diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-pci-devices-pvpanic | 12 | ||||
| -rw-r--r-- | drivers/misc/pvpanic.c | 31 |
2 files changed, 38 insertions, 5 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-pci-devices-pvpanic b/Documentation/ABI/testing/sysfs-bus-pci-devices-pvpanic new file mode 100644 index 000000000000..79b7dc31cd55 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-pci-devices-pvpanic @@ -0,0 +1,12 @@ +What: /sys/devices/pci0000:00/*/QEMU0001:00/capability +Date: Jan 2021 +Contact: zhenwei pi <pizhenwei@bytedance.com> +Description: + Read-only attribute. Capabilities of pvpanic device which + are supported by QEMU. + + Format: %x. + + Detailed bit definition refers to section <Bit Definition> + from pvpanic device specification: + https://git.qemu.org/?p=qemu.git;a=blob_plain;f=docs/specs/pvpanic.txt diff --git a/drivers/misc/pvpanic.c b/drivers/misc/pvpanic.c index 41cab297d66e..80cdfa8f951a 100644 --- a/drivers/misc/pvpanic.c +++ b/drivers/misc/pvpanic.c @@ -19,6 +19,20 @@ #include <uapi/misc/pvpanic.h> static void __iomem *base; +static unsigned int capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED; + +static ssize_t capability_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%x", capability); +} +static DEVICE_ATTR_RO(capability); + +static struct attribute *pvpanic_dev_attrs[] = { + &dev_attr_capability.attr, + NULL +}; +ATTRIBUTE_GROUPS(pvpanic_dev); MODULE_AUTHOR("Hu Tao <hutao@cn.fujitsu.com>"); MODULE_DESCRIPTION("pvpanic device driver"); @@ -27,7 +41,8 @@ MODULE_LICENSE("GPL"); static void pvpanic_send_event(unsigned int event) { - iowrite8(event, base); + if (event & capability) + iowrite8(event, base); } static int @@ -73,8 +88,12 @@ static int pvpanic_mmio_probe(struct platform_device *pdev) return -EINVAL; } - atomic_notifier_chain_register(&panic_notifier_list, - &pvpanic_panic_nb); + /* initlize capability by RDPT */ + capability &= ioread8(base); + + if (capability) + atomic_notifier_chain_register(&panic_notifier_list, + &pvpanic_panic_nb); return 0; } @@ -82,8 +101,9 @@ static int pvpanic_mmio_probe(struct platform_device *pdev) static int pvpanic_mmio_remove(struct platform_device *pdev) { - atomic_notifier_chain_unregister(&panic_notifier_list, - &pvpanic_panic_nb); + if (capability) + atomic_notifier_chain_unregister(&panic_notifier_list, + &pvpanic_panic_nb); return 0; } @@ -104,6 +124,7 @@ static struct platform_driver pvpanic_mmio_driver = { .name = "pvpanic-mmio", .of_match_table = pvpanic_mmio_match, .acpi_match_table = pvpanic_device_ids, + .dev_groups = pvpanic_dev_groups, }, .probe = pvpanic_mmio_probe, .remove = pvpanic_mmio_remove, |