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Date:   Mon, 5 Sep 2022 08:06:04 -0700
From:   Jerry Snitselaar <jsnitsel@redhat.com>
To:     John Garry <john.garry@huawei.com>
Cc:     robin.murphy@arm.com, joro@8bytes.org, will@kernel.org,
        iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
        linuxarm@huawei.com
Subject: Re: [PATCH v2 1/2] iova: Remove some magazine pointer NULL checks
Message-ID: <20220905150604.7bijcbeuuyw44rkl@cantor>
References: <1662369083-238529-1-git-send-email-john.garry@huawei.com>
 <1662369083-238529-2-git-send-email-john.garry@huawei.com>
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On Mon, Sep 05, 2022 at 05:11:22PM +0800, John Garry wrote:
> Since commit 32e92d9f6f87 ("iommu/iova: Separate out rcache init") it
> has not been possible to have NULL CPU rcache "loaded" or "prev" magazine
> pointers. As such, the checks in iova_magazine_full(),
> iova_magazine_empty(), and iova_magazine_free_pfns() may be dropped.
> 
> Signed-off-by: John Garry <john.garry@huawei.com>
> Reviewed-by: Robin Murphy <robin.murphy@arm.com>

Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com

> ---
>  drivers/iommu/iova.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
> index 47d1983dfa2a..580fdf669922 100644
> --- a/drivers/iommu/iova.c
> +++ b/drivers/iommu/iova.c
> @@ -661,9 +661,6 @@ iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
>  	unsigned long flags;
>  	int i;
>  
> -	if (!mag)
> -		return;
> -
>  	spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
>  
>  	for (i = 0 ; i < mag->size; ++i) {
> @@ -683,12 +680,12 @@ iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
>  
>  static bool iova_magazine_full(struct iova_magazine *mag)
>  {
> -	return (mag && mag->size == IOVA_MAG_SIZE);
> +	return mag->size == IOVA_MAG_SIZE;
>  }
>  
>  static bool iova_magazine_empty(struct iova_magazine *mag)
>  {
> -	return (!mag || mag->size == 0);
> +	return mag->size == 0;
>  }
>  
>  static unsigned long iova_magazine_pop(struct iova_magazine *mag,
> -- 
> 2.35.3
>