On 2015/11/18 0:32, David Vrabel wrote: > On 17/11/15 09:57, shannon.zhao@xxxxxxxxxx wrote: >> From: Shannon Zhao <shannon.zhao@xxxxxxxxxx> >> >> Add a bus_notifier for platform bus device in order to map the device >> mmio regions when DOM0 booting with ACPI. > [...] >> --- /dev/null >> +++ b/drivers/xen/platform.c >> @@ -0,0 +1,104 @@ >> +/* >> + * Copyright (c) 2015, Linaro Limited. >> + * >> + * 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, write to the Free Software Foundation, Inc., 59 Temple >> + * Place - Suite 330, Boston, MA 02111-1307 USA. > > "You should have received a copy of the GNU General Public License > along with this program. If not, see <http://www.gnu.org/licenses/>." > >> + * >> + * Author: Shannon Zhao <shannon.zhao@xxxxxxxxxx> > > Omit this since it just becomes stale and git will know the correct > authorship. > >> +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 (!acpi_disabled && (action == BUS_NOTIFY_ADD_DEVICE)) >> + r = xen_map_platform_device_mmio(pdev); > > Why even register the notifier if acpi_disabled? > >> + >> + if (r) >> + { >> + dev_err(&pdev->dev, "Failed to add_to_physmap device (%s) mmio!\n", >> + pdev->name); >> + return NOTIFY_OK; > > Return NOTIFY_BAD here? The device will be unusable. > >> + } >> + >> + return NOTIFY_DONE; >> +} >> + >> +static struct notifier_block platform_device_nb = { >> + .notifier_call = xen_platform_notifier, >> +}; >> + >> +static int __init register_xen_platform_notifier(void) >> +{ >> + if (!xen_initial_domain()) >> + return 0; >> + >> + return bus_register_notifier(&platform_bus_type, &platform_device_nb); > > Why only platform busses? What about PCI devices? Where will they get > added to dom0's physmap? > I've said in the design doc[1] that "And for PCI bus devices, Linux could reuse the existing PCI bus_notifier like X86." Since currently Xen on ARM doesn't support PCI (IIRC) and if it adds the support in the future, we could make the codes in drivers/xen/pci.c common to ARM and x86 at that moment. Thanks, [1] http://lists.xen.org/archives/html/xen-devel/2015-11/msg00488.html -- Shannon -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
