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        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        suravee.suthikulpanit@amd.com, john.garry@huawei.com,
        dianders@chromium.org, Marek Szyprowski <m.szyprowski@samsung.com>,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Yong Wu <yong.wu@mediatek.com>,
        Heiko Stuebner <heiko@sntech.de>,
        Chunyan Zhang <chunyan.zhang@unisoc.com>,
        Maxime Ripard <mripard@kernel.org>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>
Subject: Re: [PATCH v2 01/24] iommu: Pull IOVA cookie management into the core
To:     Robin Murphy <robin.murphy@arm.com>, joro@8bytes.org,
        will@kernel.org
References: <cover.1627468308.git.robin.murphy@arm.com>
 <fcd58f6e0265b5339091cbabdea88151d437ad40.1627468309.git.robin.murphy@arm.com>
From:   Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <19face6d-daae-fe36-5154-a1f6e409064d@linux.intel.com>
Date:   Fri, 30 Jul 2021 14:06:38 +0800
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On 7/28/21 11:58 PM, Robin Murphy wrote:
> Now that everyone has converged on iommu-dma for IOMMU_DOMAIN_DMA
> support, we can abandon the notion of drivers being responsible for the
> cookie type, and consolidate all the management into the core code.
> 
> CC: Marek Szyprowski <m.szyprowski@samsung.com>
> CC: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> CC: Geert Uytterhoeven <geert+renesas@glider.be>
> CC: Yong Wu <yong.wu@mediatek.com>
> CC: Heiko Stuebner <heiko@sntech.de>
> CC: Chunyan Zhang <chunyan.zhang@unisoc.com>
> CC: Chunyan Zhang <chunyan.zhang@unisoc.com>
> CC: Maxime Ripard <mripard@kernel.org>
> CC: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>   drivers/iommu/iommu.c | 7 +++++++
>   include/linux/iommu.h | 3 ++-
>   2 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index f2cda9950bd5..ea5a9ea8d431 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -7,6 +7,7 @@
>   #define pr_fmt(fmt)    "iommu: " fmt
>   
>   #include <linux/device.h>
> +#include <linux/dma-iommu.h>
>   #include <linux/kernel.h>
>   #include <linux/bits.h>
>   #include <linux/bug.h>
> @@ -1946,6 +1947,11 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
>   	/* Assume all sizes by default; the driver may override this later */
>   	domain->pgsize_bitmap  = bus->iommu_ops->pgsize_bitmap;
>   
> +	/* Temporarily ignore -EEXIST while drivers still get their own cookies */
> +	if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(domain) == -ENOMEM) {
> +		iommu_domain_free(domain);
> +		domain = NULL;
> +	}
>   	return domain;
>   }
>   
> @@ -1957,6 +1963,7 @@ EXPORT_SYMBOL_GPL(iommu_domain_alloc);
>   
>   void iommu_domain_free(struct iommu_domain *domain)
>   {
> +	iommu_put_dma_cookie(domain);
>   	domain->ops->domain_free(domain);
>   }
>   EXPORT_SYMBOL_GPL(iommu_domain_free);
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 4997c78e2670..141779d76035 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -40,6 +40,7 @@ struct iommu_domain;
>   struct notifier_block;
>   struct iommu_sva;
>   struct iommu_fault_event;
> +struct iommu_dma_cookie;
>   
>   /* iommu fault flags */
>   #define IOMMU_FAULT_READ	0x0
> @@ -86,7 +87,7 @@ struct iommu_domain {
>   	iommu_fault_handler_t handler;
>   	void *handler_token;
>   	struct iommu_domain_geometry geometry;
> -	void *iova_cookie;
> +	struct iommu_dma_cookie *iova_cookie;
>   };
>   
>   enum iommu_cap {
> 

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

Best regards,
baolu