IB/uverbs: Add support to advise_mr

Add new ioctl method for the MR object - ADVISE_MR.

This command can be used by users to give an advice or directions to the
kernel about an address range that belongs to memory regions.

A new ib_device callback, advise_mr(), is introduced here to suupport the
new command. This command takes the following arguments:

- pd:		The protection domain to which all memory regions belong
- advice: 	The type of the advice
	  	* IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH - Pre-fetch a range of
		an on-demand paging MR
	  	* IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE - Pre-fetch a range
		of an on-demand paging MR with write intention
- flags:	The properties of the advice
		* IB_UVERBS_ADVISE_MR_FLAG_FLUSH - Operation must end before
		return to the caller
- sg_list:	The list of memory ranges
- num_sge:	The number of memory ranges in the list
- attrs:	More attributes to be parsed by the provider

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

drivers/infiniband/core/uverbs_std_types_mr.c

@@ -39,6 +39,42 @@ static int uverbs_free_mr(struct ib_uobject *uobject,
 	return ib_dereg_mr((struct ib_mr *)uobject->object);
 }
 
+static int UVERBS_HANDLER(UVERBS_METHOD_ADVISE_MR)(
+	struct uverbs_attr_bundle *attrs)
+{
+	struct ib_pd *pd =
+		uverbs_attr_get_obj(attrs, UVERBS_ATTR_ADVISE_MR_PD_HANDLE);
+	enum ib_uverbs_advise_mr_advice advice;
+	struct ib_device *ib_dev = pd->device;
+	struct ib_sge *sg_list;
+	u32 num_sge;
+	u32 flags;
+	int ret;
+
+	/* FIXME: Extend the UAPI_DEF_OBJ_NEEDS_FN stuff.. */
+	if (!ib_dev->ops.advise_mr)
+		return -EOPNOTSUPP;
+
+	ret = uverbs_get_const(&advice, attrs, UVERBS_ATTR_ADVISE_MR_ADVICE);
+	if (ret)
+		return ret;
+
+	ret = uverbs_get_flags32(&flags, attrs, UVERBS_ATTR_ADVISE_MR_FLAGS,
+				 IB_UVERBS_ADVISE_MR_FLAG_FLUSH);
+	if (ret)
+		return ret;
+
+	num_sge = uverbs_attr_ptr_get_array_size(
+		attrs, UVERBS_ATTR_ADVISE_MR_SGE_LIST, sizeof(struct ib_sge));
+	if (num_sge < 0)
+		return num_sge;
+
+	sg_list = uverbs_attr_get_alloced_ptr(attrs,
+					      UVERBS_ATTR_ADVISE_MR_SGE_LIST);
+	return ib_dev->ops.advise_mr(pd, advice, flags, sg_list, num_sge,
+				     attrs);
+}
+
 static int UVERBS_HANDLER(UVERBS_METHOD_DM_MR_REG)(
 	struct uverbs_attr_bundle *attrs)
 {
@@ -114,6 +150,23 @@ err_dereg:
 	return ret;
 }
 
+DECLARE_UVERBS_NAMED_METHOD(
+	UVERBS_METHOD_ADVISE_MR,
+	UVERBS_ATTR_IDR(UVERBS_ATTR_ADVISE_MR_PD_HANDLE,
+			UVERBS_OBJECT_PD,
+			UVERBS_ACCESS_READ,
+			UA_MANDATORY),
+	UVERBS_ATTR_CONST_IN(UVERBS_ATTR_ADVISE_MR_ADVICE,
+			     enum ib_uverbs_advise_mr_advice,
+			     UA_MANDATORY),
+	UVERBS_ATTR_FLAGS_IN(UVERBS_ATTR_ADVISE_MR_FLAGS,
+			     enum ib_uverbs_advise_mr_flag,
+			     UA_MANDATORY),
+	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_ADVISE_MR_SGE_LIST,
+			   UVERBS_ATTR_MIN_SIZE(sizeof(struct ib_uverbs_sge)),
+			   UA_MANDATORY,
+			   UA_ALLOC_AND_COPY));
+
 DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_METHOD_DM_MR_REG,
 	UVERBS_ATTR_IDR(UVERBS_ATTR_REG_DM_MR_HANDLE,
@@ -154,7 +207,8 @@ DECLARE_UVERBS_NAMED_OBJECT(
 	UVERBS_OBJECT_MR,
 	UVERBS_TYPE_ALLOC_IDR(uverbs_free_mr),
 	&UVERBS_METHOD(UVERBS_METHOD_DM_MR_REG),
-	&UVERBS_METHOD(UVERBS_METHOD_MR_DESTROY));
+	&UVERBS_METHOD(UVERBS_METHOD_MR_DESTROY),
+	&UVERBS_METHOD(UVERBS_METHOD_ADVISE_MR));
 
 const struct uapi_definition uverbs_def_obj_mr[] = {
 	UAPI_DEF_CHAIN_OBJ_TREE_NAMED(UVERBS_OBJECT_MR,

include/rdma/ib_verbs.h

@@ -2415,6 +2415,10 @@ struct ib_device_ops {
 	int (*dereg_mr)(struct ib_mr *mr);
 	struct ib_mr *(*alloc_mr)(struct ib_pd *pd, enum ib_mr_type mr_type,
 				  u32 max_num_sg);
+	int (*advise_mr)(struct ib_pd *pd,
+			 enum ib_uverbs_advise_mr_advice advice, u32 flags,
+			 struct ib_sge *sg_list, u32 num_sge,
+			 struct uverbs_attr_bundle *attrs);
 	int (*map_mr_sg)(struct ib_mr *mr, struct scatterlist *sg, int sg_nents,
 			 unsigned int *sg_offset);
 	int (*check_mr_status)(struct ib_mr *mr, u32 check_mask,

include/uapi/rdma/ib_user_ioctl_cmds.h

@@ -147,12 +147,20 @@ enum uverbs_attrs_reg_dm_mr_cmd_attr_ids {
 enum uverbs_methods_mr {
 	UVERBS_METHOD_DM_MR_REG,
 	UVERBS_METHOD_MR_DESTROY,
+	UVERBS_METHOD_ADVISE_MR,
 };
 
 enum uverbs_attrs_mr_destroy_ids {
 	UVERBS_ATTR_DESTROY_MR_HANDLE,
 };
 
+enum uverbs_attrs_advise_mr_cmd_attr_ids {
+	UVERBS_ATTR_ADVISE_MR_PD_HANDLE,
+	UVERBS_ATTR_ADVISE_MR_ADVICE,
+	UVERBS_ATTR_ADVISE_MR_FLAGS,
+	UVERBS_ATTR_ADVISE_MR_SGE_LIST,
+};
+
 enum uverbs_attrs_create_counters_cmd_attr_ids {
 	UVERBS_ATTR_CREATE_COUNTERS_HANDLE,
 };

include/uapi/rdma/ib_user_ioctl_verbs.h

@@ -157,4 +157,13 @@ enum ib_uverbs_read_counters_flags {
 	IB_UVERBS_READ_COUNTERS_PREFER_CACHED = 1 << 0,
 };
 
+enum ib_uverbs_advise_mr_advice {
+	IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH,
+	IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE,
+};
+
+enum ib_uverbs_advise_mr_flag {
+	IB_UVERBS_ADVISE_MR_FLAG_FLUSH = 1 << 0,
+};
+
 #endif