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         ipmi_smi_t              intf;
  27         unsigned int            irq;
  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                 /* If came via the poll, and response was not yet ready */
 146                 if (rc == OPAL_EMPTY) {
 147                         spin_unlock_irqrestore(&smi->msg_lock, flags);
 148                         return 0;
 149                 }
 150
 151                 smi->cur_msg = NULL;
 152                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 153                 send_error_reply(smi, msg, IPMI_ERR_UNSPECIFIED);
 154                 return 0;
 155         }
 156
 157         if (size < sizeof(*opal_msg)) {
 158                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 159                 pr_warn("unexpected IPMI message size %lld\n", size);
 160                 return 0;
 161         }
 162
 163         if (opal_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
 164                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 165                 pr_warn("unexpected IPMI message format (version %d)\n",
 166                                 opal_msg->version);
 167                 return 0;
 168         }
 169
 170         msg->rsp[0] = opal_msg->netfn;
 171         msg->rsp[1] = opal_msg->cmd;
 172         if (size > sizeof(*opal_msg))
 173                 memcpy(&msg->rsp[2], opal_msg->data, size - sizeof(*opal_msg));
 174         msg->rsp_size = 2 + size - sizeof(*opal_msg);
 175
 176         smi->cur_msg = NULL;
 177         spin_unlock_irqrestore(&smi->msg_lock, flags);
 178         ipmi_smi_msg_received(smi->intf, msg);
 179         return 0;
 180 }
 181
 182 static void ipmi_powernv_request_events(void *send_info)
 183 {
 184 }
 185
 186 static void ipmi_powernv_set_run_to_completion(void *send_info,
 187                 bool run_to_completion)
 188 {
 189 }
 190
 191 static void ipmi_powernv_poll(void *send_info)
 192 {
 193         struct ipmi_smi_powernv *smi = send_info;
 194
 195         ipmi_powernv_recv(smi);
 196 }
 197
 198 static const struct ipmi_smi_handlers ipmi_powernv_smi_handlers = {
 199         .owner                  = THIS_MODULE,
 200         .start_processing       = ipmi_powernv_start_processing,
 201         .sender                 = ipmi_powernv_send,
 202         .request_events         = ipmi_powernv_request_events,
 203         .set_run_to_completion  = ipmi_powernv_set_run_to_completion,
 204         .poll                   = ipmi_powernv_poll,
 205 };
 206
 207 static irqreturn_t ipmi_opal_event(int irq, void *data)
 208 {
 209         struct ipmi_smi_powernv *smi = data;
 210
 211         ipmi_powernv_recv(smi);
 212         return IRQ_HANDLED;
 213 }
 214
 215 static int ipmi_powernv_probe(struct platform_device *pdev)
 216 {
 217         struct ipmi_smi_powernv *ipmi;
 218         struct device *dev;
 219         u32 prop;
 220         int rc;
 221
 222         if (!pdev || !pdev->dev.of_node)
 223                 return -ENODEV;
 224
 225         dev = &pdev->dev;
 226
 227         ipmi = devm_kzalloc(dev, sizeof(*ipmi), GFP_KERNEL);
 228         if (!ipmi)
 229                 return -ENOMEM;
 230
 231         spin_lock_init(&ipmi->msg_lock);
 232
 233         rc = of_property_read_u32(dev->of_node, "ibm,ipmi-interface-id",
 234                         &prop);
 235         if (rc) {
 236                 dev_warn(dev, "No interface ID property\n");
 237                 goto err_free;
 238         }
 239         ipmi->interface_id = prop;
 240
 241         rc = of_property_read_u32(dev->of_node, "interrupts", &prop);
 242         if (rc) {
 243                 dev_warn(dev, "No interrupts property\n");
 244                 goto err_free;
 245         }
 246
 247         ipmi->irq = irq_of_parse_and_map(dev->of_node, 0);
 248         if (!ipmi->irq) {
 249                 dev_info(dev, "Unable to map irq from device tree\n");
 250                 ipmi->irq = opal_event_request(prop);
 251         }
 252
 253         rc = request_irq(ipmi->irq, ipmi_opal_event, IRQ_TYPE_LEVEL_HIGH,
 254                          "opal-ipmi", ipmi);
 255         if (rc) {
 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         rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi, dev, 0);
 269         if (rc) {
 270                 dev_warn(dev, "IPMI SMI registration failed (%d)\n", rc);
 271                 goto err_free_msg;
 272         }
 273
 274         dev_set_drvdata(dev, ipmi);
 275         return 0;
 276
 277 err_free_msg:
 278         devm_kfree(dev, ipmi->opal_msg);
 279 err_unregister:
 280         free_irq(ipmi->irq, ipmi);
 281 err_dispose:
 282         irq_dispose_mapping(ipmi->irq);
 283 err_free:
 284         devm_kfree(dev, ipmi);
 285         return rc;
 286 }
 287
 288 static int ipmi_powernv_remove(struct platform_device *pdev)
 289 {
 290         struct ipmi_smi_powernv *smi = dev_get_drvdata(&pdev->dev);
 291
 292         ipmi_unregister_smi(smi->intf);
 293         free_irq(smi->irq, smi);
 294         irq_dispose_mapping(smi->irq);
 295
 296         return 0;
 297 }
 298
 299 static const struct of_device_id ipmi_powernv_match[] = {
 300         { .compatible = "ibm,opal-ipmi" },
 301         { },
 302 };
 303
 304
 305 static struct platform_driver powernv_ipmi_driver = {
 306         .driver = {
 307                 .name           = "ipmi-powernv",
 308                 .of_match_table = ipmi_powernv_match,
 309         },
 310         .probe  = ipmi_powernv_probe,
 311         .remove = ipmi_powernv_remove,
 312 };
 313
 314
 315 module_platform_driver(powernv_ipmi_driver);
 316
 317 MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
 318 MODULE_DESCRIPTION("powernv IPMI driver");
 319 MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
 320 MODULE_LICENSE("GPL");