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-rw-r--r--include/linux/swiotlb.h3
-rw-r--r--kernel/dma/swiotlb.c46
2 files changed, 49 insertions, 0 deletions
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index ecde0312dd52..ea23097e351f 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -120,6 +120,8 @@ struct io_tlb_pool {
* debugfs.
* @used_hiwater: The high water mark for total_used. Used only for reporting
* in debugfs.
+ * @transient_nslabs: The total number of slots in all transient pools that
+ * are currently used across all areas.
*/
struct io_tlb_mem {
struct io_tlb_pool defpool;
@@ -137,6 +139,7 @@ struct io_tlb_mem {
#ifdef CONFIG_DEBUG_FS
atomic_long_t total_used;
atomic_long_t used_hiwater;
+ atomic_long_t transient_nslabs;
#endif
};
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index b079a9a8e087..77974cea3e69 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -956,6 +956,28 @@ static void dec_used(struct io_tlb_mem *mem, unsigned int nslots)
}
#endif /* CONFIG_DEBUG_FS */
+#ifdef CONFIG_SWIOTLB_DYNAMIC
+#ifdef CONFIG_DEBUG_FS
+static void inc_transient_used(struct io_tlb_mem *mem, unsigned int nslots)
+{
+ atomic_long_add(nslots, &mem->transient_nslabs);
+}
+
+static void dec_transient_used(struct io_tlb_mem *mem, unsigned int nslots)
+{
+ atomic_long_sub(nslots, &mem->transient_nslabs);
+}
+
+#else /* !CONFIG_DEBUG_FS */
+static void inc_transient_used(struct io_tlb_mem *mem, unsigned int nslots)
+{
+}
+static void dec_transient_used(struct io_tlb_mem *mem, unsigned int nslots)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+#endif /* CONFIG_SWIOTLB_DYNAMIC */
+
/**
* swiotlb_search_pool_area() - search one memory area in one pool
* @dev: Device which maps the buffer.
@@ -1170,6 +1192,7 @@ static int swiotlb_find_slots(struct device *dev, phys_addr_t orig_addr,
spin_lock_irqsave(&dev->dma_io_tlb_lock, flags);
list_add_rcu(&pool->node, &dev->dma_io_tlb_pools);
spin_unlock_irqrestore(&dev->dma_io_tlb_lock, flags);
+ inc_transient_used(mem, pool->nslabs);
found:
WRITE_ONCE(dev->dma_uses_io_tlb, true);
@@ -1415,6 +1438,7 @@ static bool swiotlb_del_transient(struct device *dev, phys_addr_t tlb_addr)
dec_used(dev->dma_io_tlb_mem, pool->nslabs);
swiotlb_del_pool(dev, pool);
+ dec_transient_used(dev->dma_io_tlb_mem, pool->nslabs);
return true;
}
@@ -1557,6 +1581,23 @@ phys_addr_t default_swiotlb_limit(void)
}
#ifdef CONFIG_DEBUG_FS
+#ifdef CONFIG_SWIOTLB_DYNAMIC
+static unsigned long mem_transient_used(struct io_tlb_mem *mem)
+{
+ return atomic_long_read(&mem->transient_nslabs);
+}
+
+static int io_tlb_transient_used_get(void *data, u64 *val)
+{
+ struct io_tlb_mem *mem = data;
+
+ *val = mem_transient_used(mem);
+ return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(fops_io_tlb_transient_used, io_tlb_transient_used_get,
+ NULL, "%llu\n");
+#endif /* CONFIG_SWIOTLB_DYNAMIC */
static int io_tlb_used_get(void *data, u64 *val)
{
@@ -1605,6 +1646,11 @@ static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem,
&fops_io_tlb_used);
debugfs_create_file("io_tlb_used_hiwater", 0600, mem->debugfs, mem,
&fops_io_tlb_hiwater);
+#ifdef CONFIG_SWIOTLB_DYNAMIC
+ atomic_long_set(&mem->transient_nslabs, 0);
+ debugfs_create_file("io_tlb_transient_nslabs", 0400, mem->debugfs,
+ mem, &fops_io_tlb_transient_used);
+#endif
}
static int __init swiotlb_create_default_debugfs(void)