// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
* Copyright (c) 2024 Oracle. All rights reserved.
*/
/* #include <linux/module.h>
#include <linux/slab.h> */
#include <linux/xarray.h>
#include <linux/types.h>
#include <linux/kref.h>
#include <linux/completion.h>
#include <linux/sunrpc/svc_rdma.h>
#include <linux/sunrpc/rdma_rn.h>
#include "xprt_rdma.h"
#include <trace/events/rpcrdma.h>
/* Per-ib_device private data for rpcrdma */
struct rpcrdma_device {
struct kref rd_kref;
unsigned long rd_flags;
struct ib_device *rd_device;
struct xarray rd_xa;
struct completion rd_done;
};
#define RPCRDMA_RD_F_REMOVING (0)
static struct ib_client rpcrdma_ib_client;
/*
* Listeners have no associated device, so we never register them.
* Note that ib_get_client_data() does not check if @device is
* NULL for us.
*/
static struct rpcrdma_device *rpcrdma_get_client_data(struct ib_device *device)
{
if (!device)
return NULL;
return ib_get_client_data(device, &rpcrdma_ib_client);
}
/**
* rpcrdma_rn_register - register to get device removal notifications
* @device: device to monitor
* @rn: notification object that wishes to be notified
* @done: callback to notify caller of device removal
*
* Returns zero on success. The callback in rn_done is guaranteed
* to be invoked when the device is removed, unless this notification
* is unregistered first.
*
* On failure, a negative errno is returned.
*/
int rpcrdma_rn_register(struct ib_device *device,
struct rpcrdma_notification *rn,
void (*done)(struct rpcrdma_notification *rn))
{
struct rpcrdma_device *rd = rpcrdma_get_client_data(device);
if (!rd || test_bit(RPCRDMA_RD_F_REMOVING, &rd->rd_flags))
return -ENETUNREACH;
if (xa_alloc(&rd->rd_xa, &rn->rn_index, rn, xa_limit_32b, GFP_KERNEL) < 0)
return -ENOMEM;
kref_get(&rd->rd_kref);
rn->rn_done = done;
trace_rpcrdma_client_register(device, rn);
return 0;
}
static void rpcrdma_rn_release(struct kref *kref)
{
struct rpcrdma_device *rd = container_of(kref, struct rpcrdma_device,
rd_kref);
trace_rpcrdma_client_completion(rd->rd_device);
complete(&rd->rd_done);
}
/**
* rpcrdma_rn_unregister - stop device removal notifications
* @device: monitored device
* @rn: notification object that no longer wishes to be notified
*/
void rpcrdma_rn_unregister(struct ib_device *device,
struct rpcrdma_notification *rn)
{
struct rpcrdma_device *rd = rpcrdma_get_client_data(device);
if (!rd)
return;
trace_rpcrdma_client_unregister(device, rn);
xa_erase(&rd->rd_xa, rn->rn_index);
kref_put(&rd->rd_kref, rpcrdma_rn_release);
}
/**
* rpcrdma_add_one - ib_client device insertion callback
* @device: device about to be inserted
*
* Returns zero on success. xprtrdma private data has been allocated
* for this device. On failure, a negative errno is returned.
*/
static int rpcrdma_add_one(struct ib_device *device)
{
struct rpcrdma_device *rd;
rd = kzalloc(sizeof(*rd), GFP_KERNEL);
if (!rd)
return -ENOMEM;
kref_init(&rd->rd_kref);
xa_init_flags(&rd->rd_xa, XA_FLAGS_ALLOC);
rd->rd_device = device;
init_completion(&rd->rd_done);
ib_set_client_data(device, &rpcrdma_ib_client, rd);
trace_rpcrdma_client_add_one(device);
return 0;
}
/**
* rpcrdma_remove_one - ib_client device removal callback
* @device: device about to be removed
* @client_data: this module's private per-device data
*
* Upon return, all transports associated with @device have divested
* themselves from IB hardware resources.
*/
static void rpcrdma_remove_one(struct ib_device *device,
void *client_data)
{
struct rpcrdma_device *rd = client_data;
struct rpcrdma_notification *rn;
unsigned long index;
trace_rpcrdma_client_remove_one(device);
set_bit(RPCRDMA_RD_F_REMOVING, &rd->rd_flags);
xa_for_each(&rd->rd_xa, index, rn)
rn->rn_done(rn);
/*
* Wait only if there are still outstanding notification
* registrants for this device.
*/
if (!refcount_dec_and_test(&rd->rd_kref.refcount)) {
trace_rpcrdma_client_wait_on(device);
wait_for_completion(&rd->rd_done);
}
trace_rpcrdma_client_remove_one_done(device);
kfree(rd);
}
static struct ib_client rpcrdma_ib_client = {
.name = "rpcrdma",
.add = rpcrdma_add_one,
.remove = rpcrdma_remove_one,
};
/**
* rpcrdma_ib_client_unregister - unregister ib_client for xprtrdma
*
* cel: watch for orphaned rpcrdma_device objects on module unload
*/
void rpcrdma_ib_client_unregister(void)
{
ib_unregister_client(&rpcrdma_ib_client);
}
/**
* rpcrdma_ib_client_register - register ib_client for rpcrdma
*
* Returns zero on success, or a negative errno.
*/
int rpcrdma_ib_client_register(void)
{
return ib_register_client(&rpcrdma_ib_client);
}