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IB/umad: Add P_Key index support
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Add support for setting the P_Key index of sent MADs and getting the
P_Key index of received MADs.  This requires a change to the layout of
the ABI structure struct ib_user_mad_hdr, so to avoid breaking
compatibility, we default to the old (unchanged) ABI and add a new
ioctl IB_USER_MAD_ENABLE_PKEY that allows applications that are aware
of the new ABI to opt into using it.

We plan on switching to the new ABI by default in a year or so, and
this patch adds a warning that is printed when an application uses the
old ABI, to push people towards converting to the new ABI.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Reviewed-by: Hal Rosenstock <hal@xsigo.com>
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Roland Dreier committed Oct 10, 2007
1 parent c01759c commit 2be8e3e
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Showing 3 changed files with 135 additions and 29 deletions.
14 changes: 14 additions & 0 deletions Documentation/infiniband/user_mad.txt
View file
Original file line number Diff line number Diff line change
Expand Up @@ -99,6 +99,20 @@ Transaction IDs
request/response pairs. The upper 32 bits are reserved for use by
the kernel and will be overwritten before a MAD is sent.

P_Key Index Handling

The old ib_umad interface did not allow setting the P_Key index for
MADs that are sent and did not provide a way for obtaining the P_Key
index of received MADs. A new layout for struct ib_user_mad_hdr
with a pkey_index member has been defined; however, to preserve
binary compatibility with older applications, this new layout will
not be used unless the IB_USER_MAD_ENABLE_PKEY ioctl is called
before a file descriptor is used for anything else.

In September 2008, the IB_USER_MAD_ABI_VERSION will be incremented
to 6, the new layout of struct ib_user_mad_hdr will be used by
default, and the IB_USER_MAD_ENABLE_PKEY ioctl will be removed.

Setting IsSM Capability Bit

To set the IsSM capability bit for a port, simply open the
Expand Down
102 changes: 73 additions & 29 deletions drivers/infiniband/core/user_mad.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -118,6 +118,8 @@ struct ib_umad_file {
wait_queue_head_t recv_wait;
struct ib_mad_agent *agent[IB_UMAD_MAX_AGENTS];
int agents_dead;
u8 use_pkey_index;
u8 already_used;
};

struct ib_umad_packet {
Expand Down Expand Up @@ -147,6 +149,12 @@ static void ib_umad_release_dev(struct kref *ref)
kfree(dev);
}

static int hdr_size(struct ib_umad_file *file)
{
return file->use_pkey_index ? sizeof (struct ib_user_mad_hdr) :
sizeof (struct ib_user_mad_hdr_old);
}

/* caller must hold port->mutex at least for reading */
static struct ib_mad_agent *__get_agent(struct ib_umad_file *file, int id)
{
Expand Down Expand Up @@ -221,13 +229,13 @@ static void recv_handler(struct ib_mad_agent *agent,
packet->length = mad_recv_wc->mad_len;
packet->recv_wc = mad_recv_wc;

packet->mad.hdr.status = 0;
packet->mad.hdr.length = sizeof (struct ib_user_mad) +
mad_recv_wc->mad_len;
packet->mad.hdr.qpn = cpu_to_be32(mad_recv_wc->wc->src_qp);
packet->mad.hdr.lid = cpu_to_be16(mad_recv_wc->wc->slid);
packet->mad.hdr.sl = mad_recv_wc->wc->sl;
packet->mad.hdr.path_bits = mad_recv_wc->wc->dlid_path_bits;
packet->mad.hdr.status = 0;
packet->mad.hdr.length = hdr_size(file) + mad_recv_wc->mad_len;
packet->mad.hdr.qpn = cpu_to_be32(mad_recv_wc->wc->src_qp);
packet->mad.hdr.lid = cpu_to_be16(mad_recv_wc->wc->slid);
packet->mad.hdr.sl = mad_recv_wc->wc->sl;
packet->mad.hdr.path_bits = mad_recv_wc->wc->dlid_path_bits;
packet->mad.hdr.pkey_index = mad_recv_wc->wc->pkey_index;
packet->mad.hdr.grh_present = !!(mad_recv_wc->wc->wc_flags & IB_WC_GRH);
if (packet->mad.hdr.grh_present) {
struct ib_ah_attr ah_attr;
Expand All @@ -253,24 +261,24 @@ static void recv_handler(struct ib_mad_agent *agent,
ib_free_recv_mad(mad_recv_wc);
}

static ssize_t copy_recv_mad(char __user *buf, struct ib_umad_packet *packet,
size_t count)
static ssize_t copy_recv_mad(struct ib_umad_file *file, char __user *buf,
struct ib_umad_packet *packet, size_t count)
{
struct ib_mad_recv_buf *recv_buf;
int left, seg_payload, offset, max_seg_payload;

/* We need enough room to copy the first (or only) MAD segment. */
recv_buf = &packet->recv_wc->recv_buf;
if ((packet->length <= sizeof (*recv_buf->mad) &&
count < sizeof (packet->mad) + packet->length) ||
count < hdr_size(file) + packet->length) ||
(packet->length > sizeof (*recv_buf->mad) &&
count < sizeof (packet->mad) + sizeof (*recv_buf->mad)))
count < hdr_size(file) + sizeof (*recv_buf->mad)))
return -EINVAL;

if (copy_to_user(buf, &packet->mad, sizeof (packet->mad)))
if (copy_to_user(buf, &packet->mad, hdr_size(file)))
return -EFAULT;

buf += sizeof (packet->mad);
buf += hdr_size(file);
seg_payload = min_t(int, packet->length, sizeof (*recv_buf->mad));
if (copy_to_user(buf, recv_buf->mad, seg_payload))
return -EFAULT;
Expand All @@ -280,7 +288,7 @@ static ssize_t copy_recv_mad(char __user *buf, struct ib_umad_packet *packet,
* Multipacket RMPP MAD message. Copy remainder of message.
* Note that last segment may have a shorter payload.
*/
if (count < sizeof (packet->mad) + packet->length) {
if (count < hdr_size(file) + packet->length) {
/*
* The buffer is too small, return the first RMPP segment,
* which includes the RMPP message length.
Expand All @@ -300,18 +308,23 @@ static ssize_t copy_recv_mad(char __user *buf, struct ib_umad_packet *packet,
return -EFAULT;
}
}
return sizeof (packet->mad) + packet->length;
return hdr_size(file) + packet->length;
}

static ssize_t copy_send_mad(char __user *buf, struct ib_umad_packet *packet,
size_t count)
static ssize_t copy_send_mad(struct ib_umad_file *file, char __user *buf,
struct ib_umad_packet *packet, size_t count)
{
ssize_t size = sizeof (packet->mad) + packet->length;
ssize_t size = hdr_size(file) + packet->length;

if (count < size)
return -EINVAL;

if (copy_to_user(buf, &packet->mad, size))
if (copy_to_user(buf, &packet->mad, hdr_size(file)))
return -EFAULT;

buf += hdr_size(file);

if (copy_to_user(buf, packet->mad.data, packet->length))
return -EFAULT;

return size;
Expand All @@ -324,7 +337,7 @@ static ssize_t ib_umad_read(struct file *filp, char __user *buf,
struct ib_umad_packet *packet;
ssize_t ret;

if (count < sizeof (struct ib_user_mad))
if (count < hdr_size(file))
return -EINVAL;

spin_lock_irq(&file->recv_lock);
Expand All @@ -348,9 +361,9 @@ static ssize_t ib_umad_read(struct file *filp, char __user *buf,
spin_unlock_irq(&file->recv_lock);

if (packet->recv_wc)
ret = copy_recv_mad(buf, packet, count);
ret = copy_recv_mad(file, buf, packet, count);
else
ret = copy_send_mad(buf, packet, count);
ret = copy_send_mad(file, buf, packet, count);

if (ret < 0) {
/* Requeue packet */
Expand Down Expand Up @@ -442,15 +455,14 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
__be64 *tid;
int ret, data_len, hdr_len, copy_offset, rmpp_active;

if (count < sizeof (struct ib_user_mad) + IB_MGMT_RMPP_HDR)
if (count < hdr_size(file) + IB_MGMT_RMPP_HDR)
return -EINVAL;

packet = kzalloc(sizeof *packet + IB_MGMT_RMPP_HDR, GFP_KERNEL);
if (!packet)
return -ENOMEM;

if (copy_from_user(&packet->mad, buf,
sizeof (struct ib_user_mad) + IB_MGMT_RMPP_HDR)) {
if (copy_from_user(&packet->mad, buf, hdr_size(file))) {
ret = -EFAULT;
goto err;
}
Expand All @@ -461,6 +473,13 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
goto err;
}

buf += hdr_size(file);

if (copy_from_user(packet->mad.data, buf, IB_MGMT_RMPP_HDR)) {
ret = -EFAULT;
goto err;
}

down_read(&file->port->mutex);

agent = __get_agent(file, packet->mad.hdr.id);
Expand Down Expand Up @@ -500,11 +519,11 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,
IB_MGMT_RMPP_FLAG_ACTIVE;
}

data_len = count - sizeof (struct ib_user_mad) - hdr_len;
data_len = count - hdr_size(file) - hdr_len;
packet->msg = ib_create_send_mad(agent,
be32_to_cpu(packet->mad.hdr.qpn),
0, rmpp_active, hdr_len,
data_len, GFP_KERNEL);
packet->mad.hdr.pkey_index, rmpp_active,
hdr_len, data_len, GFP_KERNEL);
if (IS_ERR(packet->msg)) {
ret = PTR_ERR(packet->msg);
goto err_ah;
Expand All @@ -517,7 +536,6 @@ static ssize_t ib_umad_write(struct file *filp, const char __user *buf,

/* Copy MAD header. Any RMPP header is already in place. */
memcpy(packet->msg->mad, packet->mad.data, IB_MGMT_MAD_HDR);
buf += sizeof (struct ib_user_mad);

if (!rmpp_active) {
if (copy_from_user(packet->msg->mad + copy_offset,
Expand Down Expand Up @@ -646,6 +664,16 @@ static int ib_umad_reg_agent(struct ib_umad_file *file, unsigned long arg)
goto out;
}

if (!file->already_used) {
file->already_used = 1;
if (!file->use_pkey_index) {
printk(KERN_WARNING "user_mad: process %s did not enable "
"P_Key index support.\n", current->comm);
printk(KERN_WARNING "user_mad: Documentation/infiniband/user_mad.txt "
"has info on the new ABI.\n");
}
}

file->agent[agent_id] = agent;
ret = 0;

Expand Down Expand Up @@ -682,6 +710,20 @@ static int ib_umad_unreg_agent(struct ib_umad_file *file, unsigned long arg)
return ret;
}

static long ib_umad_enable_pkey(struct ib_umad_file *file)
{
int ret = 0;

down_write(&file->port->mutex);
if (file->already_used)
ret = -EINVAL;
else
file->use_pkey_index = 1;
up_write(&file->port->mutex);

return ret;
}

static long ib_umad_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
Expand All @@ -690,6 +732,8 @@ static long ib_umad_ioctl(struct file *filp, unsigned int cmd,
return ib_umad_reg_agent(filp->private_data, arg);
case IB_USER_MAD_UNREGISTER_AGENT:
return ib_umad_unreg_agent(filp->private_data, arg);
case IB_USER_MAD_ENABLE_PKEY:
return ib_umad_enable_pkey(filp->private_data);
default:
return -ENOIOCTLCMD;
}
Expand Down
48 changes: 48 additions & 0 deletions include/rdma/ib_user_mad.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,8 +51,51 @@
* 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
Expand All @@ -70,6 +113,7 @@
* @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;
Expand All @@ -88,6 +132,8 @@ struct ib_user_mad_hdr {
__u8 traffic_class;
__u8 gid[16];
__be32 flow_label;
__u16 pkey_index;
__u8 reserved[6];
};

/**
Expand Down Expand Up @@ -134,4 +180,6 @@ 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 */

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