linux/drivers/char/ipmi/ipmi_powernv.c
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   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
  24struct 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
  41static 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
  49static 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
  59static 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;
 109err_unlock:
 110        spin_unlock_irqrestore(&smi->msg_lock, flags);
 111err:
 112        send_error_reply(smi, msg, comp);
 113}
 114
 115static 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
 183static void ipmi_powernv_request_events(void *send_info)
 184{
 185}
 186
 187static void ipmi_powernv_set_run_to_completion(void *send_info,
 188                bool run_to_completion)
 189{
 190}
 191
 192static void ipmi_powernv_poll(void *send_info)
 193{
 194        struct ipmi_smi_powernv *smi = send_info;
 195
 196        ipmi_powernv_recv(smi);
 197}
 198
 199static 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
 208static 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
 216static 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
 279err_free_msg:
 280        devm_kfree(dev, ipmi->opal_msg);
 281err_unregister:
 282        free_irq(ipmi->irq, ipmi);
 283err_dispose:
 284        irq_dispose_mapping(ipmi->irq);
 285err_free:
 286        devm_kfree(dev, ipmi);
 287        return rc;
 288}
 289
 290static 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
 301static const struct of_device_id ipmi_powernv_match[] = {
 302        { .compatible = "ibm,opal-ipmi" },
 303        { },
 304};
 305
 306
 307static 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
 317module_platform_driver(powernv_ipmi_driver);
 318
 319MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
 320MODULE_DESCRIPTION("powernv IPMI driver");
 321MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
 322MODULE_LICENSE("GPL");
 323