* 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);
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.
+ * leaking dma-mappings.
*/
WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
pr_fmt("exceeded %d overlapping mappings of cacheline %pa\n"),
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 (dma_debug_disabled())
- return;
-
- 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,
- "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.