IB/uverbs: Add IDRs array attribute type to ioctl() interface

Methods sometimes need to get a flexible set of IDRs and not a strict set
as can be achieved today by the conventional IDR attribute. Add a new
IDRS_ARRAY attribute to the generic uverbs ioctl layer.

IDRS_ARRAY points to array of idrs of the same object type and same access
rights, only write and read are supported.

Signed-off-by: Guy Levi <guyle@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>``
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

2 files changed, 126 insertions, 0 deletions

diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
index 4bafd4671de2..0e95a5888274 100644
--- a/drivers/infiniband/core/uverbs_ioctl.c
+++ b/drivers/infiniband/core/uverbs_ioctl.c
@@ -57,6 +57,7 @@ struct bundle_priv {
 	struct ib_uverbs_attr *uattrs;
 
 	DECLARE_BITMAP(uobj_finalize, UVERBS_API_ATTR_BKEY_LEN);
+	DECLARE_BITMAP(spec_finalize, UVERBS_API_ATTR_BKEY_LEN);
 
 	/*
 	 * Must be last. bundle ends in a flex array which overlaps
@@ -143,6 +144,86 @@ static bool uverbs_is_attr_cleared(const struct ib_uverbs_attr *uattr,
 			   0, uattr->len - len);
 }
 
+static int uverbs_process_idrs_array(struct bundle_priv *pbundle,
+				     const struct uverbs_api_attr *attr_uapi,
+				     struct uverbs_objs_arr_attr *attr,
+				     struct ib_uverbs_attr *uattr,
+				     u32 attr_bkey)
+{
+	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
+	size_t array_len;
+	u32 *idr_vals;
+	int ret = 0;
+	size_t i;
+
+	if (uattr->attr_data.reserved)
+		return -EINVAL;
+
+	if (uattr->len % sizeof(u32))
+		return -EINVAL;
+
+	array_len = uattr->len / sizeof(u32);
+	if (array_len < spec->u2.objs_arr.min_len ||
+	    array_len > spec->u2.objs_arr.max_len)
+		return -EINVAL;
+
+	attr->uobjects =
+		uverbs_alloc(&pbundle->bundle,
+			     array_size(array_len, sizeof(*attr->uobjects)));
+	if (IS_ERR(attr->uobjects))
+		return PTR_ERR(attr->uobjects);
+
+	/*
+	 * Since idr is 4B and *uobjects is >= 4B, we can use attr->uobjects
+	 * to store idrs array and avoid additional memory allocation. The
+	 * idrs array is offset to the end of the uobjects array so we will be
+	 * able to read idr and replace with a pointer.
+	 */
+	idr_vals = (u32 *)(attr->uobjects + array_len) - array_len;
+
+	if (uattr->len > sizeof(uattr->data)) {
+		ret = copy_from_user(idr_vals, u64_to_user_ptr(uattr->data),
+				     uattr->len);
+		if (ret)
+			return -EFAULT;
+	} else {
+		memcpy(idr_vals, &uattr->data, uattr->len);
+	}
+
+	for (i = 0; i != array_len; i++) {
+		attr->uobjects[i] = uverbs_get_uobject_from_file(
+			spec->u2.objs_arr.obj_type, pbundle->bundle.ufile,
+			spec->u2.objs_arr.access, idr_vals[i]);
+		if (IS_ERR(attr->uobjects[i])) {
+			ret = PTR_ERR(attr->uobjects[i]);
+			break;
+		}
+	}
+
+	attr->len = i;
+	__set_bit(attr_bkey, pbundle->spec_finalize);
+	return ret;
+}
+
+static int uverbs_free_idrs_array(const struct uverbs_api_attr *attr_uapi,
+				  struct uverbs_objs_arr_attr *attr,
+				  bool commit)
+{
+	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
+	int current_ret;
+	int ret = 0;
+	size_t i;
+
+	for (i = 0; i != attr->len; i++) {
+		current_ret = uverbs_finalize_object(
+			attr->uobjects[i], spec->u2.objs_arr.access, commit);
+		if (!ret)
+			ret = current_ret;
+	}
+
+	return ret;
+}
+
 static int uverbs_process_attr(struct bundle_priv *pbundle,
 			       const struct uverbs_api_attr *attr_uapi,
 			       struct ib_uverbs_attr *uattr, u32 attr_bkey)
@@ -246,6 +327,11 @@ static int uverbs_process_attr(struct bundle_priv *pbundle,
 		}
 
 		break;
+
+	case UVERBS_ATTR_TYPE_IDRS_ARRAY:
+		return uverbs_process_idrs_array(pbundle, attr_uapi,
+						 &e->objs_arr_attr, uattr,
+						 attr_bkey);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -384,6 +470,7 @@ static int bundle_destroy(struct bundle_priv *pbundle, bool commit)
 	unsigned int i;
 	int ret = 0;
 
+	/* fast path for simple uobjects */
 	i = -1;
 	while ((i = find_next_bit(pbundle->uobj_finalize, key_bitmap_len,
 				  i + 1)) < key_bitmap_len) {
@@ -397,6 +484,32 @@ static int bundle_destroy(struct bundle_priv *pbundle, bool commit)
 			ret = current_ret;
 	}
 
+	i = -1;
+	while ((i = find_next_bit(pbundle->spec_finalize, key_bitmap_len,
+				  i + 1)) < key_bitmap_len) {
+		struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
+		const struct uverbs_api_attr *attr_uapi;
+		void __rcu **slot;
+		int current_ret;
+
+		slot = uapi_get_attr_for_method(
+			pbundle,
+			pbundle->method_key | uapi_bkey_to_key_attr(i));
+		if (WARN_ON(!slot))
+			continue;
+
+		attr_uapi = srcu_dereference(
+			*slot,
+			&pbundle->bundle.ufile->device->disassociate_srcu);
+
+		if (attr_uapi->spec.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
+			current_ret = uverbs_free_idrs_array(
+				attr_uapi, &attr->objs_arr_attr, commit);
+			if (!ret)
+				ret = current_ret;
+		}
+	}
+
 	for (memblock = pbundle->allocated_mem; memblock;) {
 		struct bundle_alloc_head *tmp = memblock;
 
@@ -461,6 +574,7 @@ static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
 	memset(pbundle->bundle.attr_present, 0,
 	       sizeof(pbundle->bundle.attr_present));
 	memset(pbundle->uobj_finalize, 0, sizeof(pbundle->uobj_finalize));
+	memset(pbundle->spec_finalize, 0, sizeof(pbundle->spec_finalize));
 
 	ret = ib_uverbs_run_method(pbundle, hdr->num_attrs);
 	destroy_ret = bundle_destroy(pbundle, ret == 0);
diff --git a/drivers/infiniband/core/uverbs_uapi.c b/drivers/infiniband/core/uverbs_uapi.c
index 73ea6f0db88f..cdf5ced2c84f 100644
--- a/drivers/infiniband/core/uverbs_uapi.c
+++ b/drivers/infiniband/core/uverbs_uapi.c
@@ -73,6 +73,18 @@ static int uapi_merge_method(struct uverbs_api *uapi,
 		if (attr->attr.type == UVERBS_ATTR_TYPE_ENUM_IN)
 			method_elm->driver_method |= is_driver;
 
+		/*
+		 * Like other uobject based things we only support a single
+		 * uobject being NEW'd or DESTROY'd
+		 */
+		if (attr->attr.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
+			u8 access = attr->attr.u2.objs_arr.access;
+
+			if (WARN_ON(access == UVERBS_ACCESS_NEW ||
+				    access == UVERBS_ACCESS_DESTROY))
+				return -EINVAL;
+		}
+
 		attr_slot =
 			uapi_add_elm(uapi, method_key | uapi_key_attr(attr->id),
 				     sizeof(*attr_slot));