public inbox for linux-arm-kernel@lists.infradead.org 
 help / color / mirror / Atom feed
From: robin.murphy@arm•com (Robin Murphy)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM64: dma-mapping: fix handling of devices registered before arch_initcall
Date: Tue, 16 Feb 2016 19:05:59 +0000	[thread overview]
Message-ID: <56C37317.9020104@arm.com> (raw)
In-Reply-To: <1455632084-14666-1-git-send-email-m.szyprowski@samsung.com>

On 16/02/16 14:14, Marek Szyprowski wrote:
> This patch ensures that devices, which got registered before arch_initcall
> will be handled correctly by IOMMU-based DMA-mapping code.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung•com>
> ---
>   arch/arm64/mm/dma-mapping.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
> index 573b1e6..ce6019f 100644
> --- a/arch/arm64/mm/dma-mapping.c
> +++ b/arch/arm64/mm/dma-mapping.c
> @@ -928,6 +928,10 @@ static int __init __iommu_dma_init(void)
>   		ret = register_iommu_dma_ops_notifier(&platform_bus_type);
>   	if (!ret)
>   		ret = register_iommu_dma_ops_notifier(&amba_bustype);
> +
> +	/* handle devices queued before this arch_initcall */
> +	if (!ret)
> +		__iommu_attach_notifier(NULL, BUS_NOTIFY_ADD_DEVICE, NULL);

Hmm, surely unless *all* the devices on the relevant buses are created 
before arch_initcall level, then the next one is going to kick off the 
notifier to walk the whole list anyway. Have you seen this being a 
problem in practice?

Robin.

>   	return ret;
>   }
>   arch_initcall(__iommu_dma_init);
>

  reply	other threads:[~2016-02-16 19:05 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-16 14:14 [PATCH] ARM64: dma-mapping: fix handling of devices registered before arch_initcall Marek Szyprowski
2016-02-16 19:05 ` Robin Murphy [this message]
2016-02-17  7:06   ` Marek Szyprowski
2016-02-17 10:19     ` Robin Murphy

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=56C37317.9020104@arm.com \
    --to=robin.murphy@arm$(echo .)com \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox