linux-kernel - Re: [PATCH v3 05/25] iommu/exynos: Drop IOVA cookie management

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Date:   Thu, 5 Aug 2021 09:19:23 +0200
From:   Marek Szyprowski <m.szyprowski@...sung.com>
To:     Robin Murphy <robin.murphy@....com>, joro@...tes.org,
        will@...nel.org
Cc:     iommu@...ts.linux-foundation.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        suravee.suthikulpanit@....com, baolu.lu@...ux.intel.com,
        john.garry@...wei.com, dianders@...omium.org, rajatja@...gle.com,
        chenxiang66@...ilicon.com
Subject: Re: [PATCH v3 05/25] iommu/exynos: Drop IOVA cookie management


On 04.08.2021 19:15, Robin Murphy wrote:
> The core code bakes its own cookies now.
>
> CC: Marek Szyprowski <m.szyprowski@...sung.com>
> Signed-off-by: Robin Murphy <robin.murphy@....com>

Acked-by: Marek Szyprowski <m.szyprowski@...sung.com>

Tested-by: Marek Szyprowski <m.szyprowski@...sung.com>

> ---
>
> v3: Also remove unneeded include
> ---
>   drivers/iommu/exynos-iommu.c | 19 ++++---------------
>   1 file changed, 4 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index d0fbf1d10e18..939ffa768986 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -21,7 +21,6 @@
>   #include <linux/platform_device.h>
>   #include <linux/pm_runtime.h>
>   #include <linux/slab.h>
> -#include <linux/dma-iommu.h>
>   
>   typedef u32 sysmmu_iova_t;
>   typedef u32 sysmmu_pte_t;
> @@ -735,20 +734,16 @@ static struct iommu_domain *exynos_iommu_domain_alloc(unsigned type)
>   	/* Check if correct PTE offsets are initialized */
>   	BUG_ON(PG_ENT_SHIFT < 0 || !dma_dev);
>   
> +	if (type != IOMMU_DOMAIN_DMA && type != IOMMU_DOMAIN_UNMANAGED)
> +		return NULL;
> +
>   	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
>   	if (!domain)
>   		return NULL;
>   
> -	if (type == IOMMU_DOMAIN_DMA) {
> -		if (iommu_get_dma_cookie(&domain->domain) != 0)
> -			goto err_pgtable;
> -	} else if (type != IOMMU_DOMAIN_UNMANAGED) {
> -		goto err_pgtable;
> -	}
> -
>   	domain->pgtable = (sysmmu_pte_t *)__get_free_pages(GFP_KERNEL, 2);
>   	if (!domain->pgtable)
> -		goto err_dma_cookie;
> +		goto err_pgtable;
>   
>   	domain->lv2entcnt = (short *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 1);
>   	if (!domain->lv2entcnt)
> @@ -779,9 +774,6 @@ static struct iommu_domain *exynos_iommu_domain_alloc(unsigned type)
>   	free_pages((unsigned long)domain->lv2entcnt, 1);
>   err_counter:
>   	free_pages((unsigned long)domain->pgtable, 2);
> -err_dma_cookie:
> -	if (type == IOMMU_DOMAIN_DMA)
> -		iommu_put_dma_cookie(&domain->domain);
>   err_pgtable:
>   	kfree(domain);
>   	return NULL;
> @@ -809,9 +801,6 @@ static void exynos_iommu_domain_free(struct iommu_domain *iommu_domain)
>   
>   	spin_unlock_irqrestore(&domain->lock, flags);
>   
> -	if (iommu_domain->type == IOMMU_DOMAIN_DMA)
> -		iommu_put_dma_cookie(iommu_domain);
> -
>   	dma_unmap_single(dma_dev, virt_to_phys(domain->pgtable), LV1TABLE_SIZE,
>   			 DMA_TO_DEVICE);
>   

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland