[PATCH v10 08/16] iommu: Prepare for separating SVA and IOPF

Lu Baolu
2024-01-22T05:49:07Z

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 2320548a90f8..c9d4f175f121 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