#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
+#include <linux/stacktrace.h>
#include <linux/dma-debug.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <linux/list.h>
#include <linux/slab.h>
+#include <asm/sections.h>
+
#define HASH_SIZE 1024ULL
#define HASH_FN_SHIFT 13
#define HASH_FN_MASK (HASH_SIZE - 1)
dma_debug_coherent,
};
+#define DMA_DEBUG_STACKTRACE_ENTRIES 5
+
struct dma_debug_entry {
struct list_head list;
struct device *dev;
int direction;
int sg_call_ents;
int sg_mapped_ents;
+#ifdef CONFIG_STACKTRACE
+ struct stack_trace stacktrace;
+ unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
+#endif
};
struct hash_bucket {
static u32 num_free_entries;
static u32 min_free_entries;
+static u32 nr_total_entries;
/* number of preallocated entries requested by kernel cmdline */
static u32 req_entries;
static struct dentry *num_free_entries_dent __read_mostly;
static struct dentry *min_free_entries_dent __read_mostly;
+/* per-driver filter related state */
+
+#define NAME_MAX_LEN 64
+
+static char current_driver_name[NAME_MAX_LEN] __read_mostly;
+static struct device_driver *current_driver __read_mostly;
+
+static DEFINE_RWLOCK(driver_name_lock);
+
static const char *type2name[4] = { "single", "page",
"scather-gather", "coherent" };
* system log than the user configured. This variable is
* writeable via debugfs.
*/
-#define err_printk(dev, format, arg...) do { \
+static inline void dump_entry_trace(struct dma_debug_entry *entry)
+{
+#ifdef CONFIG_STACKTRACE
+ if (entry) {
+ printk(KERN_WARNING "Mapped at:\n");
+ print_stack_trace(&entry->stacktrace, 0);
+ }
+#endif
+}
+
+static bool driver_filter(struct device *dev)
+{
+ /* driver filter off */
+ if (likely(!current_driver_name[0]))
+ return true;
+
+ /* driver filter on and initialized */
+ if (current_driver && dev->driver == current_driver)
+ return true;
+
+ /* driver filter on but not yet initialized */
+ if (!current_driver && current_driver_name[0]) {
+ struct device_driver *drv = get_driver(dev->driver);
+ unsigned long flags;
+ bool ret = false;
+
+ if (!drv)
+ return false;
+
+ /* lock to protect against change of current_driver_name */
+ read_lock_irqsave(&driver_name_lock, flags);
+
+ if (drv->name &&
+ strncmp(current_driver_name, drv->name, 63) == 0) {
+ current_driver = drv;
+ ret = true;
+ }
+
+ read_unlock_irqrestore(&driver_name_lock, flags);
+ put_driver(drv);
+
+ return ret;
+ }
+
+ return false;
+}
+
+#define err_printk(dev, entry, format, arg...) do { \
error_count += 1; \
- if (show_all_errors || show_num_errors > 0) { \
+ if (driver_filter(dev) && \
+ (show_all_errors || show_num_errors > 0)) { \
WARN(1, "%s %s: " format, \
dev_driver_string(dev), \
dev_name(dev) , ## arg); \
+ dump_entry_trace(entry); \
} \
if (!show_all_errors && show_num_errors > 0) \
show_num_errors -= 1; \
}
/*
+ * Dump mapping entries for debugging purposes
+ */
+void debug_dma_dump_mappings(struct device *dev)
+{
+ int idx;
+
+ for (idx = 0; idx < HASH_SIZE; idx++) {
+ struct hash_bucket *bucket = &dma_entry_hash[idx];
+ struct dma_debug_entry *entry;
+ unsigned long flags;
+
+ spin_lock_irqsave(&bucket->lock, flags);
+
+ 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",
+ type2name[entry->type], idx,
+ (unsigned long long)entry->paddr,
+ entry->dev_addr, entry->size,
+ dir2name[entry->direction]);
+ }
+ }
+
+ spin_unlock_irqrestore(&bucket->lock, flags);
+ }
+}
+EXPORT_SYMBOL(debug_dma_dump_mappings);
+
+/*
* Wrapper function for adding an entry to the hash.
* This function takes care of locking itself.
*/
put_hash_bucket(bucket, &flags);
}
+static struct dma_debug_entry *__dma_entry_alloc(void)
+{
+ struct dma_debug_entry *entry;
+
+ entry = list_entry(free_entries.next, struct dma_debug_entry, list);
+ list_del(&entry->list);
+ memset(entry, 0, sizeof(*entry));
+
+ num_free_entries -= 1;
+ if (num_free_entries < min_free_entries)
+ min_free_entries = num_free_entries;
+
+ return entry;
+}
+
/* struct dma_entry allocator
*
* The next two functions implement the allocator for
goto out;
}
- entry = list_entry(free_entries.next, struct dma_debug_entry, list);
- list_del(&entry->list);
- memset(entry, 0, sizeof(*entry));
+ entry = __dma_entry_alloc();
- num_free_entries -= 1;
- if (num_free_entries < min_free_entries)
- min_free_entries = num_free_entries;
+#ifdef CONFIG_STACKTRACE
+ entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
+ entry->stacktrace.entries = entry->st_entries;
+ entry->stacktrace.skip = 2;
+ save_stack_trace(&entry->stacktrace);
+#endif
out:
spin_unlock_irqrestore(&free_entries_lock, flags);
spin_unlock_irqrestore(&free_entries_lock, flags);
}
+int dma_debug_resize_entries(u32 num_entries)
+{
+ int i, delta, ret = 0;
+ unsigned long flags;
+ struct dma_debug_entry *entry;
+ LIST_HEAD(tmp);
+
+ spin_lock_irqsave(&free_entries_lock, flags);
+
+ if (nr_total_entries < num_entries) {
+ delta = num_entries - nr_total_entries;
+
+ spin_unlock_irqrestore(&free_entries_lock, flags);
+
+ for (i = 0; i < delta; i++) {
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ break;
+
+ list_add_tail(&entry->list, &tmp);
+ }
+
+ spin_lock_irqsave(&free_entries_lock, flags);
+
+ list_splice(&tmp, &free_entries);
+ nr_total_entries += i;
+ num_free_entries += i;
+ } else {
+ delta = nr_total_entries - num_entries;
+
+ for (i = 0; i < delta && !list_empty(&free_entries); i++) {
+ entry = __dma_entry_alloc();
+ kfree(entry);
+ }
+
+ nr_total_entries -= i;
+ }
+
+ if (nr_total_entries != num_entries)
+ ret = 1;
+
+ spin_unlock_irqrestore(&free_entries_lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(dma_debug_resize_entries);
+
/*
* DMA-API debugging init code
*
return -ENOMEM;
}
+void dma_debug_add_bus(struct bus_type *bus)
+{
+ /* FIXME: register notifier */
+}
/*
* Let the architectures decide how many entries should be preallocated.
return;
}
+ nr_total_entries = num_free_entries;
+
printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
}
struct hash_bucket *bucket;
unsigned long flags;
- if (dma_mapping_error(ref->dev, ref->dev_addr))
+ 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 = hash_bucket_find(bucket, ref);
if (!entry) {
- err_printk(ref->dev, "DMA-API: device driver tries "
+ 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);
}
if (ref->size != entry->size) {
- err_printk(ref->dev, "DMA-API: device driver frees "
+ err_printk(ref->dev, entry, "DMA-API: device driver frees "
"DMA memory with different size "
"[device address=0x%016llx] [map size=%llu bytes] "
"[unmap size=%llu bytes]\n",
}
if (ref->type != entry->type) {
- err_printk(ref->dev, "DMA-API: device driver frees "
+ err_printk(ref->dev, entry, "DMA-API: device driver frees "
"DMA memory with wrong function "
"[device address=0x%016llx] [size=%llu bytes] "
"[mapped as %s] [unmapped as %s]\n",
type2name[entry->type], type2name[ref->type]);
} else if ((entry->type == dma_debug_coherent) &&
(ref->paddr != entry->paddr)) {
- err_printk(ref->dev, "DMA-API: device driver frees "
+ err_printk(ref->dev, entry, "DMA-API: device driver frees "
"DMA memory with different CPU address "
"[device address=0x%016llx] [size=%llu bytes] "
"[cpu alloc address=%p] [cpu free address=%p]",
if (ref->sg_call_ents && ref->type == dma_debug_sg &&
ref->sg_call_ents != entry->sg_call_ents) {
- err_printk(ref->dev, "DMA-API: device driver frees "
+ err_printk(ref->dev, entry, "DMA-API: device driver frees "
"DMA sg list with different entry count "
"[map count=%d] [unmap count=%d]\n",
entry->sg_call_ents, ref->sg_call_ents);
* DMA API don't handle this properly, so check for it here
*/
if (ref->direction != entry->direction) {
- err_printk(ref->dev, "DMA-API: device driver frees "
+ err_printk(ref->dev, entry, "DMA-API: device driver frees "
"DMA memory with different direction "
"[device address=0x%016llx] [size=%llu bytes] "
"[mapped with %s] [unmapped with %s]\n",
static void check_for_stack(struct device *dev, void *addr)
{
if (object_is_on_stack(addr))
- err_printk(dev, "DMA-API: device driver maps memory from stack"
- " [addr=%p]\n", addr);
+ err_printk(dev, NULL, "DMA-API: device driver maps memory from"
+ "stack [addr=%p]\n", addr);
+}
+
+static inline bool overlap(void *addr, u64 size, void *start, void *end)
+{
+ void *addr2 = (char *)addr + size;
+
+ return ((addr >= start && addr < end) ||
+ (addr2 >= start && addr2 < end) ||
+ ((addr < start) && (addr2 >= end)));
+}
+
+static void check_for_illegal_area(struct device *dev, void *addr, u64 size)
+{
+ if (overlap(addr, size, _text, _etext) ||
+ overlap(addr, size, __start_rodata, __end_rodata))
+ err_printk(dev, NULL, "DMA-API: device driver maps "
+ "memory from kernel text or rodata "
+ "[addr=%p] [size=%llu]\n", addr, size);
}
static void check_sync(struct device *dev, dma_addr_t addr,
entry = hash_bucket_find(bucket, &ref);
if (!entry) {
- err_printk(dev, "DMA-API: device driver tries "
+ err_printk(dev, NULL, "DMA-API: device driver tries "
"to sync DMA memory it has not allocated "
"[device address=0x%016llx] [size=%llu bytes]\n",
- addr, size);
+ (unsigned long long)addr, size);
goto out;
}
if ((offset + size) > entry->size) {
- err_printk(dev, "DMA-API: device driver syncs"
+ err_printk(dev, entry, "DMA-API: device driver syncs"
" DMA memory outside allocated range "
"[device address=0x%016llx] "
"[allocation size=%llu bytes] [sync offset=%llu] "
}
if (direction != entry->direction) {
- err_printk(dev, "DMA-API: device driver syncs "
+ err_printk(dev, entry, "DMA-API: device driver syncs "
"DMA memory with different direction "
"[device address=0x%016llx] [size=%llu bytes] "
"[mapped with %s] [synced with %s]\n",
- addr, entry->size,
+ (unsigned long long)addr, entry->size,
dir2name[entry->direction],
dir2name[direction]);
}
if (to_cpu && !(entry->direction == DMA_FROM_DEVICE) &&
!(direction == DMA_TO_DEVICE))
- err_printk(dev, "DMA-API: device driver syncs "
+ err_printk(dev, entry, "DMA-API: device driver syncs "
"device read-only DMA memory for cpu "
"[device address=0x%016llx] [size=%llu bytes] "
"[mapped with %s] [synced with %s]\n",
- addr, entry->size,
+ (unsigned long long)addr, entry->size,
dir2name[entry->direction],
dir2name[direction]);
if (!to_cpu && !(entry->direction == DMA_TO_DEVICE) &&
!(direction == DMA_FROM_DEVICE))
- err_printk(dev, "DMA-API: device driver syncs "
+ err_printk(dev, entry, "DMA-API: device driver syncs "
"device write-only DMA memory to device "
"[device address=0x%016llx] [size=%llu bytes] "
"[mapped with %s] [synced with %s]\n",
- addr, entry->size,
+ (unsigned long long)addr, entry->size,
dir2name[entry->direction],
dir2name[direction]);
entry->size = size;
entry->direction = direction;
- if (map_single) {
+ if (map_single)
entry->type = dma_debug_single;
- check_for_stack(dev, page_address(page) + offset);
+
+ if (!PageHighMem(page)) {
+ void *addr = ((char *)page_address(page)) + offset;
+ check_for_stack(dev, addr);
+ check_for_illegal_area(dev, addr, size);
}
add_dma_entry(entry);
entry->sg_call_ents = nents;
entry->sg_mapped_ents = mapped_ents;
- check_for_stack(dev, sg_virt(s));
+ if (!PageHighMem(sg_page(s))) {
+ check_for_stack(dev, sg_virt(s));
+ check_for_illegal_area(dev, sg_virt(s), s->length);
+ }
add_dma_entry(entry);
}
}
EXPORT_SYMBOL(debug_dma_sync_single_range_for_device);
+void debug_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+ int nelems, int direction)
+{
+ struct scatterlist *s;
+ int i;
+
+ if (unlikely(global_disable))
+ return;
+
+ for_each_sg(sg, s, nelems, i) {
+ check_sync(dev, s->dma_address, s->dma_length, 0,
+ direction, true);
+ }
+}
+EXPORT_SYMBOL(debug_dma_sync_sg_for_cpu);
+
+void debug_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+ int nelems, int direction)
+{
+ struct scatterlist *s;
+ int i;
+
+ if (unlikely(global_disable))
+ return;
+
+ for_each_sg(sg, s, nelems, i) {
+ check_sync(dev, s->dma_address, s->dma_length, 0,
+ direction, false);
+ }
+}
+EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
+
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