RDMA/core: Make a new module for the uverbs components needed by drivers

To maintain the split where ib_uverbs.ko should not be depended on by
drivers, add a new module ib_uverbs_support.ko which contains the driver
called functions that are too large or too rare to be placed in
ib_uverbs_core.ko

Start by moving most of rdma_core.c into this module, making some
adjustments to split it from the actual uverbs FD code.

This was not done originally because we lacked EXPORT_SYMBOL_NS and I had
a fear that drivers would abuse this interface surface.

Link: https://patch.msgid.link/r/4-v3-43aba1969751+1988-ib_uverbs_support_ko_jgg@nvidia.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

5 files changed, 133 insertions, 105 deletions

diff --git a/drivers/infiniband/core/Makefile b/drivers/infiniband/core/Makefile
index 8c2ba2ce0351..e2ff9c2be9d3 100644
--- a/drivers/infiniband/core/Makefile
+++ b/drivers/infiniband/core/Makefile
@@ -5,7 +5,9 @@ user_access-$(CONFIG_INFINIBAND_ADDR_TRANS)	:= rdma_ucm.o
 obj-$(CONFIG_INFINIBAND) +=		ib_core.o ib_cm.o iw_cm.o \
 					$(infiniband-y)
 obj-$(CONFIG_INFINIBAND_USER_MAD) +=	ib_umad.o
-obj-$(CONFIG_INFINIBAND_USER_ACCESS) += ib_uverbs.o $(user_access-y)
+obj-$(CONFIG_INFINIBAND_USER_ACCESS) += ib_uverbs.o \
+					$(user_access-y) \
+					ib_uverbs_support.o
 
 ib_core-y :=			packer.o ud_header.o verbs.o cq.o rw.o sysfs.o \
 				device.o cache.o netlink.o \
@@ -34,7 +36,7 @@ rdma_ucm-y :=			ucma.o
 ib_umad-y :=			user_mad.o
 
 ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
-				rdma_core.o uverbs_std_types.o uverbs_ioctl.o \
+				uverbs_std_types.o uverbs_ioctl.o \
 				uverbs_std_types_cq.o \
 				uverbs_std_types_dmabuf.o \
 				uverbs_std_types_dmah.o \
@@ -46,3 +48,5 @@ ib_uverbs-y :=			uverbs_main.o uverbs_cmd.o uverbs_marshall.o \
 				uverbs_std_types_wq.o \
 				uverbs_std_types_qp.o \
 				ucaps.o
+
+ib_uverbs_support-y :=		rdma_core.o
diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c
index 8934d0d227ab..fd5651c003ae 100644
--- a/drivers/infiniband/core/rdma_core.c
+++ b/drivers/infiniband/core/rdma_core.c
@@ -42,6 +42,40 @@
 #include "core_priv.h"
 #include "rdma_core.h"
 
+static void release_ufile_idr_uobject(struct ib_uverbs_file *ufile);
+
+void ib_uverbs_release_file(struct kref *ref)
+{
+	struct ib_uverbs_file *file =
+		container_of(ref, struct ib_uverbs_file, ref);
+	struct ib_device *ib_dev;
+	int srcu_key;
+
+	release_ufile_idr_uobject(file);
+
+	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
+	ib_dev = srcu_dereference(file->device->ib_dev,
+				  &file->device->disassociate_srcu);
+	if (ib_dev && !ib_dev->ops.disassociate_ucontext)
+		module_put(ib_dev->ops.owner);
+	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
+
+	if (refcount_dec_and_test(&file->device->refcount))
+		ib_uverbs_comp_dev(file->device);
+
+	if (file->default_async_file)
+		uverbs_uobject_put(&file->default_async_file->uobj);
+	put_device(&file->device->dev);
+
+	if (file->disassociate_page)
+		__free_pages(file->disassociate_page, 0);
+	mutex_destroy(&file->disassociation_lock);
+	mutex_destroy(&file->umap_lock);
+	mutex_destroy(&file->ucontext_lock);
+	kfree(file);
+}
+EXPORT_SYMBOL_NS_GPL(ib_uverbs_release_file, "rdma_core");
+
 static void uverbs_uobject_free(struct kref *ref)
 {
 	kfree_rcu(container_of(ref, struct ib_uobject, ref), rcu);
@@ -214,6 +248,7 @@ out_unlock:
 	up_read(&ufile->hw_destroy_rwsem);
 	return ret;
 }
+EXPORT_SYMBOL_NS_GPL(uobj_destroy, "rdma_core");
 
 /*
  * uobj_get_destroy destroys the HW object and returns a handle to the uobj
@@ -239,6 +274,7 @@ struct ib_uobject *__uobj_get_destroy(const struct uverbs_api_object *obj,
 
 	return uobj;
 }
+EXPORT_SYMBOL_NS_GPL(__uobj_get_destroy, "rdma_core");
 
 /*
  * Does both uobj_get_destroy() and uobj_put_destroy().  Returns 0 on success
@@ -255,6 +291,7 @@ int __uobj_perform_destroy(const struct uverbs_api_object *obj, u32 id,
 	uobj_put_destroy(uobj);
 	return 0;
 }
+EXPORT_SYMBOL_NS_GPL(__uobj_perform_destroy, "rdma_core");
 
 /* alloc_uobj must be undone by uverbs_destroy_uobject() */
 static struct ib_uobject *alloc_uobj(struct uverbs_attr_bundle *attrs,
@@ -420,6 +457,7 @@ free:
 	uverbs_uobject_put(uobj);
 	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_NS_GPL(rdma_lookup_get_uobject, "rdma_core");
 
 static struct ib_uobject *
 alloc_begin_idr_uobject(const struct uverbs_api_object *obj,
@@ -522,6 +560,7 @@ struct ib_uobject *rdma_alloc_begin_uobject(const struct uverbs_api_object *obj,
 	}
 	return ret;
 }
+EXPORT_SYMBOL_NS_GPL(rdma_alloc_begin_uobject, "rdma_core");
 
 static void alloc_abort_idr_uobject(struct ib_uobject *uobj)
 {
@@ -668,6 +707,7 @@ void rdma_alloc_commit_uobject(struct ib_uobject *uobj,
 	/* Matches the down_read in rdma_alloc_begin_uobject */
 	up_read(&ufile->hw_destroy_rwsem);
 }
+EXPORT_SYMBOL_NS_GPL(rdma_alloc_commit_uobject, "rdma_core");
 
 /*
  * new_uobj will be assigned to the handle currently used by to_uobj, and
@@ -697,6 +737,7 @@ void rdma_assign_uobject(struct ib_uobject *to_uobj, struct ib_uobject *new_uobj
 	 */
 	uverbs_destroy_uobject(to_uobj, RDMA_REMOVE_DESTROY, attrs);
 }
+EXPORT_SYMBOL_NS_GPL(rdma_assign_uobject, "rdma_core");
 
 /*
  * This consumes the kref for uobj. It is up to the caller to unwind the HW
@@ -727,6 +768,7 @@ void rdma_alloc_abort_uobject(struct ib_uobject *uobj,
 	/* Matches the down_read in rdma_alloc_begin_uobject */
 	up_read(&ufile->hw_destroy_rwsem);
 }
+EXPORT_SYMBOL_NS_GPL(rdma_alloc_abort_uobject, "rdma_core");
 
 static void lookup_put_idr_uobject(struct ib_uobject *uobj,
 				   enum rdma_lookup_mode mode)
@@ -770,13 +812,15 @@ void rdma_lookup_put_uobject(struct ib_uobject *uobj,
 	/* Pairs with the kref obtained by type->lookup_get */
 	uverbs_uobject_put(uobj);
 }
+EXPORT_SYMBOL_NS_GPL(rdma_lookup_put_uobject, "rdma_core");
 
 void setup_ufile_idr_uobject(struct ib_uverbs_file *ufile)
 {
 	xa_init_flags(&ufile->idr, XA_FLAGS_ALLOC);
 }
+EXPORT_SYMBOL_NS_GPL(setup_ufile_idr_uobject, "rdma_core");
 
-void release_ufile_idr_uobject(struct ib_uverbs_file *ufile)
+static void release_ufile_idr_uobject(struct ib_uverbs_file *ufile)
 {
 	struct ib_uobject *entry;
 	unsigned long id;
@@ -839,6 +883,7 @@ int uverbs_uobject_release(struct ib_uobject *uobj)
 	uverbs_uobject_put(uobj);
 	return 0;
 }
+EXPORT_SYMBOL_NS_GPL(uverbs_uobject_release, "rdma_core");
 
 /*
  * Users of UVERBS_TYPE_ALLOC_FD should set this function as the struct
@@ -880,41 +925,8 @@ int uverbs_uobject_fd_release(struct inode *inode, struct file *filp)
 }
 EXPORT_SYMBOL(uverbs_uobject_fd_release);
 
-/*
- * Drop the ucontext off the ufile and completely disconnect it from the
- * ib_device
- */
-static void ufile_destroy_ucontext(struct ib_uverbs_file *ufile,
-				   enum rdma_remove_reason reason)
-{
-	struct ib_ucontext *ucontext = ufile->ucontext;
-	struct ib_device *ib_dev = ucontext->device;
-
-	/*
-	 * If we are closing the FD then the user mmap VMAs must have
-	 * already been destroyed as they hold on to the filep, otherwise
-	 * they need to be zap'd.
-	 */
-	if (reason == RDMA_REMOVE_DRIVER_REMOVE) {
-		uverbs_user_mmap_disassociate(ufile);
-		if (ib_dev->ops.disassociate_ucontext)
-			ib_dev->ops.disassociate_ucontext(ucontext);
-	}
-
-	ib_rdmacg_uncharge(&ucontext->cg_obj, ib_dev,
-			   RDMACG_RESOURCE_HCA_HANDLE);
-
-	rdma_restrack_del(&ucontext->res);
-
-	ib_dev->ops.dealloc_ucontext(ucontext);
-	WARN_ON(!xa_empty(&ucontext->mmap_xa));
-	kfree(ucontext);
-
-	ufile->ucontext = NULL;
-}
-
-static int __uverbs_cleanup_ufile(struct ib_uverbs_file *ufile,
-				  enum rdma_remove_reason reason)
+int __uverbs_cleanup_ufile(struct ib_uverbs_file *ufile,
+			   enum rdma_remove_reason reason)
 {
 	struct uverbs_attr_bundle attrs = { .ufile = ufile };
 	struct ib_ucontext *ucontext = ufile->ucontext;
@@ -955,36 +967,7 @@ static int __uverbs_cleanup_ufile(struct ib_uverbs_file *ufile,
 	}
 	return ret;
 }
-
-/*
- * Destroy the ucontext and every uobject associated with it.
- *
- * This is internally locked and can be called in parallel from multiple
- * contexts.
- */
-void uverbs_destroy_ufile_hw(struct ib_uverbs_file *ufile,
-			     enum rdma_remove_reason reason)
-{
-	down_write(&ufile->hw_destroy_rwsem);
-
-	/*
-	 * If a ucontext was never created then we can't have any uobjects to
-	 * cleanup, nothing to do.
-	 */
-	if (!ufile->ucontext)
-		goto done;
-
-	while (!list_empty(&ufile->uobjects) &&
-	       !__uverbs_cleanup_ufile(ufile, reason)) {
-	}
-
-	if (WARN_ON(!list_empty(&ufile->uobjects)))
-		__uverbs_cleanup_ufile(ufile, RDMA_REMOVE_DRIVER_FAILURE);
-	ufile_destroy_ucontext(ufile, reason);
-
-done:
-	up_write(&ufile->hw_destroy_rwsem);
-}
+EXPORT_SYMBOL_NS_GPL(__uverbs_cleanup_ufile, "rdma_core");
 
 const struct uverbs_obj_type_class uverbs_fd_class = {
 	.alloc_begin = alloc_begin_fd_uobject,
@@ -1022,6 +1005,7 @@ uverbs_get_uobject_from_file(u16 object_id, enum uverbs_obj_access access,
 		return ERR_PTR(-EOPNOTSUPP);
 	}
 }
+EXPORT_SYMBOL_NS_GPL(uverbs_get_uobject_from_file, "rdma_core");
 
 void uverbs_finalize_object(struct ib_uobject *uobj,
 			    enum uverbs_obj_access access, bool hw_obj_valid,
@@ -1054,6 +1038,7 @@ void uverbs_finalize_object(struct ib_uobject *uobj,
 		WARN_ON(true);
 	}
 }
+EXPORT_SYMBOL_NS_GPL(uverbs_finalize_object, "rdma_core");
 
 /**
  * rdma_uattrs_has_raw_cap() - Returns whether a rdma device linked to the
@@ -1083,3 +1068,6 @@ out:
 	return has_cap;
 }
 EXPORT_SYMBOL(rdma_uattrs_has_raw_cap);
+
+MODULE_DESCRIPTION("InfiniBand uverbs objects");
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/infiniband/core/rdma_core.h b/drivers/infiniband/core/rdma_core.h
index 55f1e3558856..b626d3d24d08 100644
--- a/drivers/infiniband/core/rdma_core.h
+++ b/drivers/infiniband/core/rdma_core.h
@@ -70,7 +70,6 @@ void uverbs_finalize_object(struct ib_uobject *uobj,
 int uverbs_output_written(const struct uverbs_attr_bundle *bundle, size_t idx);
 
 void setup_ufile_idr_uobject(struct ib_uverbs_file *ufile);
-void release_ufile_idr_uobject(struct ib_uverbs_file *ufile);
 
 struct ib_udata *uverbs_get_cleared_udata(struct uverbs_attr_bundle *attrs);
 
diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index a1de8fe9c90b..c64dd6b94e10 100644
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -359,4 +359,13 @@ static inline void ib_uverbs_dmabuf_done(struct kref *kref)
 	complete(&priv->comp);
 }
 
+int __uverbs_cleanup_ufile(struct ib_uverbs_file *ufile,
+			   enum rdma_remove_reason reason);
+
+static inline void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
+{
+	complete(&dev->comp);
+}
+
+
 #endif /* UVERBS_H */
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index a937d276c5c0..ab6f1e3cb47a 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -61,6 +61,7 @@
 MODULE_AUTHOR("Roland Dreier");
 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
 MODULE_LICENSE("Dual BSD/GPL");
+MODULE_IMPORT_NS("rdma_core");
 
 enum {
 	IB_UVERBS_MAJOR       = 231,
@@ -165,42 +166,6 @@ void ib_uverbs_detach_umcast(struct ib_qp *qp,
 	}
 }
 
-static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
-{
-	complete(&dev->comp);
-}
-
-void ib_uverbs_release_file(struct kref *ref)
-{
-	struct ib_uverbs_file *file =
-		container_of(ref, struct ib_uverbs_file, ref);
-	struct ib_device *ib_dev;
-	int srcu_key;
-
-	release_ufile_idr_uobject(file);
-
-	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
-	ib_dev = srcu_dereference(file->device->ib_dev,
-				  &file->device->disassociate_srcu);
-	if (ib_dev && !ib_dev->ops.disassociate_ucontext)
-		module_put(ib_dev->ops.owner);
-	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
-
-	if (refcount_dec_and_test(&file->device->refcount))
-		ib_uverbs_comp_dev(file->device);
-
-	if (file->default_async_file)
-		uverbs_uobject_put(&file->default_async_file->uobj);
-	put_device(&file->device->dev);
-
-	if (file->disassociate_page)
-		__free_pages(file->disassociate_page, 0);
-	mutex_destroy(&file->disassociation_lock);
-	mutex_destroy(&file->umap_lock);
-	mutex_destroy(&file->ucontext_lock);
-	kfree(file);
-}
-
 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
 				    struct file *filp, char __user *buf,
 				    size_t count, loff_t *pos,
@@ -985,6 +950,69 @@ err:
 	return ret;
 }
 
+/*
+ * Drop the ucontext off the ufile and completely disconnect it from the
+ * ib_device
+ */
+static void ufile_destroy_ucontext(struct ib_uverbs_file *ufile,
+			    enum rdma_remove_reason reason)
+{
+	struct ib_ucontext *ucontext = ufile->ucontext;
+	struct ib_device *ib_dev = ucontext->device;
+
+	/*
+	 * If we are closing the FD then the user mmap VMAs must have
+	 * already been destroyed as they hold on to the filep, otherwise
+	 * they need to be zap'd.
+	 */
+	if (reason == RDMA_REMOVE_DRIVER_REMOVE) {
+		uverbs_user_mmap_disassociate(ufile);
+		if (ib_dev->ops.disassociate_ucontext)
+			ib_dev->ops.disassociate_ucontext(ucontext);
+	}
+
+	ib_rdmacg_uncharge(&ucontext->cg_obj, ib_dev,
+			   RDMACG_RESOURCE_HCA_HANDLE);
+
+	rdma_restrack_del(&ucontext->res);
+
+	ib_dev->ops.dealloc_ucontext(ucontext);
+	WARN_ON(!xa_empty(&ucontext->mmap_xa));
+	kfree(ucontext);
+
+	ufile->ucontext = NULL;
+}
+
+/*
+ * Destroy the ucontext and every uobject associated with it.
+ *
+ * This is internally locked and can be called in parallel from multiple
+ * contexts.
+ */
+void uverbs_destroy_ufile_hw(struct ib_uverbs_file *ufile,
+			     enum rdma_remove_reason reason)
+{
+	down_write(&ufile->hw_destroy_rwsem);
+
+	/*
+	 * If a ucontext was never created then we can't have any uobjects to
+	 * cleanup, nothing to do.
+	 */
+	if (!ufile->ucontext)
+		goto done;
+
+	while (!list_empty(&ufile->uobjects) &&
+	       !__uverbs_cleanup_ufile(ufile, reason)) {
+	}
+
+	if (WARN_ON(!list_empty(&ufile->uobjects)))
+		__uverbs_cleanup_ufile(ufile, RDMA_REMOVE_DRIVER_FAILURE);
+	ufile_destroy_ucontext(ufile, reason);
+
+done:
+	up_write(&ufile->hw_destroy_rwsem);
+}
+
 static int ib_uverbs_close(struct inode *inode, struct file *filp)
 {
 	struct ib_uverbs_file *file = filp->private_data;