dma-debug: Record DMA attributes in debug entry

To enable reliable comparison of DMA attributes between map and
unmap operations, store the attribute value in dma_debug_entry.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Samiullah Khawaja <skhawaja@google.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260501-dma-attrs-debug-v2-4-8dbac75cd501@nvidia.com

diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 3b53495337f5c169fc2116a0c44b03f9f09fdb7e..f07e6a1e9fbabfd51e9b075fb8f443fab6ff7234 100644 (file)
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -63,7 +63,7 @@ enum map_err_types {
  * @sg_mapped_ents: 'mapped_ents' from dma_map_sg
  * @paddr: physical start address of the mapping
  * @map_err_type: track whether dma_mapping_error() was checked
- * @is_cache_clean: driver promises not to write to buffer while mapped
+ * @attrs: dma attributes
  * @stack_len: number of backtrace entries in @stack_entries
  * @stack_entries: stack of backtrace history
  */
@@ -78,7 +78,7 @@ struct dma_debug_entry {
        int              sg_mapped_ents;
        phys_addr_t      paddr;
        enum map_err_types map_err_type;
-       bool             is_cache_clean;
+       unsigned long    attrs;
 #ifdef CONFIG_STACKTRACE
        unsigned int    stack_len;
        unsigned long   stack_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
@@ -478,6 +478,9 @@ static int active_cacheline_insert(struct dma_debug_entry *entry,
                                   bool *overlap_cache_clean)
 {
        phys_addr_t cln = to_cacheline_number(entry);
+       bool is_cache_clean = entry->attrs &
+                             (DMA_ATTR_DEBUGGING_IGNORE_CACHELINES |
+                              DMA_ATTR_REQUIRE_COHERENT);
        unsigned long flags;
        int rc;
 
@@ -495,12 +498,15 @@ static int active_cacheline_insert(struct dma_debug_entry *entry,
        if (rc == -EEXIST) {
                struct dma_debug_entry *existing;
 
-               active_cacheline_inc_overlap(cln, entry->is_cache_clean);
+               active_cacheline_inc_overlap(cln, is_cache_clean);
                existing = radix_tree_lookup(&dma_active_cacheline, cln);
                /* A lookup failure here after we got -EEXIST is unexpected. */
                WARN_ON(!existing);
                if (existing)
-                       *overlap_cache_clean = existing->is_cache_clean;
+                       *overlap_cache_clean =
+                               existing->attrs &
+                               (DMA_ATTR_DEBUGGING_IGNORE_CACHELINES |
+                                DMA_ATTR_REQUIRE_COHERENT);
        }
        spin_unlock_irqrestore(&radix_lock, flags);
 
@@ -544,12 +550,13 @@ void debug_dma_dump_mappings(struct device *dev)
                        if (!dev || dev == entry->dev) {
                                cln = to_cacheline_number(entry);
                                dev_info(entry->dev,
-                                        "%s idx %d P=%pa D=%llx L=%llx cln=%pa %s %s\n",
+                                        "%s idx %d P=%pa D=%llx L=%llx cln=%pa %s %s attrs=0x%lx\n",
                                         type2name[entry->type], idx,
                                         &entry->paddr, entry->dev_addr,
                                         entry->size, &cln,
                                         dir2name[entry->direction],
-                                        maperr2str[entry->map_err_type]);
+                                        maperr2str[entry->map_err_type],
+                                        entry->attrs);
                        }
                }
                spin_unlock_irqrestore(&bucket->lock, flags);
@@ -575,14 +582,15 @@ static int dump_show(struct seq_file *seq, void *v)
                list_for_each_entry(entry, &bucket->list, list) {
                        cln = to_cacheline_number(entry);
                        seq_printf(seq,
-                                  "%s %s %s idx %d P=%pa D=%llx L=%llx cln=%pa %s %s\n",
+                                  "%s %s %s idx %d P=%pa D=%llx L=%llx cln=%pa %s %s attrs=0x%lx\n",
                                   dev_driver_string(entry->dev),
                                   dev_name(entry->dev),
                                   type2name[entry->type], idx,
                                   &entry->paddr, entry->dev_addr,
                                   entry->size, &cln,
                                   dir2name[entry->direction],
-                                  maperr2str[entry->map_err_type]);
+                                  maperr2str[entry->map_err_type],
+                                  entry->attrs);
                }
                spin_unlock_irqrestore(&bucket->lock, flags);
        }
@@ -594,16 +602,14 @@ DEFINE_SHOW_ATTRIBUTE(dump);
  * Wrapper function for adding an entry to the hash.
  * This function takes care of locking itself.
  */
-static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs)
+static void add_dma_entry(struct dma_debug_entry *entry)
 {
+       unsigned long attrs = entry->attrs;
        bool overlap_cache_clean;
        struct hash_bucket *bucket;
        unsigned long flags;
        int rc;
 
-       entry->is_cache_clean = attrs & (DMA_ATTR_DEBUGGING_IGNORE_CACHELINES |
-                                        DMA_ATTR_REQUIRE_COHERENT);
-
        bucket = get_hash_bucket(entry, &flags);
        hash_bucket_add(bucket, entry);
        put_hash_bucket(bucket, flags);
@@ -612,9 +618,10 @@ static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs)
        if (rc == -ENOMEM) {
                pr_err_once("cacheline tracking ENOMEM, dma-debug disabled\n");
                global_disable = true;
-       } else if (rc == -EEXIST &&
-                  !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
-                  !(entry->is_cache_clean && overlap_cache_clean) &&
+       } else if (rc == -EEXIST && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
+                  !(attrs & (DMA_ATTR_DEBUGGING_IGNORE_CACHELINES |
+                             DMA_ATTR_REQUIRE_COHERENT) &&
+                    overlap_cache_clean) &&
                   dma_get_cache_alignment() >= L1_CACHE_BYTES &&
                   !(IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) &&
                     is_swiotlb_active(entry->dev))) {
@@ -1250,6 +1257,7 @@ void debug_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
        entry->size      = size;
        entry->direction = direction;
        entry->map_err_type = MAP_ERR_NOT_CHECKED;
+       entry->attrs     = attrs;
 
        if (!(attrs & DMA_ATTR_MMIO)) {
                check_for_stack(dev, phys);
@@ -1258,7 +1266,7 @@ void debug_dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
                        check_for_illegal_area(dev, phys_to_virt(phys), size);
        }
 
-       add_dma_entry(entry, attrs);
+       add_dma_entry(entry);
 }
 
 void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
@@ -1345,10 +1353,11 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
                entry->direction      = direction;
                entry->sg_call_ents   = nents;
                entry->sg_mapped_ents = mapped_ents;
+               entry->attrs          = attrs;
 
                check_sg_segment(dev, s);
 
-               add_dma_entry(entry, attrs);
+               add_dma_entry(entry);
        }
 }
 
@@ -1440,8 +1449,9 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size,
        entry->size      = size;
        entry->dev_addr  = dma_addr;
        entry->direction = DMA_BIDIRECTIONAL;
+       entry->attrs     = attrs;
 
-       add_dma_entry(entry, attrs);
+       add_dma_entry(entry);
 }
 
 void debug_dma_free_coherent(struct device *dev, size_t size,
@@ -1585,7 +1595,7 @@ void debug_dma_alloc_pages(struct device *dev, struct page *page,
        entry->dev_addr  = dma_addr;
        entry->direction = direction;
 
-       add_dma_entry(entry, 0);
+       add_dma_entry(entry);
 }
 
 void debug_dma_free_pages(struct device *dev, struct page *page,