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From: Murali Karicheri <m-karicheri2@ti.com>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>
Subject: Re: [PATCH v4 6/6] arm: dma-mapping: updates to limit dma_mask and iommu mapping size
Date: Tue, 27 Jan 2015 10:19:55 -0500	[thread overview]
Message-ID: <54C7AC9B.1040308@ti.com> (raw)
In-Reply-To: <20150127113416.GB3226@e104818-lin.cambridge.arm.com>

On 01/27/2015 06:34 AM, Catalin Marinas wrote:
> On Tue, Jan 27, 2015 at 11:12:32AM +0000, Robin Murphy wrote:
>> On 23/01/15 22:32, Murali Karicheri wrote:
>>> Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.
>>>
>>> Also arm_iommu_create_mapping() has size parameter of size_t and
>>> arm_setup_iommu_dma_ops() can take a value higher than that. So
>>> limit the size to SIZE_MAX.
>>>
>>> Signed-off-by: Murali Karicheri<m-karicheri2@ti.com>
>>> ---
>>>    arch/arm/mm/dma-mapping.c |   10 ++++++++++
>>>    1 file changed, 10 insertions(+)
>>>
>>> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
>>> index 7864797..a1f9030 100644
>>> --- a/arch/arm/mm/dma-mapping.c
>>> +++ b/arch/arm/mm/dma-mapping.c
>>> @@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
>>>    	if (!iommu)
>>>    		return false;
>>>
>>> +	/*
>>> +	 * currently arm_iommu_create_mapping() takes a max of size_t
>>> +	 * for size param. So check this limit for now.
>>> +	 */
>>> +	if (size>  SIZE_MAX)
>>> +		return false;
>>> +
>>>    	mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
>>>    	if (IS_ERR(mapping)) {
>>>    		pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
>>> @@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
>>>    {
>>>    	struct dma_map_ops *dma_ops;
>>>
>>> +	/* limit dma_mask to the lower of the two values */
>>> +	*dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
>>> +
>>
>> Is there any reason not to do this in of_dma_configure? It seems like
>> something everyone could benefit from - I'd cooked up a dodgy workaround
>> for the same issue in my arm64 IOMMU code, but handling it generically
>> in common code would be much nicer.

Ok Will move this to of_dma_configure().

Murali

>
> I agree. I started something here:
>
> http://article.gmane.org/gmane.linux.kernel/1835096
>
> but I don't remember to have got to a clear conclusion.
>


-- 
Murali Karicheri
Linux Kernel, Texas Instruments

      reply	other threads:[~2015-01-27 15:20 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-23 22:32 [PATCH v4 0/6] PCI: get DMA configuration from parent device Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 1/6] of: iommu: add ptr to OF node arg to of_iommu_configure() Murali Karicheri
2015-01-25 13:32   ` Laurent Pinchart
2015-01-26 18:49     ` Murali Karicheri
2015-01-28 11:33       ` Will Deacon
2015-01-28 12:23         ` Laurent Pinchart
2015-01-28 12:29           ` Will Deacon
2015-01-28 13:15             ` Laurent Pinchart
2015-01-28 13:32               ` Will Deacon
2015-01-28 15:21                 ` Murali Karicheri
2015-01-28 23:32                 ` Laurent Pinchart
2015-01-29 14:59                   ` Murali Karicheri
2015-01-29 16:49                   ` Rob Herring
2015-01-30  0:24                     ` Laurent Pinchart
2015-01-30 15:23                       ` Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 2/6] of: move of_dma_configure() to device.c to help re-use Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 3/6] of: fix size when dma-range is not used Murali Karicheri
2015-01-27 11:27   ` Robin Murphy
2015-01-27 15:44     ` Murali Karicheri
2015-01-27 18:55     ` Murali Karicheri
2015-01-28 11:05       ` Catalin Marinas
2015-01-28 15:45         ` Rob Herring
2015-01-28 17:23           ` Catalin Marinas
2015-01-28 17:34           ` Murali Karicheri
2015-01-28 15:55         ` Robin Murphy
2015-01-28 17:30           ` Catalin Marinas
2015-01-30 18:06             ` Murali Karicheri
2015-02-02 12:18               ` Catalin Marinas
2015-02-02 16:10                 ` Murali Karicheri
2015-02-05 21:42                 ` Murali Karicheri
2015-02-05 22:44                   ` Catalin Marinas
2015-01-23 22:32 ` [PATCH v4 4/6] of/pci: add of_pci_dma_configure() update dma configuration Murali Karicheri
2015-01-23 23:41   ` Bjorn Helgaas
2015-01-26 23:25     ` Murali Karicheri
2015-01-26 23:59       ` Bjorn Helgaas
2015-01-27 18:14         ` Murali Karicheri
2015-01-27 18:42           ` Bjorn Helgaas
2015-01-27 18:45             ` Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 5/6] PCI: update dma configuration from DT Murali Karicheri
2015-01-23 23:27   ` Bjorn Helgaas
2015-01-26 23:28     ` Murali Karicheri
2015-01-23 22:32 ` [PATCH v4 6/6] arm: dma-mapping: updates to limit dma_mask and iommu mapping size Murali Karicheri
2015-01-27 11:12   ` Robin Murphy
2015-01-27 11:34     ` Catalin Marinas
2015-01-27 15:19       ` Murali Karicheri [this message]

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