From: m.szyprowski@samsung.com (Marek Szyprowski)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/8] arm: dma-mapping: Don't override dma_ops in arch_setup_dma_ops()
Date: Fri, 02 Sep 2016 10:16:22 +0200 [thread overview]
Message-ID: <16c9743e-e531-25aa-76f1-8746a6b8ef11@samsung.com> (raw)
In-Reply-To: <1470696550-3416-2-git-send-email-sricharan@codeaurora.org>
Hi Sricharan and Laurent,
On 2016-08-09 00:49, Sricharan R wrote:
> From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>
> The arch_setup_dma_ops() function is in charge of setting dma_ops with a
> call to set_dma_ops(). set_dma_ops() is also called from
>
> - highbank and mvebu bus notifiers
> - dmabounce (to be replaced with swiotlb)
> - arm_iommu_attach_device
>
> (arm_iommu_attach_device is itself called from IOMMU and bus master
> device drivers)
>
> To allow the arch_setup_dma_ops() call to be moved from device add time
> to device probe time we must ensure that dma_ops already setup by any of
> the above callers will not be overridden.
>
> Aftering replacing dmabounce with swiotlb, converting IOMMU drivers to
> of_xlate and taking care of highbank and mvebu, the workaround should be
> removed.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> ---
> arch/arm/mm/dma-mapping.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index ff7ed56..4686d66 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -2259,6 +2259,15 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
> struct dma_map_ops *dma_ops;
>
> dev->archdata.dma_coherent = coherent;
> +
> + /*
> + * Don't override the dma_ops if they have already been set. Ideally
> + * this should be the only location where dma_ops are set, remove this
> + * check when all other callers of set_dma_ops will have disappeared.
> + */
> + if (dev->archdata.dma_ops)
> + return;
> +
> if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
> dma_ops = arm_get_iommu_dma_map_ops(coherent);
> else
Please add also set_dma_ops(dev, NULL) to arm_teardown_iommu_dma_ops()
function
to this patch, because otherwise dma_ops won't be configured properly if
deferred
probe of the given device happens: iommu dma ops will be set for the
first probe
try, then iommu structures will be teared down after EPROBEDEFER error,
and then
before next probe ties dma_ops will be already set, but no iommu
structures are
available.
For a convenience, this a fixup patch:
https://git.linaro.org/people/marek.szyprowski/linux-srpol.git/commitdiff/55adefd43cee9d4beb15cb1bbd805c5059b56b4f
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
next prev parent reply other threads:[~2016-09-02 8:16 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-08 22:49 [PATCH 0/8] IOMMU Probe deferral support Sricharan R
2016-08-08 22:49 ` [PATCH 1/8] arm: dma-mapping: Don't override dma_ops in arch_setup_dma_ops() Sricharan R
2016-09-02 8:16 ` Marek Szyprowski [this message]
2016-09-07 6:24 ` Sricharan
2016-08-08 22:49 ` [PATCH 2/8] of: dma: Move range size workaround to of_dma_get_range() Sricharan R
2016-08-08 22:49 ` [PATCH 3/8] of: dma: Make of_dma_deconfigure() public Sricharan R
2016-08-08 22:49 ` [PATCH 4/8] of: dma: Split of_configure_dma() into mask and ops configuration Sricharan R
2016-08-12 7:31 ` Tomasz Figa
2016-08-12 15:18 ` Laurent Pinchart
2016-08-12 15:45 ` Sricharan
2016-09-09 6:53 ` Magnus Damm
2016-09-09 9:48 ` Sricharan
2016-08-08 22:49 ` [PATCH 5/8] drivers: platform: Configure dma operations at probe time Sricharan R
2016-08-16 9:25 ` Laurent Pinchart
2016-08-16 12:28 ` Sricharan
2016-08-08 22:49 ` [PATCH 6/8] drivers: platform: Remove call to of_dma_(con/decon)figure_ops Sricharan R
2016-08-12 7:33 ` Tomasz Figa
2016-08-12 15:42 ` Sricharan
2016-08-08 22:49 ` [PATCH 7/8] iommu: of: Handle IOMMU lookup failure with deferred probing or error Sricharan R
2016-08-12 7:46 ` Tomasz Figa
2016-08-12 15:40 ` Sricharan
2016-09-02 8:09 ` Marek Szyprowski
2016-09-07 6:16 ` Sricharan
2016-09-02 12:52 ` Marek Szyprowski
2016-09-07 6:29 ` Sricharan
2016-08-08 22:49 ` [PATCH 8/8] drivers: iommu: arm-smmu: Set iommu_ops in probe Sricharan R
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