));
}
int
xenmem_free(device_t dev, int res_id, struct resource *res)
{
device_t parent;
parent = device_get_parent(dev);
if (parent == NULL)
return (ENXIO);
return (XENMEM_FREE(parent, dev, res_id, res));
}