diff options
Diffstat (limited to 'kernel/dma/debug.c')
| -rw-r--r-- | kernel/dma/debug.c | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 138ede653de4..43d6a996d7a7 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -63,6 +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 * @stack_len: number of backtrace entries in @stack_entries * @stack_entries: stack of backtrace history */ @@ -76,7 +77,8 @@ struct dma_debug_entry { int sg_call_ents; int sg_mapped_ents; phys_addr_t paddr; - enum map_err_types map_err_type; + enum map_err_types map_err_type; + bool is_cache_clean; #ifdef CONFIG_STACKTRACE unsigned int stack_len; unsigned long stack_entries[DMA_DEBUG_STACKTRACE_ENTRIES]; @@ -472,12 +474,15 @@ static int active_cacheline_dec_overlap(phys_addr_t cln) return active_cacheline_set_overlap(cln, --overlap); } -static int active_cacheline_insert(struct dma_debug_entry *entry) +static int active_cacheline_insert(struct dma_debug_entry *entry, + bool *overlap_cache_clean) { phys_addr_t cln = to_cacheline_number(entry); unsigned long flags; int rc; + *overlap_cache_clean = false; + /* 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. @@ -487,8 +492,16 @@ static int active_cacheline_insert(struct dma_debug_entry *entry) spin_lock_irqsave(&radix_lock, flags); rc = radix_tree_insert(&dma_active_cacheline, cln, entry); - if (rc == -EEXIST) + if (rc == -EEXIST) { + struct dma_debug_entry *existing; + active_cacheline_inc_overlap(cln); + 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; + } spin_unlock_irqrestore(&radix_lock, flags); return rc; @@ -583,19 +596,24 @@ DEFINE_SHOW_ATTRIBUTE(dump); */ static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs) { + bool overlap_cache_clean; struct hash_bucket *bucket; unsigned long flags; int rc; + entry->is_cache_clean = !!(attrs & DMA_ATTR_CPU_CACHE_CLEAN); + bucket = get_hash_bucket(entry, &flags); hash_bucket_add(bucket, entry); put_hash_bucket(bucket, flags); - rc = active_cacheline_insert(entry); + rc = active_cacheline_insert(entry, &overlap_cache_clean); 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) && + } else if (rc == -EEXIST && + !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && + !(entry->is_cache_clean && overlap_cache_clean) && !(IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && is_swiotlb_active(entry->dev))) { err_printk(entry->dev, entry, |