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Subject[PATCH v4 2/3] misc/pvpanic: probe multiple instances
Date
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 <mihai.carabas@oracle.com>
---
drivers/misc/pvpanic/pvpanic-mmio.c | 9 ++---
drivers/misc/pvpanic/pvpanic.c | 76 ++++++++++++++++++++++++++++++++-----
drivers/misc/pvpanic/pvpanic.h | 5 +--
3 files changed, 73 insertions(+), 17 deletions(-)

diff --git a/drivers/misc/pvpanic/pvpanic-mmio.c b/drivers/misc/pvpanic/pvpanic-mmio.c
index 7454eeb..5425369 100644
--- a/drivers/misc/pvpanic/pvpanic-mmio.c
+++ b/drivers/misc/pvpanic/pvpanic-mmio.c
@@ -22,11 +22,12 @@
MODULE_DESCRIPTION("pvpanic device driver");
MODULE_LICENSE("GPL");

+static void __iomem *base;
+
static int pvpanic_mmio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
- void __iomem *base;

res = platform_get_mem_or_io(pdev, 0);
if (!res)
@@ -47,15 +48,13 @@ static int pvpanic_mmio_probe(struct platform_device *pdev)
return -EINVAL;
}

- pvpanic_probe(base);
-
- return 0;
+ return pvpanic_probe(base);
}

static int pvpanic_mmio_remove(struct platform_device *pdev)
{

- pvpanic_remove();
+ pvpanic_remove(base);

return 0;
}
diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c
index 652ae01..43b65a3 100644
--- a/drivers/misc/pvpanic/pvpanic.c
+++ b/drivers/misc/pvpanic/pvpanic.c
@@ -14,15 +14,30 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>
+#include <linux/cdev.h>
+#include <linux/list.h>
+#include <linux/slab.h>

#include <uapi/misc/pvpanic.h>

-static void __iomem *base;
+struct pvpanic_instance {
+ void __iomem *base;
+ struct list_head list;
+};
+
+struct list_head pvpanic_list;
+spinlock_t pvpanic_lock;

static void
pvpanic_send_event(unsigned int event)
{
- iowrite8(event, base);
+ struct pvpanic_instance *pi_cur;
+
+ spin_lock(&pvpanic_lock);
+ list_for_each_entry(pi_cur, &pvpanic_list, list) {
+ iowrite8(event, pi_cur->base);
+ }
+ spin_unlock(&pvpanic_lock);
}

static int
@@ -44,19 +59,62 @@
.priority = 1, /* let this called before broken drm_fb_helper */
};

-void pvpanic_probe(void __iomem *pbase)
+int pvpanic_probe(void __iomem *pbase)
{
- base = pbase;
- atomic_notifier_chain_register(&panic_notifier_list,
- &pvpanic_panic_nb);
+ struct pvpanic_instance *pi;
+
+ if(!pbase)
+ return -EINVAL;
+
+ pi = kmalloc(sizeof(*pi), GFP_ATOMIC);
+ if (!pi)
+ return -ENOMEM;
+
+ pi->base = pbase;
+ 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(void __iomem *pbase)
+{
+ struct pvpanic_instance *pi_cur, *pi_next;
+
+ if(!pbase)
+ return -EINVAL;
+
+ spin_lock(&pvpanic_lock);
+ list_for_each_entry_safe(pi_cur, pi_next, &pvpanic_list, list) {
+ if (pi_cur->base == pbase) {
+ list_del(&pi_cur->list);
+ kfree(pi_cur);
+ break;
+ }
+ }
+ spin_unlock(&pvpanic_lock);
+}
+EXPORT_SYMBOL_GPL(pvpanic_remove);
+
+static int pvpanic_init(void)
{
+ INIT_LIST_HEAD(&pvpanic_list);
+ spin_lock_init(&pvpanic_lock);
+
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &pvpanic_panic_nb);

+ return 0;
+}
+
+static void pvpanic_exit(void)
+{
atomic_notifier_chain_unregister(&panic_notifier_list,
&pvpanic_panic_nb);
- base = NULL;
+
}
-EXPORT_SYMBOL_GPL(pvpanic_remove);
+
+module_init(pvpanic_init);
+module_exit(pvpanic_exit);
diff --git a/drivers/misc/pvpanic/pvpanic.h b/drivers/misc/pvpanic/pvpanic.h
index 7e75dce..02023d7 100644
--- a/drivers/misc/pvpanic/pvpanic.h
+++ b/drivers/misc/pvpanic/pvpanic.h
@@ -8,10 +8,9 @@
#ifndef PVPANIC_H_
#define PVPANIC_H_

-
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

-void pvpanic_probe(void __iomem *base);
-void pvpanic_remove(void);
+int pvpanic_probe(void __iomem *base);
+void pvpanic_remove(void __iomem *base);

#endif /* PVPANIC_H_ */
--
1.8.3.1
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