Since AMDs mail servers blocked me from sending this out, here once more from my gmail account.

Regards, Christian.

On 9/4/26 15:00, Christian König wrote:

On 9/4/26 12:44, Thierry Reding wrote:

...

From: Thierry Reding treding@nvidia.com

Add a callback to struct dma_heap_ops that heap providers can implement to show information about the state of the heap in debugfs. A top-level directory named "dma_heap" is created in debugfs and individual files will be named after the heaps.

Reviewed-by: Maxime Ripard mripard@kernel.org Signed-off-by: Thierry Reding treding@nvidia.com

One minimal nit pick below, with that taken care of Reviewed-by: Christian König christian.koenig@amd.com.

...

---

Changes in v5:

• fix failure handling during debugfs root directory creation
• add more cleanup to the newly introduced dma_heap_exit()

---

drivers/dma-buf/dma-heap.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-heap.h | 2 ++ 2 files changed, 54 insertions(+)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 8a6c2b6e0cc6..65c80dac6500 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -7,6 +7,7 @@ */ #include <linux/cdev.h> +#include <linux/debugfs.h> #include <linux/device.h> #include <linux/dma-buf.h> #include <linux/dma-heap.h> @@ -225,6 +226,40 @@ const char *dma_heap_get_name(struct dma_heap *heap) } EXPORT_SYMBOL_NS_GPL(dma_heap_get_name, "DMA_BUF_HEAP"); +#ifdef CONFIG_DEBUG_FS +static int dma_heap_debug_show(struct seq_file *s, void *unused) +{

• struct dma_heap *heap = s->private;
• int err = 0;
• if (heap->ops && heap->ops->show)

• err = heap->ops->show(s, heap);
  

• return err;

+} +DEFINE_SHOW_ATTRIBUTE(dma_heap_debug);

+static struct dentry *dma_heap_debugfs_dir;

+static void dma_heap_init_debugfs(void) +{

• dma_heap_debugfs_dir = debugfs_create_dir("dma_heap", NULL);

+}

+static void dma_heap_exit_debugfs(void) +{

• debugfs_remove_recursive(dma_heap_debugfs_dir);

+} +#else +static void dma_heap_init_debugfs(void) +{ +}

+static void dma_heap_exit_debugfs(void) +{ +} +#endif

/**

• dma_heap_add - adds a heap to dmabuf heaps
• @exp_info: information needed to register this heap

@@ -299,6 +334,13 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) /* Add heap to the list */ list_add(&heap->list, &heap_list);

+#ifdef CONFIG_DEBUG_FS

• if (heap->ops && heap->ops->show)

• debugfs_create_file(heap->name, 0444, dma_heap_debugfs_dir,
  

• 		    heap, &dma_heap_debug_fops);
  

+#endif

• mutex_unlock(&heap_list_lock);

return heap; @@ -335,6 +377,16 @@ static int dma_heap_init(void) } dma_heap_class->devnode = dma_heap_devnode;

• dma_heap_init_debugfs();
• return 0;

} subsys_initcall(dma_heap_init);

+static void __exit dma_heap_exit(void) +{

• dma_heap_exit_debugfs();
• class_destroy(dma_heap_class);
• unregister_chrdev_region(dma_heap_devt, NUM_HEAP_MINORS);

+} +__exitcall(dma_heap_exit); diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h index 648328a64b27..1c9bed1f4dde 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -12,6 +12,7 @@ #include <linux/types.h> struct dma_heap; +struct seq_file; /**

• struct dma_heap_ops - ops to operate on a given heap

@@ -24,6 +25,7 @@ struct dma_heap_ops { unsigned long len, u32 fd_flags, u64 heap_flags);

• int (*show)(struct seq_file *s, struct dma_heap *heap);

I found it good coding practice for objects ops pointer tables to have the object the function works with as first parameter.

Absolutely not a must have, but just looks a little bit more consistent.

Regards, Christian.

...

}; /**