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| author |   Corentin Labbe <clabbe@baylibre.com> | 2019-01-18 13:44:18 +0000 |
|---|---|---|
| committer |   Christoph Hellwig <hch@lst.de> | 2019-02-01 10:06:44 +0100 |
| commit | 0a3b192c26da198fce38e1ee242a34f558670246 (patch) | |
| tree | 50c7205f8335fed7863f9446db981936cd350a6e | |
| parent | dma: debug: no need to check return value of debugfs_create functions (diff) | |
| download | linux-dev-0a3b192c26da198fce38e1ee242a34f558670246.tar.xz linux-dev-0a3b192c26da198fce38e1ee242a34f558670246.zip | |
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 <clabbe@baylibre.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to '')
| -rw-r--r-- | Documentation/DMA-API.txt | 3 | ||||
| -rw-r--r-- | kernel/dma/debug.c | 28 |
2 files changed, 31 insertions, 0 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index e133ccd60228..78114ee63057 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -696,6 +696,9 @@ dma-api/disabled This read-only file contains the character 'Y' happen when it runs out of memory or if it was disabled at boot time +dma-api/dump This read-only file contains current DMA + mappings. + dma-api/error_count This file is read-only and shows the total numbers of errors found. 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) |