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Message-ID: <db3be8a2-6520-9652-6bee-dbceb320cfc2@linux.intel.com>
Date:   Wed, 3 May 2023 14:32:15 +0800
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Cc:     baolu.lu@linux.intel.com, Will Deacon <will@kernel.org>,
        David Woodhouse <dwmw2@infradead.org>,
        Raj Ashok <ashok.raj@intel.com>,
        "Tian, Kevin" <kevin.tian@intel.com>, Yi Liu <yi.l.liu@intel.com>,
        "Yu, Fenghua" <fenghua.yu@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Tony Luck <tony.luck@intel.com>,
        "Zanussi, Tom" <tom.zanussi@intel.com>,
        narayan.ranganathan@intel.com
Subject: Re: [PATCH v5 3/7] iommu: Move global PASID allocation from SVA to
 core
Content-Language: en-US
To:     Jacob Pan <jacob.jun.pan@linux.intel.com>,
        LKML <linux-kernel@vger.kernel.org>, iommu@lists.linux.dev,
        Robin Murphy <robin.murphy@arm.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Joerg Roedel <joro@8bytes.org>, dmaengine@vger.kernel.org,
        vkoul@kernel.org
References: <20230427174937.471668-1-jacob.jun.pan@linux.intel.com>
 <20230427174937.471668-4-jacob.jun.pan@linux.intel.com>
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <20230427174937.471668-4-jacob.jun.pan@linux.intel.com>
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On 4/28/23 1:49 AM, Jacob Pan wrote:
> +ioasid_t iommu_alloc_global_pasid_dev(struct device *dev)
> +{
> +	int ret;
> +	ioasid_t max;
> +
> +	max = dev_iommu_get_max_pasids(dev);

Perhaps you can use dev->iommu->max_pasids. It's static, so no need to
recalculate it.

> +	ret = ida_alloc_range(&iommu_global_pasid_ida, IOMMU_DEF_RID_PASID + 1, max, GFP_KERNEL);
> +	if (ret < 0)
> +		return IOMMU_PASID_INVALID;
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(iommu_alloc_global_pasid_dev);

Best regards,
baolu