[RFC 2/8] iommufd: replace attach_fn with a structure

Yi Liu
2023-09-26T09:27:06Z

Most of the core logic before conducting the actual device attach/
replace operation can be shared with pasid attach/replace. Create
a new structure so more information (e.g. pasid) can be later added
along with the attach_fn.

Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/iommu/iommufd/device.c | 35 ++++++++++++++++---------
drivers/iommu/iommufd/iommufd_private.h | 8 ++++++
2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 645ab5d290fe..4fa4153c5df7 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -597,8 +597,11 @@ iommufd_device_do_replace(struct iommufd_device *idev,
return ERR_PTR(rc);
}

-typedef struct iommufd_hw_pagetable *(*attach_fn)(
- struct iommufd_device *idev, struct iommufd_hw_pagetable *hwpt);
+static struct iommufd_hw_pagetable *do_attach(struct iommufd_device *idev,
+ struct iommufd_hw_pagetable *hwpt, struct attach_data *data)
+{
+ return data->attach_fn(idev, hwpt);
+}

/*
* When automatically managing the domains we search for a compatible domain in
@@ -608,7 +611,7 @@ typedef struct iommufd_hw_pagetable *(*attach_fn)(
static struct iommufd_hw_pagetable *
iommufd_device_auto_get_domain(struct iommufd_device *idev,
struct iommufd_ioas *ioas, u32 *pt_id,
- attach_fn do_attach)
+ struct attach_data *data)
{
/*
* iommufd_hw_pagetable_attach() is called by
@@ -617,7 +620,7 @@ iommufd_device_auto_get_domain(struct iommufd_device *idev,
* to use the immediate_attach path as it supports drivers that can't
* directly allocate a domain.
*/
- bool immediate_attach = do_attach == iommufd_device_do_attach;
+ bool immediate_attach = data->attach_fn == iommufd_device_do_attach;
struct iommufd_hw_pagetable *destroy_hwpt;
struct iommufd_hw_pagetable *hwpt;

@@ -633,7 +636,7 @@ iommufd_device_auto_get_domain(struct iommufd_device *idev,

if (!iommufd_lock_obj(&hwpt->obj))
continue;
- destroy_hwpt = (*do_attach)(idev, hwpt);
+ destroy_hwpt = do_attach(idev, hwpt, data);
if (IS_ERR(destroy_hwpt)) {
iommufd_put_object(&hwpt->obj);
/*
@@ -660,7 +663,7 @@ iommufd_device_auto_get_domain(struct iommufd_device *idev,
}

if (!immediate_attach) {
- destroy_hwpt = (*do_attach)(idev, hwpt);
+ destroy_hwpt = do_attach(idev, hwpt, data);
if (IS_ERR(destroy_hwpt))
goto out_abort;
} else {
@@ -681,8 +684,8 @@ iommufd_device_auto_get_domain(struct iommufd_device *idev,
return destroy_hwpt;
}

-static int iommufd_device_change_pt(struct iommufd_device *idev, u32 *pt_id,
- attach_fn do_attach)
+int iommufd_device_change_pt(struct iommufd_device *idev, u32 *pt_id,
+ struct attach_data *data)
{
struct iommufd_hw_pagetable *destroy_hwpt;
struct iommufd_object *pt_obj;
@@ -696,7 +699,7 @@ static int iommufd_device_change_pt(struct iommufd_device *idev, u32 *pt_id,
struct iommufd_hw_pagetable *hwpt =
container_of(pt_obj, struct iommufd_hw_pagetable, obj);

- destroy_hwpt = (*do_attach)(idev, hwpt);
+ destroy_hwpt = do_attach(idev, hwpt, data);
if (IS_ERR(destroy_hwpt))
goto out_put_pt_obj;
break;
@@ -706,7 +709,7 @@ static int iommufd_device_change_pt(struct iommufd_device *idev, u32 *pt_id,
container_of(pt_obj, struct iommufd_ioas, obj);

destroy_hwpt = iommufd_device_auto_get_domain(idev, ioas, pt_id,
- do_attach);
+ data);
if (IS_ERR(destroy_hwpt))
goto out_put_pt_obj;
break;
@@ -742,8 +745,11 @@ static int iommufd_device_change_pt(struct iommufd_device *idev, u32 *pt_id,
int iommufd_device_attach(struct iommufd_device *idev, u32 *pt_id)
{
int rc;
+ struct attach_data data = {
+ .attach_fn = &iommufd_device_do_attach,
+ };

- rc = iommufd_device_change_pt(idev, pt_id, &iommufd_device_do_attach);
+ rc = iommufd_device_change_pt(idev, pt_id, &data);
if (rc)
return rc;

@@ -773,8 +779,11 @@ EXPORT_SYMBOL_NS_GPL(iommufd_device_attach, IOMMUFD);
*/
int iommufd_device_replace(struct iommufd_device *idev, u32 *pt_id)
{
- return iommufd_device_change_pt(idev, pt_id,
- &iommufd_device_do_replace);
+ struct attach_data data = {
+ .attach_fn = &iommufd_device_do_replace,
+ };
+
+ return iommufd_device_change_pt(idev, pt_id, &data);
}
EXPORT_SYMBOL_NS_GPL(iommufd_device_replace, IOMMUFD);

diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 1bd412cff2d6..f1fe4120c3b1 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -353,6 +353,14 @@ int iommufd_get_hw_info(struct iommufd_ucmd *ucmd);
int iommufd_set_dev_data(struct iommufd_ucmd *ucmd);
int iommufd_unset_dev_data(struct iommufd_ucmd *ucmd);

+struct attach_data {
+ union {
+ struct iommufd_hw_pagetable *(*attach_fn)(
+ struct iommufd_device *idev,
+ struct iommufd_hw_pagetable *hwpt);
+ };
+};
+
struct iommufd_access {
struct iommufd_object obj;
struct iommufd_ctx *ictx;
--
2.34.1