Re: [Linaro-mm-sig] [PATCH v4 4/4] dma-buf: heaps: add chunk heap to dmabuf heaps

On Mon, Jan 25, 2021 at 11:32:57PM -0800, John Stultz wrote:

On Thu, Jan 21, 2021 at 9:55 AM Minchan Kim minchan@kernel.org wrote:

Hey Minchan, Thanks for sending this out! I'm still working through testing with this patch set, so I may have some more feedback tomorrow, but a few quick items I did hit below.

...

+#define CHUNK_PREFIX "chunk-"

+static int register_chunk_heap(struct chunk_heap *chunk_heap_info) +{

•   struct dma_heap_export_info exp_info;
  

•   const char *name = cma_get_name(chunk_heap_info->cma);
  

•   size_t len = strlen(CHUNK_PREFIX) + strlen(name) + 1;
  

•   char *buf = kmalloc(len, GFP_KERNEL);
  

•   if (!buf)
  

•           return -ENOMEM;
  

•   sprintf(buf, CHUNK_PREFIX"%s", cma_get_name(chunk_heap_info->cma));
  

•   buf[len] = '\0';
  

•   exp_info.name = buf;
  

•   exp_info.name = cma_get_name(chunk_heap_info->cma);
  

I think you intended to delete this line, as it's overwriting your prefixed name.

Hi John,

You're right. Will fix it.

...

•   exp_info.ops = &chunk_heap_ops;
  

•   exp_info.priv = chunk_heap_info;
  

•   chunk_heap_info->heap = dma_heap_add(&exp_info);
  

•   if (IS_ERR(chunk_heap_info->heap)) {
  

•           kfree(buf);
  

•           return PTR_ERR(chunk_heap_info->heap);
  

•   }
  

•   return 0;
  

+}

+static int __init chunk_heap_init(void) +{

•   unsigned int i;
  

•   for (i = 0; i < chunk_heap_count; i++)
  

•           register_chunk_heap(&chunk_heaps[i]);
  

•   return 0;
  

+} +module_init(chunk_heap_init);

+#ifdef CONFIG_OF_EARLY_FLATTREE

+static int __init dmabuf_chunk_heap_area_init(struct reserved_mem *rmem) +{

•   int ret;
  

•   struct cma *cma;
  

•   struct chunk_heap *chunk_heap_info;
  

•   const __be32 *chunk_order;
  

•   phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
  

•   phys_addr_t mask = align - 1;
  

•   if ((rmem->base & mask) || (rmem->size & mask)) {
  

•           pr_err("Incorrect alignment for CMA region\n");
  

•           return -EINVAL;
  

Passing this check can be tough if you're using dynamically assigned rmem, so it might be helpful for debugging to print the base/size/mask values?

Let me fold this into next respin.

diff --git a/drivers/dma-buf/heaps/chunk_heap.c b/drivers/dma-buf/heaps/chunk_heap.c index 6fe8e69d108f..cc2ed5341b54 100644 --- a/drivers/dma-buf/heaps/chunk_heap.c +++ b/drivers/dma-buf/heaps/chunk_heap.c @@ -456,7 +456,8 @@ static int __init dmabuf_chunk_heap_area_init(struct reserved_mem *rmem) phys_addr_t mask = align - 1;

if ((rmem->base & mask) || (rmem->size & mask)) { - pr_err("Incorrect alignment for CMA region\n"); + pr_err("Incorrect alignment for CMA region: base %pa size %pa mask %pa\n", + rmem->base, rmem->size, mask); return -EINVAL; }

Thanks for the review, John!