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From: Lu Baolu <baolu.lu@linux.intel.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>,
	iommu@lists.linux-foundation.org,
	LKML <linux-kernel@vger.kernel.org>,
	 Joerg Roedel <joro@8bytes.org>,
	David Woodhouse <dwmw2@infradead.org>,
	 Alex Williamson <alex.williamson@redhat.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>,
	Raj Ashok <ashok.raj@intel.com>,
	Jonathan Cameron <jic23@kernel.org>
Subject: Re: [PATCH v7 08/11] iommu/vt-d: Misc macro clean up for SVM
Date: Sat, 26 Oct 2019 09:00:51 +0800
Message-ID: <c07409eb-83e1-58eb-92d9-7e3c8208d5b7@linux.intel.com> (raw)
In-Reply-To: <1571946904-86776-9-git-send-email-jacob.jun.pan@linux.intel.com>

Hi,

On 10/25/19 3:55 AM, Jacob Pan wrote:
> Use combined macros for_each_svm_dev() to simplify SVM device iteration
> and error checking.
> 
> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> ---
>   drivers/iommu/intel-svm.c | 89 ++++++++++++++++++++++-------------------------
>   1 file changed, 42 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
> index a9a7f85a09bc..a18b02a9709d 100644
> --- a/drivers/iommu/intel-svm.c
> +++ b/drivers/iommu/intel-svm.c
> @@ -212,6 +212,10 @@ static const struct mmu_notifier_ops intel_mmuops = {
>   static DEFINE_MUTEX(pasid_mutex);
>   static LIST_HEAD(global_svm_list);
>   
> +#define for_each_svm_dev(svm, dev)			\
> +	list_for_each_entry(sdev, &svm->devs, list)	\
> +	if (dev == sdev->dev)				\
> +
>   int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops)
>   {
>   	struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
> @@ -257,15 +261,13 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
>   				goto out;
>   			}
>   
> -			list_for_each_entry(sdev, &svm->devs, list) {
> -				if (dev == sdev->dev) {
> -					if (sdev->ops != ops) {
> -						ret = -EBUSY;
> -						goto out;
> -					}
> -					sdev->users++;
> -					goto success;
> +			for_each_svm_dev(svm, dev) {
> +				if (sdev->ops != ops) {
> +					ret = -EBUSY;
> +					goto out;
>   				}
> +				sdev->users++;
> +				goto success;
>   			}
>   
>   			break;
> @@ -402,50 +404,43 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
>   		goto out;
>   
>   	svm = ioasid_find(NULL, pasid, NULL);
> -	if (IS_ERR(svm)) {
> +	if (IS_ERR_OR_NULL(svm)) {
>   		ret = PTR_ERR(svm);
>   		goto out;
>   	}
>   
> -	if (!svm)
> -		goto out;

If svm == NULL here, this function will return success. This isn't
expected, right?

Others looks good to me.

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

Best regards,
baolu

> -
> -	list_for_each_entry(sdev, &svm->devs, list) {
> -		if (dev == sdev->dev) {
> -			ret = 0;
> -			sdev->users--;
> -			if (!sdev->users) {
> -				list_del_rcu(&sdev->list);
> -				/* Flush the PASID cache and IOTLB for this device.
> -				 * Note that we do depend on the hardware *not* using
> -				 * the PASID any more. Just as we depend on other
> -				 * devices never using PASIDs that they have no right
> -				 * to use. We have a *shared* PASID table, because it's
> -				 * large and has to be physically contiguous. So it's
> -				 * hard to be as defensive as we might like. */
> -				intel_pasid_tear_down_entry(iommu, dev, svm->pasid);
> -				intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
> -				kfree_rcu(sdev, rcu);
> -
> -				if (list_empty(&svm->devs)) {
> -					/* Clear private data so that free pass check */
> -					ioasid_set_data(svm->pasid, NULL);
> -					ioasid_free(svm->pasid);
> -					if (svm->mm)
> -						mmu_notifier_unregister(&svm->notifier, svm->mm);
> -
> -					list_del(&svm->list);
> -
> -					/* We mandate that no page faults may be outstanding
> -					 * for the PASID when intel_svm_unbind_mm() is called.
> -					 * If that is not obeyed, subtle errors will happen.
> -					 * Let's make them less subtle... */
> -					memset(svm, 0x6b, sizeof(*svm));
> -					kfree(svm);
> -				}
> +	for_each_svm_dev(svm, dev) {
> +		ret = 0;
> +		sdev->users--;
> +		if (!sdev->users) {
> +			list_del_rcu(&sdev->list);
> +			/* Flush the PASID cache and IOTLB for this device.
> +			 * Note that we do depend on the hardware *not* using
> +			 * the PASID any more. Just as we depend on other
> +			 * devices never using PASIDs that they have no right
> +			 * to use. We have a *shared* PASID table, because it's
> +			 * large and has to be physically contiguous. So it's
> +			 * hard to be as defensive as we might like. */
> +			intel_pasid_tear_down_entry(iommu, dev, svm->pasid);
> +			intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
> +			kfree_rcu(sdev, rcu);
> +
> +			if (list_empty(&svm->devs)) {
> +				/* Clear private data so that free pass check */
> +				ioasid_set_data(svm->pasid, NULL);
> +				ioasid_free(svm->pasid);
> +				if (svm->mm)
> +					mmu_notifier_unregister(&svm->notifier, svm->mm);
> +				list_del(&svm->list);
> +				/* We mandate that no page faults may be outstanding
> +				 * for the PASID when intel_svm_unbind_mm() is called.
> +				 * If that is not obeyed, subtle errors will happen.
> +				 * Let's make them less subtle... */
> +				memset(svm, 0x6b, sizeof(*svm));
> +				kfree(svm);
>   			}
> -			break;
>   		}
> +		break;
>   	}
>    out:
>   	mutex_unlock(&pasid_mutex);
> @@ -581,7 +576,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
>   			 * to unbind the mm while any page faults are outstanding.
>   			 * So we only need RCU to protect the internal idr code. */
>   			rcu_read_unlock();
> -			if (IS_ERR(svm) || !svm) {
> +			if (IS_ERR_OR_NULL(svm)) {
>   				pr_err("%s: Page request for invalid PASID %d: %08llx %08llx\n",
>   				       iommu->name, req->pasid, ((unsigned long long *)req)[0],
>   				       ((unsigned long long *)req)[1]);
> 
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  reply index

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-24 19:54 [PATCH v7 00/11] Nested Shared Virtual Address (SVA) VT-d support Jacob Pan
2019-10-24 19:54 ` [PATCH v7 01/11] iommu/vt-d: Cache virtual command capability register Jacob Pan
2019-10-25  2:53   ` Lu Baolu
2019-10-25  6:06   ` Tian, Kevin
2019-11-08 10:32   ` Auger Eric
2019-10-24 19:54 ` [PATCH v7 02/11] iommu/vt-d: Enlightened PASID allocation Jacob Pan
2019-10-25  6:19   ` Tian, Kevin
2019-10-29 17:14     ` Jacob Pan
2019-10-29 18:16       ` Tian, Kevin
2019-11-08 10:33   ` Auger Eric
2019-11-08 22:22     ` Jacob Pan
2019-10-24 19:54 ` [PATCH v7 03/11] iommu/vt-d: Add custom allocator for IOASID Jacob Pan
2019-10-25  2:30   ` Lu Baolu
2019-10-25  4:43     ` Jacob Pan
2019-10-25  6:40       ` Tian, Kevin
2019-10-25 14:39         ` Lu Baolu
2019-10-25 15:52           ` Tian, Kevin
2019-10-28 22:49             ` Jacob Pan
2019-10-29  2:22               ` Lu Baolu
2019-10-25  6:31   ` Tian, Kevin
2019-10-28 22:52     ` Jacob Pan
2019-11-08 10:40   ` Auger Eric
2019-11-08 22:26     ` Jacob Pan
2019-10-24 19:54 ` [PATCH v7 04/11] iommu/vt-d: Replace Intel specific PASID allocator with IOASID Jacob Pan
2019-10-25  5:47   ` Lu Baolu
2019-11-01 18:29     ` Jacob Pan
2019-10-25  6:41   ` Tian, Kevin
2019-10-28 22:46     ` Jacob Pan
2019-11-08 11:30   ` Auger Eric
2019-11-08 22:55     ` Jacob Pan
2019-11-12  9:54       ` Auger Eric
2019-10-24 19:54 ` [PATCH v7 05/11] iommu/vt-d: Move domain helper to header Jacob Pan
2019-10-25  5:26   ` Lu Baolu
2019-10-24 19:54 ` [PATCH v7 06/11] iommu/vt-d: Avoid duplicated code for PASID setup Jacob Pan
2019-10-25  5:32   ` Lu Baolu
2019-10-25  6:42   ` Tian, Kevin
2019-10-28 22:41     ` Jacob Pan
2019-11-12  9:54   ` Auger Eric
2019-10-24 19:55 ` [PATCH v7 07/11] iommu/vt-d: Add nested translation helper function Jacob Pan
2019-10-25  7:04   ` Tian, Kevin
2019-11-01 21:10     ` Jacob Pan
2019-10-25 15:04   ` Lu Baolu
2019-10-25 16:06     ` Jacob Pan
2019-11-08 13:55   ` Auger Eric
2019-10-24 19:55 ` [PATCH v7 08/11] iommu/vt-d: Misc macro clean up for SVM Jacob Pan
2019-10-26  1:00   ` Lu Baolu [this message]
2019-10-28 22:38     ` Jacob Pan
2019-10-24 19:55 ` [PATCH v7 09/11] iommu/vt-d: Add bind guest PASID support Jacob Pan
2019-10-25  7:19   ` Tian, Kevin
2019-10-25 17:33     ` Jacob Pan
2019-10-28  6:03       ` Tian, Kevin
2019-10-28 16:02         ` Jacob Pan
2019-10-29  7:57           ` Tian, Kevin
2019-10-29 16:11             ` Jacob Pan
2019-10-29 18:04               ` Tian, Kevin
2019-10-29  2:33         ` Lu Baolu
2019-10-26  2:01   ` Lu Baolu
2019-10-28 22:29     ` Jacob Pan
2019-10-29  2:54       ` Lu Baolu
2019-10-29  4:11         ` Jacob Pan
2019-10-29  5:04           ` Lu Baolu
2019-10-24 19:55 ` [PATCH v7 10/11] iommu/vt-d: Support flushing more translation cache types Jacob Pan
2019-10-25  7:21   ` Tian, Kevin
2019-11-01 21:30     ` Jacob Pan
2019-10-26  2:22   ` Lu Baolu
2019-11-01 21:28     ` Jacob Pan
2019-11-08 16:18   ` Auger Eric
2019-11-08 23:05     ` Jacob Pan
2019-10-24 19:55 ` [PATCH v7 11/11] iommu/vt-d: Add svm/sva invalidate function Jacob Pan
2019-10-25  7:27   ` Tian, Kevin
2019-10-26  2:40     ` Lu Baolu
2019-10-26  7:03       ` Lu Baolu
2019-10-28  6:06         ` Tian, Kevin
2019-10-28 16:10           ` Jacob Pan
2019-10-29 18:52             ` Tian, Kevin
2019-10-29 19:25               ` Jacob Pan
2019-10-28 16:13     ` Jacob Pan
2019-11-12 10:28   ` Auger Eric

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