dma-debug: add variables and checks for driver filter
This patch adds the state variables for the driver filter and a function
to check if the filter is enabled and matches to the current device. The
check is built into the err_printk function.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index cdd205d..c01f647 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -99,6 +99,15 @@
static struct dentry *num_free_entries_dent __read_mostly;
static struct dentry *min_free_entries_dent __read_mostly;
+/* per-driver filter related state */
+
+#define NAME_MAX_LEN 64
+
+static char current_driver_name[NAME_MAX_LEN] __read_mostly;
+static struct device_driver *current_driver __read_mostly;
+
+static DEFINE_RWLOCK(driver_name_lock);
+
static const char *type2name[4] = { "single", "page",
"scather-gather", "coherent" };
@@ -128,9 +137,47 @@
#endif
}
+static bool driver_filter(struct device *dev)
+{
+ /* driver filter off */
+ if (likely(!current_driver_name[0]))
+ return true;
+
+ /* driver filter on and initialized */
+ if (current_driver && dev->driver == current_driver)
+ return true;
+
+ /* driver filter on but not yet initialized */
+ if (!current_driver && current_driver_name[0]) {
+ struct device_driver *drv = get_driver(dev->driver);
+ unsigned long flags;
+ bool ret = false;
+
+ if (!drv)
+ return false;
+
+ /* lock to protect against change of current_driver_name */
+ read_lock_irqsave(&driver_name_lock, flags);
+
+ if (drv->name &&
+ strncmp(current_driver_name, drv->name, 63) == 0) {
+ current_driver = drv;
+ ret = true;
+ }
+
+ read_unlock_irqrestore(&driver_name_lock, flags);
+ put_driver(drv);
+
+ return ret;
+ }
+
+ return false;
+}
+
#define err_printk(dev, entry, format, arg...) do { \
error_count += 1; \
- if (show_all_errors || show_num_errors > 0) { \
+ if (driver_filter(dev) && \
+ (show_all_errors || show_num_errors > 0)) { \
WARN(1, "%s %s: " format, \
dev_driver_string(dev), \
dev_name(dev) , ## arg); \