diff options
Diffstat (limited to 'drivers/dma/dmaengine.c')
| -rw-r--r-- | drivers/dma/dmaengine.c | 104 |
1 files changed, 102 insertions, 2 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index c3b1283b6d31..4830ba658ce1 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -58,6 +58,87 @@ static DEFINE_IDA(dma_ida); static LIST_HEAD(dma_device_list); static long dmaengine_ref_count; +/* --- debugfs implementation --- */ +#ifdef CONFIG_DEBUG_FS +#include <linux/debugfs.h> + +static struct dentry *rootdir; + +static void dmaengine_debug_register(struct dma_device *dma_dev) +{ + dma_dev->dbg_dev_root = debugfs_create_dir(dev_name(dma_dev->dev), + rootdir); + if (IS_ERR(dma_dev->dbg_dev_root)) + dma_dev->dbg_dev_root = NULL; +} + +static void dmaengine_debug_unregister(struct dma_device *dma_dev) +{ + debugfs_remove_recursive(dma_dev->dbg_dev_root); + dma_dev->dbg_dev_root = NULL; +} + +static void dmaengine_dbg_summary_show(struct seq_file *s, + struct dma_device *dma_dev) +{ + struct dma_chan *chan; + + list_for_each_entry(chan, &dma_dev->channels, device_node) { + if (chan->client_count) { + seq_printf(s, " %-13s| %s", dma_chan_name(chan), + chan->dbg_client_name ?: "in-use"); + + if (chan->router) + seq_printf(s, " (via router: %s)\n", + dev_name(chan->router->dev)); + else + seq_puts(s, "\n"); + } + } +} + +static int dmaengine_summary_show(struct seq_file *s, void *data) +{ + struct dma_device *dma_dev = NULL; + + mutex_lock(&dma_list_mutex); + list_for_each_entry(dma_dev, &dma_device_list, global_node) { + seq_printf(s, "dma%d (%s): number of channels: %u\n", + dma_dev->dev_id, dev_name(dma_dev->dev), + dma_dev->chancnt); + + if (dma_dev->dbg_summary_show) + dma_dev->dbg_summary_show(s, dma_dev); + else + dmaengine_dbg_summary_show(s, dma_dev); + + if (!list_is_last(&dma_dev->global_node, &dma_device_list)) + seq_puts(s, "\n"); + } + mutex_unlock(&dma_list_mutex); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(dmaengine_summary); + +static void __init dmaengine_debugfs_init(void) +{ + rootdir = debugfs_create_dir("dmaengine", NULL); + + /* /sys/kernel/debug/dmaengine/summary */ + debugfs_create_file("summary", 0444, rootdir, NULL, + &dmaengine_summary_fops); +} +#else +static inline void dmaengine_debugfs_init(void) { } +static inline int dmaengine_debug_register(struct dma_device *dma_dev) +{ + return 0; +} + +static inline void dmaengine_debug_unregister(struct dma_device *dma_dev) { } +#endif /* DEBUG_FS */ + /* --- sysfs implementation --- */ #define DMA_SLAVE_NAME "slave" @@ -760,6 +841,11 @@ struct dma_chan *dma_request_chan(struct device *dev, const char *name) return chan ? chan : ERR_PTR(-EPROBE_DEFER); found: +#ifdef CONFIG_DEBUG_FS + chan->dbg_client_name = kasprintf(GFP_KERNEL, "%s:%s", dev_name(dev), + name); +#endif + chan->name = kasprintf(GFP_KERNEL, "dma:%s", name); if (!chan->name) return chan; @@ -837,6 +923,11 @@ void dma_release_channel(struct dma_chan *chan) chan->name = NULL; chan->slave = NULL; } + +#ifdef CONFIG_DEBUG_FS + kfree(chan->dbg_client_name); + chan->dbg_client_name = NULL; +#endif mutex_unlock(&dma_list_mutex); } EXPORT_SYMBOL_GPL(dma_release_channel); @@ -1151,7 +1242,7 @@ int dma_async_device_register(struct dma_device *device) } if (!device->device_release) - dev_warn(device->dev, + dev_dbg(device->dev, "WARN: Device release is not defined so it is not safe to unbind this driver while in use\n"); kref_init(&device->ref); @@ -1196,6 +1287,8 @@ int dma_async_device_register(struct dma_device *device) dma_channel_rebalance(); mutex_unlock(&dma_list_mutex); + dmaengine_debug_register(device); + return 0; err_out: @@ -1229,6 +1322,8 @@ void dma_async_device_unregister(struct dma_device *device) { struct dma_chan *chan, *n; + dmaengine_debug_unregister(device); + list_for_each_entry_safe(chan, n, &device->channels, device_node) __dma_async_device_channel_unregister(device, chan); @@ -1559,6 +1654,11 @@ static int __init dma_bus_init(void) if (err) return err; - return class_register(&dma_devclass); + + err = class_register(&dma_devclass); + if (!err) + dmaengine_debugfs_init(); + + return err; } arch_initcall(dma_bus_init); |