From ac26c18bd35d982d1ba06020a992b1085fefc3e2 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Thu, 12 Feb 2009 16:19:13 +0100 Subject: [PATCH] dma-debug: add function to dump dma mappings This adds a function to dump the DMA mappings that the debugging code is aware of -- either for a single device, or for _all_ devices. This can be useful for debugging -- sticking a call to it in the DMA page fault handler, for example, to see if the faulting address _should_ be mapped or not, and hence work out whether it's IOMMU bugs we're seeing, or driver bugs. Signed-off-by: David Woodhouse --- include/linux/dma-debug.h | 6 ++++++ lib/dma-debug.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/include/linux/dma-debug.h b/include/linux/dma-debug.h index 4985c6c5237e..46a11c10da04 100644 --- a/include/linux/dma-debug.h +++ b/include/linux/dma-debug.h @@ -76,6 +76,8 @@ extern void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nelems, int direction); +extern void debug_dma_dump_mappings(struct device *dev); + #else /* CONFIG_DMA_API_DEBUG */ static inline void dma_debug_init(u32 num_entries) @@ -156,6 +158,10 @@ static inline void debug_dma_sync_sg_for_device(struct device *dev, { } +static inline void debug_dma_dump_mappings(struct device *dev) +{ +} + #endif /* CONFIG_DMA_API_DEBUG */ #endif /* __DMA_DEBUG_H */ diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 9d11e89c2ee2..91ed1dfdbaac 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -193,6 +193,36 @@ static void hash_bucket_del(struct dma_debug_entry *entry) list_del(&entry->list); } +/* + * Dump mapping entries for debugging purposes + */ +void debug_dma_dump_mappings(struct device *dev) +{ + 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) { + if (!dev || dev == entry->dev) { + dev_info(entry->dev, + "%s idx %d P=%Lx D=%Lx L=%Lx %s\n", + type2name[entry->type], idx, + (unsigned long long)entry->paddr, + entry->dev_addr, entry->size, + dir2name[entry->direction]); + } + } + + spin_unlock_irqrestore(&bucket->lock, flags); + } +} +EXPORT_SYMBOL(debug_dma_dump_mappings); + /* * Wrapper function for adding an entry to the hash. * This function takes care of locking itself. -- 2.20.1