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                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 147                 ipmi_free_smi_msg(msg);
 148                 return 0;
 149         }
 150
 151         if (size < sizeof(*opal_msg)) {
 152                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 153                 pr_warn("unexpected IPMI message size %lld\n", size);
 154                 return 0;
 155         }
 156
 157         if (opal_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
 158                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 159                 pr_warn("unexpected IPMI message format (version %d)\n",
 160                                 opal_msg->version);
 161                 return 0;
 162         }
 163
 164         msg->rsp[0] = opal_msg->netfn;
 165         msg->rsp[1] = opal_msg->cmd;
 166         if (size > sizeof(*opal_msg))
 167                 memcpy(&msg->rsp[2], opal_msg->data, size - sizeof(*opal_msg));
 168         msg->rsp_size = 2 + size - sizeof(*opal_msg);
 169
 170         smi->cur_msg = NULL;
 171         spin_unlock_irqrestore(&smi->msg_lock, flags);
 172         ipmi_smi_msg_received(smi->intf, msg);
 173         return 0;
 174 }
 175
 176 static void ipmi_powernv_request_events(void *send_info)
 177 {
 178 }
 179
 180 static void ipmi_powernv_set_run_to_completion(void *send_info,
 181                 bool run_to_completion)
 182 {
 183 }
 184
 185 static void ipmi_powernv_poll(void *send_info)
 186 {
 187         struct ipmi_smi_powernv *smi = send_info;
 188
 189         ipmi_powernv_recv(smi);
 190 }
 191
 192 static struct ipmi_smi_handlers ipmi_powernv_smi_handlers = {
 193         .owner                  = THIS_MODULE,
 194         .start_processing       = ipmi_powernv_start_processing,
 195         .sender                 = ipmi_powernv_send,
 196         .request_events         = ipmi_powernv_request_events,
 197         .set_run_to_completion  = ipmi_powernv_set_run_to_completion,
 198         .poll                   = ipmi_powernv_poll,
 199 };
 200
 201 static irqreturn_t ipmi_opal_event(int irq, void *data)
 202 {
 203         struct ipmi_smi_powernv *smi = data;
 204
 205         ipmi_powernv_recv(smi);
 206         return IRQ_HANDLED;
 207 }
 208
 209 static int ipmi_powernv_probe(struct platform_device *pdev)
 210 {
 211         struct ipmi_smi_powernv *ipmi;
 212         struct device *dev;
 213         u32 prop;
 214         int rc;
 215
 216         if (!pdev || !pdev->dev.of_node)
 217                 return -ENODEV;
 218
 219         dev = &pdev->dev;
 220
 221         ipmi = devm_kzalloc(dev, sizeof(*ipmi), GFP_KERNEL);
 222         if (!ipmi)
 223                 return -ENOMEM;
 224
 225         spin_lock_init(&ipmi->msg_lock);
 226
 227         rc = of_property_read_u32(dev->of_node, "ibm,ipmi-interface-id",
 228                         &prop);
 229         if (rc) {
 230                 dev_warn(dev, "No interface ID property\n");
 231                 goto err_free;
 232         }
 233         ipmi->interface_id = prop;
 234
 235         rc = of_property_read_u32(dev->of_node, "interrupts", &prop);
 236         if (rc) {
 237                 dev_warn(dev, "No interrupts property\n");
 238                 goto err_free;
 239         }
 240
 241         ipmi->irq = irq_of_parse_and_map(dev->of_node, 0);
 242         if (!ipmi->irq) {
 243                 dev_info(dev, "Unable to map irq from device tree\n");
 244                 ipmi->irq = opal_event_request(prop);
 245         }
 246
 247         if (request_irq(ipmi->irq, ipmi_opal_event, IRQ_TYPE_LEVEL_HIGH,
 248                                 "opal-ipmi", ipmi)) {
 249                 dev_warn(dev, "Unable to request irq\n");
 250                 goto err_dispose;
 251         }
 252
 253         ipmi->opal_msg = devm_kmalloc(dev,
 254                         sizeof(*ipmi->opal_msg) + IPMI_MAX_MSG_LENGTH,
 255                         GFP_KERNEL);
 256         if (!ipmi->opal_msg) {
 257                 rc = -ENOMEM;
 258                 goto err_unregister;
 259         }
 260
 261         /* todo: query actual ipmi_device_id */
 262         rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi,
 263                         &ipmi->ipmi_id, dev, 0);
 264         if (rc) {
 265                 dev_warn(dev, "IPMI SMI registration failed (%d)\n", rc);
 266                 goto err_free_msg;
 267         }
 268
 269         dev_set_drvdata(dev, ipmi);
 270         return 0;
 271
 272 err_free_msg:
 273         devm_kfree(dev, ipmi->opal_msg);
 274 err_unregister:
 275         free_irq(ipmi->irq, ipmi);
 276 err_dispose:
 277         irq_dispose_mapping(ipmi->irq);
 278 err_free:
 279         devm_kfree(dev, ipmi);
 280         return rc;
 281 }
 282
 283 static int ipmi_powernv_remove(struct platform_device *pdev)
 284 {
 285         struct ipmi_smi_powernv *smi = dev_get_drvdata(&pdev->dev);
 286
 287         ipmi_unregister_smi(smi->intf);
 288         free_irq(smi->irq, smi);
 289         irq_dispose_mapping(smi->irq);
 290
 291         return 0;
 292 }
 293
 294 static const struct of_device_id ipmi_powernv_match[] = {
 295         { .compatible = "ibm,opal-ipmi" },
 296         { },
 297 };
 298
 299
 300 static struct platform_driver powernv_ipmi_driver = {
 301         .driver = {
 302                 .name           = "ipmi-powernv",
 303                 .owner          = THIS_MODULE,
 304                 .of_match_table = ipmi_powernv_match,
 305         },
 306         .probe  = ipmi_powernv_probe,
 307         .remove = ipmi_powernv_remove,
 308 };
 309
 310
 311 module_platform_driver(powernv_ipmi_driver);
 312
 313 MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
 314 MODULE_DESCRIPTION("powernv IPMI driver");
 315 MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
 316 MODULE_LICENSE("GPL");