The following patch will add a new vIOMMU allocator that will require this
_iommufd_object_alloc to be sharable with IOMMU drivers (and iommufd too).
Add a new driver.c file that will be built with CONFIG_IOMMUFD_DRIVER_CORE
selected by CONFIG_IOMMUFD, and put the CONFIG_DRIVER under that remaining
to be selectable for drivers to build the existing iova_bitmap.c file.
Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
drivers/iommu/iommufd/Kconfig | 4 +++
drivers/iommu/iommufd/Makefile | 1 +
drivers/iommu/iommufd/iommufd_private.h | 4 ---
include/linux/iommufd.h | 13 ++++++++
drivers/iommu/iommufd/driver.c | 40 +++++++++++++++++++++++++
drivers/iommu/iommufd/main.c | 32 --------------------
6 files changed, 58 insertions(+), 36 deletions(-)
create mode 100644 drivers/iommu/iommufd/driver.c
diff --git a/drivers/iommu/iommufd/Kconfig b/drivers/iommu/iommufd/Kconfig
index 76656fe0470d..0a07f9449fd9 100644
--- a/drivers/iommu/iommufd/Kconfig
+++ b/drivers/iommu/iommufd/Kconfig
@@ -1,4 +1,8 @@
# SPDX-License-Identifier: GPL-2.0-only
+config IOMMUFD_DRIVER_CORE
+ tristate
+ default (IOMMUFD_DRIVER || IOMMUFD) if IOMMUFD!=n
+
config IOMMUFD
tristate "IOMMU Userspace API"
select INTERVAL_TREE
diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile
index cf4605962bea..de675df52913 100644
--- a/drivers/iommu/iommufd/Makefile
+++ b/drivers/iommu/iommufd/Makefile
@@ -13,3 +13,4 @@ iommufd-$(CONFIG_IOMMUFD_TEST) += selftest.o
obj-$(CONFIG_IOMMUFD) += iommufd.o
obj-$(CONFIG_IOMMUFD_DRIVER) += iova_bitmap.o
+obj-$(CONFIG_IOMMUFD_DRIVER_CORE) += driver.o
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 94cfcab7e9de..be347f726fda 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -206,10 +206,6 @@ iommufd_object_put_and_try_destroy(struct iommufd_ctx *ictx,
iommufd_object_remove(ictx, obj, obj->id, 0);
}
-struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
- size_t size,
- enum iommufd_object_type type);
-
#define __iommufd_object_alloc(ictx, ptr, type, obj) \
container_of(_iommufd_object_alloc( \
ictx, \
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 22948dd03d67..94522d4029ca 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -135,4 +135,17 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx)
return -EOPNOTSUPP;
}
#endif /* CONFIG_IOMMUFD */
+
+#if IS_ENABLED(CONFIG_IOMMUFD_DRIVER_CORE)
+struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
+ size_t size,
+ enum iommufd_object_type type);
+#else /* !CONFIG_IOMMUFD_DRIVER_CORE */
+static inline struct iommufd_object *
+_iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
+ enum iommufd_object_type type)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+#endif /* CONFIG_IOMMUFD_DRIVER_CORE */
#endif
diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c
new file mode 100644
index 000000000000..2bc47d92a0ab
--- /dev/null
+++ b/drivers/iommu/iommufd/driver.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2024, NVIDIA CORPORATION & AFFILIATES
+ */
+#include "iommufd_private.h"
+
+struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
+ size_t size,
+ enum iommufd_object_type type)
+{
+ struct iommufd_object *obj;
+ int rc;
+
+ obj = kzalloc(size, GFP_KERNEL_ACCOUNT);
+ if (!obj)
+ return ERR_PTR(-ENOMEM);
+ obj->type = type;
+ /* Starts out bias'd by 1 until it is removed from the xarray */
+ refcount_set(&obj->shortterm_users, 1);
+ refcount_set(&obj->users, 1);
+
+ /*
+ * Reserve an ID in the xarray but do not publish the pointer yet since
+ * the caller hasn't initialized it yet. Once the pointer is published
+ * in the xarray and visible to other threads we can't reliably destroy
+ * it anymore, so the caller must complete all errorable operations
+ * before calling iommufd_object_finalize().
+ */
+ rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY, xa_limit_31b,
+ GFP_KERNEL_ACCOUNT);
+ if (rc)
+ goto out_free;
+ return obj;
+out_free:
+ kfree(obj);
+ return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_NS_GPL(_iommufd_object_alloc, IOMMUFD);
+
+MODULE_DESCRIPTION("iommufd code shared with builtin modules");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 826a2b2be52f..3c32b440471b 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -29,38 +29,6 @@ struct iommufd_object_ops {
static const struct iommufd_object_ops iommufd_object_ops[];
static struct miscdevice vfio_misc_dev;
-struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
- size_t size,
- enum iommufd_object_type type)
-{
- struct iommufd_object *obj;
- int rc;
-
- obj = kzalloc(size, GFP_KERNEL_ACCOUNT);
- if (!obj)
- return ERR_PTR(-ENOMEM);
- obj->type = type;
- /* Starts out bias'd by 1 until it is removed from the xarray */
- refcount_set(&obj->shortterm_users, 1);
- refcount_set(&obj->users, 1);
-
- /*
- * Reserve an ID in the xarray but do not publish the pointer yet since
- * the caller hasn't initialized it yet. Once the pointer is published
- * in the xarray and visible to other threads we can't reliably destroy
- * it anymore, so the caller must complete all errorable operations
- * before calling iommufd_object_finalize().
- */
- rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY,
- xa_limit_31b, GFP_KERNEL_ACCOUNT);
- if (rc)
- goto out_free;
- return obj;
-out_free:
- kfree(obj);
- return ERR_PTR(rc);
-}
-
/*
* Allow concurrent access to the object.
*
--
2.43.0
