Commit 2e507d84 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

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: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 41fb454e

lib/dma-debug.c

+48 −1
Original line number Diff line number Diff line
@@ -99,6 +99,15 @@ static struct dentry *show_num_errors_dent __read_mostly; 
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 @@ static inline void dump_entry_trace(struct dma_debug_entry *entry) 
#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);		\