RDMA/verbs: Store the write/write_ex uapi entry points in the uverbs_api

Bringing all uapi entry points into one place lets us deal with them
consistently. For instance the write, write_ex and ioctl paths can be
disabled when an API is not supported by the driver.

This will replace the uverbs_cmd_table static arrays.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

drivers/infiniband/core/rdma_core.h

@@ -136,6 +136,15 @@ struct uverbs_api_ioctl_method {
 	u8 destroy_bkey;
 };
 
+struct uverbs_api_write_method {
+	ssize_t (*handler)(struct ib_uverbs_file *file, const char __user *buf,
+			   int in_len, int out_len);
+	int (*handler_ex)(struct ib_uverbs_file *file, struct ib_udata *ucore,
+			  struct ib_udata *uhw);
+	u8 disabled:1;
+	u8 is_ex:1;
+};
+
 struct uverbs_api_attr {
 	struct uverbs_attr_spec spec;
 };
@@ -144,6 +153,12 @@ struct uverbs_api {
 	/* radix tree contains struct uverbs_api_* pointers */
 	struct radix_tree_root radix;
 	enum rdma_driver_id driver_id;
+
+	unsigned int num_write;
+	unsigned int num_write_ex;
+	struct uverbs_api_write_method notsupp_method;
+	const struct uverbs_api_write_method **write_methods;
+	const struct uverbs_api_write_method **write_ex_methods;
 };
 
 static inline const struct uverbs_api_object *

drivers/infiniband/core/uverbs_uapi.c

@@ -8,6 +8,19 @@
 #include "rdma_core.h"
 #include "uverbs.h"
 
+static ssize_t ib_uverbs_notsupp(struct ib_uverbs_file *file,
+				 const char __user *buf, int in_len,
+				 int out_len)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ib_uverbs_ex_notsupp(struct ib_uverbs_file *file,
+				struct ib_udata *ucore, struct ib_udata *uhw)
+{
+	return -EOPNOTSUPP;
+}
+
 static void *uapi_add_elm(struct uverbs_api *uapi, u32 key, size_t alloc_size)
 {
 	void *elm;
@@ -47,6 +60,42 @@ static void *uapi_add_get_elm(struct uverbs_api *uapi, u32 key,
 	return elm;
 }
 
+static int uapi_create_write(struct uverbs_api *uapi, struct ib_device *ibdev,
+			     const struct uapi_definition *def, u32 obj_key)
+{
+	struct uverbs_api_write_method *method_elm;
+	u32 method_key = obj_key;
+	bool exists;
+
+	if (def->write.is_ex)
+		method_key |= uapi_key_write_ex_method(def->write.command_num);
+	else
+		method_key |= uapi_key_write_method(def->write.command_num);
+
+	method_elm = uapi_add_get_elm(uapi, method_key, sizeof(*method_elm),
+				      &exists);
+	if (IS_ERR(method_elm))
+		return PTR_ERR(method_elm);
+
+	if (WARN_ON(exists && (def->write.is_ex != method_elm->is_ex ||
+			       method_elm->handler_ex || method_elm->handler)))
+		return -EINVAL;
+
+	method_elm->is_ex = def->write.is_ex;
+	if (def->write.is_ex) {
+		method_elm->handler_ex = def->func_write_ex;
+
+		method_elm->disabled = !(ibdev->uverbs_ex_cmd_mask &
+					 BIT_ULL(def->write.command_num));
+	} else {
+		method_elm->handler = def->func_write;
+
+		method_elm->disabled = !(ibdev->uverbs_cmd_mask &
+					 BIT_ULL(def->write.command_num));
+	}
+	return 0;
+}
+
 static int uapi_merge_method(struct uverbs_api *uapi,
 			     struct uverbs_api_object *obj_elm, u32 obj_key,
 			     const struct uverbs_method_def *method,
@@ -194,6 +243,7 @@ static int uapi_merge_def(struct uverbs_api *uapi, struct ib_device *ibdev,
 {
 	const struct uapi_definition *def = def_list;
 	u32 cur_obj_key = UVERBS_API_KEY_ERR;
+	bool exists;
 	int rc;
 
 	if (!def_list)
@@ -240,6 +290,23 @@ static int uapi_merge_def(struct uverbs_api *uapi, struct ib_device *ibdev,
 			if (rc)
 				return rc;
 			continue;
+
+		case UAPI_DEF_OBJECT_START: {
+			struct uverbs_api_object *obj_elm;
+
+			cur_obj_key = uapi_key_obj(def->object_start.object_id);
+			obj_elm = uapi_add_get_elm(uapi, cur_obj_key,
+						   sizeof(*obj_elm), &exists);
+			if (IS_ERR(obj_elm))
+				return PTR_ERR(obj_elm);
+			continue;
+		}
+
+		case UAPI_DEF_WRITE:
+			rc = uapi_create_write(uapi, ibdev, def, cur_obj_key);
+			if (rc)
+				return rc;
+			continue;
 		}
 		WARN_ON(true);
 		return -EINVAL;
@@ -266,8 +333,8 @@ uapi_finalize_ioctl_method(struct uverbs_api *uapi,
 		u32 attr_bkey = uapi_bkey_attr(attr_key);
 		u8 type = elm->spec.type;
 
-		if (uapi_key_attr_to_method(iter.index) !=
-		    uapi_key_attr_to_method(method_key))
+		if (uapi_key_attr_to_ioctl_method(iter.index) !=
+		    uapi_key_attr_to_ioctl_method(method_key))
 			break;
 
 		if (elm->spec.mandatory)
@@ -309,9 +376,13 @@ uapi_finalize_ioctl_method(struct uverbs_api *uapi,
 
 static int uapi_finalize(struct uverbs_api *uapi)
 {
+	const struct uverbs_api_write_method **data;
+	unsigned long max_write_ex = 0;
+	unsigned long max_write = 0;
 	struct radix_tree_iter iter;
 	void __rcu **slot;
 	int rc;
+	int i;
 
 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 		struct uverbs_api_ioctl_method *method_elm =
@@ -323,6 +394,36 @@ static int uapi_finalize(struct uverbs_api *uapi)
 			if (rc)
 				return rc;
 		}
+
+		if (uapi_key_is_write_method(iter.index))
+			max_write = max(max_write,
+					iter.index & UVERBS_API_ATTR_KEY_MASK);
+		if (uapi_key_is_write_ex_method(iter.index))
+			max_write_ex =
+				max(max_write_ex,
+				    iter.index & UVERBS_API_ATTR_KEY_MASK);
+	}
+
+	uapi->notsupp_method.handler = ib_uverbs_notsupp;
+	uapi->notsupp_method.handler_ex = ib_uverbs_ex_notsupp;
+	uapi->num_write = max_write + 1;
+	uapi->num_write_ex = max_write_ex + 1;
+	data = kmalloc_array(uapi->num_write + uapi->num_write_ex,
+			     sizeof(*uapi->write_methods), GFP_KERNEL);
+	for (i = 0; i != uapi->num_write + uapi->num_write_ex; i++)
+		data[i] = &uapi->notsupp_method;
+	uapi->write_methods = data;
+	uapi->write_ex_methods = data + uapi->num_write;
+
+	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
+		if (uapi_key_is_write_method(iter.index))
+			uapi->write_methods[iter.index &
+					    UVERBS_API_ATTR_KEY_MASK] =
+				rcu_dereference_protected(*slot, true);
+		if (uapi_key_is_write_ex_method(iter.index))
+			uapi->write_ex_methods[iter.index &
+					       UVERBS_API_ATTR_KEY_MASK] =
+				rcu_dereference_protected(*slot, true);
 	}
 
 	return 0;
@@ -365,6 +466,23 @@ static u32 uapi_get_obj_id(struct uverbs_attr_spec *spec)
 	return UVERBS_API_KEY_ERR;
 }
 
+static void uapi_key_okay(u32 key)
+{
+	unsigned int count = 0;
+
+	if (uapi_key_is_object(key))
+		count++;
+	if (uapi_key_is_ioctl_method(key))
+		count++;
+	if (uapi_key_is_write_method(key))
+		count++;
+	if (uapi_key_is_write_ex_method(key))
+		count++;
+	if (uapi_key_is_attr(key))
+		count++;
+	WARN(count != 1, "Bad count %d key=%x", count, key);
+}
+
 static void uapi_finalize_disable(struct uverbs_api *uapi)
 {
 	struct radix_tree_iter iter;
@@ -374,6 +492,8 @@ static void uapi_finalize_disable(struct uverbs_api *uapi)
 
 again:
 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, starting_key) {
+		uapi_key_okay(iter.index);
+
 		if (uapi_key_is_object(iter.index)) {
 			struct uverbs_api_object *obj_elm =
 				rcu_dereference_protected(*slot, true);
@@ -400,6 +520,18 @@ static void uapi_finalize_disable(struct uverbs_api *uapi)
 			continue;
 		}
 
+		if (uapi_key_is_write_method(iter.index) ||
+		    uapi_key_is_write_ex_method(iter.index)) {
+			struct uverbs_api_write_method *method_elm =
+				rcu_dereference_protected(*slot, true);
+
+			if (method_elm->disabled) {
+				kfree(method_elm);
+				radix_tree_iter_delete(&uapi->radix, &iter, slot);
+			}
+			continue;
+		}
+
 		if (uapi_key_is_attr(iter.index)) {
 			struct uverbs_api_attr *attr_elm =
 				rcu_dereference_protected(*slot, true);
@@ -444,6 +576,7 @@ void uverbs_destroy_api(struct uverbs_api *uapi)
 		return;
 
 	uapi_remove_range(uapi, 0, U32_MAX);
+	kfree(uapi->write_methods);
 	kfree(uapi);
 }
 

include/rdma/uverbs_ioctl.h

@@ -140,6 +140,13 @@ struct uverbs_attr_spec {
  *
  * The tree encodes multiple types, and uses a scheme where OBJ_ID,0,0 returns
  * the object slot, and OBJ_ID,METH_ID,0 and returns the method slot.
+ *
+ * This also encodes the tables for the write() and write() extended commands
+ * using the coding
+ *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE,command #
+ *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE_EX,command_ex #
+ * ie the WRITE path is treated as a special method type in the ioctl
+ * framework.
  */
 enum uapi_radix_data {
 	UVERBS_API_NS_FLAG = 1U << UVERBS_ID_NS_SHIFT,
@@ -147,12 +154,16 @@ enum uapi_radix_data {
 	UVERBS_API_ATTR_KEY_BITS = 6,
 	UVERBS_API_ATTR_KEY_MASK = GENMASK(UVERBS_API_ATTR_KEY_BITS - 1, 0),
 	UVERBS_API_ATTR_BKEY_LEN = (1 << UVERBS_API_ATTR_KEY_BITS) - 1,
+	UVERBS_API_WRITE_KEY_NUM = 1 << UVERBS_API_ATTR_KEY_BITS,
 
 	UVERBS_API_METHOD_KEY_BITS = 5,
 	UVERBS_API_METHOD_KEY_SHIFT = UVERBS_API_ATTR_KEY_BITS,
-	UVERBS_API_METHOD_KEY_NUM_CORE = 24,
-	UVERBS_API_METHOD_KEY_NUM_DRIVER = (1 << UVERBS_API_METHOD_KEY_BITS) -
-					   UVERBS_API_METHOD_KEY_NUM_CORE,
+	UVERBS_API_METHOD_KEY_NUM_CORE = 22,
+	UVERBS_API_METHOD_IS_WRITE = 30 << UVERBS_API_METHOD_KEY_SHIFT,
+	UVERBS_API_METHOD_IS_WRITE_EX = 31 << UVERBS_API_METHOD_KEY_SHIFT,
+	UVERBS_API_METHOD_KEY_NUM_DRIVER =
+		(UVERBS_API_METHOD_IS_WRITE >> UVERBS_API_METHOD_KEY_SHIFT) -
+		UVERBS_API_METHOD_KEY_NUM_CORE,
 	UVERBS_API_METHOD_KEY_MASK = GENMASK(
 		UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT - 1,
 		UVERBS_API_METHOD_KEY_SHIFT),
@@ -205,7 +216,22 @@ static inline __attribute_const__ u32 uapi_key_ioctl_method(u32 id)
 	return id << UVERBS_API_METHOD_KEY_SHIFT;
 }
 
-static inline __attribute_const__ u32 uapi_key_attr_to_method(u32 attr_key)
+static inline __attribute_const__ u32 uapi_key_write_method(u32 id)
+{
+	if (id >= UVERBS_API_WRITE_KEY_NUM)
+		return UVERBS_API_KEY_ERR;
+	return UVERBS_API_METHOD_IS_WRITE | id;
+}
+
+static inline __attribute_const__ u32 uapi_key_write_ex_method(u32 id)
+{
+	if (id >= UVERBS_API_WRITE_KEY_NUM)
+		return UVERBS_API_KEY_ERR;
+	return UVERBS_API_METHOD_IS_WRITE_EX | id;
+}
+
+static inline __attribute_const__ u32
+uapi_key_attr_to_ioctl_method(u32 attr_key)
 {
 	return attr_key &
 	       (UVERBS_API_OBJ_KEY_MASK | UVERBS_API_METHOD_KEY_MASK);
@@ -213,10 +239,23 @@ static inline __attribute_const__ u32 uapi_key_attr_to_method(u32 attr_key)
 
 static inline __attribute_const__ bool uapi_key_is_ioctl_method(u32 key)
 {
-	return (key & UVERBS_API_METHOD_KEY_MASK) != 0 &&
+	unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
+
+	return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&
 	       (key & UVERBS_API_ATTR_KEY_MASK) == 0;
 }
 
+static inline __attribute_const__ bool uapi_key_is_write_method(u32 key)
+{
+	return (key & UVERBS_API_METHOD_KEY_MASK) == UVERBS_API_METHOD_IS_WRITE;
+}
+
+static inline __attribute_const__ bool uapi_key_is_write_ex_method(u32 key)
+{
+	return (key & UVERBS_API_METHOD_KEY_MASK) ==
+	       UVERBS_API_METHOD_IS_WRITE_EX;
+}
+
 static inline __attribute_const__ u32 uapi_key_attrs_start(u32 ioctl_method_key)
 {
 	/* 0 is the method slot itself */
@@ -246,9 +285,12 @@ static inline __attribute_const__ u32 uapi_key_attr(u32 id)
 	return id;
 }
 
+/* Only true for ioctl methods */
 static inline __attribute_const__ bool uapi_key_is_attr(u32 key)
 {
-	return (key & UVERBS_API_METHOD_KEY_MASK) != 0 &&
+	unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
+
+	return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&
 	       (key & UVERBS_API_ATTR_KEY_MASK) != 0;
 }
 
@@ -298,6 +340,8 @@ struct uverbs_object_def {
 
 enum uapi_definition_kind {
 	UAPI_DEF_END = 0,
+	UAPI_DEF_OBJECT_START,
+	UAPI_DEF_WRITE,
 	UAPI_DEF_CHAIN_OBJ_TREE,
 	UAPI_DEF_CHAIN,
 	UAPI_DEF_IS_SUPPORTED_FUNC,
@@ -315,16 +359,54 @@ struct uapi_definition {
 		struct {
 			u16 object_id;
 		} object_start;
+		struct {
+			u8 is_ex;
+			u16 command_num;
+		} write;
 	};
 
 	union {
 		bool (*func_is_supported)(struct ib_device *device);
+		ssize_t (*func_write)(struct ib_uverbs_file *file,
+				      const char __user *buf, int in_len,
+				      int out_len);
+		int (*func_write_ex)(struct ib_uverbs_file *file,
+				     struct ib_udata *ucore,
+				     struct ib_udata *uhw);
 		const struct uapi_definition *chain;
 		const struct uverbs_object_def *chain_obj_tree;
 		size_t needs_fn_offset;
 	};
 };
 
+/* Define things connected to object_id */
+#define DECLARE_UVERBS_OBJECT(_object_id, ...)                                 \
+	{                                                                      \
+		.kind = UAPI_DEF_OBJECT_START,                                 \
+		.object_start = { .object_id = _object_id },                   \
+	},                                                                     \
+		##__VA_ARGS__
+
+/* Use in a var_args of DECLARE_UVERBS_OBJECT */
+#define DECLARE_UVERBS_WRITE(_command_num, _func, ...)                         \
+	{                                                                      \
+		.kind = UAPI_DEF_WRITE,                                        \
+		.scope = UAPI_SCOPE_OBJECT,                                    \
+		.write = { .is_ex = 0, .command_num = _command_num },          \
+		.func_write = _func,                                           \
+	},                                                                     \
+		##__VA_ARGS__
+
+/* Use in a var_args of DECLARE_UVERBS_OBJECT */
+#define DECLARE_UVERBS_WRITE_EX(_command_num, _func, ...)                      \
+	{                                                                      \
+		.kind = UAPI_DEF_WRITE,                                        \
+		.scope = UAPI_SCOPE_OBJECT,                                    \
+		.write = { .is_ex = 1, .command_num = _command_num },          \
+		.func_write_ex = _func,                                        \
+	},                                                                     \
+		##__VA_ARGS__
+
 /*
  * Object is only supported if the function pointer named ibdev_fn in struct
  * ib_device is not NULL.