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Diffstat (limited to 'lib/dma-debug.c')
-rw-r--r--lib/dma-debug.c65
1 files changed, 43 insertions, 22 deletions
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 7f5cdc1e6b29..c007d25bee09 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);
}
}