Hi, [adding devicetree] On Wed, Oct 17, 2018 at 06:08:23PM +0800, Peng Hao wrote: > Add a platform device driver, pvpanic-mmio that is similar > to x86's pvpanic device. It would be worth noting in the commit message that this is a QEMU-specific device. Is this already in upstream QEMU? > Signed-off-by: Peng Hao <peng.hao2@xxxxxxxxxx> > --- > drivers/platform/Kconfig | 3 + > drivers/platform/Makefile | 1 + > drivers/platform/arm/Kconfig | 6 ++ > drivers/platform/arm/Makefile | 6 ++ > drivers/platform/arm/pvpanic-mmio.c | 123 ++++++++++++++++++++++++++++++++++++ > 5 files changed, 139 insertions(+) > create mode 100644 drivers/platform/arm/Kconfig > create mode 100644 drivers/platform/arm/Makefile > create mode 100644 drivers/platform/arm/pvpanic-mmio.c If this is an MMIO device, why does this need to be specific to arm? Surely *any* architecture could use this? > > diff --git a/drivers/platform/Kconfig b/drivers/platform/Kconfig > index d4c2e42..8b64b78 100644 > --- a/drivers/platform/Kconfig > +++ b/drivers/platform/Kconfig > @@ -1,3 +1,6 @@ > +if ARM64 > +source "drivers/platform/arm/Kconfig" > +endif > if X86 > source "drivers/platform/x86/Kconfig" > endif > diff --git a/drivers/platform/Makefile b/drivers/platform/Makefile > index 4b2ce58..232231c 100644 > --- a/drivers/platform/Makefile > +++ b/drivers/platform/Makefile > @@ -3,6 +3,7 @@ > # Makefile for linux/drivers/platform > # > > +obj-$(CONFIG_ARM64) += arm/ > obj-$(CONFIG_X86) += x86/ > obj-$(CONFIG_MELLANOX_PLATFORM) += mellanox/ > obj-$(CONFIG_MIPS) += mips/ > diff --git a/drivers/platform/arm/Kconfig b/drivers/platform/arm/Kconfig > new file mode 100644 > index 0000000..89fd694 > --- /dev/null > +++ b/drivers/platform/arm/Kconfig > @@ -0,0 +1,6 @@ > +config PVPANIC_MMIO > + tristate "pvpanic mmio device support" > + help > + This driver provides support for the pvpanic mmio device. pvpanic mmio > + is a paravirtualized device provided by QEMU; it lets a virtual machine > + (guest) communicate panic events to the host. > diff --git a/drivers/platform/arm/Makefile b/drivers/platform/arm/Makefile > new file mode 100644 > index 0000000..a68af01 > --- /dev/null > +++ b/drivers/platform/arm/Makefile > @@ -0,0 +1,6 @@ > +# SPDX-License-Identifier: GPL-2.0 > +# > +# Makefile for linux/drivers/platform/arm > +# arm Platform-Specific Drivers > +# > +obj-$(CONFIG_PVPANIC_MMIO) = pvpanic-mmio.o > diff --git a/drivers/platform/arm/pvpanic-mmio.c b/drivers/platform/arm/pvpanic-mmio.c > new file mode 100644 > index 0000000..6a06d24 > --- /dev/null > +++ b/drivers/platform/arm/pvpanic-mmio.c > @@ -0,0 +1,123 @@ > +/* > + * pvpanic mmio device driver > + * > + * Copyright (C) 2018 ZTE Ltd. > + * Author: Peng Hao <peng.hao2@xxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that 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/>. > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/init.h> > +#include <linux/types.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <asm/virt.h> > +#include <linux/platform_device.h> > + > +#define PVPANIC_MMIO_CRASHED (1 << 0) This looks like it's identical to PVPANIC_PANICKED in the existing ACPI IO pvpanic driver. I suspect on the QEMU side, there's one device, and the distinction is only in how this is described. Can't one driver support both? > + > +struct pvpanic_mmio_device { > + void __iomem *base; > +}; > + > +static struct pvpanic_mmio_device pvpanic_mmio_dev; > + > +static void > +pvpanic_mmio_trigger_event(unsigned int event) > +{ > + writeb(event, pvpanic_mmio_dev.base); > +} > + > +static int > +pvpanic_mmio_crash_notify(struct notifier_block *nb, unsigned long code, > + void *unused) > +{ > + pvpanic_mmio_trigger_event(PVPANIC_MMIO_CRASHED); > + return NOTIFY_DONE; > +} > + > +static struct notifier_block pvpanic_mmio_crash_nb = { > + .notifier_call = pvpanic_mmio_crash_notify, > + .priority = 1, > +}; > + > +static int pvpanic_mmio_probe(struct platform_device *pdev) > +{ > + struct resource *mem; > + > + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!mem) > + return -EINVAL; > + > + if (!devm_request_mem_region(&pdev->dev, mem->start, > + resource_size(mem), pdev->name)) > + return -EBUSY; > + > + pvpanic_mmio_dev.base = devm_ioremap(&pdev->dev, mem->start, > + resource_size(mem)); > + if (pvpanic_mmio_dev.base == NULL) > + return -EFAULT; > + > + platform_set_drvdata(pdev, &pvpanic_mmio_dev); > + > + atomic_notifier_chain_register(&panic_notifier_list, > + &pvpanic_mmio_crash_nb); > + > + return 0; > +} > + > + > +static int pvpanic_mmio_remove(struct platform_device *pdev) > +{ > + > + atomic_notifier_chain_unregister(&panic_notifier_list, > + &pvpanic_mmio_crash_nb); > + devm_kfree(&pdev->dev, &pvpanic_mmio_dev); > + return 0; > +} > + > +static const struct of_device_id pvpanic_mmio_match[] = { > + { .compatible = "pvpanic,mmio", }, > + {}, > +}; This should be "qemu,pvpanic-mmio"; "pvpanic" is not the vendor. This should also have a binding document somewhere. Thanks, Mark. > +MODULE_DEVICE_TABLE(of, pvpanic_mmio_match); > + > +static struct platform_driver pvpanic_mmio_driver = { > + .probe = pvpanic_mmio_probe, > + .remove = pvpanic_mmio_remove, > + .driver = { > + .name = "pvpanic-mmio", > + .of_match_table = pvpanic_mmio_match, > + }, > +}; > + > +static int __init pvpanic_mmio_init(void) > +{ > + return platform_driver_register(&pvpanic_mmio_driver); > +} > + > +static void __exit pvpanic_mmio_exit(void) > +{ > + platform_driver_unregister(&pvpanic_mmio_driver); > +} > + > +module_init(pvpanic_mmio_init); > +module_exit(pvpanic_mmio_exit); > + > +MODULE_AUTHOR("Peng Hao<peng.hao2@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("pvpanic mmio device driver"); > +MODULE_LICENSE("GPL"); > -- > 1.8.3.1 >
