Re: [PATCH v4 02/12] iommu/vt-d: Change flags type to unsigned int in binding mm

From: Lu Baolu <baolu.lu@linux.intel.com>
To: Fenghua Yu <fenghua.yu@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Joerg Roedel <joro@8bytes.org>, Ingo Molnar <mingo@redhat.com>,
	Borislav Petkov <bp@alien8.de>,
	Peter Zijlstra <peterz@infradead.org>,
	H Peter Anvin <hpa@zytor.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Tony Luck <tony.luck@intel.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	Christoph Hellwig <hch@infradeed.org>,
	Ashok Raj <ashok.raj@intel.com>,
	Jacob Jun Pan <jacob.jun.pan@intel.com>,
	Dave Jiang <dave.jiang@intel.com>,
	Sohil Mehta <sohil.mehta@intel.com>,
	Ravi V Shankar <ravi.v.shankar@intel.com>
Cc: iommu@lists.linux-foundation.org, x86 <x86@kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 02/12] iommu/vt-d: Change flags type to unsigned int in binding mm
Date: Fri, 26 Jun 2020 09:14:17 +0800	[thread overview]
Message-ID: <888dc4b1-663e-3c62-c5dd-34167382aec1@linux.intel.com> (raw)
In-Reply-To: <1593116242-31507-3-git-send-email-fenghua.yu@intel.com>

Hi Fenghua,

On 2020/6/26 4:17, Fenghua Yu wrote:
> "flags" passed to intel_svm_bind_mm() is a bit mask and should be
> defined as "unsigned int" instead of "int".
> 
> Change its type to "unsigned int".

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

Best regards,
baolu

> 
> Suggested-by: Thomas Gleixner <tglx@linutronix.de>
> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
> Reviewed-by: Tony Luck <tony.luck@intel.com>
> ---
> v2:
> - Add this new patch per Thomas' comment.
> 
>   drivers/iommu/intel/svm.c   | 7 ++++---
>   include/linux/intel-iommu.h | 2 +-
>   2 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> index 778089d198eb..8a0cf2f0dd54 100644
> --- a/drivers/iommu/intel/svm.c
> +++ b/drivers/iommu/intel/svm.c
> @@ -427,7 +427,8 @@ int intel_svm_unbind_gpasid(struct device *dev, u32 pasid)
>   
>   /* Caller must hold pasid_mutex, mm reference */
>   static int
> -intel_svm_bind_mm(struct device *dev, int flags, struct svm_dev_ops *ops,
> +intel_svm_bind_mm(struct device *dev, unsigned int flags,
> +		  struct svm_dev_ops *ops,
>   		  struct mm_struct *mm, struct intel_svm_dev **sd)
>   {
>   	struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
> @@ -954,7 +955,7 @@ intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
>   {
>   	struct iommu_sva *sva = ERR_PTR(-EINVAL);
>   	struct intel_svm_dev *sdev = NULL;
> -	int flags = 0;
> +	unsigned int flags = 0;
>   	int ret;
>   
>   	/*
> @@ -963,7 +964,7 @@ intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
>   	 * and intel_svm etc.
>   	 */
>   	if (drvdata)
> -		flags = *(int *)drvdata;
> +		flags = *(unsigned int *)drvdata;
>   	mutex_lock(&pasid_mutex);
>   	ret = intel_svm_bind_mm(dev, flags, NULL, mm, &sdev);
>   	if (ret)
> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
> index 314a95870e47..4d20f93a5e2d 100644
> --- a/include/linux/intel-iommu.h
> +++ b/include/linux/intel-iommu.h
> @@ -759,7 +759,7 @@ struct intel_svm {
>   	struct mm_struct *mm;
>   
>   	struct intel_iommu *iommu;
> -	int flags;
> +	unsigned int flags;
>   	u32 pasid;
>   	int gpasid; /* In case that guest PASID is different from host PASID */
>   	struct list_head devs;
> 
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