Re: [PATCH 1/7] iommu/iova: fix incorrect variable types

From: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
To: Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>,
	iommu <iommu@lists.linux-foundation.org>,
	David Woodhouse <dwmw2@infradead.org>,
	Sudeep Dutt <sudeep.dutt@intel.com>,
	Ashutosh Dixit <ashutosh.dixit@intel.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Joerg Roedel <jroedel@suse.de>
Cc: Zefan Li <lizefan@huawei.com>, Xinwei Hu <huxinwei@huawei.com>,
	"Tianhong Ding" <dingtianhong@huawei.com>,
	Hanjun Guo <guohanjun@huawei.com>
Subject: Re: [PATCH 1/7] iommu/iova: fix incorrect variable types
Date: Fri, 31 Mar 2017 11:30:19 +0800	[thread overview]
Message-ID: <58DDCD4B.8070607@huawei.com> (raw)
In-Reply-To: <58D48401.10009@huawei.com>


On 2017/3/24 10:27, Leizhen (ThunderTown) wrote:
> 
> 
> On 2017/3/23 19:42, Robin Murphy wrote:
>> On 22/03/17 06:27, Zhen Lei wrote:
>>> Keep these four variables type consistent with the paramters of function
>>> __alloc_and_insert_iova_range and the members of struct iova:
>>>
>>> 1. static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
>>> 		unsigned long size, unsigned long limit_pfn,
>>>
>>> 2. struct iova {
>>> 	unsigned long	pfn_hi;
>>> 	unsigned long	pfn_lo;
>>>
>>> In fact, limit_pfn is most likely larger than 32 bits on DMA64.
>>
>> FWIW if pad_size manages to overflow an int something's probably gone
>> horribly wrong, but there's no harm in making it consistent with
>> everything else here. However, given that patch #6 makes this irrelevant
>> anyway, do we really need to bother?
> 
> Because I'm not sure whether patch #6 can be applied or not.
So if Patch #6 can be applied, I can merge this patch and patch #6 into one.

> 
>>
>> Robin.
>>
>>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
>>> ---
>>>  drivers/iommu/iova.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
>>> index b7268a1..8ba8b496 100644
>>> --- a/drivers/iommu/iova.c
>>> +++ b/drivers/iommu/iova.c
>>> @@ -104,8 +104,8 @@ __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
>>>   * Computes the padding size required, to make the start address
>>>   * naturally aligned on the power-of-two order of its size
>>>   */
>>> -static unsigned int
>>> -iova_get_pad_size(unsigned int size, unsigned int limit_pfn)
>>> +static unsigned long
>>> +iova_get_pad_size(unsigned long size, unsigned long limit_pfn)
>>>  {
>>>  	return (limit_pfn + 1 - size) & (__roundup_pow_of_two(size) - 1);
>>>  }
>>> @@ -117,7 +117,7 @@ static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
>>>  	struct rb_node *prev, *curr = NULL;
>>>  	unsigned long flags;
>>>  	unsigned long saved_pfn;
>>> -	unsigned int pad_size = 0;
>>> +	unsigned long pad_size = 0;
>>>  
>>>  	/* Walk the tree backwards */
>>>  	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
>>>
>>
>>
>> .
>>
> 

-- 
Thanks!
BestRegards