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From: Lu Baolu <baolu.lu@linux.intel.com>
To: Joerg Roedel <joro@8bytes.org>,
	Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Jason Gunthorpe <jgg@ziepe.ca>,
	Kevin Tian <kevin.tian@intel.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	Nicolin Chen <nicolinc@nvidia.com>
Cc: Yi Liu <yi.l.liu@intel.com>,
	Jacob Pan <jacob.jun.pan@linux.intel.com>,
	Longfang Liu <liulongfang@huawei.com>,
	Yan Zhao <yan.y.zhao@intel.com>,
	iommu@lists.linux.dev,
	kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Lu Baolu <baolu.lu@linux.intel.com>,
	Jason Gunthorpe <jgg@nvidia.com>
Subject: [PATCH v9 08/14] iommu: Prepare for separating SVA and IOPF
Date: Wed, 20 Dec 2023 09:23:26 +0800
Message-Id: <20231220012332.168188-9-baolu.lu@linux.intel.com>
In-Reply-To: <20231220012332.168188-1-baolu.lu@linux.intel.com>
References: <20231220012332.168188-1-baolu.lu@linux.intel.com>
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Move iopf_group data structure to iommu.h to make it a minimal set of
faults that a domain's page fault handler should handle.

Add a new function, iopf_free_group(), to free a fault group after all
faults in the group are handled. This function will be made global so
that it can be called from other files, such as iommu-sva.c.

Move iopf_queue data structure to iommu.h to allow the workqueue to be
scheduled out of this file.

This will simplify the sequential patches.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Longfang Liu <liulongfang@huawei.com>
---
 include/linux/iommu.h      | 20 +++++++++++++++++++-
 drivers/iommu/io-pgfault.c | 37 +++++++++++++------------------------
 2 files changed, 32 insertions(+), 25 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index f97a5ab52af6..799b56563026 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -41,7 +41,6 @@ struct iommu_dirty_ops;
 struct notifier_block;
 struct iommu_sva;
 struct iommu_dma_cookie;
-struct iopf_queue;
 
 #define IOMMU_FAULT_PERM_READ	(1 << 0) /* read */
 #define IOMMU_FAULT_PERM_WRITE	(1 << 1) /* write */
@@ -126,6 +125,25 @@ struct iopf_fault {
 	struct list_head list;
 };
 
+struct iopf_group {
+	struct iopf_fault last_fault;
+	struct list_head faults;
+	struct work_struct work;
+	struct device *dev;
+};
+
+/**
+ * struct iopf_queue - IO Page Fault queue
+ * @wq: the fault workqueue
+ * @devices: devices attached to this queue
+ * @lock: protects the device list
+ */
+struct iopf_queue {
+	struct workqueue_struct *wq;
+	struct list_head devices;
+	struct mutex lock;
+};
+
 /* iommu fault flags */
 #define IOMMU_FAULT_READ	0x0
 #define IOMMU_FAULT_WRITE	0x1
diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 10d48eb72608..c7e6bbed5c05 100644
--- a/drivers/iommu/io-pgfault.c
+++ b/drivers/iommu/io-pgfault.c
@@ -13,24 +13,17 @@
 
 #include "iommu-sva.h"
 
-/**
- * struct iopf_queue - IO Page Fault queue
- * @wq: the fault workqueue
- * @devices: devices attached to this queue
- * @lock: protects the device list
- */
-struct iopf_queue {
-	struct workqueue_struct		*wq;
-	struct list_head		devices;
-	struct mutex			lock;
-};
+static void iopf_free_group(struct iopf_group *group)
+{
+	struct iopf_fault *iopf, *next;
 
-struct iopf_group {
-	struct iopf_fault		last_fault;
-	struct list_head		faults;
-	struct work_struct		work;
-	struct device			*dev;
-};
+	list_for_each_entry_safe(iopf, next, &group->faults, list) {
+		if (!(iopf->fault.prm.flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
+			kfree(iopf);
+	}
+
+	kfree(group);
+}
 
 static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
 			       enum iommu_page_response_code status)
@@ -50,9 +43,9 @@ static int iopf_complete_group(struct device *dev, struct iopf_fault *iopf,
 
 static void iopf_handler(struct work_struct *work)
 {
+	struct iopf_fault *iopf;
 	struct iopf_group *group;
 	struct iommu_domain *domain;
-	struct iopf_fault *iopf, *next;
 	enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
 
 	group = container_of(work, struct iopf_group, work);
@@ -61,7 +54,7 @@ static void iopf_handler(struct work_struct *work)
 	if (!domain || !domain->iopf_handler)
 		status = IOMMU_PAGE_RESP_INVALID;
 
-	list_for_each_entry_safe(iopf, next, &group->faults, list) {
+	list_for_each_entry(iopf, &group->faults, list) {
 		/*
 		 * For the moment, errors are sticky: don't handle subsequent
 		 * faults in the group if there is an error.
@@ -69,14 +62,10 @@ static void iopf_handler(struct work_struct *work)
 		if (status == IOMMU_PAGE_RESP_SUCCESS)
 			status = domain->iopf_handler(&iopf->fault,
 						      domain->fault_data);
-
-		if (!(iopf->fault.prm.flags &
-		      IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
-			kfree(iopf);
 	}
 
 	iopf_complete_group(group->dev, &group->last_fault, status);
-	kfree(group);
+	iopf_free_group(group);
 }
 
 /**
-- 
2.34.1