diff options
Diffstat (limited to 'lib/dma-debug.c')
| -rw-r--r-- | lib/dma-debug.c | 65 |
1 files changed, 43 insertions, 22 deletions
diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 7f5cdc1e6b298..c007d25bee098 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -41,6 +41,11 @@ #define HASH_FN_SHIFT 13 #define HASH_FN_MASK (HASH_SIZE - 1) +/* allow architectures to override this if absolutely required */ +#ifndef PREALLOC_DMA_DEBUG_ENTRIES +#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16) +#endif + enum { dma_debug_single, dma_debug_page, @@ -127,7 +132,7 @@ static u32 min_free_entries; static u32 nr_total_entries; /* number of preallocated entries requested by kernel cmdline */ -static u32 req_entries; +static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES; /* debugfs dentry's for the stuff above */ static struct dentry *dma_debug_dent __read_mostly; @@ -439,7 +444,6 @@ void debug_dma_dump_mappings(struct device *dev) spin_unlock_irqrestore(&bucket->lock, flags); } } -EXPORT_SYMBOL(debug_dma_dump_mappings); /* * For each mapping (initial cacheline in the case of @@ -748,7 +752,6 @@ int dma_debug_resize_entries(u32 num_entries) return ret; } -EXPORT_SYMBOL(dma_debug_resize_entries); /* * DMA-API debugging init code @@ -1004,10 +1007,7 @@ void dma_debug_add_bus(struct bus_type *bus) bus_register_notifier(bus, nb); } -/* - * Let the architectures decide how many entries should be preallocated. - */ -void dma_debug_init(u32 num_entries) +static int dma_debug_init(void) { int i; @@ -1015,7 +1015,7 @@ void dma_debug_init(u32 num_entries) * called to set dma_debug_initialized */ if (global_disable) - return; + return 0; for (i = 0; i < HASH_SIZE; ++i) { INIT_LIST_HEAD(&dma_entry_hash[i].list); @@ -1026,17 +1026,14 @@ void dma_debug_init(u32 num_entries) pr_err("DMA-API: error creating debugfs entries - disabling\n"); global_disable = true; - return; + return 0; } - if (req_entries) - num_entries = req_entries; - - if (prealloc_memory(num_entries) != 0) { + if (prealloc_memory(nr_prealloc_entries) != 0) { pr_err("DMA-API: debugging out of memory error - disabled\n"); global_disable = true; - return; + return 0; } nr_total_entries = num_free_entries; @@ -1044,7 +1041,9 @@ void dma_debug_init(u32 num_entries) dma_debug_initialized = true; pr_info("DMA-API: debugging enabled by kernel config\n"); + return 0; } +core_initcall(dma_debug_init); static __init int dma_debug_cmdline(char *str) { @@ -1061,16 +1060,10 @@ static __init int dma_debug_cmdline(char *str) static __init int dma_debug_entries_cmdline(char *str) { - int res; - if (!str) return -EINVAL; - - res = get_option(&str, &req_entries); - - if (!res) - req_entries = 0; - + if (!get_option(&str, &nr_prealloc_entries)) + nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES; return 0; } @@ -1293,6 +1286,32 @@ out: put_hash_bucket(bucket, &flags); } +static void check_sg_segment(struct device *dev, struct scatterlist *sg) +{ +#ifdef CONFIG_DMA_API_DEBUG_SG + unsigned int max_seg = dma_get_max_seg_size(dev); + u64 start, end, boundary = dma_get_seg_boundary(dev); + + /* + * Either the driver forgot to set dma_parms appropriately, or + * whoever generated the list forgot to check them. + */ + if (sg->length > max_seg) + err_printk(dev, NULL, "DMA-API: mapping sg segment longer than device claims to support [len=%u] [max=%u]\n", + sg->length, max_seg); + /* + * In some cases this could potentially be the DMA API + * implementation's fault, but it would usually imply that + * the scatterlist was built inappropriately to begin with. + */ + start = sg_dma_address(sg); + end = start + sg_dma_len(sg) - 1; + if ((start ^ end) & ~boundary) + err_printk(dev, NULL, "DMA-API: mapping sg segment across boundary [start=0x%016llx] [end=0x%016llx] [boundary=0x%016llx]\n", + start, end, boundary); +#endif +} + void debug_dma_map_page(struct device *dev, struct page *page, size_t offset, size_t size, int direction, dma_addr_t dma_addr, bool map_single) @@ -1423,6 +1442,8 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg, check_for_illegal_area(dev, sg_virt(s), sg_dma_len(s)); } + check_sg_segment(dev, s); + add_dma_entry(entry); } } |