arm-device.c
/*
* Copyright (c) 2015, Linaro Limited, Shannon Zhao
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/platform_device.h>
#include <linux/acpi.h>
#include <xen/xen.h>
#include <xen/page.h>
#include <xen/interface/memory.h>
#include <asm/xen/hypervisor.h>
#include <asm/xen/hypercall.h>
static int xen_unmap_device_mmio(const struct resource *resources,
unsigned int count)
{
unsigned int i, j, nr;
int rc = 0;
const struct resource *r;
struct xen_remove_from_physmap xrp;
for (i = 0; i < count; i++) {
r = &resources[i];
nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
continue;
for (j = 0; j < nr; j++) {
xrp.domid = DOMID_SELF;
xrp.gpfn = XEN_PFN_DOWN(r->start) + j;
rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap,
&xrp);
if (rc)
return rc;
}
}
return rc;
}
static int xen_map_device_mmio(const struct resource *resources,
unsigned int count)
{
unsigned int i, j, nr;
int rc = 0;
const struct resource *r;
xen_pfn_t *gpfns;
xen_ulong_t *idxs;
int *errs;
struct xen_add_to_physmap_range xatp;
for (i = 0; i < count; i++) {
r = &resources[i];
nr = DIV_ROUND_UP(resource_size(r), XEN_PAGE_SIZE);
if ((resource_type(r) != IORESOURCE_MEM) || (nr == 0))
continue;
gpfns = kzalloc(sizeof(xen_pfn_t) * nr, GFP_KERNEL);
idxs = kzalloc(sizeof(xen_ulong_t) * nr, GFP_KERNEL);
errs = kzalloc(sizeof(int) * nr, GFP_KERNEL);
if (!gpfns || !idxs || !errs) {
kfree(gpfns);
kfree(idxs);
kfree(errs);
rc = -ENOMEM;
goto unmap;
}
for (j = 0; j < nr; j++) {
/*
* The regions are always mapped 1:1 to DOM0 and this is
* fine because the memory map for DOM0 is the same as
* the host (except for the RAM).
*/
gpfns[j] = XEN_PFN_DOWN(r->start) + j;
idxs[j] = XEN_PFN_DOWN(r->start) + j;
}
xatp.domid = DOMID_SELF;
xatp.size = nr;
xatp.space = XENMAPSPACE_dev_mmio;
set_xen_guest_handle(xatp.gpfns, gpfns);
set_xen_guest_handle(xatp.idxs, idxs);
set_xen_guest_handle(xatp.errs, errs);
rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
kfree(gpfns);
kfree(idxs);
kfree(errs);
if (rc)
goto unmap;
}
return rc;
unmap:
xen_unmap_device_mmio(resources, i);
return rc;
}
static int xen_platform_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
struct platform_device *pdev = to_platform_device(data);
int r = 0;
if (pdev->num_resources == 0 || pdev->resource == NULL)
return NOTIFY_OK;
switch (action) {
case BUS_NOTIFY_ADD_DEVICE:
r = xen_map_device_mmio(pdev->resource, pdev->num_resources);
break;
case BUS_NOTIFY_DEL_DEVICE:
r = xen_unmap_device_mmio(pdev->resource, pdev->num_resources);
break;
default:
return NOTIFY_DONE;
}
if (r)
dev_err(&pdev->dev, "Platform: Failed to %s device %s MMIO!\n",
action == BUS_NOTIFY_ADD_DEVICE ? "map" :
(action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
pdev->name);
return NOTIFY_OK;
}
static struct notifier_block platform_device_nb = {
.notifier_call = xen_platform_notifier,
};
static int __init register_xen_platform_notifier(void)
{
if (!xen_initial_domain() || acpi_disabled)
return 0;
return bus_register_notifier(&platform_bus_type, &platform_device_nb);
}
arch_initcall(register_xen_platform_notifier);
#ifdef CONFIG_ARM_AMBA
#include <linux/amba/bus.h>
static int xen_amba_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
struct amba_device *adev = to_amba_device(data);
int r = 0;
switch (action) {
case BUS_NOTIFY_ADD_DEVICE:
r = xen_map_device_mmio(&adev->res, 1);
break;
case BUS_NOTIFY_DEL_DEVICE:
r = xen_unmap_device_mmio(&adev->res, 1);
break;
default:
return NOTIFY_DONE;
}
if (r)
dev_err(&adev->dev, "AMBA: Failed to %s device %s MMIO!\n",
action == BUS_NOTIFY_ADD_DEVICE ? "map" :
(action == BUS_NOTIFY_DEL_DEVICE ? "unmap" : "?"),
adev->dev.init_name);
return NOTIFY_OK;
}
static struct notifier_block amba_device_nb = {
.notifier_call = xen_amba_notifier,
};
static int __init register_xen_amba_notifier(void)
{
if (!xen_initial_domain() || acpi_disabled)
return 0;
return bus_register_notifier(&amba_bustype, &amba_device_nb);
}
arch_initcall(register_xen_amba_notifier);
#endif