From 2e507d849f1834d3fe9aae71b7aabf4c2a3827b8 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 22 May 2009 18:24:20 +0200 Subject: 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 --- lib/dma-debug.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/dma-debug.c b/lib/dma-debug.c index cdd205d6bf7c..c01f64780caf 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -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); \ -- cgit v1.2.3