From 0a3b192c26da198fce38e1ee242a34f558670246 Mon Sep 17 00:00:00 2001 From: Corentin Labbe Date: Fri, 18 Jan 2019 13:44:18 +0000 Subject: dma-debug: add dumping facility via debugfs While debugging a DMA mapping leak, I needed to access debug_dma_dump_mappings() but easily from user space. This patch adds a /sys/kernel/debug/dma-api/dump file which contain all current DMA mapping. Signed-off-by: Corentin Labbe Signed-off-by: Christoph Hellwig --- kernel/dma/debug.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'kernel/dma') diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 56cd836a902c..45d51e8e26f6 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -829,6 +829,33 @@ static const struct file_operations filter_fops = { .llseek = default_llseek, }; +static int dump_show(struct seq_file *seq, void *v) +{ + int idx; + + for (idx = 0; idx < HASH_SIZE; idx++) { + struct hash_bucket *bucket = &dma_entry_hash[idx]; + struct dma_debug_entry *entry; + unsigned long flags; + + spin_lock_irqsave(&bucket->lock, flags); + list_for_each_entry(entry, &bucket->list, list) { + seq_printf(seq, + "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx %s %s\n", + dev_name(entry->dev), + dev_driver_string(entry->dev), + type2name[entry->type], idx, + phys_addr(entry), entry->pfn, + entry->dev_addr, entry->size, + dir2name[entry->direction], + maperr2str[entry->map_err_type]); + } + spin_unlock_irqrestore(&bucket->lock, flags); + } + return 0; +} +DEFINE_SHOW_ATTRIBUTE(dump); + static void dma_debug_fs_init(void) { struct dentry *dentry = debugfs_create_dir("dma-api", NULL); @@ -841,6 +868,7 @@ static void dma_debug_fs_init(void) debugfs_create_u32("min_free_entries", 0444, dentry, &min_free_entries); debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries); debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops); + debugfs_create_file("dump", 0444, dentry, NULL, &dump_fops); } static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry) -- cgit v1.2.3-59-g8ed1b