drivers/char/ipmi/ipmi_powernv.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * PowerNV OPAL IPMI driver
   4  *
   5  * Copyright 2014 IBM Corp.
   6  */
   7
   8 #define pr_fmt(fmt)        "ipmi-powernv: " fmt
   9
  10 #include <linux/ipmi_smi.h>
  11 #include <linux/list.h>
  12 #include <linux/module.h>
  13 #include <linux/of.h>
  14 #include <linux/of_irq.h>
  15 #include <linux/interrupt.h>
  16
  17 #include <asm/opal.h>
  18
  19
  20 struct ipmi_smi_powernv {
  21         u64                     interface_id;
  22         struct ipmi_smi         *intf;
  23         unsigned int            irq;
  24
  25         /**
  26          * We assume that there can only be one outstanding request, so
  27          * keep the pending message in cur_msg. We protect this from concurrent
  28          * updates through send & recv calls, (and consequently opal_msg, which
  29          * is in-use when cur_msg is set) with msg_lock
  30          */
  31         spinlock_t              msg_lock;
  32         struct ipmi_smi_msg     *cur_msg;
  33         struct opal_ipmi_msg    *opal_msg;
  34 };
  35
  36 static int ipmi_powernv_start_processing(void *send_info, struct ipmi_smi *intf)
  37 {
  38         struct ipmi_smi_powernv *smi = send_info;
  39
  40         smi->intf = intf;
  41         return 0;
  42 }
  43
  44 static void send_error_reply(struct ipmi_smi_powernv *smi,
  45                 struct ipmi_smi_msg *msg, u8 completion_code)
  46 {
  47         msg->rsp[0] = msg->data[0] | 0x4;
  48         msg->rsp[1] = msg->data[1];
  49         msg->rsp[2] = completion_code;
  50         msg->rsp_size = 3;
  51         ipmi_smi_msg_received(smi->intf, msg);
  52 }
  53
  54 static void ipmi_powernv_send(void *send_info, struct ipmi_smi_msg *msg)
  55 {
  56         struct ipmi_smi_powernv *smi = send_info;
  57         struct opal_ipmi_msg *opal_msg;
  58         unsigned long flags;
  59         int comp, rc;
  60         size_t size;
  61
  62         /* ensure data_len will fit in the opal_ipmi_msg buffer... */
  63         if (msg->data_size > IPMI_MAX_MSG_LENGTH) {
  64                 comp = IPMI_REQ_LEN_EXCEEDED_ERR;
  65                 goto err;
  66         }
  67
  68         /* ... and that we at least have netfn and cmd bytes */
  69         if (msg->data_size < 2) {
  70                 comp = IPMI_REQ_LEN_INVALID_ERR;
  71                 goto err;
  72         }
  73
  74         spin_lock_irqsave(&smi->msg_lock, flags);
  75
  76         if (smi->cur_msg) {
  77                 comp = IPMI_NODE_BUSY_ERR;
  78                 goto err_unlock;
  79         }
  80
  81         /* format our data for the OPAL API */
  82         opal_msg = smi->opal_msg;
  83         opal_msg->version = OPAL_IPMI_MSG_FORMAT_VERSION_1;
  84         opal_msg->netfn = msg->data[0];
  85         opal_msg->cmd = msg->data[1];
  86         if (msg->data_size > 2)
  87                 memcpy(opal_msg->data, msg->data + 2, msg->data_size - 2);
  88
  89         /* data_size already includes the netfn and cmd bytes */
  90         size = sizeof(*opal_msg) + msg->data_size - 2;
  91
  92         pr_devel("%s: opal_ipmi_send(0x%llx, %p, %ld)\n", __func__,
  93                         smi->interface_id, opal_msg, size);
  94         rc = opal_ipmi_send(smi->interface_id, opal_msg, size);
  95         pr_devel("%s:  -> %d\n", __func__, rc);
  96
  97         if (!rc) {
  98                 smi->cur_msg = msg;
  99                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 100                 return;
 101         }
 102
 103         comp = IPMI_ERR_UNSPECIFIED;
 104 err_unlock:
 105         spin_unlock_irqrestore(&smi->msg_lock, flags);
 106 err:
 107         send_error_reply(smi, msg, comp);
 108 }
 109
 110 static int ipmi_powernv_recv(struct ipmi_smi_powernv *smi)
 111 {
 112         struct opal_ipmi_msg *opal_msg;
 113         struct ipmi_smi_msg *msg;
 114         unsigned long flags;
 115         uint64_t size;
 116         int rc;
 117
 118         pr_devel("%s: opal_ipmi_recv(%llx, msg, sz)\n", __func__,
 119                         smi->interface_id);
 120
 121         spin_lock_irqsave(&smi->msg_lock, flags);
 122
 123         if (!smi->cur_msg) {
 124                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 125                 pr_warn("no current message?\n");
 126                 return 0;
 127         }
 128
 129         msg = smi->cur_msg;
 130         opal_msg = smi->opal_msg;
 131
 132         size = cpu_to_be64(sizeof(*opal_msg) + IPMI_MAX_MSG_LENGTH);
 133
 134         rc = opal_ipmi_recv(smi->interface_id,
 135                         opal_msg,
 136                         &size);
 137         size = be64_to_cpu(size);
 138         pr_devel("%s:   -> %d (size %lld)\n", __func__,
 139                         rc, rc == 0 ? size : 0);
 140         if (rc) {
 141                 /* If came via the poll, and response was not yet ready */
 142                 if (rc == OPAL_EMPTY) {
 143                         spin_unlock_irqrestore(&smi->msg_lock, flags);
 144                         return 0;
 145                 }
 146
 147                 smi->cur_msg = NULL;
 148                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 149                 send_error_reply(smi, msg, IPMI_ERR_UNSPECIFIED);
 150                 return 0;
 151         }
 152
 153         if (size < sizeof(*opal_msg)) {
 154                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 155                 pr_warn("unexpected IPMI message size %lld\n", size);
 156                 return 0;
 157         }
 158
 159         if (opal_msg->version != OPAL_IPMI_MSG_FORMAT_VERSION_1) {
 160                 spin_unlock_irqrestore(&smi->msg_lock, flags);
 161                 pr_warn("unexpected IPMI message format (version %d)\n",
 162                                 opal_msg->version);
 163                 return 0;
 164         }
 165
 166         msg->rsp[0] = opal_msg->netfn;
 167         msg->rsp[1] = opal_msg->cmd;
 168         if (size > sizeof(*opal_msg))
 169                 memcpy(&msg->rsp[2], opal_msg->data, size - sizeof(*opal_msg));
 170         msg->rsp_size = 2 + size - sizeof(*opal_msg);
 171
 172         smi->cur_msg = NULL;
 173         spin_unlock_irqrestore(&smi->msg_lock, flags);
 174         ipmi_smi_msg_received(smi->intf, msg);
 175         return 0;
 176 }
 177
 178 static void ipmi_powernv_request_events(void *send_info)
 179 {
 180 }
 181
 182 static void ipmi_powernv_set_run_to_completion(void *send_info,
 183                 bool run_to_completion)
 184 {
 185 }
 186
 187 static void ipmi_powernv_poll(void *send_info)
 188 {
 189         struct ipmi_smi_powernv *smi = send_info;
 190
 191         ipmi_powernv_recv(smi);
 192 }
 193
 194 static const struct ipmi_smi_handlers ipmi_powernv_smi_handlers = {
 195         .owner                  = THIS_MODULE,
 196         .start_processing       = ipmi_powernv_start_processing,
 197         .sender                 = ipmi_powernv_send,
 198         .request_events         = ipmi_powernv_request_events,
 199         .set_run_to_completion  = ipmi_powernv_set_run_to_completion,
 200         .poll                   = ipmi_powernv_poll,
 201 };
 202
 203 static irqreturn_t ipmi_opal_event(int irq, void *data)
 204 {
 205         struct ipmi_smi_powernv *smi = data;
 206
 207         ipmi_powernv_recv(smi);
 208         return IRQ_HANDLED;
 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->irq = irq_of_parse_and_map(dev->of_node, 0);
 244         if (!ipmi->irq) {
 245                 dev_info(dev, "Unable to map irq from device tree\n");
 246                 ipmi->irq = opal_event_request(prop);
 247         }
 248
 249         rc = request_irq(ipmi->irq, ipmi_opal_event, IRQ_TYPE_LEVEL_HIGH,
 250                          "opal-ipmi", ipmi);
 251         if (rc) {
 252                 dev_warn(dev, "Unable to request irq\n");
 253                 goto err_dispose;
 254         }
 255
 256         ipmi->opal_msg = devm_kmalloc(dev,
 257                         sizeof(*ipmi->opal_msg) + IPMI_MAX_MSG_LENGTH,
 258                         GFP_KERNEL);
 259         if (!ipmi->opal_msg) {
 260                 rc = -ENOMEM;
 261                 goto err_unregister;
 262         }
 263
 264         rc = ipmi_register_smi(&ipmi_powernv_smi_handlers, ipmi, dev, 0);
 265         if (rc) {
 266                 dev_warn(dev, "IPMI SMI registration failed (%d)\n", rc);
 267                 goto err_free_msg;
 268         }
 269
 270         dev_set_drvdata(dev, ipmi);
 271         return 0;
 272
 273 err_free_msg:
 274         devm_kfree(dev, ipmi->opal_msg);
 275 err_unregister:
 276         free_irq(ipmi->irq, ipmi);
 277 err_dispose:
 278         irq_dispose_mapping(ipmi->irq);
 279 err_free:
 280         devm_kfree(dev, ipmi);
 281         return rc;
 282 }
 283
 284 static int ipmi_powernv_remove(struct platform_device *pdev)
 285 {
 286         struct ipmi_smi_powernv *smi = dev_get_drvdata(&pdev->dev);
 287
 288         ipmi_unregister_smi(smi->intf);
 289         free_irq(smi->irq, smi);
 290         irq_dispose_mapping(smi->irq);
 291
 292         return 0;
 293 }
 294
 295 static const struct of_device_id ipmi_powernv_match[] = {
 296         { .compatible = "ibm,opal-ipmi" },
 297         { },
 298 };
 299
 300
 301 static struct platform_driver powernv_ipmi_driver = {
 302         .driver = {
 303                 .name           = "ipmi-powernv",
 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");