1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause 2 /* 3 * Copyright (c) 2024 Oracle. All rights reserved. 4 */ 5 6 /* #include <linux/module.h> 7 #include <linux/slab.h> */ 8 #include <linux/xarray.h> 9 #include <linux/types.h> 10 #include <linux/kref.h> 11 #include <linux/completion.h> 12 13 #include <linux/sunrpc/svc_rdma.h> 14 #include <linux/sunrpc/rdma_rn.h> 15 16 #include "xprt_rdma.h" 17 #include <trace/events/rpcrdma.h> 18 19 /* Per-ib_device private data for rpcrdma */ 20 struct rpcrdma_device { 21 struct kref rd_kref; 22 unsigned long rd_flags; 23 struct ib_device *rd_device; 24 struct xarray rd_xa; 25 struct completion rd_done; 26 }; 27 28 #define RPCRDMA_RD_F_REMOVING (0) 29 30 static struct ib_client rpcrdma_ib_client; 31 32 /* 33 * Listeners have no associated device, so we never register them. 34 * Note that ib_get_client_data() does not check if @device is 35 * NULL for us. 36 */ 37 static struct rpcrdma_device *rpcrdma_get_client_data(struct ib_device *device) 38 { 39 if (!device) 40 return NULL; 41 return ib_get_client_data(device, &rpcrdma_ib_client); 42 } 43 44 /** 45 * rpcrdma_rn_register - register to get device removal notifications 46 * @device: device to monitor 47 * @rn: notification object that wishes to be notified 48 * @done: callback to notify caller of device removal 49 * 50 * Returns zero on success. The callback in rn_done is guaranteed 51 * to be invoked when the device is removed, unless this notification 52 * is unregistered first. 53 * 54 * On failure, a negative errno is returned. 55 */ 56 int rpcrdma_rn_register(struct ib_device *device, 57 struct rpcrdma_notification *rn, 58 void (*done)(struct rpcrdma_notification *rn)) 59 { 60 struct rpcrdma_device *rd = rpcrdma_get_client_data(device); 61 62 if (!rd || test_bit(RPCRDMA_RD_F_REMOVING, &rd->rd_flags)) 63 return -ENETUNREACH; 64 65 kref_get(&rd->rd_kref); 66 if (xa_alloc(&rd->rd_xa, &rn->rn_index, rn, xa_limit_32b, GFP_KERNEL) < 0) 67 return -ENOMEM; 68 rn->rn_done = done; 69 return 0; 70 } 71 72 static void rpcrdma_rn_release(struct kref *kref) 73 { 74 struct rpcrdma_device *rd = container_of(kref, struct rpcrdma_device, 75 rd_kref); 76 77 trace_rpcrdma_client_completion(rd->rd_device); 78 complete(&rd->rd_done); 79 } 80 81 /** 82 * rpcrdma_rn_unregister - stop device removal notifications 83 * @device: monitored device 84 * @rn: notification object that no longer wishes to be notified 85 */ 86 void rpcrdma_rn_unregister(struct ib_device *device, 87 struct rpcrdma_notification *rn) 88 { 89 struct rpcrdma_device *rd = rpcrdma_get_client_data(device); 90 91 if (!rd) 92 return; 93 94 xa_erase(&rd->rd_xa, rn->rn_index); 95 kref_put(&rd->rd_kref, rpcrdma_rn_release); 96 } 97 98 /** 99 * rpcrdma_add_one - ib_client device insertion callback 100 * @device: device about to be inserted 101 * 102 * Returns zero on success. xprtrdma private data has been allocated 103 * for this device. On failure, a negative errno is returned. 104 */ 105 static int rpcrdma_add_one(struct ib_device *device) 106 { 107 struct rpcrdma_device *rd; 108 109 rd = kzalloc(sizeof(*rd), GFP_KERNEL); 110 if (!rd) 111 return -ENOMEM; 112 113 kref_init(&rd->rd_kref); 114 xa_init_flags(&rd->rd_xa, XA_FLAGS_ALLOC1); 115 rd->rd_device = device; 116 init_completion(&rd->rd_done); 117 ib_set_client_data(device, &rpcrdma_ib_client, rd); 118 119 trace_rpcrdma_client_add_one(device); 120 return 0; 121 } 122 123 /** 124 * rpcrdma_remove_one - ib_client device removal callback 125 * @device: device about to be removed 126 * @client_data: this module's private per-device data 127 * 128 * Upon return, all transports associated with @device have divested 129 * themselves from IB hardware resources. 130 */ 131 static void rpcrdma_remove_one(struct ib_device *device, 132 void *client_data) 133 { 134 struct rpcrdma_device *rd = client_data; 135 struct rpcrdma_notification *rn; 136 unsigned long index; 137 138 trace_rpcrdma_client_remove_one(device); 139 140 set_bit(RPCRDMA_RD_F_REMOVING, &rd->rd_flags); 141 xa_for_each(&rd->rd_xa, index, rn) 142 rn->rn_done(rn); 143 144 /* 145 * Wait only if there are still outstanding notification 146 * registrants for this device. 147 */ 148 if (!refcount_dec_and_test(&rd->rd_kref.refcount)) { 149 trace_rpcrdma_client_wait_on(device); 150 wait_for_completion(&rd->rd_done); 151 } 152 153 trace_rpcrdma_client_remove_one_done(device); 154 kfree(rd); 155 } 156 157 static struct ib_client rpcrdma_ib_client = { 158 .name = "rpcrdma", 159 .add = rpcrdma_add_one, 160 .remove = rpcrdma_remove_one, 161 }; 162 163 /** 164 * rpcrdma_ib_client_unregister - unregister ib_client for xprtrdma 165 * 166 * cel: watch for orphaned rpcrdma_device objects on module unload 167 */ 168 void rpcrdma_ib_client_unregister(void) 169 { 170 ib_unregister_client(&rpcrdma_ib_client); 171 } 172 173 /** 174 * rpcrdma_ib_client_register - register ib_client for rpcrdma 175 * 176 * Returns zero on success, or a negative errno. 177 */ 178 int rpcrdma_ib_client_register(void) 179 { 180 return ib_register_client(&rpcrdma_ib_client); 181 } 182