From b3c0f8774668fd30a3efb2d0afc1a6527dacb858 Mon Sep 17 00:00:00 2001 From: Mihai Carabas Date: Wed, 24 Mar 2021 16:49:15 +0200 Subject: [PATCH] misc/pvpanic: probe multiple instances Create the mecahism that allows multiple pvpanic instances to call pvpanic_probe and receive panic events. A global list will retain all the mapped addresses where to write panic events. Signed-off-by: Mihai Carabas Link: https://lore.kernel.org/r/1616597356-20696-3-git-send-email-mihai.carabas@oracle.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/pvpanic/pvpanic-mmio.c | 42 ++++++++++------- drivers/misc/pvpanic/pvpanic.c | 72 +++++++++++++++++++++-------- drivers/misc/pvpanic/pvpanic.h | 12 +++-- 3 files changed, 87 insertions(+), 39 deletions(-) diff --git a/drivers/misc/pvpanic/pvpanic-mmio.c b/drivers/misc/pvpanic/pvpanic-mmio.c index d7bf7db6c19c..4c0841776087 100644 --- a/drivers/misc/pvpanic/pvpanic-mmio.c +++ b/drivers/misc/pvpanic/pvpanic-mmio.c @@ -14,6 +14,7 @@ #include #include #include +#include #include @@ -23,25 +24,26 @@ MODULE_AUTHOR("Hu Tao "); MODULE_DESCRIPTION("pvpanic-mmio device driver"); MODULE_LICENSE("GPL"); -static void __iomem *base; -static unsigned int capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED; -static unsigned int events; - static ssize_t capability_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%x\n", capability); + struct pvpanic_instance *pi = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%x\n", pi->capability); } static DEVICE_ATTR_RO(capability); static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%x\n", events); + struct pvpanic_instance *pi = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%x\n", pi->events); } static ssize_t events_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { + struct pvpanic_instance *pi = dev_get_drvdata(dev); unsigned int tmp; int err; @@ -49,15 +51,12 @@ static ssize_t events_store(struct device *dev, struct device_attribute *attr, if (err) return err; - if ((tmp & capability) != tmp) + if ((tmp & pi->capability) != tmp) return -EINVAL; - events = tmp; - - pvpanic_set_events(events); + pi->events = tmp; return count; - } static DEVICE_ATTR_RW(events); @@ -71,7 +70,9 @@ ATTRIBUTE_GROUPS(pvpanic_mmio_dev); static int pvpanic_mmio_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; + struct pvpanic_instance *pi; struct resource *res; + void __iomem *base; res = platform_get_mem_or_io(pdev, 0); if (!res) @@ -92,19 +93,28 @@ static int pvpanic_mmio_probe(struct platform_device *pdev) return -EINVAL; } + pi = kmalloc(sizeof(*pi), GFP_ATOMIC); + if (!pi) + return -ENOMEM; + + pi->base = base; + pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED; + /* initlize capability by RDPT */ - capability &= ioread8(base); - events = capability; + pi->capability &= ioread8(base); + pi->events = pi->capability; - pvpanic_probe(base, capability); + dev_set_drvdata(dev, pi); - return 0; + return pvpanic_probe(pi); } static int pvpanic_mmio_remove(struct platform_device *pdev) { + struct pvpanic_instance *pi = dev_get_drvdata(&pdev->dev); - pvpanic_remove(); + pvpanic_remove(pi); + kfree(pi); return 0; } diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c index a9605f90c534..804099c2d7fa 100644 --- a/drivers/misc/pvpanic/pvpanic.c +++ b/drivers/misc/pvpanic/pvpanic.c @@ -14,6 +14,8 @@ #include #include #include +#include +#include #include @@ -23,15 +25,20 @@ MODULE_AUTHOR("Mihai Carabas "); MODULE_DESCRIPTION("pvpanic device driver "); MODULE_LICENSE("GPL"); -static void __iomem *base; -static unsigned int capability; -static unsigned int events; +struct list_head pvpanic_list; +spinlock_t pvpanic_lock; static void pvpanic_send_event(unsigned int event) { - if (event & capability & events) - iowrite8(event, base); + struct pvpanic_instance *pi_cur; + + spin_lock(&pvpanic_lock); + list_for_each_entry(pi_cur, &pvpanic_list, list) { + if (event & pi_cur->capability & pi_cur->events) + iowrite8(event, pi_cur->base); + } + spin_unlock(&pvpanic_lock); } static int @@ -53,29 +60,54 @@ static struct notifier_block pvpanic_panic_nb = { .priority = 1, /* let this called before broken drm_fb_helper */ }; -void pvpanic_probe(void __iomem *pbase, unsigned int dev_cap) +int pvpanic_probe(struct pvpanic_instance *pi) { - base = pbase; - capability = dev_cap; - events = capability; + if (!pi || !pi->base) + return -EINVAL; - if (capability) - atomic_notifier_chain_register(&panic_notifier_list, - &pvpanic_panic_nb); + spin_lock(&pvpanic_lock); + list_add(&pi->list, &pvpanic_list); + spin_unlock(&pvpanic_lock); + + return 0; } EXPORT_SYMBOL_GPL(pvpanic_probe); -void pvpanic_remove(void) +void pvpanic_remove(struct pvpanic_instance *pi) { - if (capability) - atomic_notifier_chain_unregister(&panic_notifier_list, - &pvpanic_panic_nb); - base = NULL; + struct pvpanic_instance *pi_cur, *pi_next; + + if (!pi) + return; + + spin_lock(&pvpanic_lock); + list_for_each_entry_safe(pi_cur, pi_next, &pvpanic_list, list) { + if (pi_cur == pi) { + list_del(&pi_cur->list); + break; + } + } + spin_unlock(&pvpanic_lock); } EXPORT_SYMBOL_GPL(pvpanic_remove); -void pvpanic_set_events(unsigned int dev_events) +static int pvpanic_init(void) { - events = dev_events; + INIT_LIST_HEAD(&pvpanic_list); + spin_lock_init(&pvpanic_lock); + + atomic_notifier_chain_register(&panic_notifier_list, + &pvpanic_panic_nb); + + return 0; } -EXPORT_SYMBOL_GPL(pvpanic_set_events); + +static void pvpanic_exit(void) +{ + atomic_notifier_chain_unregister(&panic_notifier_list, + &pvpanic_panic_nb); + +} + +module_init(pvpanic_init); +module_exit(pvpanic_exit); diff --git a/drivers/misc/pvpanic/pvpanic.h b/drivers/misc/pvpanic/pvpanic.h index 3abe15fa24b8..1afccc2e9fec 100644 --- a/drivers/misc/pvpanic/pvpanic.h +++ b/drivers/misc/pvpanic/pvpanic.h @@ -8,8 +8,14 @@ #ifndef PVPANIC_H_ #define PVPANIC_H_ -void pvpanic_probe(void __iomem *base, unsigned int dev_cap); -void pvpanic_remove(void); -void pvpanic_set_events(unsigned int dev_events); +struct pvpanic_instance { + void __iomem *base; + unsigned int capability; + unsigned int events; + struct list_head list; +}; + +int pvpanic_probe(struct pvpanic_instance *pi); +void pvpanic_remove(struct pvpanic_instance *pi); #endif /* PVPANIC_H_ */