ucm.c

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/*
 * Copyright (c) 2005 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005 Intel Corporation.  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: ucm.c 2594 2005-06-13 19:46:02Z libor $
 */
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/poll.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/cdev.h>

#include <asm/uaccess.h>

#include "ucm.h"

MODULE_AUTHOR("Libor Michalek");
MODULE_DESCRIPTION("InfiniBand userspace Connection Manager access");
MODULE_LICENSE("Dual BSD/GPL");

static int ucm_debug_level;

module_param_named(debug_level, ucm_debug_level, int, 0644);
MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0");

enum {
	IB_UCM_MAJOR = 231,
	IB_UCM_MINOR = 255
};

#define IB_UCM_DEV MKDEV(IB_UCM_MAJOR, IB_UCM_MINOR)

#define PFX "UCM: "

#define ucm_dbg(format, arg...)			\
	do {					\
		if (ucm_debug_level > 0)	\
			printk(KERN_DEBUG PFX format, ## arg); \
	} while (0)

static struct semaphore ctx_id_mutex;
static struct idr       ctx_id_table;

static struct ib_ucm_context *ib_ucm_ctx_get(struct ib_ucm_file *file, int id)
{
	struct ib_ucm_context *ctx;

	down(&ctx_id_mutex);
	ctx = idr_find(&ctx_id_table, id);
	if (!ctx)
		ctx = ERR_PTR(-ENOENT);
	else if (ctx->file != file)
		ctx = ERR_PTR(-EINVAL);
	else
		atomic_inc(&ctx->ref);
	up(&ctx_id_mutex);

	return ctx;
}

static void ib_ucm_ctx_put(struct ib_ucm_context *ctx)
{
	if (atomic_dec_and_test(&ctx->ref))
		wake_up(&ctx->wait);
}

static inline int ib_ucm_new_cm_id(int event)
{
	return event == IB_CM_REQ_RECEIVED || event == IB_CM_SIDR_REQ_RECEIVED;
}

static void ib_ucm_cleanup_events(struct ib_ucm_context *ctx)
{
	struct ib_ucm_event *uevent;

	down(&ctx->file->mutex);
	list_del(&ctx->file_list);
	while (!list_empty(&ctx->events)) {

		uevent = list_entry(ctx->events.next,
				    struct ib_ucm_event, ctx_list);
		list_del(&uevent->file_list);
		list_del(&uevent->ctx_list);

		/* clear incoming connections. */
		if (ib_ucm_new_cm_id(uevent->resp.event))
			ib_destroy_cm_id(uevent->cm_id);

		kfree(uevent);
	}
	up(&ctx->file->mutex);
}

static struct ib_ucm_context *ib_ucm_ctx_alloc(struct ib_ucm_file *file)
{
	struct ib_ucm_context *ctx;
	int result;

	ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return NULL;

	memset(ctx, 0, sizeof *ctx);
	atomic_set(&ctx->ref, 1);
	init_waitqueue_head(&ctx->wait);
	ctx->file = file;
	INIT_LIST_HEAD(&ctx->events);

	do {
		result = idr_pre_get(&ctx_id_table, GFP_KERNEL);
		if (!result)
			goto error;

		down(&ctx_id_mutex);
		result = idr_get_new(&ctx_id_table, ctx, &ctx->id);
		up(&ctx_id_mutex);
	} while (result == -EAGAIN);

	if (result)
		goto error;

	list_add_tail(&ctx->file_list, &file->ctxs);
	ucm_dbg("Allocated CM ID <%d>\n", ctx->id);
	return ctx;

error:
	kfree(ctx);
	return NULL;
}
/*
 * Event portion of the API, handle CM events
 * and allow event polling.
 */
static void ib_ucm_event_path_get(struct ib_ucm_path_rec *upath,
				  struct ib_sa_path_rec	 *kpath)
{
	if (!kpath || !upath)
		return;

	memcpy(upath->dgid, kpath->dgid.raw, sizeof *upath->dgid);
	memcpy(upath->sgid, kpath->sgid.raw, sizeof *upath->sgid);

	upath->dlid             = kpath->dlid;
	upath->slid             = kpath->slid;
	upath->raw_traffic      = kpath->raw_traffic;
	upath->flow_label       = kpath->flow_label;
	upath->hop_limit        = kpath->hop_limit;
	upath->traffic_class    = kpath->traffic_class;
	upath->reversible       = kpath->reversible;
	upath->numb_path        = kpath->numb_path;
	upath->pkey             = kpath->pkey;
	upath->sl	        = kpath->sl;
	upath->mtu_selector     = kpath->mtu_selector;
	upath->mtu              = kpath->mtu;
	upath->rate_selector    = kpath->rate_selector;
	upath->rate             = kpath->rate;
	upath->packet_life_time = kpath->packet_life_time;
	upath->preference       = kpath->preference;

	upath->packet_life_time_selector =
		kpath->packet_life_time_selector;
}

static void ib_ucm_event_req_get(struct ib_ucm_req_event_resp *ureq,
				 struct ib_cm_req_event_param *kreq)
{
	ureq->remote_ca_guid             = kreq->remote_ca_guid;
	ureq->remote_qkey                = kreq->remote_qkey;
	ureq->remote_qpn                 = kreq->remote_qpn;
	ureq->qp_type                    = kreq->qp_type;
	ureq->starting_psn               = kreq->starting_psn;
	ureq->responder_resources        = kreq->responder_resources;
	ureq->initiator_depth            = kreq->initiator_depth;
	ureq->local_cm_response_timeout  = kreq->local_cm_response_timeout;
	ureq->flow_control               = kreq->flow_control;
	ureq->remote_cm_response_timeout = kreq->remote_cm_response_timeout;
	ureq->retry_count                = kreq->retry_count;
	ureq->rnr_retry_count            = kreq->rnr_retry_count;
	ureq->srq                        = kreq->srq;

	ib_ucm_event_path_get(&ureq->primary_path, kreq->primary_path);
	ib_ucm_event_path_get(&ureq->alternate_path, kreq->alternate_path);
}

static void ib_ucm_event_rep_get(struct ib_ucm_rep_event_resp *urep,
				 struct ib_cm_rep_event_param *krep)
{
	urep->remote_ca_guid      = krep->remote_ca_guid;
	urep->remote_qkey         = krep->remote_qkey;
	urep->remote_qpn          = krep->remote_qpn;
	urep->starting_psn        = krep->starting_psn;
	urep->responder_resources = krep->responder_resources;
	urep->initiator_depth     = krep->initiator_depth;
	urep->target_ack_delay    = krep->target_ack_delay;
	urep->failover_accepted   = krep->failover_accepted;
	urep->flow_control        = krep->flow_control;
	urep->rnr_retry_count     = krep->rnr_retry_count;
	urep->srq                 = krep->srq;
}

static void ib_ucm_event_sidr_rep_get(struct ib_ucm_sidr_rep_event_resp *urep,
				      struct ib_cm_sidr_rep_event_param *krep)
{
	urep->status = krep->status;
	urep->qkey   = krep->qkey;
	urep->qpn    = krep->qpn;
};

static int ib_ucm_event_process(struct ib_cm_event *evt,
				struct ib_ucm_event *uvt)
{
	void *info = NULL;

	switch (evt->event) {
	case IB_CM_REQ_RECEIVED:
		ib_ucm_event_req_get(&uvt->resp.u.req_resp,
				     &evt->param.req_rcvd);
		uvt->data_len      = IB_CM_REQ_PRIVATE_DATA_SIZE;
		uvt->resp.present  = IB_UCM_PRES_PRIMARY;
		uvt->resp.present |= (evt->param.req_rcvd.alternate_path ?
				      IB_UCM_PRES_ALTERNATE : 0);
		break;
	case IB_CM_REP_RECEIVED:
		ib_ucm_event_rep_get(&uvt->resp.u.rep_resp,
				     &evt->param.rep_rcvd);
		uvt->data_len = IB_CM_REP_PRIVATE_DATA_SIZE;
		break;
	case IB_CM_RTU_RECEIVED:
		uvt->data_len = IB_CM_RTU_PRIVATE_DATA_SIZE;
		uvt->resp.u.send_status = evt->param.send_status;
		break;
	case IB_CM_DREQ_RECEIVED:
		uvt->data_len = IB_CM_DREQ_PRIVATE_DATA_SIZE;
		uvt->resp.u.send_status = evt->param.send_status;
		break;
	case IB_CM_DREP_RECEIVED:
		uvt->data_len = IB_CM_DREP_PRIVATE_DATA_SIZE;
		uvt->resp.u.send_status = evt->param.send_status;
		break;
	case IB_CM_MRA_RECEIVED:
		uvt->resp.u.mra_resp.timeout =
					evt->param.mra_rcvd.service_timeout;
		uvt->data_len = IB_CM_MRA_PRIVATE_DATA_SIZE;
		break;
	case IB_CM_REJ_RECEIVED:
		uvt->resp.u.rej_resp.reason = evt->param.rej_rcvd.reason;
		uvt->data_len = IB_CM_REJ_PRIVATE_DATA_SIZE;
		uvt->info_len = evt->param.rej_rcvd.ari_length;
		info	      = evt->param.rej_rcvd.ari;
		break;
	case IB_CM_LAP_RECEIVED:
		ib_ucm_event_path_get(&uvt->resp.u.lap_resp.path,
				      evt->param.lap_rcvd.alternate_path);
		uvt->data_len = IB_CM_LAP_PRIVATE_DATA_SIZE;
		uvt->resp.present = IB_UCM_PRES_ALTERNATE;
		break;
	case IB_CM_APR_RECEIVED:
		uvt->resp.u.apr_resp.status = evt->param.apr_rcvd.ap_status;
		uvt->data_len = IB_CM_APR_PRIVATE_DATA_SIZE;
		uvt->info_len = evt->param.apr_rcvd.info_len;
		info	      = evt->param.apr_rcvd.apr_info;
		break;
	case IB_CM_SIDR_REQ_RECEIVED:
		uvt->resp.u.sidr_req_resp.pkey = 
					evt->param.sidr_req_rcvd.pkey;
		uvt->data_len = IB_CM_SIDR_REQ_PRIVATE_DATA_SIZE;
		break;
	case IB_CM_SIDR_REP_RECEIVED:
		ib_ucm_event_sidr_rep_get(&uvt->resp.u.sidr_rep_resp,
					  &evt->param.sidr_rep_rcvd);
		uvt->data_len = IB_CM_SIDR_REP_PRIVATE_DATA_SIZE;
		uvt->info_len = evt->param.sidr_rep_rcvd.info_len;
		info	      = evt->param.sidr_rep_rcvd.info;
		break;
	default:
		uvt->resp.u.send_status = evt->param.send_status;
		break;
	}

	if (uvt->data_len) {
		uvt->data = kmalloc(uvt->data_len, GFP_KERNEL);
		if (!uvt->data)
			goto err1;

		memcpy(uvt->data, evt->private_data, uvt->data_len);
		uvt->resp.present |= IB_UCM_PRES_DATA;
	}

	if (uvt->info_len) {
		uvt->info = kmalloc(uvt->info_len, GFP_KERNEL);
		if (!uvt->info)
			goto err2;

		memcpy(uvt->info, info, uvt->info_len);
		uvt->resp.present |= IB_UCM_PRES_INFO;
	}
	return 0;

err2:
	kfree(uvt->data);
err1:
	return -ENOMEM;
}

static int ib_ucm_event_handler(struct ib_cm_id *cm_id,
				struct ib_cm_event *event)
{
	struct ib_ucm_event *uevent;
	struct ib_ucm_context *ctx;
	int result = 0;

	ctx = cm_id->context;

	uevent = kmalloc(sizeof(*uevent), GFP_KERNEL);
	if (!uevent)
		goto err1;

	memset(uevent, 0, sizeof(*uevent));
	uevent->ctx = ctx;
	uevent->cm_id = cm_id;
	uevent->resp.uid = ctx->uid;
	uevent->resp.id = ctx->id;
	uevent->resp.event = event->event;

	result = ib_ucm_event_process(event, uevent);
	if (result)
		goto err2;

	down(&ctx->file->mutex);
	list_add_tail(&uevent->file_list, &ctx->file->events);
	list_add_tail(&uevent->ctx_list, &ctx->events);
	wake_up_interruptible(&ctx->file->poll_wait);
	up(&ctx->file->mutex);
	return 0;

err2:
	kfree(uevent);
err1:
	/* Destroy new cm_id's */
	return ib_ucm_new_cm_id(event->event);
}

static ssize_t ib_ucm_event(struct ib_ucm_file *file,
			    const char __user *inbuf,
			    int in_len, int out_len)
{
	struct ib_ucm_context *ctx;
	struct ib_ucm_event_get cmd;
	struct ib_ucm_event *uevent;
	int result = 0;
	DEFINE_WAIT(wait);

	if (out_len < sizeof(struct ib_ucm_event_resp))
		return -ENOSPC;

	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
		return -EFAULT;
	/*
	 * wait
	 */
	down(&file->mutex);
	while (list_empty(&file->events)) {

		if (file->filp->f_flags & O_NONBLOCK) {
			result = -EAGAIN;
			break;
		}

		if (signal_pending(current)) {
			result = -ERESTARTSYS;
			break;
		}

		prepare_to_wait(&file->poll_wait, &wait, TASK_INTERRUPTIBLE);

		up(&file->mutex);
		schedule();
		down(&file->mutex);

		finish_wait(&file->poll_wait, &wait);
	}

	if (result)
		goto done;

	uevent = list_entry(file->events.next, struct ib_ucm_event, file_list);

	if (ib_ucm_new_cm_id(uevent->resp.event)) {
		ctx = ib_ucm_ctx_alloc(file);
		if (!ctx) {
			result = -ENOMEM;
			goto done;
		}

		ctx->cm_id = uevent->cm_id;
		ctx->cm_id->context = ctx;
		uevent->resp.id = ctx->id;
	}

	if (copy_to_user((void __user *)(unsigned long)cmd.response,
			 &uevent->resp, sizeof(uevent->resp))) {
		result = -EFAULT;
		goto done;
	}

	if (uevent->data) {
		if (cmd.data_len < uevent->data_len) {
			result = -ENOMEM;
			goto done;
		}
		if (copy_to_user((void __user *)(unsigned long)cmd.data,