RDMA/uverbs: Expose the new GID query API to user space

Expose the query GID table and entry API to user space by adding two new
methods and method handlers to the device object.

This API provides a faster way to query a GID table using single call and
will be used in libibverbs to improve current approach that requires
multiple calls to open, close and read multiple sysfs files for a single
GID table entry.

Link: https://lore.kernel.org/r/20200923165015.2491894-5-leon@kernel.org
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 195 insertions, 1 deletions

diff --git a/drivers/infiniband/core/uverbs_std_types_device.c b/drivers/infiniband/core/uverbs_std_types_device.c
index 9f43c0161a8e..f367d523a46b 100644
--- a/drivers/infiniband/core/uverbs_std_types_device.c
+++ b/drivers/infiniband/core/uverbs_std_types_device.c
@@ -3,11 +3,13 @@
  * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
  */
 
+#include <linux/overflow.h>
 #include <rdma/uverbs_std_types.h>
 #include "rdma_core.h"
 #include "uverbs.h"
 #include <rdma/uverbs_ioctl.h>
 #include <rdma/opa_addr.h>
+#include <rdma/ib_cache.h>
 
 /*
  * This ioctl method allows calling any defined write or write_ex
@@ -266,6 +268,172 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_CONTEXT)(
 	return ucontext->device->ops.query_ucontext(ucontext, attrs);
 }
 
+static int copy_gid_entries_to_user(struct uverbs_attr_bundle *attrs,
+				    struct ib_uverbs_gid_entry *entries,
+				    size_t num_entries, size_t user_entry_size)
+{
+	const struct uverbs_attr *attr;
+	void __user *user_entries;
+	size_t copy_len;
+	int ret;
+	int i;
+
+	if (user_entry_size == sizeof(*entries)) {
+		ret = uverbs_copy_to(attrs,
+				     UVERBS_ATTR_QUERY_GID_TABLE_RESP_ENTRIES,
+				     entries, sizeof(*entries) * num_entries);
+		return ret;
+	}
+
+	copy_len = min_t(size_t, user_entry_size, sizeof(*entries));
+	attr = uverbs_attr_get(attrs, UVERBS_ATTR_QUERY_GID_TABLE_RESP_ENTRIES);
+	if (IS_ERR(attr))
+		return PTR_ERR(attr);
+
+	user_entries = u64_to_user_ptr(attr->ptr_attr.data);
+	for (i = 0; i < num_entries; i++) {
+		if (copy_to_user(user_entries, entries, copy_len))
+			return -EFAULT;
+
+		if (user_entry_size > sizeof(*entries)) {
+			if (clear_user(user_entries + sizeof(*entries),
+				       user_entry_size - sizeof(*entries)))
+				return -EFAULT;
+		}
+
+		entries++;
+		user_entries += user_entry_size;
+	}
+
+	return uverbs_output_written(attrs,
+				     UVERBS_ATTR_QUERY_GID_TABLE_RESP_ENTRIES);
+}
+
+static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_GID_TABLE)(
+	struct uverbs_attr_bundle *attrs)
+{
+	struct ib_uverbs_gid_entry *entries;
+	struct ib_ucontext *ucontext;
+	struct ib_device *ib_dev;
+	size_t user_entry_size;
+	ssize_t num_entries;
+	size_t max_entries;
+	size_t num_bytes;
+	u32 flags;
+	int ret;
+
+	ret = uverbs_get_flags32(&flags, attrs,
+				 UVERBS_ATTR_QUERY_GID_TABLE_FLAGS, 0);
+	if (ret)
+		return ret;
+
+	ret = uverbs_get_const(&user_entry_size, attrs,
+			       UVERBS_ATTR_QUERY_GID_TABLE_ENTRY_SIZE);
+	if (ret)
+		return ret;
+
+	max_entries = uverbs_attr_ptr_get_array_size(
+		attrs, UVERBS_ATTR_QUERY_GID_TABLE_RESP_ENTRIES,
+		user_entry_size);
+	if (max_entries <= 0)
+		return -EINVAL;
+
+	ucontext = ib_uverbs_get_ucontext(attrs);
+	if (IS_ERR(ucontext))
+		return PTR_ERR(ucontext);
+	ib_dev = ucontext->device;
+
+	if (check_mul_overflow(max_entries, sizeof(*entries), &num_bytes))
+		return -EINVAL;
+
+	entries = uverbs_zalloc(attrs, num_bytes);
+	if (!entries)
+		return -ENOMEM;
+
+	num_entries = rdma_query_gid_table(ib_dev, entries, max_entries);
+	if (num_entries < 0)
+		return -EINVAL;
+
+	ret = copy_gid_entries_to_user(attrs, entries, num_entries,
+				       user_entry_size);
+	if (ret)
+		return ret;
+
+	ret = uverbs_copy_to(attrs,
+			     UVERBS_ATTR_QUERY_GID_TABLE_RESP_NUM_ENTRIES,
+			     &num_entries, sizeof(num_entries));
+	return ret;
+}
+
+static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_GID_ENTRY)(
+	struct uverbs_attr_bundle *attrs)
+{
+	struct ib_uverbs_gid_entry entry = {};
+	const struct ib_gid_attr *gid_attr;
+	struct ib_ucontext *ucontext;
+	struct ib_device *ib_dev;
+	struct net_device *ndev;
+	u32 gid_index;
+	u32 port_num;
+	u32 flags;
+	int ret;
+
+	ret = uverbs_get_flags32(&flags, attrs,
+				 UVERBS_ATTR_QUERY_GID_ENTRY_FLAGS, 0);
+	if (ret)
+		return ret;
+
+	ret = uverbs_get_const(&port_num, attrs,
+			       UVERBS_ATTR_QUERY_GID_ENTRY_PORT);
+	if (ret)
+		return ret;
+
+	ret = uverbs_get_const(&gid_index, attrs,
+			       UVERBS_ATTR_QUERY_GID_ENTRY_GID_INDEX);
+	if (ret)
+		return ret;
+
+	ucontext = ib_uverbs_get_ucontext(attrs);
+	if (IS_ERR(ucontext))
+		return PTR_ERR(ucontext);
+	ib_dev = ucontext->device;
+
+	if (!rdma_is_port_valid(ib_dev, port_num))
+		return -EINVAL;
+
+	if (!rdma_ib_or_roce(ib_dev, port_num))
+		return -EOPNOTSUPP;
+
+	gid_attr = rdma_get_gid_attr(ib_dev, port_num, gid_index);
+	if (IS_ERR(gid_attr))
+		return PTR_ERR(gid_attr);
+
+	memcpy(&entry.gid, &gid_attr->gid, sizeof(gid_attr->gid));
+	entry.gid_index = gid_attr->index;
+	entry.port_num = gid_attr->port_num;
+	entry.gid_type = gid_attr->gid_type;
+
+	rcu_read_lock();
+	ndev = rdma_read_gid_attr_ndev_rcu(gid_attr);
+	if (IS_ERR(ndev)) {
+		if (PTR_ERR(ndev) != -ENODEV) {
+			ret = PTR_ERR(ndev);
+			rcu_read_unlock();
+			goto out;
+		}
+	} else {
+		entry.netdev_ifindex = ndev->ifindex;
+	}
+	rcu_read_unlock();
+
+	ret = uverbs_copy_to_struct_or_zero(
+		attrs, UVERBS_ATTR_QUERY_GID_ENTRY_RESP_ENTRY, &entry,
+		sizeof(entry));
+out:
+	rdma_put_gid_attr(gid_attr);
+	return ret;
+}
+
 DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_METHOD_GET_CONTEXT,
 	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_GET_CONTEXT_NUM_COMP_VECTORS,
@@ -300,12 +468,38 @@ DECLARE_UVERBS_NAMED_METHOD(
 				   reserved),
 		UA_MANDATORY));
 
+DECLARE_UVERBS_NAMED_METHOD(
+	UVERBS_METHOD_QUERY_GID_TABLE,
+	UVERBS_ATTR_CONST_IN(UVERBS_ATTR_QUERY_GID_TABLE_ENTRY_SIZE, u64,
+			     UA_MANDATORY),
+	UVERBS_ATTR_FLAGS_IN(UVERBS_ATTR_QUERY_GID_TABLE_FLAGS, u32,
+			     UA_OPTIONAL),
+	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_QUERY_GID_TABLE_RESP_ENTRIES,
+			    UVERBS_ATTR_MIN_SIZE(0), UA_MANDATORY),
+	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_QUERY_GID_TABLE_RESP_NUM_ENTRIES,
+			    UVERBS_ATTR_TYPE(u64), UA_MANDATORY));
+
+DECLARE_UVERBS_NAMED_METHOD(
+	UVERBS_METHOD_QUERY_GID_ENTRY,
+	UVERBS_ATTR_CONST_IN(UVERBS_ATTR_QUERY_GID_ENTRY_PORT, u32,
+			     UA_MANDATORY),
+	UVERBS_ATTR_CONST_IN(UVERBS_ATTR_QUERY_GID_ENTRY_GID_INDEX, u32,
+			     UA_MANDATORY),
+	UVERBS_ATTR_FLAGS_IN(UVERBS_ATTR_QUERY_GID_ENTRY_FLAGS, u32,
+			     UA_MANDATORY),
+	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_QUERY_GID_ENTRY_RESP_ENTRY,
+			    UVERBS_ATTR_STRUCT(struct ib_uverbs_gid_entry,
+					       netdev_ifindex),
+			    UA_MANDATORY));
+
 DECLARE_UVERBS_GLOBAL_METHODS(UVERBS_OBJECT_DEVICE,
 			      &UVERBS_METHOD(UVERBS_METHOD_GET_CONTEXT),
 			      &UVERBS_METHOD(UVERBS_METHOD_INVOKE_WRITE),
 			      &UVERBS_METHOD(UVERBS_METHOD_INFO_HANDLES),
 			      &UVERBS_METHOD(UVERBS_METHOD_QUERY_PORT),
-			      &UVERBS_METHOD(UVERBS_METHOD_QUERY_CONTEXT));
+			      &UVERBS_METHOD(UVERBS_METHOD_QUERY_CONTEXT),
+			      &UVERBS_METHOD(UVERBS_METHOD_QUERY_GID_TABLE),
+			      &UVERBS_METHOD(UVERBS_METHOD_QUERY_GID_ENTRY));
 
 const struct uapi_definition uverbs_def_obj_device[] = {
 	UAPI_DEF_CHAIN_OBJ_TREE_NAMED(UVERBS_OBJECT_DEVICE),