Merge tag 'dma-mapping-5.9-1' of git://git.infradead.org/users/hch/dma-mapping

[linux-2.6-microblaze.git] / kernel / dma / debug.c

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index f7f807f..8e9f7b3 100644 (file)
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -448,9 +448,6 @@ void debug_dma_dump_mappings(struct device *dev)
  * 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);
@@ -497,10 +494,7 @@ static void active_cacheline_inc_overlap(phys_addr_t 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.
+        * leaking dma-mappings.
         */
        WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
                  pr_fmt("exceeded %d overlapping mappings of cacheline %pa\n"),
@@ -555,53 +549,6 @@ static void active_cacheline_remove(struct dma_debug_entry *entry)
        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.