kernel-ark/include/rdma/ib_user_mad.h
Roland Dreier a394f83bdf IB/umad: Fix bit ordering and 32-on-64 problems on big endian systems
The declaration of struct ib_user_mad_reg_req.method_mask[] exported
to userspace was an array of __u32, but the kernel internally treated
it as a bitmap made up of longs.  This makes a difference for 64-bit
big-endian kernels, where numbering the bits in an array of__u32 gives:

    |31.....0|63....31|95....64|127...96|

while numbering the bits in an array of longs gives:

    |63..............0|127............64|

64-bit userspace can handle this by just treating method_mask[] as an
array of longs, but 32-bit userspace is really stuck: the meaning of
the bits in method_mask[] depends on whether the kernel is 32-bit or
64-bit, and there's no sane way for userspace to know that.

Fix this by updating <rdma/ib_user_mad.h> to make it clear that
method_mask[] is an array of longs, and using a compat_ioctl method to
convert to an array of 64-bit longs to handle the 32-on-64 problem.
This fixes the interface description to match existing behavior (so
working binaries continue to work) in almost all situations, and gives
consistent semantics in the case of 32-bit userspace that can run on
either a 32-bit or 64-bit kernel, so that the same binary can work for
both 32-on-32 and 32-on-64 systems.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
2007-10-09 19:59:15 -07:00

206 lines
7.0 KiB
C

/*
* Copyright (c) 2004 Topspin Communications. All rights reserved.
* Copyright (c) 2005 Voltaire, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* $Id: ib_user_mad.h 2814 2005-07-06 19:14:09Z halr $
*/
#ifndef IB_USER_MAD_H
#define IB_USER_MAD_H
#include <linux/types.h>
#include <linux/ioctl.h>
/*
* Increment this value if any changes that break userspace ABI
* compatibility are made.
*/
#define IB_USER_MAD_ABI_VERSION 5
/*
* Make sure that all structs defined in this file remain laid out so
* that they pack the same way on 32-bit and 64-bit architectures (to
* avoid incompatibility between 32-bit userspace and 64-bit kernels).
*/
/**
* ib_user_mad_hdr_old - Old version of MAD packet header without pkey_index
* @id - ID of agent MAD received with/to be sent with
* @status - 0 on successful receive, ETIMEDOUT if no response
* received (transaction ID in data[] will be set to TID of original
* request) (ignored on send)
* @timeout_ms - Milliseconds to wait for response (unset on receive)
* @retries - Number of automatic retries to attempt
* @qpn - Remote QP number received from/to be sent to
* @qkey - Remote Q_Key to be sent with (unset on receive)
* @lid - Remote lid received from/to be sent to
* @sl - Service level received with/to be sent with
* @path_bits - Local path bits received with/to be sent with
* @grh_present - If set, GRH was received/should be sent
* @gid_index - Local GID index to send with (unset on receive)
* @hop_limit - Hop limit in GRH
* @traffic_class - Traffic class in GRH
* @gid - Remote GID in GRH
* @flow_label - Flow label in GRH
*/
struct ib_user_mad_hdr_old {
__u32 id;
__u32 status;
__u32 timeout_ms;
__u32 retries;
__u32 length;
__be32 qpn;
__be32 qkey;
__be16 lid;
__u8 sl;
__u8 path_bits;
__u8 grh_present;
__u8 gid_index;
__u8 hop_limit;
__u8 traffic_class;
__u8 gid[16];
__be32 flow_label;
};
/**
* ib_user_mad_hdr - MAD packet header
* This layout allows specifying/receiving the P_Key index. To use
* this capability, an application must call the
* IB_USER_MAD_ENABLE_PKEY ioctl on the user MAD file handle before
* any other actions with the file handle.
* @id - ID of agent MAD received with/to be sent with
* @status - 0 on successful receive, ETIMEDOUT if no response
* received (transaction ID in data[] will be set to TID of original
* request) (ignored on send)
* @timeout_ms - Milliseconds to wait for response (unset on receive)
* @retries - Number of automatic retries to attempt
* @qpn - Remote QP number received from/to be sent to
* @qkey - Remote Q_Key to be sent with (unset on receive)
* @lid - Remote lid received from/to be sent to
* @sl - Service level received with/to be sent with
* @path_bits - Local path bits received with/to be sent with
* @grh_present - If set, GRH was received/should be sent
* @gid_index - Local GID index to send with (unset on receive)
* @hop_limit - Hop limit in GRH
* @traffic_class - Traffic class in GRH
* @gid - Remote GID in GRH
* @flow_label - Flow label in GRH
* @pkey_index - P_Key index
*/
struct ib_user_mad_hdr {
__u32 id;
__u32 status;
__u32 timeout_ms;
__u32 retries;
__u32 length;
__be32 qpn;
__be32 qkey;
__be16 lid;
__u8 sl;
__u8 path_bits;
__u8 grh_present;
__u8 gid_index;
__u8 hop_limit;
__u8 traffic_class;
__u8 gid[16];
__be32 flow_label;
__u16 pkey_index;
__u8 reserved[6];
};
/**
* ib_user_mad - MAD packet
* @hdr - MAD packet header
* @data - Contents of MAD
*
*/
struct ib_user_mad {
struct ib_user_mad_hdr hdr;
__u64 data[0];
};
/*
* Earlier versions of this interface definition declared the
* method_mask[] member as an array of __u32 but treated it as a
* bitmap made up of longs in the kernel. This ambiguity meant that
* 32-bit big-endian applications that can run on both 32-bit and
* 64-bit kernels had no consistent ABI to rely on, and 64-bit
* big-endian applications that treated method_mask as being made up
* of 32-bit words would have their bitmap misinterpreted.
*
* To clear up this confusion, we change the declaration of
* method_mask[] to use unsigned long and handle the conversion from
* 32-bit userspace to 64-bit kernel for big-endian systems in the
* compat_ioctl method. Unfortunately, to keep the structure layout
* the same, we need the method_mask[] array to be aligned only to 4
* bytes even when long is 64 bits, which forces us into this ugly
* typedef.
*/
typedef unsigned long __attribute__((aligned(4))) packed_ulong;
#define IB_USER_MAD_LONGS_PER_METHOD_MASK (128 / (8 * sizeof (long)))
/**
* ib_user_mad_reg_req - MAD registration request
* @id - Set by the kernel; used to identify agent in future requests.
* @qpn - Queue pair number; must be 0 or 1.
* @method_mask - The caller will receive unsolicited MADs for any method
* where @method_mask = 1.
* @mgmt_class - Indicates which management class of MADs should be receive
* by the caller. This field is only required if the user wishes to
* receive unsolicited MADs, otherwise it should be 0.
* @mgmt_class_version - Indicates which version of MADs for the given
* management class to receive.
* @oui: Indicates IEEE OUI when mgmt_class is a vendor class
* in the range from 0x30 to 0x4f. Otherwise not used.
* @rmpp_version: If set, indicates the RMPP version used.
*
*/
struct ib_user_mad_reg_req {
__u32 id;
packed_ulong method_mask[IB_USER_MAD_LONGS_PER_METHOD_MASK];
__u8 qpn;
__u8 mgmt_class;
__u8 mgmt_class_version;
__u8 oui[3];
__u8 rmpp_version;
};
#define IB_IOCTL_MAGIC 0x1b
#define IB_USER_MAD_REGISTER_AGENT _IOWR(IB_IOCTL_MAGIC, 1, \
struct ib_user_mad_reg_req)
#define IB_USER_MAD_UNREGISTER_AGENT _IOW(IB_IOCTL_MAGIC, 2, __u32)
#define IB_USER_MAD_ENABLE_PKEY _IO(IB_IOCTL_MAGIC, 3)
#endif /* IB_USER_MAD_H */