qdio: Keep device-specific dbf entries

Keep the per-device dbf entries until module is removed, with
proper error checking for debug feature setup.

Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index 4221b02..f1f3baa 100644 (file)
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -7,6 +7,7 @@
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/export.h>
+#include <linux/slab.h>
 #include <asm/debug.h>
 #include "qdio_debug.h"
 #include "qdio.h"
@@ -16,11 +17,51 @@ debug_info_t *qdio_dbf_error;
 
 static struct dentry *debugfs_root;
 #define QDIO_DEBUGFS_NAME_LEN  10
+#define QDIO_DBF_NAME_LEN      20
 
-void qdio_allocate_dbf(struct qdio_initialize *init_data,
+struct qdio_dbf_entry {
+       char dbf_name[QDIO_DBF_NAME_LEN];
+       debug_info_t *dbf_info;
+       struct list_head dbf_list;
+};
+
+static LIST_HEAD(qdio_dbf_list);
+static DEFINE_MUTEX(qdio_dbf_list_mutex);
+
+static debug_info_t *qdio_get_dbf_entry(char *name)
+{
+       struct qdio_dbf_entry *entry;
+       debug_info_t *rc = NULL;
+
+       mutex_lock(&qdio_dbf_list_mutex);
+       list_for_each_entry(entry, &qdio_dbf_list, dbf_list) {
+               if (strcmp(entry->dbf_name, name) == 0) {
+                       rc = entry->dbf_info;
+                       break;
+               }
+       }
+       mutex_unlock(&qdio_dbf_list_mutex);
+       return rc;
+}
+
+static void qdio_clear_dbf_list(void)
+{
+       struct qdio_dbf_entry *entry, *tmp;
+
+       mutex_lock(&qdio_dbf_list_mutex);
+       list_for_each_entry_safe(entry, tmp, &qdio_dbf_list, dbf_list) {
+               list_del(&entry->dbf_list);
+               debug_unregister(entry->dbf_info);
+               kfree(entry);
+       }
+       mutex_unlock(&qdio_dbf_list_mutex);
+}
+
+int qdio_allocate_dbf(struct qdio_initialize *init_data,
                       struct qdio_irq *irq_ptr)
 {
-       char text[20];
+       char text[QDIO_DBF_NAME_LEN];
+       struct qdio_dbf_entry *new_entry;
 
        DBF_EVENT("qfmt:%1d", init_data->q_format);
        DBF_HEX(init_data->adapter_name, 8);
@@ -38,11 +79,34 @@ void qdio_allocate_dbf(struct qdio_initialize *init_data,
        DBF_EVENT("irq:%8lx", (unsigned long)irq_ptr);
 
        /* allocate trace view for the interface */
-       snprintf(text, 20, "qdio_%s", dev_name(&init_data->cdev->dev));
-       irq_ptr->debug_area = debug_register(text, 2, 1, 16);
-       debug_register_view(irq_ptr->debug_area, &debug_hex_ascii_view);
-       debug_set_level(irq_ptr->debug_area, DBF_WARN);
-       DBF_DEV_EVENT(DBF_ERR, irq_ptr, "dbf created");
+       snprintf(text, QDIO_DBF_NAME_LEN, "qdio_%s",
+                                       dev_name(&init_data->cdev->dev));
+       irq_ptr->debug_area = qdio_get_dbf_entry(text);
+       if (irq_ptr->debug_area)
+               DBF_DEV_EVENT(DBF_ERR, irq_ptr, "dbf reused");
+       else {
+               irq_ptr->debug_area = debug_register(text, 2, 1, 16);
+               if (!irq_ptr->debug_area)
+                       return -ENOMEM;
+               if (debug_register_view(irq_ptr->debug_area,
+                                               &debug_hex_ascii_view)) {
+                       debug_unregister(irq_ptr->debug_area);
+                       return -ENOMEM;
+               }
+               debug_set_level(irq_ptr->debug_area, DBF_WARN);
+               DBF_DEV_EVENT(DBF_ERR, irq_ptr, "dbf created");
+               new_entry = kzalloc(sizeof(struct qdio_dbf_entry), GFP_KERNEL);
+               if (!new_entry) {
+                       debug_unregister(irq_ptr->debug_area);
+                       return -ENOMEM;
+               }
+               strlcpy(new_entry->dbf_name, text, QDIO_DBF_NAME_LEN);
+               new_entry->dbf_info = irq_ptr->debug_area;
+               mutex_lock(&qdio_dbf_list_mutex);
+               list_add(&new_entry->dbf_list, &qdio_dbf_list);
+               mutex_unlock(&qdio_dbf_list_mutex);
+       }
+       return 0;
 }
 
 static int qstat_show(struct seq_file *m, void *v)
@@ -300,6 +364,7 @@ int __init qdio_debug_init(void)
 
 void qdio_debug_exit(void)
 {
+       qdio_clear_dbf_list();
        debugfs_remove(debugfs_root);
        if (qdio_dbf_setup)
                debug_unregister(qdio_dbf_setup);

diff --git a/drivers/s390/cio/qdio_debug.h b/drivers/s390/cio/qdio_debug.h
index dfac9bf..f33ce85 100644 (file)
--- a/drivers/s390/cio/qdio_debug.h
+++ b/drivers/s390/cio/qdio_debug.h
@@ -75,7 +75,7 @@ static inline void DBF_DEV_HEX(struct qdio_irq *dev, void *addr,
        }
 }
 
-void qdio_allocate_dbf(struct qdio_initialize *init_data,
+int qdio_allocate_dbf(struct qdio_initialize *init_data,
                       struct qdio_irq *irq_ptr);
 void qdio_setup_debug_entries(struct qdio_irq *irq_ptr,
                              struct ccw_device *cdev);

diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index f5f42c4..848e3b6 100644 (file)
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -1233,12 +1233,10 @@ int qdio_free(struct ccw_device *cdev)
                return -ENODEV;
 
        DBF_EVENT("qfree:%4x", cdev->private->schid.sch_no);
+       DBF_DEV_EVENT(DBF_ERR, irq_ptr, "dbf abandoned");
        mutex_lock(&irq_ptr->setup_mutex);
 
-       if (irq_ptr->debug_area != NULL) {
-               debug_unregister(irq_ptr->debug_area);
-               irq_ptr->debug_area = NULL;
-       }
+       irq_ptr->debug_area = NULL;
        cdev->private->qdio_data = NULL;
        mutex_unlock(&irq_ptr->setup_mutex);
 
@@ -1275,7 +1273,8 @@ int qdio_allocate(struct qdio_initialize *init_data)
                goto out_err;
 
        mutex_init(&irq_ptr->setup_mutex);
-       qdio_allocate_dbf(init_data, irq_ptr);
+       if (qdio_allocate_dbf(init_data, irq_ptr))
+               goto out_rel;
 
        /*
         * Allocate a page for the chsc calls in qdio_establish.