From: m.szyprowski@samsung•com (Marek Szyprowski)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 01/18] arm: dma-mapping: arm_iommu_attach_device: automatically set max_seg_size
Date: Thu, 25 Sep 2014 12:43:35 +0200 [thread overview]
Message-ID: <5423F1D7.3060400@samsung.com> (raw)
In-Reply-To: <20140924170627.GK16244@arm.com>
Hello,
On 2014-09-24 19:06, Will Deacon wrote:
> Hi Marek,
>
> On Tue, Sep 16, 2014 at 12:54:28PM +0100, Marek Szyprowski wrote:
>> If device has no max_seg_size set, we assume that there is no limit and
>> force it to DMA_BIT_MASK(32) to always use contiguous mappings in DMA
>> address space.
>>
>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung•com>
>> ---
>> arch/arm/mm/dma-mapping.c | 16 ++++++++++++++++
>> 1 file changed, 16 insertions(+)
>>
>> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
>> index bcd5f836f27e..84705e24571b 100644
>> --- a/arch/arm/mm/dma-mapping.c
>> +++ b/arch/arm/mm/dma-mapping.c
>> @@ -2050,6 +2050,22 @@ int arm_iommu_attach_device(struct device *dev,
>> {
>> int err;
>>
>> + /*
>> + * if device has no max_seg_size set, we assume that there is no limit
>> + * and force it to DMA_BIT_MASK(32) to always use contiguous mappings
>> + * in DMA address space
>> + */
>> + if (!dev->dma_parms) {
>> + dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL);
>> + if (!dev->dma_parms)
>> + return -ENOMEM;
>> + }
>> + if (!dev->dma_parms->max_segment_size) {
>> + err = dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
> Would it make more sense to base this default value off the dma_mask?
> In my IOMMU series, of_dma_configure passes back a size parameter to
> arch_setup_dma_ops which is calculated from the dma-ranges property or the
> coherent dma mask if the ranges property is absent, so maybe we should set
> this there too?
Right, good idea. This patch predates your arch_setup_dma_ops changes, so I
had to use something. The value taken from dma_mask is much better than
hardcoded
DMA_BIT_MASK(32). Do you want to include an updated patch in next
version of your
arch_setup_dma_ops patchset?
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
next prev parent reply other threads:[~2014-09-25 10:43 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-16 11:54 [PATCH v2 00/18] Exynos SYSMMU (IOMMU) integration with DT and DMA-mapping subsystem Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 01/18] arm: dma-mapping: arm_iommu_attach_device: automatically set max_seg_size Marek Szyprowski
2014-09-24 17:06 ` Will Deacon
2014-09-25 10:43 ` Marek Szyprowski [this message]
2014-09-25 18:34 ` Will Deacon
2014-09-16 11:54 ` [PATCH v2 02/18] arm: exynos: bind power domains earlier, on device creation Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 03/18] drm: exynos: detach from default dma-mapping domain on init Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 04/18] clk: exynos: add missing smmu_g2d clock and update comments Marek Szyprowski
2014-09-22 12:09 ` Tomasz Figa
2014-09-16 11:54 ` [PATCH v2 05/18] ARM: DTS: Exynos4: add System MMU nodes Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 06/18] iommu: exynos: don't read version register on every tlb operation Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 07/18] iommu: exynos: remove unused functions Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 08/18] iommu: exynos: remove useless spinlock Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 09/18] iommu: exynos: refactor function parameters to simplify code Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 10/18] iommu: exynos: remove unused functions, part 2 Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 11/18] iommu: exynos: remove useless device_add/remove callbacks Marek Szyprowski
2014-10-21 10:59 ` Alban Browaeys
2014-10-22 9:15 ` Alban Browaeys
2014-10-22 9:26 ` Arnd Bergmann
2014-10-22 9:54 ` Marek Szyprowski
2014-10-23 14:02 ` Arnd Bergmann
2014-10-24 7:41 ` [PATCH] iommu: exynos: make driver multiarch friendly Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 12/18] iommu: exynos: add support for binding more than one sysmmu to master device Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 13/18] iommu: exynos: add support for runtime_pm Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 14/18] iommu: exynos: rename variables to reflect their purpose Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 15/18] iommu: exynos: document internal structures Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 16/18] iommu: exynos: remove excessive includes and sort others alphabetically Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 17/18] iommu: exynos: init from dt-specific callback instead of initcall Marek Szyprowski
2014-09-16 11:54 ` [PATCH v2 18/18] iommu: exynos: add callback for initializing devices from device tree Marek Szyprowski
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