diff options
Diffstat (limited to 'lib/dma-debug.c')
| -rw-r--r-- | lib/dma-debug.c | 95 |
1 files changed, 80 insertions, 15 deletions
diff --git a/lib/dma-debug.c b/lib/dma-debug.c index d84beb994f36..d87a17a819d0 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -45,6 +45,12 @@ enum { dma_debug_coherent, }; +enum map_err_types { + MAP_ERR_CHECK_NOT_APPLICABLE, + MAP_ERR_NOT_CHECKED, + MAP_ERR_CHECKED, +}; + #define DMA_DEBUG_STACKTRACE_ENTRIES 5 struct dma_debug_entry { @@ -57,6 +63,7 @@ struct dma_debug_entry { int direction; int sg_call_ents; int sg_mapped_ents; + enum map_err_types map_err_type; #ifdef CONFIG_STACKTRACE struct stack_trace stacktrace; unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES]; @@ -114,6 +121,12 @@ static struct device_driver *current_driver __read_mostly; static DEFINE_RWLOCK(driver_name_lock); +static const char *const maperr2str[] = { + [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable", + [MAP_ERR_NOT_CHECKED] = "dma map error not checked", + [MAP_ERR_CHECKED] = "dma map error checked", +}; + static const char *type2name[4] = { "single", "page", "scather-gather", "coherent" }; @@ -376,11 +389,12 @@ 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 D=%Lx L=%Lx %s\n", + "%s idx %d P=%Lx D=%Lx L=%Lx %s %s\n", type2name[entry->type], idx, (unsigned long long)entry->paddr, entry->dev_addr, entry->size, - dir2name[entry->direction]); + dir2name[entry->direction], + maperr2str[entry->map_err_type]); } } @@ -844,21 +858,25 @@ static void check_unmap(struct dma_debug_entry *ref) struct hash_bucket *bucket; unsigned long flags; - if (dma_mapping_error(ref->dev, ref->dev_addr)) { - err_printk(ref->dev, NULL, "DMA-API: device driver tries " - "to free an invalid DMA memory address\n"); - return; - } - bucket = get_hash_bucket(ref, &flags); entry = bucket_find_exact(bucket, ref); if (!entry) { - err_printk(ref->dev, NULL, "DMA-API: device driver tries " - "to free DMA memory it has not allocated " - "[device address=0x%016llx] [size=%llu bytes]\n", - ref->dev_addr, ref->size); - goto out; + /* must drop lock before calling dma_mapping_error */ + put_hash_bucket(bucket, &flags); + + if (dma_mapping_error(ref->dev, ref->dev_addr)) { + err_printk(ref->dev, NULL, + "DMA-API: device driver tries to free an " + "invalid DMA memory address\n"); + } else { + err_printk(ref->dev, NULL, + "DMA-API: device driver tries to free DMA " + "memory it has not allocated [device " + "address=0x%016llx] [size=%llu bytes]\n", + ref->dev_addr, ref->size); + } + return; } if (ref->size != entry->size) { @@ -910,10 +928,18 @@ static void check_unmap(struct dma_debug_entry *ref) dir2name[ref->direction]); } + if (entry->map_err_type == MAP_ERR_NOT_CHECKED) { + err_printk(ref->dev, entry, + "DMA-API: device driver failed to check map error" + "[device address=0x%016llx] [size=%llu bytes] " + "[mapped as %s]", + ref->dev_addr, ref->size, + type2name[entry->type]); + } + hash_bucket_del(entry); dma_entry_free(entry); -out: put_hash_bucket(bucket, &flags); } @@ -1017,7 +1043,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, if (unlikely(global_disable)) return; - if (unlikely(dma_mapping_error(dev, dma_addr))) + if (dma_mapping_error(dev, dma_addr)) return; entry = dma_entry_alloc(); @@ -1030,6 +1056,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, entry->dev_addr = dma_addr; entry->size = size; entry->direction = direction; + entry->map_err_type = MAP_ERR_NOT_CHECKED; if (map_single) entry->type = dma_debug_single; @@ -1045,6 +1072,44 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, } EXPORT_SYMBOL(debug_dma_map_page); +void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) +{ + struct dma_debug_entry ref; + struct dma_debug_entry *entry; + struct hash_bucket *bucket; + unsigned long flags; + + if (unlikely(global_disable)) + return; + + ref.dev = dev; + ref.dev_addr = dma_addr; + bucket = get_hash_bucket(&ref, &flags); + + list_for_each_entry(entry, &bucket->list, list) { + if (!exact_match(&ref, entry)) + continue; + + /* + * The same physical address can be mapped multiple + * times. Without a hardware IOMMU this results in the + * same device addresses being put into the dma-debug + * hash multiple times too. This can result in false + * positives being reported. Therefore we implement a + * best-fit algorithm here which updates the first entry + * from the hash which fits the reference value and is + * not currently listed as being checked. + */ + if (entry->map_err_type == MAP_ERR_NOT_CHECKED) { + entry->map_err_type = MAP_ERR_CHECKED; + break; + } + } + + put_hash_bucket(bucket, &flags); +} +EXPORT_SYMBOL(debug_dma_mapping_error); + void debug_dma_unmap_page(struct device *dev, dma_addr_t addr, size_t size, int direction, bool map_single) { |