linux/drivers/char/ipmi/ipmi_powernv.c
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   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
  20struct ipmi_smi_powernv {
  21        u64                     interface_id;
  22        ipmi_smi_t              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
  36static int ipmi_powernv_start_processing(void *send_info, ipmi_smi_t intf)
  37{
  38        struct ipmi_smi_powernv *smi = send_info;
  39
  40        smi->intf = intf;
  41        return 0;
  42}
  43
  44static 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
  54static 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;
 104err_unlock:
 105        spin_unlock_irqrestore(&smi->msg_lock, flags);
 106err:
 107        send_error_reply(smi, msg, comp);
 108}
 109
 110static 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
 178static void ipmi_powernv_request_events(void *send_info)
 179{
 180}
 181
 182static void ipmi_powernv_set_run_to_completion(void *send_info,
 183                bool run_to_completion)
 184{
 185}
 186
 187static void ipmi_powernv_poll(void *send_info)
 188{
 189        struct ipmi_smi_powernv *smi = send_info;
 190
 191        ipmi_powernv_recv(smi);
 192}
 193
 194static 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
 203static 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
 211static 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
 273err_free_msg:
 274        devm_kfree(dev, ipmi->opal_msg);
 275err_unregister:
 276        free_irq(ipmi->irq, ipmi);
 277err_dispose:
 278        irq_dispose_mapping(ipmi->irq);
 279err_free:
 280        devm_kfree(dev, ipmi);
 281        return rc;
 282}
 283
 284static 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
 295static const struct of_device_id ipmi_powernv_match[] = {
 296        { .compatible = "ibm,opal-ipmi" },
 297        { },
 298};
 299
 300
 301static 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
 311module_platform_driver(powernv_ipmi_driver);
 312
 313MODULE_DEVICE_TABLE(of, ipmi_powernv_match);
 314MODULE_DESCRIPTION("powernv IPMI driver");
 315MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
 316MODULE_LICENSE("GPL");
 317