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 #include <linux/of_irq.h>
  19 #include <linux/interrupt.h>
  20
  21 #include <asm/opal.h>
  22
  23
  24 struct ipmi_smi_powernv {
  25         u64                     interface_id;
  26         struct ipmi_device_id   ipmi_id;
  27         ipmi_smi_t              intf;
  28         unsigned int            irq;
  29
  30         /**
  31          * We assume that there can only be one outstanding request, so
  32          * keep the pending message in cur_msg. We protect this from concurrent
  33          * updates through send & recv calls, (and consequently opal_msg, which
  34          * is in-use when cur_msg is set) with msg_lock
  35          */
  36         spinlock_t              msg_lock;
  37         struct ipmi_smi_msg     *cur_msg;
  38         struct opal_ipmi_msg    *opal_msg;
  39 };
  40
  41 static int ipmi_powernv_start_processing(void *send_info, ipmi_smi_t intf)
  42 {
  43         struct ipmi_smi_powernv *smi = send_info;
  44
  45         smi->intf = intf;
  46         return 0;
  47 }
  48
  49 static void send_error_reply(struct ipmi_smi_powernv *smi,
  50                 struct ipmi_smi_msg *msg, u8 completion_code)
  51 {
  52         msg->rsp[0] = msg->data[0] | 0x4;
  53         msg->rsp[1] = msg->data[1];
  54         msg->rsp[2] = completion_code;
  55         msg->rsp_size = 3;
  56         ipmi_smi_msg_received(smi->intf, msg);
  57 }
  58
  59 static void ipmi_powernv_send(void *send_info, struct ipmi_smi_msg *msg)
  60 {
  61         struct ipmi_smi_powernv *smi = send_info;
  62         struct opal_ipmi_msg *opal_msg;
  63         unsigned long flags;
  64         int comp, rc;
  65         size_t size;
  66
  67         /* ensure data_len will fit in the opal_ipmi_msg buffer... */
  68         if (msg->data_size > IPMI_MAX_MSG_LENGTH) {
  69                 comp = IPMI_REQ_LEN_EXCEEDED_ERR;
  70                 goto err;
  71         }
  72
  73         /* ... and that we at least have netfn and cmd bytes */
  74         if (msg->data_size < 2) {
  75                 comp = IPMI_REQ_LEN_INVALID_ERR;
  76                 goto err;
  77         }
  78
  79         spin_lock_irqsave(&smi->msg_lock, flags);
  80
  81         if (smi->cur_msg) {
  82                 comp = IPMI_NODE_BUSY_ERR;
  83                 goto err_unlock;
  84         }
  85
  86         /* format our data for the OPAL API */
  87         opal_msg = smi->opal_msg;
  88         opal_msg->version = OPAL_IPMI_MSG_FORMAT_VERSION_1;
  89         opal_msg->netfn = msg->data[0];
  90         opal_msg->cmd = msg->data[1];
  91         if (msg->data_size > 2)
  92                 memcpy(opal_msg->data, msg->data + 2, msg->data_size - 2);
  93
  94         /* data_size already includes the netfn and cmd bytes */
  95         size = sizeof(*opal_msg) + msg->data_size - 2;
  96
  97         pr_devel("%s: opal_ipmi_send(0x%llx, %p, %ld)\n", __func__,
  98                         smi->interface_id, opal_msg, size);
  99         rc = opal_ipmi_send(smi->interface_id, opal_msg, size);
 100         pr_devel("%s:  -> %d\n", __func__, rc);
 101
 102         if (!rc) {
 103                 smi->cur_msg = msg;
 104                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 105                 return;
 106         }
 107
 108         comp = IPMI_ERR_UNSPECIFIED;
 109 err_unlock:
 110         spin_unlock_irqrestore(&smi->msg_lock, flags);
 111 err:
 112         send_error_reply(smi, msg, comp);
 113 }
 114
 115 static int ipmi_powernv_recv(struct ipmi_smi_powernv *smi)
 116 {
 117         struct opal_ipmi_msg *opal_msg;
 118         struct ipmi_smi_msg *msg;
 119         unsigned long flags;
 120         uint64_t size;
 121         int rc;
 122
 123         pr_devel("%s: opal_ipmi_recv(%llx, msg, sz)\n", __func__,
 124                         smi->interface_id);
 125
 126         spin_lock_irqsave(&smi->msg_lock, flags);
 127
 128         if (!smi->cur_msg) {
 129                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 130                 pr_warn("no current message?\n");
 131                 return 0;
 132         }
 133
 134         msg = smi->cur_msg;
 135         opal_msg = smi->opal_msg;
 136
 137         size = cpu_to_be64(sizeof(*opal_msg) + IPMI_MAX_MSG_LENGTH);
 138
 139         rc = opal_ipmi_recv(smi->interface_id,
 140                         opal_msg,
 141                         &size);
 142         size = be64_to_cpu(size);
 143         pr_devel("%s:   -> %d (size %lld)\n", __func__,
 144                         rc, rc == 0 ? size : 0);
 145         if (rc) {
 146                 /* If came via the poll, and response was not yet ready */
 147                 if (rc == OPAL_EMPTY) {
 148                         spin_unlock_irqrestore(&smi->msg_lock, flags);
 149                         return 0;
 150                 }
 151
 152                 smi->cur_msg = NULL;
 153                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 154                 send_error_reply(smi, msg, IPMI_ERR_UNSPECIFIED);
 155                 return 0;
 156         }
 157
 158         if (size < sizeof(*opal_msg)) {
 159                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 160                 pr_warn("unexpected IPMI message size %lld\n", size);
 161                 return 0;
 162         }
 163
 164         if (opal_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
 165                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 166                 pr_warn("unexpected IPMI message format (version %d)\n",
 167                                 opal_msg->version);
 168                 return 0;
 169         }
 170
 171         msg->rsp[0] = opal_msg->netfn;
 172         msg->rsp[1] = opal_msg->cmd;
 173         if (size > sizeof(*opal_msg))
 174                 memcpy(&msg->rsp[2], opal_msg->data, size - sizeof(*opal_msg));
 175         msg->rsp_size = 2 + size - sizeof(*opal_msg);
 176
 177         smi->cur_msg = NULL;
 178         spin_unlock_irqrestore(&smi->msg_lock, flags);
 179         ipmi_smi_msg_received(smi->intf, msg);
 180         return 0;
 181 }
 182
 183 static void ipmi_powernv_request_events(void *send_info)
 184 {
 185 }
 186
 187 static void ipmi_powernv_set_run_to_completion(void *send_info,
 188                 bool run_to_completion)
 189 {
 190 }
 191
 192 static void ipmi_powernv_poll(void *send_info)
 193 {
 194         struct ipmi_smi_powernv *smi = send_info;
 195
 196         ipmi_powernv_recv(smi);
 197 }
 198
 199 static struct ipmi_smi_handlers ipmi_powernv_smi_handlers = {
 200         .owner                  = THIS_MODULE,
 201         .start_processing       = ipmi_powernv_start_processing,
 202         .sender                 = ipmi_powernv_send,
 203         .request_events         = ipmi_powernv_request_events,
 204         .set_run_to_completion  = ipmi_powernv_set_run_to_completion,
 205         .poll                   = ipmi_powernv_poll,
 206 };
 207
 208 static irqreturn_t ipmi_opal_event(int irq, void *data)
 209 {
 210         struct ipmi_smi_powernv *smi = data;
 211
 212         ipmi_powernv_recv(smi);
 213         return IRQ_HANDLED;
 214 }
 215
 216 static int ipmi_powernv_probe(struct platform_device *pdev)
 217 {
 218         struct ipmi_smi_powernv *ipmi;
 219         struct device *dev;
 220         u32 prop;
 221         int rc;
 222
 223         if (!pdev || !pdev->dev.of_node)
 224                 return -ENODEV;
 225
 226         dev = &pdev->dev;
 227
 228         ipmi = devm_kzalloc(dev, sizeof(*ipmi), GFP_KERNEL);
 229         if (!ipmi)
 230                 return -ENOMEM;
 231
 232         spin_lock_init(&ipmi->msg_lock);
 233
 234         rc = of_property_read_u32(dev->of_node, "ibm,ipmi-interface-id",
 235                         &prop);
 236         if (rc) {
 237                 dev_warn(dev, "No interface ID property\n");
 238                 goto err_free;
 239         }
 240         ipmi->interface_id = prop;
 241
 242         rc = of_property_read_u32(dev->of_node, "interrupts", &prop);
 243         if (rc) {
 244                 dev_warn(dev, "No interrupts property\n");
 245                 goto err_free;
 246         }
 247
 248         ipmi->irq = irq_of_parse_and_map(dev->of_node, 0);
 249         if (!ipmi->irq) {
 250                 dev_info(dev, "Unable to map irq from device tree\n");
 251                 ipmi->irq = opal_event_request(prop);
 252         }
 253
 254         if (request_irq(ipmi->irq, ipmi_opal_event, IRQ_TYPE_LEVEL_HIGH,
 255                                 "opal-ipmi", ipmi)) {
 256                 dev_warn(dev, "Unable to request irq\n");
 257                 goto err_dispose;
 258         }
 259
 260         ipmi->opal_msg = devm_kmalloc(dev,
 261                         sizeof(*ipmi->opal_msg) + IPMI_MAX_MSG_LENGTH,
 262                         GFP_KERNEL);
 263         if (!ipmi->opal_msg) {
 264                 rc = -ENOMEM;
 265                 goto err_unregister;
 266         }
 267
 268         /* todo: query actual ipmi_device_id */
 269         rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi,
 270                         &ipmi->ipmi_id, dev, 0);
 271         if (rc) {
 272                 dev_warn(dev, "IPMI SMI registration failed (%d)\n", rc);
 273                 goto err_free_msg;
 274         }
 275
 276         dev_set_drvdata(dev, ipmi);
 277         return 0;
 278
 279 err_free_msg:
 280         devm_kfree(dev, ipmi->opal_msg);
 281 err_unregister:
 282         free_irq(ipmi->irq, ipmi);
 283 err_dispose:
 284         irq_dispose_mapping(ipmi->irq);
 285 err_free:
 286         devm_kfree(dev, ipmi);
 287         return rc;
 288 }
 289
 290 static int ipmi_powernv_remove(struct platform_device *pdev)
 291 {
 292         struct ipmi_smi_powernv *smi = dev_get_drvdata(&pdev->dev);
 293
 294         ipmi_unregister_smi(smi->intf);
 295         free_irq(smi->irq, smi);
 296         irq_dispose_mapping(smi->irq);
 297
 298         return 0;
 299 }
 300
 301 static const struct of_device_id ipmi_powernv_match[] = {
 302         { .compatible = "ibm,opal-ipmi" },
 303         { },
 304 };
 305
 306
 307 static struct platform_driver powernv_ipmi_driver = {
 308         .driver = {
 309                 .name           = "ipmi-powernv",
 310                 .of_match_table = ipmi_powernv_match,
 311         },
 312         .probe  = ipmi_powernv_probe,
 313         .remove = ipmi_powernv_remove,
 314 };
 315
 316
 317 module_platform_driver(powernv_ipmi_driver);
 318
 319 MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
 320 MODULE_DESCRIPTION("powernv IPMI driver");
 321 MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
 322 MODULE_LICENSE("GPL");