Linux-Devicetree Archive on lore.kernel.org
 help / color / Atom feed
From: John Stultz <john.stultz@linaro.org>
To: Minchan Kim <minchan@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-mm <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Hyesoo Yu <hyesoo.yu@samsung.com>,
	david@redhat.com, Michal Hocko <mhocko@suse.com>,
	Suren Baghdasaryan <surenb@google.com>,
	KyongHo Cho <pullip.cho@samsung.com>,
	John Dias <joaodias@google.com>,
	Hridya Valsaraju <hridya@google.com>,
	Sumit Semwal <sumit.semwal@linaro.org>,
	linux-media <linux-media@vger.kernel.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>,
	Christoph Hellwig <hch@infradead.org>,
	Rob Herring <robh+dt@kernel.org>,
	"moderated list:DMA BUFFER SHARING FRAMEWORK" 
	<linaro-mm-sig@lists.linaro.org>
Subject: Re: [PATCH v4 3/4] dt-bindings: reserved-memory: Make DMA-BUF CMA heap DT-configurable
Date: Mon, 25 Jan 2021 23:07:21 -0800
Message-ID: <CALAqxLU3yU8e006G0W-mSBLogWAru6jOJcBbuH5wFHoi1JitPA@mail.gmail.com> (raw)
In-Reply-To: <20210121175502.274391-4-minchan@kernel.org>

On Thu, Jan 21, 2021 at 9:55 AM Minchan Kim <minchan@kernel.org> wrote:
>  .../reserved-memory/dma_heap_chunk.yaml       | 56 +++++++++++++++++++
>  1 file changed, 56 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/reserved-memory/dma_heap_chunk.yaml
>
> diff --git a/Documentation/devicetree/bindings/reserved-memory/dma_heap_chunk.yaml b/Documentation/devicetree/bindings/reserved-memory/dma_heap_chunk.yaml
> new file mode 100644
> index 000000000000..00db0ae6af61
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/reserved-memory/dma_heap_chunk.yaml
> @@ -0,0 +1,56 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/reserved-memory/dma_heap_chunk.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Device tree binding for chunk heap on DMA HEAP FRAMEWORK
> +
> +description: |
> +  The DMA chunk heap is backed by the Contiguous Memory Allocator (CMA) and
> +  supports bulk allocation of fixed size pages.
> +
> +maintainers:
> +  - Hyesoo Yu <hyesoo.yu@samsung.com>
> +  - John Stultz <john.stultz@linaro.org>
> +  - Minchan Kim <minchan@kernel.org>
> +  - Hridya Valsaraju<hridya@google.com>
> +
> +
> +properties:
> +  compatible:
> +    enum:
> +      - dma_heap,chunk
> +
> +  chunk-order:
> +    description: |
> +            order of pages that will get allocated from the chunk DMA heap.
> +    maxItems: 1
> +
> +  size:
> +    maxItems: 1
> +
> +  alignment:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - size
> +  - alignment
> +  - chunk-order
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    reserved-memory {
> +        #address-cells = <2>;
> +        #size-cells = <1>;
> +
> +        chunk_memory: chunk_memory {
> +            compatible = "dma_heap,chunk";
> +            size = <0x3000000>;

Hey Minchan,
  Looking closer here, would it make more sense to document the "reg =
<>" parameter here as well instead of just "size = <>"?

That way the address of the region could be explicitly specified (for
instance, to ensure the CMA region created is 32bit addressable). And
more practically, trying to satisfy the base address alignment checks
in the final patch when its set dynamically may require a fair amount
of luck  - I couldn't manage it in my own testing on the hikey960 w/o
resorting to reg=  :)

It does look like the RESERVEDMEM_OF_DECLARE() logic already supports
this, so it's likely just a matter of documenting it here?

thanks
-john

  reply index

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-21 17:54 [PATCH v4 0/4] Chunk Heap Support on DMA-HEAP Minchan Kim
2021-01-21 17:54 ` [PATCH v4 1/4] mm: cma: introduce gfp flag in cma_alloc instead of no_warn Minchan Kim
2021-01-21 18:46   ` David Hildenbrand
2021-01-21 18:50   ` Minchan Kim
2021-01-25 13:07   ` Michal Hocko
2021-01-25 19:42     ` Minchan Kim
2021-01-26  7:38       ` Michal Hocko
2021-01-26 19:12         ` Minchan Kim
2021-01-27 20:21           ` Minchan Kim
2021-01-21 17:55 ` [PATCH v4 2/4] mm: failfast mode with __GFP_NORETRY in alloc_contig_range Minchan Kim
2021-01-25 13:12   ` Michal Hocko
2021-01-25 13:13     ` Michal Hocko
2021-01-25 19:33     ` Minchan Kim
2021-01-26  7:44       ` Michal Hocko
2021-01-26 19:10         ` Minchan Kim
2021-01-27  8:14           ` Michal Hocko
2021-01-27 20:42         ` Minchan Kim
2021-01-28  7:53           ` Michal Hocko
2021-01-28 16:56             ` Minchan Kim
2021-01-21 17:55 ` [PATCH v4 3/4] dt-bindings: reserved-memory: Make DMA-BUF CMA heap DT-configurable Minchan Kim
2021-01-26  7:07   ` John Stultz [this message]
2021-01-27 20:25     ` Hridya Valsaraju
2021-02-05 22:55   ` Rob Herring
2021-01-21 17:55 ` [PATCH v4 4/4] dma-buf: heaps: add chunk heap to dmabuf heaps Minchan Kim
2021-01-26  7:07   ` Christoph Hellwig
2021-01-26 19:27     ` Minchan Kim
2021-01-26  7:32   ` John Stultz
2021-01-26 19:24     ` Minchan Kim
2021-01-26  7:46   ` Michal Hocko
2021-01-26 19:25     ` Minchan Kim
2021-01-27  8:09       ` Michal Hocko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CALAqxLU3yU8e006G0W-mSBLogWAru6jOJcBbuH5wFHoi1JitPA@mail.gmail.com \
    --to=john.stultz@linaro.org \
    --cc=akpm@linux-foundation.org \
    --cc=david@redhat.com \
    --cc=devicetree@vger.kernel.org \
    --cc=hch@infradead.org \
    --cc=hridya@google.com \
    --cc=hyesoo.yu@samsung.com \
    --cc=joaodias@google.com \
    --cc=linaro-mm-sig@lists.linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.com \
    --cc=minchan@kernel.org \
    --cc=pullip.cho@samsung.com \
    --cc=robh+dt@kernel.org \
    --cc=sumit.semwal@linaro.org \
    --cc=surenb@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Devicetree Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-devicetree/0 linux-devicetree/git/0.git
	git clone --mirror https://lore.kernel.org/linux-devicetree/1 linux-devicetree/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-devicetree linux-devicetree/ https://lore.kernel.org/linux-devicetree \
		devicetree@vger.kernel.org
	public-inbox-index linux-devicetree

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-devicetree


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git