kernel/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                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 129                 pr_warn("no current message?\n");
 130                 return 0;
 131         }
 132
 133         msg = smi->cur_msg;
 134         opal_msg = smi->opal_msg;
 135
 136         size = cpu_to_be64(sizeof(*opal_msg) + IPMI_MAX_MSG_LENGTH);
 137
 138         rc = opal_ipmi_recv(smi->interface_id,
 139                         opal_msg,
 140                         &size);
 141         size = be64_to_cpu(size);
 142         pr_devel("%s:   -> %d (size %lld)\n", __func__,
 143                         rc, rc == 0 ? size : 0);
 144         if (rc) {
 145                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 146                 ipmi_free_smi_msg(msg);
 147                 return 0;
 148         }
 149
 150         if (size < sizeof(*opal_msg)) {
 151                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 152                 pr_warn("unexpected IPMI message size %lld\n", size);
 153                 return 0;
 154         }
 155
 156         if (opal_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
 157                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 158                 pr_warn("unexpected IPMI message format (version %d)\n",
 159                                 opal_msg->version);
 160                 return 0;
 161         }
 162
 163         msg->rsp[0] = opal_msg->netfn;
 164         msg->rsp[1] = opal_msg->cmd;
 165         if (size > sizeof(*opal_msg))
 166                 memcpy(&msg->rsp[2], opal_msg->data, size - sizeof(*opal_msg));
 167         msg->rsp_size = 2 + size - sizeof(*opal_msg);
 168
 169         smi->cur_msg = NULL;
 170         spin_unlock_irqrestore(&smi->msg_lock, flags);
 171         ipmi_smi_msg_received(smi->intf, msg);
 172         return 0;
 173 }
 174
 175 static void ipmi_powernv_request_events(void *send_info)
 176 {
 177 }
 178
 179 static void ipmi_powernv_set_run_to_completion(void *send_info,
 180                 bool run_to_completion)
 181 {
 182 }
 183
 184 static void ipmi_powernv_poll(void *send_info)
 185 {
 186         struct ipmi_smi_powernv *smi = send_info;
 187
 188         ipmi_powernv_recv(smi);
 189 }
 190
 191 static struct ipmi_smi_handlers ipmi_powernv_smi_handlers = {
 192         .owner                  = THIS_MODULE,
 193         .start_processing       = ipmi_powernv_start_processing,
 194         .sender                 = ipmi_powernv_send,
 195         .request_events         = ipmi_powernv_request_events,
 196         .set_run_to_completion  = ipmi_powernv_set_run_to_completion,
 197         .poll                   = ipmi_powernv_poll,
 198 };
 199
 200 static int ipmi_opal_event(struct notifier_block *nb,
 201                           unsigned long events, void *change)
 202 {
 203         struct ipmi_smi_powernv *smi = container_of(nb,
 204                                         struct ipmi_smi_powernv, event_nb);
 205
 206         if (events & smi->event)
 207                 ipmi_powernv_recv(smi);
 208         return 0;
 209 }
 210
 211 static int ipmi_powernv_probe(struct platform_device *pdev)
 212 {
 213         struct ipmi_smi_powernv *ipmi;
 214         struct device *dev;
 215         u32 prop;
 216         int rc;
 217
 218         if (!pdev || !pdev->dev.of_node)
 219                 return -ENODEV;
 220
 221         dev = &pdev->dev;
 222
 223         ipmi = devm_kzalloc(dev, sizeof(*ipmi), GFP_KERNEL);
 224         if (!ipmi)
 225                 return -ENOMEM;
 226
 227         spin_lock_init(&ipmi->msg_lock);
 228
 229         rc = of_property_read_u32(dev->of_node, "ibm,ipmi-interface-id",
 230                         &prop);
 231         if (rc) {
 232                 dev_warn(dev, "No interface ID property\n");
 233                 goto err_free;
 234         }
 235         ipmi->interface_id = prop;
 236
 237         rc = of_property_read_u32(dev->of_node, "interrupts", &prop);
 238         if (rc) {
 239                 dev_warn(dev, "No interrupts property\n");
 240                 goto err_free;
 241         }
 242
 243         ipmi->event = 1ull << prop;
 244         ipmi->event_nb.notifier_call = ipmi_opal_event;
 245
 246         rc = opal_notifier_register(&ipmi->event_nb);
 247         if (rc) {
 248                 dev_warn(dev, "OPAL notifier registration failed (%d)\n", rc);
 249                 goto err_free;
 250         }
 251
 252         ipmi->opal_msg = devm_kmalloc(dev,
 253                         sizeof(*ipmi->opal_msg) + IPMI_MAX_MSG_LENGTH,
 254                         GFP_KERNEL);
 255         if (!ipmi->opal_msg) {
 256                 rc = -ENOMEM;
 257                 goto err_unregister;
 258         }
 259
 260         /* todo: query actual ipmi_device_id */
 261         rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi,
 262                         &ipmi->ipmi_id, dev, 0);
 263         if (rc) {
 264                 dev_warn(dev, "IPMI SMI registration failed (%d)\n", rc);
 265                 goto err_free_msg;
 266         }
 267
 268         dev_set_drvdata(dev, ipmi);
 269         return 0;
 270
 271 err_free_msg:
 272         devm_kfree(dev, ipmi->opal_msg);
 273 err_unregister:
 274         opal_notifier_unregister(&ipmi->event_nb);
 275 err_free:
 276         devm_kfree(dev, ipmi);
 277         return rc;
 278 }
 279
 280 static int ipmi_powernv_remove(struct platform_device *pdev)
 281 {
 282         struct ipmi_smi_powernv *smi = dev_get_drvdata(&pdev->dev);
 283
 284         ipmi_unregister_smi(smi->intf);
 285         opal_notifier_unregister(&smi->event_nb);
 286         return 0;
 287 }
 288
 289 static const struct of_device_id ipmi_powernv_match[] = {
 290         { .compatible = "ibm,opal-ipmi" },
 291         { },
 292 };
 293
 294
 295 static struct platform_driver powernv_ipmi_driver = {
 296         .driver = {
 297                 .name           = "ipmi-powernv",
 298                 .owner          = THIS_MODULE,
 299                 .of_match_table = ipmi_powernv_match,
 300         },
 301         .probe  = ipmi_powernv_probe,
 302         .remove = ipmi_powernv_remove,
 303 };
 304
 305
 306 module_platform_driver(powernv_ipmi_driver);
 307
 308 MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
 309 MODULE_DESCRIPTION("powernv IPMI driver");
 310 MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
 311 MODULE_LICENSE("GPL");