iommu: Prepare for separating SVA and IOPF

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>
Link: https://lore.kernel.org/r/20240212012227.119381-9-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
index 10d48eb72608c2d2e92b13d41ebc295ed7f1ed9a..c7e6bbed5c05b337bd0c834539fcd7718b4ebbb2 100644 (file)
--- 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;
-};
-
-struct iopf_group {
-       struct iopf_fault               last_fault;
-       struct list_head                faults;
-       struct work_struct              work;
-       struct device                   *dev;
-};
+static void iopf_free_group(struct iopf_group *group)
+{
+       struct iopf_fault *iopf, *next;
+
+       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);
 }
 
 /**

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 2320548a90f8397ca14782ebe91dbda411f854e5..c9d4f175f121cb1c71199d83978aea82b7e84a35 100644 (file)
--- 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