1 files changed, 13 insertions, 223 deletions

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 98f2d7e91a91..d87a17a819d0 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -53,26 +53,11 @@ enum map_err_types {
 
 #define DMA_DEBUG_STACKTRACE_ENTRIES 5
 
-/**
- * struct dma_debug_entry - track a dma_map* or dma_alloc_coherent mapping
- * @list: node on pre-allocated free_entries list
- * @dev: 'dev' argument to dma_map_{page|single|sg} or dma_alloc_coherent
- * @type: single, page, sg, coherent
- * @pfn: page frame of the start address
- * @offset: offset of mapping relative to pfn
- * @size: length of the mapping
- * @direction: enum dma_data_direction
- * @sg_call_ents: 'nents' from dma_map_sg
- * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
- * @map_err_type: track whether dma_mapping_error() was checked
- * @stacktrace: support backtraces when a violation is detected
- */
 struct dma_debug_entry {
 	struct list_head list;
 	struct device    *dev;
 	int              type;
-	unsigned long	 pfn;
-	size_t		 offset;
+	phys_addr_t      paddr;
 	u64              dev_addr;
 	u64              size;
 	int              direction;
@@ -387,11 +372,6 @@ static void hash_bucket_del(struct dma_debug_entry *entry)
 	list_del(&entry->list);
 }
 
-static unsigned long long phys_addr(struct dma_debug_entry *entry)
-{
-	return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
-}
-
 /*
  * Dump mapping entries for debugging purposes
  */
@@ -409,9 +389,9 @@ void debug_dma_dump_mappings(struct device *dev)
 		list_for_each_entry(entry, &bucket->list, list) {
 			if (!dev || dev == entry->dev) {
 				dev_info(entry->dev,
-					 "%s idx %d P=%Lx N=%lx D=%Lx L=%Lx %s %s\n",
+					 "%s idx %d P=%Lx D=%Lx L=%Lx %s %s\n",
 					 type2name[entry->type], idx,
-					 phys_addr(entry), entry->pfn,
+					 (unsigned long long)entry->paddr,
 					 entry->dev_addr, entry->size,
 					 dir2name[entry->direction],
 					 maperr2str[entry->map_err_type]);
@@ -424,176 +404,6 @@ void debug_dma_dump_mappings(struct device *dev)
 EXPORT_SYMBOL(debug_dma_dump_mappings);
 
 /*
- * For each mapping (initial cacheline in the case of
- * dma_alloc_coherent/dma_map_page, initial cacheline in each page of a
- * scatterlist, or the cacheline specified in dma_map_single) insert
- * into this tree using the cacheline as the key. At
- * dma_unmap_{single|sg|page} or dma_free_coherent delete the entry.  If
- * the entry already exists at insertion time add a tag as a reference
- * count for the overlapping mappings.  For now, the overlap tracking
- * just ensures that 'unmaps' balance 'maps' before marking the
- * cacheline idle, but we should also be flagging overlaps as an API
- * violation.
- *
- * Memory usage is mostly constrained by the maximum number of available
- * dma-debug entries in that we need a free dma_debug_entry before
- * inserting into the tree.  In the case of dma_map_page and
- * dma_alloc_coherent there is only one dma_debug_entry and one
- * dma_active_cacheline entry to track per event.  dma_map_sg(), on the
- * other hand, consumes a single dma_debug_entry, but inserts 'nents'
- * entries into the tree.
- *
- * At any time debug_dma_assert_idle() can be called to trigger a
- * warning if any cachelines in the given page are in the active set.
- */
-static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT);
-static DEFINE_SPINLOCK(radix_lock);
-#define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1)
-#define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)
-#define CACHELINES_PER_PAGE (1 << CACHELINE_PER_PAGE_SHIFT)
-
-static phys_addr_t to_cacheline_number(struct dma_debug_entry *entry)
-{
-	return (entry->pfn << CACHELINE_PER_PAGE_SHIFT) +
-		(entry->offset >> L1_CACHE_SHIFT);
-}
-
-static int active_cacheline_read_overlap(phys_addr_t cln)
-{
-	int overlap = 0, i;
-
-	for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
-		if (radix_tree_tag_get(&dma_active_cacheline, cln, i))
-			overlap |= 1 << i;
-	return overlap;
-}
-
-static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
-{
-	int i;
-
-	if (overlap > ACTIVE_CACHELINE_MAX_OVERLAP || overlap < 0)
-		return overlap;
-
-	for (i = RADIX_TREE_MAX_TAGS - 1; i >= 0; i--)
-		if (overlap & 1 << i)
-			radix_tree_tag_set(&dma_active_cacheline, cln, i);
-		else
-			radix_tree_tag_clear(&dma_active_cacheline, cln, i);
-
-	return overlap;
-}
-
-static void active_cacheline_inc_overlap(phys_addr_t cln)
-{
-	int overlap = active_cacheline_read_overlap(cln);
-
-	overlap = active_cacheline_set_overlap(cln, ++overlap);
-
-	/* If we overflowed the overlap counter then we're potentially
-	 * leaking dma-mappings.  Otherwise, if maps and unmaps are
-	 * balanced then this overflow may cause false negatives in
-	 * debug_dma_assert_idle() as the cacheline may be marked idle
-	 * prematurely.
-	 */
-	WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
-		  "DMA-API: exceeded %d overlapping mappings of cacheline %pa\n",
-		  ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
-}
-
-static int active_cacheline_dec_overlap(phys_addr_t cln)
-{
-	int overlap = active_cacheline_read_overlap(cln);
-
-	return active_cacheline_set_overlap(cln, --overlap);
-}
-
-static int active_cacheline_insert(struct dma_debug_entry *entry)
-{
-	phys_addr_t cln = to_cacheline_number(entry);
-	unsigned long flags;
-	int rc;
-
-	/* If the device is not writing memory then we don't have any
-	 * concerns about the cpu consuming stale data.  This mitigates
-	 * legitimate usages of overlapping mappings.
-	 */
-	if (entry->direction == DMA_TO_DEVICE)
-		return 0;
-
-	spin_lock_irqsave(&radix_lock, flags);
-	rc = radix_tree_insert(&dma_active_cacheline, cln, entry);
-	if (rc == -EEXIST)
-		active_cacheline_inc_overlap(cln);
-	spin_unlock_irqrestore(&radix_lock, flags);
-
-	return rc;
-}
-
-static void active_cacheline_remove(struct dma_debug_entry *entry)
-{
-	phys_addr_t cln = to_cacheline_number(entry);
-	unsigned long flags;
-
-	/* ...mirror the insert case */
-	if (entry->direction == DMA_TO_DEVICE)
-		return;
-
-	spin_lock_irqsave(&radix_lock, flags);
-	/* since we are counting overlaps the final put of the
-	 * cacheline will occur when the overlap count is 0.
-	 * active_cacheline_dec_overlap() returns -1 in that case
-	 */
-	if (active_cacheline_dec_overlap(cln) < 0)
-		radix_tree_delete(&dma_active_cacheline, cln);
-	spin_unlock_irqrestore(&radix_lock, flags);
-}
-
-/**
- * debug_dma_assert_idle() - assert that a page is not undergoing dma
- * @page: page to lookup in the dma_active_cacheline tree
- *
- * Place a call to this routine in cases where the cpu touching the page
- * before the dma completes (page is dma_unmapped) will lead to data
- * corruption.
- */
-void debug_dma_assert_idle(struct page *page)
-{
-	static struct dma_debug_entry *ents[CACHELINES_PER_PAGE];
-	struct dma_debug_entry *entry = NULL;
-	void **results = (void **) &ents;
-	unsigned int nents, i;
-	unsigned long flags;
-	phys_addr_t cln;
-
-	if (!page)
-		return;
-
-	cln = (phys_addr_t) page_to_pfn(page) << CACHELINE_PER_PAGE_SHIFT;
-	spin_lock_irqsave(&radix_lock, flags);
-	nents = radix_tree_gang_lookup(&dma_active_cacheline, results, cln,
-				       CACHELINES_PER_PAGE);
-	for (i = 0; i < nents; i++) {
-		phys_addr_t ent_cln = to_cacheline_number(ents[i]);
-
-		if (ent_cln == cln) {
-			entry = ents[i];
-			break;
-		} else if (ent_cln >= cln + CACHELINES_PER_PAGE)
-			break;
-	}
-	spin_unlock_irqrestore(&radix_lock, flags);
-
-	if (!entry)
-		return;
-
-	cln = to_cacheline_number(entry);
-	err_printk(entry->dev, entry,
-		   "DMA-API: cpu touching an active dma mapped cacheline [cln=%pa]\n",
-		   &cln);
-}
-
-/*
  * Wrapper function for adding an entry to the hash.
  * This function takes care of locking itself.
  */
@@ -601,21 +411,10 @@ static void add_dma_entry(struct dma_debug_entry *entry)
 {
 	struct hash_bucket *bucket;
 	unsigned long flags;
-	int rc;
 
 	bucket = get_hash_bucket(entry, &flags);
 	hash_bucket_add(bucket, entry);
 	put_hash_bucket(bucket, &flags);
-
-	rc = active_cacheline_insert(entry);
-	if (rc == -ENOMEM) {
-		pr_err("DMA-API: cacheline tracking ENOMEM, dma-debug disabled\n");
-		global_disable = true;
-	}
-
-	/* TODO: report -EEXIST errors here as overlapping mappings are
-	 * not supported by the DMA API
-	 */
 }
 
 static struct dma_debug_entry *__dma_entry_alloc(void)
@@ -670,8 +469,6 @@ static void dma_entry_free(struct dma_debug_entry *entry)
 {
 	unsigned long flags;
 
-	active_cacheline_remove(entry);
-
 	/*
 	 * add to beginning of the list - this way the entries are
 	 * more likely cache hot when they are reallocated.
@@ -1098,15 +895,15 @@ static void check_unmap(struct dma_debug_entry *ref)
 			   ref->dev_addr, ref->size,
 			   type2name[entry->type], type2name[ref->type]);
 	} else if ((entry->type == dma_debug_coherent) &&
-		   (phys_addr(ref) != phys_addr(entry))) {
+		   (ref->paddr != entry->paddr)) {
 		err_printk(ref->dev, entry, "DMA-API: device driver frees "
 			   "DMA memory with different CPU address "
 			   "[device address=0x%016llx] [size=%llu bytes] "
 			   "[cpu alloc address=0x%016llx] "
 			   "[cpu free address=0x%016llx]",
 			   ref->dev_addr, ref->size,
-			   phys_addr(entry),
-			   phys_addr(ref));
+			   (unsigned long long)entry->paddr,
+			   (unsigned long long)ref->paddr);
 	}
 
 	if (ref->sg_call_ents && ref->type == dma_debug_sg &&
@@ -1255,8 +1052,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
 
 	entry->dev       = dev;
 	entry->type      = dma_debug_page;
-	entry->pfn	 = page_to_pfn(page);
-	entry->offset	 = offset,
+	entry->paddr     = page_to_phys(page) + offset;
 	entry->dev_addr  = dma_addr;
 	entry->size      = size;
 	entry->direction = direction;
@@ -1352,8 +1148,7 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
 
 		entry->type           = dma_debug_sg;
 		entry->dev            = dev;
-		entry->pfn	      = page_to_pfn(sg_page(s));
-		entry->offset	      = s->offset,
+		entry->paddr          = sg_phys(s);
 		entry->size           = sg_dma_len(s);
 		entry->dev_addr       = sg_dma_address(s);
 		entry->direction      = direction;
@@ -1403,8 +1198,7 @@ void debug_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
 		struct dma_debug_entry ref = {
 			.type           = dma_debug_sg,
 			.dev            = dev,
-			.pfn		= page_to_pfn(sg_page(s)),
-			.offset		= s->offset,
+			.paddr          = sg_phys(s),
 			.dev_addr       = sg_dma_address(s),
 			.size           = sg_dma_len(s),
 			.direction      = dir,
@@ -1439,8 +1233,7 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size,
 
 	entry->type      = dma_debug_coherent;
 	entry->dev       = dev;
-	entry->pfn	 = page_to_pfn(virt_to_page(virt));
-	entry->offset	 = (size_t) virt & PAGE_MASK;
+	entry->paddr     = virt_to_phys(virt);
 	entry->size      = size;
 	entry->dev_addr  = dma_addr;
 	entry->direction = DMA_BIDIRECTIONAL;
@@ -1455,8 +1248,7 @@ void debug_dma_free_coherent(struct device *dev, size_t size,
 	struct dma_debug_entry ref = {
 		.type           = dma_debug_coherent,
 		.dev            = dev,
-		.pfn		= page_to_pfn(virt_to_page(virt)),
-		.offset		= (size_t) virt & PAGE_MASK,
+		.paddr          = virt_to_phys(virt),
 		.dev_addr       = addr,
 		.size           = size,
 		.direction      = DMA_BIDIRECTIONAL,
@@ -1564,8 +1356,7 @@ void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 		struct dma_debug_entry ref = {
 			.type           = dma_debug_sg,
 			.dev            = dev,
-			.pfn		= page_to_pfn(sg_page(s)),
-			.offset		= s->offset,
+			.paddr          = sg_phys(s),
 			.dev_addr       = sg_dma_address(s),
 			.size           = sg_dma_len(s),
 			.direction      = direction,
@@ -1597,8 +1388,7 @@ void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 		struct dma_debug_entry ref = {
 			.type           = dma_debug_sg,
 			.dev            = dev,
-			.pfn		= page_to_pfn(sg_page(s)),
-			.offset		= s->offset,
+			.paddr          = sg_phys(s),
 			.dev_addr       = sg_dma_address(s),
 			.size           = sg_dma_len(s),
 			.direction      = direction,