[patch net-next/mlxsw internal preRFC 1/3] lib: introduce initial implementation of object aggregation manager
Jiri Pirko
jiri at resnulli.us
Sun Aug 5 23:01:31 AEST 2018
From: Jiri Pirko <jiri at mellanox.com>
This lib tracks objects which could be of two types:
1) root object
2) nested object - with a "delta" which differentiates it from
the associated root object
The objects are tracked by a hashtable and reference-counted. User is
responsible of implementing callbacks to create/destroy root entity
related to each root object and callback to create/destroy nested object
delta.
TODO: fill-up test_objagg.c
Signed-off-by: Jiri Pirko <jiri at mellanox.com>
---
include/linux/objagg.h | 27 ++++++
lib/Kconfig | 3 +
lib/Kconfig.debug | 10 +++
lib/Makefile | 3 +
lib/objagg.c | 231 +++++++++++++++++++++++++++++++++++++++++++++++++
lib/test_objagg.c | 8 ++
6 files changed, 282 insertions(+)
create mode 100644 include/linux/objagg.h
create mode 100644 lib/objagg.c
create mode 100644 lib/test_objagg.c
diff --git a/include/linux/objagg.h b/include/linux/objagg.h
new file mode 100644
index 000000000000..f81dd1fc1353
--- /dev/null
+++ b/include/linux/objagg.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 */
+/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */
+
+#ifndef _OBJAGG_H
+#define _OBJAGG_H
+
+struct objagg_ops {
+ size_t obj_size;
+ void * (*delta_create)(void *priv, void *parent_obj, void *obj);
+ void (*delta_destroy)(void *priv, void *delta_priv);
+ void * (*root_create)(void *priv, void *obj);
+ void (*root_destroy)(void *priv, void *root_priv);
+};
+
+struct objagg;
+struct objagg_obj;
+
+const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj);
+const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj);
+const void *objagg_obj_raw(const struct objagg_obj *objagg_obj);
+
+struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj);
+void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj);
+struct objagg *objagg_create(const struct objagg_ops *ops, void *priv);
+void objagg_destroy(struct objagg *objagg);
+
+#endif
diff --git a/lib/Kconfig b/lib/Kconfig
index 706836ec314d..f1b7f8042433 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -614,3 +614,6 @@ config GENERIC_LIB_CMPDI2
config GENERIC_LIB_UCMPDI2
bool
+
+config OBJAGG
+ tristate "magg" if COMPILE_TEST
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d3d82eccdfa5..dbd8d0ed2226 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1973,6 +1973,16 @@ config TEST_DEBUG_VIRTUAL
If unsure, say N.
+config TEST_OBJAGG
+ tristate "Perform selftest on object aggreration manager"
+ default n
+ depends on OBJAGG
+ help
+ Enable this option to test object aggregation manager on boot
+ (or module load).
+
+ If unsure, say N.
+
endif # RUNTIME_TESTING_MENU
config MEMTEST
diff --git a/lib/Makefile b/lib/Makefile
index 60d0d5f90946..02d66aa0e5cf 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_TEST_UUID) += test_uuid.o
obj-$(CONFIG_TEST_PARMAN) += test_parman.o
obj-$(CONFIG_TEST_KMOD) += test_kmod.o
obj-$(CONFIG_TEST_DEBUG_VIRTUAL) += test_debug_virtual.o
+obj-$(CONFIG_TEST_OBJAGG) += test_objagg.o
ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
@@ -258,3 +259,5 @@ obj-$(CONFIG_GENERIC_LIB_LSHRDI3) += lshrdi3.o
obj-$(CONFIG_GENERIC_LIB_MULDI3) += muldi3.o
obj-$(CONFIG_GENERIC_LIB_CMPDI2) += cmpdi2.o
obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o
+
+obj-$(CONFIG_OBJAGG) += objagg.o
diff --git a/lib/objagg.c b/lib/objagg.c
new file mode 100644
index 000000000000..936177e96f47
--- /dev/null
+++ b/lib/objagg.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/refcount.h>
+#include <linux/list.h>
+#include <linux/rhashtable.h>
+#include <linux/objagg.h>
+
+struct objagg {
+ const struct objagg_ops *ops;
+ void *priv;
+ struct rhashtable obj_ht;
+ struct rhashtable_params ht_params;
+ struct list_head obj_list;
+};
+
+struct objagg_obj {
+ struct rhash_head ht_node; /* member of objagg->obj_ht */
+ struct list_head list; /* member of objagg->obj_list */
+ struct objagg_obj *parent; /* if the object is nested, this
+ * holds pointer to parent, otherwise NULL
+ */
+ union {
+ void *delta_priv; /* user delta private */
+ void *root_priv; /* user root private */
+ };
+ refcount_t refcount; /* counts number of users of this object
+ * including nested objects.
+ */
+ unsigned long obj[0];
+};
+
+static bool objagg_obj_is_root(const struct objagg_obj *objagg_obj)
+{
+ /* Nesting is not supported, so we can use ->parent
+ * to figure out if the object is root.
+ */
+ return !objagg_obj->parent;
+}
+
+const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj)
+{
+ if (objagg_obj_is_root(objagg_obj))
+ return objagg_obj->root_priv;
+ WARN_ON(!objagg_obj_is_root(objagg_obj->parent));
+ return objagg_obj->parent->root_priv;
+}
+EXPORT_SYMBOL(objagg_obj_root_priv);
+
+const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj)
+{
+ if (objagg_obj_is_root(objagg_obj))
+ return NULL;
+ return objagg_obj->delta_priv;
+}
+EXPORT_SYMBOL(objagg_obj_delta_priv);
+
+const void *objagg_obj_raw(const struct objagg_obj *objagg_obj)
+{
+ return objagg_obj->obj;
+}
+EXPORT_SYMBOL(objagg_obj_raw);
+
+static struct objagg_obj *objagg_obj_lookup(struct objagg *objagg, void *obj)
+{
+ return rhashtable_lookup_fast(&objagg->obj_ht, obj, objagg->ht_params);
+}
+
+static int objagg_obj_parent_assign(struct objagg *objagg,
+ struct objagg_obj *objagg_obj)
+{
+ struct objagg_obj *objagg_obj_cur;
+ void *delta_priv;
+
+ list_for_each_entry(objagg_obj_cur, &objagg->obj_list, list) {
+ /* Nesting is not supported. In case the object
+ * is not root, it cannot be assigned as parent.
+ */
+ if (!objagg_obj_is_root(objagg_obj))
+ continue;
+ delta_priv = objagg->ops->delta_create(objagg->priv,
+ objagg_obj_cur->obj,
+ objagg_obj->obj);
+ if (!IS_ERR(delta_priv)) {
+ /* User returned a delta private, that means that
+ * our object can be aggregated into the cursor.
+ */
+ objagg_obj->parent = objagg_obj_cur;
+ objagg_obj->delta_priv = delta_priv;
+ refcount_inc(&objagg_obj->parent->refcount);
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
+static void objagg_obj_parent_unassign(struct objagg *objagg,
+ struct objagg_obj *objagg_obj)
+{
+ objagg->ops->delta_destroy(objagg->priv, objagg_obj->delta_priv);
+ objagg_obj_put(objagg, objagg_obj->parent);
+}
+
+static int objagg_obj_root_create(struct objagg *objagg,
+ struct objagg_obj *objagg_obj)
+{
+ objagg_obj->root_priv = objagg->ops->root_create(objagg->priv,
+ objagg_obj->obj);
+ if (IS_ERR(objagg_obj))
+ return PTR_ERR(objagg_obj);
+ return 0;
+}
+
+static void objagg_obj_root_destroy(struct objagg *objagg,
+ struct objagg_obj *objagg_obj)
+{
+ objagg->ops->root_destroy(objagg->priv, objagg_obj->root_priv);
+}
+
+static int objagg_obj_init(struct objagg *objagg,
+ struct objagg_obj *objagg_obj)
+{
+ int err;
+
+ /* Try to find if the object can be aggregated under an existing one. */
+ err = objagg_obj_parent_assign(objagg, objagg_obj);
+ if (!err)
+ return 0;
+ /* If aggregation is not possible, make the object a root. */
+ return objagg_obj_root_create(objagg, objagg_obj);
+}
+
+static void objagg_obj_fini(struct objagg *objagg,
+ struct objagg_obj *objagg_obj)
+{
+ if (!objagg_obj_is_root(objagg_obj))
+ objagg_obj_parent_unassign(objagg, objagg_obj);
+ else
+ objagg_obj_root_destroy(objagg, objagg_obj);
+}
+
+struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj)
+{
+ struct objagg_obj *objagg_obj;
+ int err;
+
+ /* First, try to find the object exactly as user passed that,
+ * perhaps it is already in use.
+ */
+ objagg_obj = objagg_obj_lookup(objagg, obj);
+ if (objagg_obj) {
+ refcount_inc(&objagg_obj->refcount);
+ return objagg_obj;
+ }
+
+ objagg_obj = kzalloc(sizeof(*objagg_obj) + objagg->ops->obj_size,
+ GFP_KERNEL);
+ if (!objagg_obj)
+ return ERR_PTR(-ENOMEM);
+ refcount_set(&objagg_obj->refcount, 1);
+ memcpy(objagg_obj->obj, obj, objagg->ops->obj_size);
+
+ err = objagg_obj_init(objagg, objagg_obj);
+ if (err)
+ goto err_obj_init;
+
+ err = rhashtable_insert_fast(&objagg->obj_ht, &objagg_obj->ht_node,
+ objagg->ht_params);
+ if (err)
+ goto err_ht_insert;
+
+ return objagg_obj;
+
+err_ht_insert:
+ objagg_obj_fini(objagg, objagg_obj);
+err_obj_init:
+ kfree(objagg_obj);
+ return ERR_PTR(err);
+}
+
+void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj)
+{
+ if (!refcount_dec_and_test(&objagg_obj->refcount))
+ return;
+ rhashtable_remove_fast(&objagg->obj_ht, &objagg_obj->ht_node,
+ objagg->ht_params);
+ objagg_obj_fini(objagg, objagg_obj);
+ kfree(objagg_obj);
+}
+EXPORT_SYMBOL(objagg_obj_put);
+
+struct objagg *objagg_create(const struct objagg_ops *ops, void *priv)
+{
+ struct objagg *objagg;
+ int err;
+
+ objagg = kzalloc(sizeof(*objagg), GFP_KERNEL);
+ if (!objagg)
+ return ERR_PTR(-ENOMEM);
+ objagg->ops = ops;
+ INIT_LIST_HEAD(&objagg->obj_list);
+
+ objagg->ht_params.key_len = ops->obj_size;
+ objagg->ht_params.key_offset = offsetof(struct objagg_obj, obj);
+ objagg->ht_params.head_offset = offsetof(struct objagg_obj, ht_node);
+
+ err = rhashtable_init(&objagg->obj_ht, &objagg->ht_params);
+ if (err)
+ goto err_rhashtable_init;
+
+ return objagg;
+
+err_rhashtable_init:
+ kfree(objagg);
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL(objagg_create);
+
+void objagg_destroy(struct objagg *objagg)
+{
+ WARN_ON(!list_empty(&objagg->obj_list));
+ rhashtable_destroy(&objagg->obj_ht);
+ kfree(objagg);
+}
+EXPORT_SYMBOL(objagg_destroy);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Jiri Pirko <jiri at mellanox.com>");
+MODULE_DESCRIPTION("Object aggregation manager");
diff --git a/lib/test_objagg.c b/lib/test_objagg.c
new file mode 100644
index 000000000000..5669bebf4a41
--- /dev/null
+++ b/lib/test_objagg.c
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */
+
+#include <linux/objagg.h>
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Jiri Pirko <jiri at mellanox.com>");
+MODULE_DESCRIPTION("Test module for objagg");
--
2.14.4
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