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From:   Lu Baolu <baolu.lu@linux.intel.com>
To:     David Woodhouse <dwmw2@infradead.org>,
        Joerg Roedel <joro@8bytes.org>
Cc:     ashok.raj@intel.com, jacob.jun.pan@intel.com, alan.cox@intel.com,
        kevin.tian@intel.com, mika.westerberg@linux.intel.com,
        pengfei.xu@intel.com,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Christoph Hellwig <hch@lst.de>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Robin Murphy <robin.murphy@arm.com>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
        Lu Baolu <baolu.lu@linux.intel.com>
Subject: [PATCH v3 01/10] iommu: Add helper to get minimal page size of domain
Date:   Sun, 21 Apr 2019 09:17:10 +0800
Message-Id: <20190421011719.14909-2-baolu.lu@linux.intel.com>
In-Reply-To: <20190421011719.14909-1-baolu.lu@linux.intel.com>
References: <20190421011719.14909-1-baolu.lu@linux.intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

This makes it possible for other modules to know the minimal
page size supported by a domain without the knowledge of the
structure details.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 include/linux/iommu.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index a5007d035218..46679ef19b7e 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -377,6 +377,14 @@ static inline void iommu_tlb_sync(struct iommu_domain *domain)
 		domain->ops->iotlb_sync(domain);
 }
 
+static inline unsigned long domain_minimal_pgsize(struct iommu_domain *domain)
+{
+	if (domain && domain->pgsize_bitmap)
+		return 1 << __ffs(domain->pgsize_bitmap);
+
+	return 0;
+}
+
 /* PCI device grouping function */
 extern struct iommu_group *pci_device_group(struct device *dev);
 /* Generic device grouping function */
@@ -704,6 +712,11 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode)
 	return NULL;
 }
 
+static inline unsigned long domain_minimal_pgsize(struct iommu_domain *domain)
+{
+	return 0;
+}
+
 #endif /* CONFIG_IOMMU_API */
 
 #ifdef CONFIG_IOMMU_DEBUGFS
-- 
2.17.1