drivers/char/ipmi/ipmi_powernv.c

   1 /*
   2  * PowerNV OPAL IPMI driver
   3  *
   4  * Copyright 2014 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  */
  11
  12 #define pr_fmt(fmt)        "ipmi-powernv: " fmt
  13
  14 #include <linux/ipmi_smi.h>
  15 #include <linux/list.h>
  16 #include <linux/module.h>
  17 #include <linux/of.h>
  18
  19 #include <asm/opal.h>
  20
  21
  22 struct ipmi_smi_powernv {
  23         u64                     interface_id;
  24         struct ipmi_device_id   ipmi_id;
  25         ipmi_smi_t              intf;
  26         u64                     event;
  27         struct notifier_block   event_nb;
  28
  29         /**
  30          * We assume that there can only be one outstanding request, so
  31          * keep the pending message in cur_msg. We protect this from concurrent
  32          * updates through send & recv calls, (and consequently opal_msg, which
  33          * is in-use when cur_msg is set) with msg_lock
  34          */
  35         spinlock_t              msg_lock;
  36         struct ipmi_smi_msg     *cur_msg;
  37         struct opal_ipmi_msg    *opal_msg;
  38 };
  39
  40 static int ipmi_powernv_start_processing(void *send_info, ipmi_smi_t intf)
  41 {
  42         struct ipmi_smi_powernv *smi = send_info;
  43
  44         smi->intf = intf;
  45         return 0;
  46 }
  47
  48 static void send_error_reply(struct ipmi_smi_powernv *smi,
  49                 struct ipmi_smi_msg *msg, u8 completion_code)
  50 {
  51         msg->rsp[0] = msg->data[0] | 0x4;
  52         msg->rsp[1] = msg->data[1];
  53         msg->rsp[2] = completion_code;
  54         msg->rsp_size = 3;
  55         ipmi_smi_msg_received(smi->intf, msg);
  56 }
  57
  58 static void ipmi_powernv_send(void *send_info, struct ipmi_smi_msg *msg)
  59 {
  60         struct ipmi_smi_powernv *smi = send_info;
  61         struct opal_ipmi_msg *opal_msg;
  62         unsigned long flags;
  63         int comp, rc;
  64         size_t size;
  65
  66         /* ensure data_len will fit in the opal_ipmi_msg buffer... */
  67         if (msg->data_size > IPMI_MAX_MSG_LENGTH) {
  68                 comp = IPMI_REQ_LEN_EXCEEDED_ERR;
  69                 goto err;
  70         }
  71
  72         /* ... and that we at least have netfn and cmd bytes */
  73         if (msg->data_size < 2) {
  74                 comp = IPMI_REQ_LEN_INVALID_ERR;
  75                 goto err;
  76         }
  77
  78         spin_lock_irqsave(&smi->msg_lock, flags);
  79
  80         if (smi->cur_msg) {
  81                 comp = IPMI_NODE_BUSY_ERR;
  82                 goto err_unlock;
  83         }
  84
  85         /* format our data for the OPAL API */
  86         opal_msg = smi->opal_msg;
  87         opal_msg->version = OPAL_IPMI_MSG_FORMAT_VERSION_1;
  88         opal_msg->netfn = msg->data[0];
  89         opal_msg->cmd = msg->data[1];
  90         if (msg->data_size > 2)
  91                 memcpy(opal_msg->data, msg->data + 2, msg->data_size - 2);
  92
  93         /* data_size already includes the netfn and cmd bytes */
  94         size = sizeof(*opal_msg) + msg->data_size - 2;
  95
  96         pr_devel("%s: opal_ipmi_send(0x%llx, %p, %ld)\n", __func__,
  97                         smi->interface_id, opal_msg, size);
  98         rc = opal_ipmi_send(smi->interface_id, opal_msg, size);
  99         pr_devel("%s:  -> %d\n", __func__, rc);
 100
 101         if (!rc) {
 102                 smi->cur_msg = msg;
 103                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 104                 return;
 105         }
 106
 107         comp = IPMI_ERR_UNSPECIFIED;
 108 err_unlock:
 109         spin_unlock_irqrestore(&smi->msg_lock, flags);
 110 err:
 111         send_error_reply(smi, msg, comp);
 112 }
 113
 114 static int ipmi_powernv_recv(struct ipmi_smi_powernv *smi)
 115 {
 116         struct opal_ipmi_msg *opal_msg;
 117         struct ipmi_smi_msg *msg;
 118         unsigned long flags;
 119         uint64_t size;
 120         int rc;
 121
 122         pr_devel("%s: opal_ipmi_recv(%llx, msg, sz)\n", __func__,
 123                         smi->interface_id);
 124
 125         spin_lock_irqsave(&smi->msg_lock, flags);
 126
 127         if (!smi->cur_msg) {
 128                 pr_warn("no current message?\n");
 129                 return 0;
 130         }
 131
 132         msg = smi->cur_msg;
 133         opal_msg = smi->opal_msg;
 134
 135         size = cpu_to_be64(sizeof(*opal_msg) + IPMI_MAX_MSG_LENGTH);
 136
 137         rc = opal_ipmi_recv(smi->interface_id,
 138                         opal_msg,
 139                         &size);
 140         size = be64_to_cpu(size);
 141         pr_devel("%s:   -> %d (size %lld)\n", __func__,
 142                         rc, rc == 0 ? size : 0);
 143         if (rc) {
 144                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 145                 ipmi_free_smi_msg(msg);
 146                 return 0;
 147         }
 148
 149         if (size < sizeof(*opal_msg)) {
 150                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 151                 pr_warn("unexpected IPMI message size %lld\n", size);
 152                 return 0;
 153         }
 154
 155         if (opal_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
 156                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 157                 pr_warn("unexpected IPMI message format (version %d)\n",
 158                                 opal_msg->version);
 159                 return 0;
 160         }
 161
 162         msg->rsp[0] = opal_msg->netfn;
 163         msg->rsp[1] = opal_msg->cmd;
 164         if (size > sizeof(*opal_msg))
 165                 memcpy(&msg->rsp[2], opal_msg->data, size - sizeof(*opal_msg));
 166         msg->rsp_size = 2 + size - sizeof(*opal_msg);
 167
 168         smi->cur_msg = NULL;
 169         spin_unlock_irqrestore(&smi->msg_lock, flags);
 170         ipmi_smi_msg_received(smi->intf, msg);
 171         return 0;
 172 }
 173
 174 static void ipmi_powernv_request_events(void *send_info)
 175 {
 176 }
 177
 178 static void ipmi_powernv_set_run_to_completion(void *send_info,
 179                 bool run_to_completion)
 180 {
 181 }
 182
 183 static void ipmi_powernv_poll(void *send_info)
 184 {
 185         struct ipmi_smi_powernv *smi = send_info;
 186
 187         ipmi_powernv_recv(smi);
 188 }
 189
 190 static struct ipmi_smi_handlers ipmi_powernv_smi_handlers = {
 191         .owner                  = THIS_MODULE,
 192         .start_processing       = ipmi_powernv_start_processing,
 193         .sender                 = ipmi_powernv_send,
 194         .request_events         = ipmi_powernv_request_events,
 195         .set_run_to_completion  = ipmi_powernv_set_run_to_completion,
 196         .poll                   = ipmi_powernv_poll,
 197 };
 198
 199 static int ipmi_opal_event(struct notifier_block *nb,
 200                           unsigned long events, void *change)
 201 {
 202         struct ipmi_smi_powernv *smi = container_of(nb,
 203                                         struct ipmi_smi_powernv, event_nb);
 204
 205         if (events & smi->event)
 206                 ipmi_powernv_recv(smi);
 207         return 0;
 208 }
 209
 210 static int ipmi_powernv_probe(struct platform_device *pdev)
 211 {
 212         struct ipmi_smi_powernv *ipmi;
 213         struct device *dev;
 214         u32 prop;
 215         int rc;
 216
 217         if (!pdev || !pdev->dev.of_node)
 218                 return -ENODEV;
 219
 220         dev = &pdev->dev;
 221
 222         ipmi = devm_kzalloc(dev, sizeof(*ipmi), GFP_KERNEL);
 223         if (!ipmi)
 224                 return -ENOMEM;
 225
 226         spin_lock_init(&ipmi->msg_lock);
 227
 228         rc = of_property_read_u32(dev->of_node, "ibm,ipmi-interface-id",
 229                         &prop);
 230         if (rc) {
 231                 dev_warn(dev, "No interface ID property\n");
 232                 goto err_free;
 233         }
 234         ipmi->interface_id = prop;
 235
 236         rc = of_property_read_u32(dev->of_node, "interrupts", &prop);
 237         if (rc) {
 238                 dev_warn(dev, "No interrupts property\n");
 239                 goto err_free;
 240         }
 241
 242         ipmi->event = 1ull << prop;
 243         ipmi->event_nb.notifier_call = ipmi_opal_event;
 244
 245         rc = opal_notifier_register(&ipmi->event_nb);
 246         if (rc) {
 247                 dev_warn(dev, "OPAL notifier registration failed (%d)\n", rc);
 248                 goto err_free;
 249         }
 250
 251         ipmi->opal_msg = devm_kmalloc(dev,
 252                         sizeof(*ipmi->opal_msg) + IPMI_MAX_MSG_LENGTH,
 253                         GFP_KERNEL);
 254         if (!ipmi->opal_msg) {
 255                 rc = -ENOMEM;
 256                 goto err_unregister;
 257         }
 258
 259         /* todo: query actual ipmi_device_id */
 260         rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi,
 261                         &ipmi->ipmi_id, dev, 0);
 262         if (rc) {
 263                 dev_warn(dev, "IPMI SMI registration failed (%d)\n", rc);
 264                 goto err_free_msg;
 265         }
 266
 267         dev_set_drvdata(dev, ipmi);
 268         return 0;
 269
 270 err_free_msg:
 271         devm_kfree(dev, ipmi->opal_msg);
 272 err_unregister:
 273         opal_notifier_unregister(&ipmi->event_nb);
 274 err_free:
 275         devm_kfree(dev, ipmi);
 276         return rc;
 277 }
 278
 279 static int ipmi_powernv_remove(struct platform_device *pdev)
 280 {
 281         struct ipmi_smi_powernv *smi = dev_get_drvdata(&pdev->dev);
 282
 283         ipmi_unregister_smi(smi->intf);
 284         opal_notifier_unregister(&smi->event_nb);
 285         return 0;
 286 }
 287
 288 static const struct of_device_id ipmi_powernv_match[] = {
 289         { .compatible = "ibm,opal-ipmi" },
 290         { },
 291 };
 292
 293
 294 static struct platform_driver powernv_ipmi_driver = {
 295         .driver = {
 296                 .name           = "ipmi-powernv",
 297                 .owner          = THIS_MODULE,
 298                 .of_match_table = ipmi_powernv_match,
 299         },
 300         .probe  = ipmi_powernv_probe,
 301         .remove = ipmi_powernv_remove,
 302 };
 303
 304
 305 module_platform_driver(powernv_ipmi_driver);
 306
 307 MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
 308 MODULE_DESCRIPTION("powernv IPMI driver");
 309 MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
 310 MODULE_LICENSE("GPL");