// SPDX-License-Identifier: GPL-2.0+
/*
 * ipmi_poweroff.c
 *
 * MontaVista IPMI Poweroff extension to sys_reboot
 *
 * Author: MontaVista Software, Inc.
 *         Steven Dake <sdake@mvista.com>
 *         Corey Minyard <cminyard@mvista.com>
 *         source@mvista.com
 *
 * Copyright 2002,2004 MontaVista Software Inc.
 */

#define pr_fmt(fmt) "IPMI poweroff: " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/proc_fs.h>
#include <linux/string.h>
#include <linux/completion.h>
#include <linux/pm.h>
#include <linux/kdev_t.h>
#include <linux/ipmi.h>
#include <linux/ipmi_smi.h>

static void ipmi_po_smi_gone(int if_num);
static void ipmi_po_new_smi(int if_num, struct device *device);

/* Definitions for controlling power off (if the system supports it).  It
 * conveniently matches the IPMI chassis control values. */
#define IPMI_CHASSIS_POWER_DOWN         0       /* power down, the default. */
#define IPMI_CHASSIS_POWER_CYCLE        0x02    /* power cycle */

/* the IPMI data command */
static int poweroff_powercycle;

/* Which interface to use, -1 means the first we see. */
static int ifnum_to_use = -1;

/* Our local state. */
static int ready;
static struct ipmi_user *ipmi_user;
static int ipmi_ifnum;
static void (*specific_poweroff_func)(struct ipmi_user *user);

/* Holds the old poweroff function so we can restore it on removal. */
static void (*old_poweroff_func)(void);

static int set_param_ifnum(const char *val, const struct kernel_param *kp)
{
        int rv = param_set_int(val, kp);
        if (rv)
                return rv;
        if ((ifnum_to_use < 0) || (ifnum_to_use == ipmi_ifnum))
                return 0;

        ipmi_po_smi_gone(ipmi_ifnum);
        ipmi_po_new_smi(ifnum_to_use, NULL);
        return 0;
}

module_param_call(ifnum_to_use, set_param_ifnum, param_get_int,
                  &ifnum_to_use, 0644);
MODULE_PARM_DESC(ifnum_to_use, "The interface number to use for the watchdog "
                 "timer.  Setting to -1 defaults to the first registered "
                 "interface");

/* parameter definition to allow user to flag power cycle */
module_param(poweroff_powercycle, int, 0644);
MODULE_PARM_DESC(poweroff_powercycle,
                 " Set to non-zero to enable power cycle instead of power"
                 " down. Power cycle is contingent on hardware support,"
                 " otherwise it defaults back to power down.");

/* Stuff from the get device id command. */
static unsigned int mfg_id;
static unsigned int prod_id;
static unsigned char capabilities;
static unsigned char ipmi_version;

/*
 * We use our own messages for this operation, we don't let the system
 * allocate them, since we may be in a panic situation.  The whole
 * thing is single-threaded, anyway, so multiple messages are not
 * required.
 */
static atomic_t dummy_count = ATOMIC_INIT(0);
static void dummy_smi_free(struct ipmi_smi_msg *msg)
{
        atomic_dec(&dummy_count);
}
static void dummy_recv_free(struct ipmi_recv_msg *msg)
{
        atomic_dec(&dummy_count);
}
static struct ipmi_smi_msg halt_smi_msg = INIT_IPMI_SMI_MSG(dummy_smi_free);
static struct ipmi_recv_msg halt_recv_msg = INIT_IPMI_RECV_MSG(dummy_recv_free);


/*
 * Code to send a message and wait for the response.
 */

static void receive_handler(struct ipmi_recv_msg *recv_msg, void *handler_data)
{
        struct completion *comp = recv_msg->user_msg_data;

        if (comp)
                complete(comp);
}

static const struct ipmi_user_hndl ipmi_poweroff_handler = {
        .ipmi_recv_hndl = receive_handler
};


static int ipmi_request_wait_for_response(struct ipmi_user       *user,
                                          struct ipmi_addr       *addr,
                                          struct kernel_ipmi_msg *send_msg)
{
        int               rv;
        struct completion comp;

        init_completion(&comp);

        rv = ipmi_request_supply_msgs(user, addr, 0, send_msg, &comp,
                                      &halt_smi_msg, &halt_recv_msg, 0);
        if (rv)
                return rv;

        wait_for_completion(&comp);

        return halt_recv_msg.msg.data[0];
}

/* Wait for message to complete, spinning. */
static int ipmi_request_in_rc_mode(struct ipmi_user       *user,
                                   struct ipmi_addr       *addr,
                                   struct kernel_ipmi_msg *send_msg)
{
        int rv;

        atomic_set(&dummy_count, 2);
        rv = ipmi_request_supply_msgs(user, addr, 0, send_msg, NULL,
                                      &halt_smi_msg, &halt_recv_msg, 0);
        if (rv) {
                atomic_set(&dummy_count, 0);
                return rv;
        }

        /*
         * Spin until our message is done.
         */
        while (atomic_read(&dummy_count) > 0) {
                ipmi_poll_interface(user);
                cpu_relax();
        }

        return halt_recv_msg.msg.data[0];
}

/*
 * ATCA Support
 */

#define IPMI_NETFN_ATCA                 0x2c
#define IPMI_ATCA_SET_POWER_CMD         0x11
#define IPMI_ATCA_GET_ADDR_INFO_CMD     0x01
#define IPMI_PICMG_ID                   0

#define IPMI_NETFN_OEM                          0x2e
#define IPMI_ATCA_PPS_GRACEFUL_RESTART          0x11
#define IPMI_ATCA_PPS_IANA                      "\x00\x40\x0A"
#define IPMI_MOTOROLA_MANUFACTURER_ID           0x0000A1
#define IPMI_MOTOROLA_PPS_IPMC_PRODUCT_ID       0x0051

static void (*atca_oem_poweroff_hook)(struct ipmi_user *user);

static void pps_poweroff_atca(struct ipmi_user *user)
{
        struct ipmi_system_interface_addr smi_addr;
        struct kernel_ipmi_msg            send_msg;
        int                               rv;
        /*
         * Configure IPMI address for local access
         */
        smi_addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
        smi_addr.channel = IPMI_BMC_CHANNEL;
        smi_addr.lun = 0;

        pr_info("PPS powerdown hook used\n");

        send_msg.netfn = IPMI_NETFN_OEM;
        send_msg.cmd = IPMI_ATCA_PPS_GRACEFUL_RESTART;
        send_msg.data = IPMI_ATCA_PPS_IANA;
        send_msg.data_len = 3;
        rv = ipmi_request_in_rc_mode(user,
                                     (struct ipmi_addr *) &smi_addr,
                                     &send_msg);
        if (rv && rv != IPMI_UNKNOWN_ERR_COMPLETION_CODE)
                pr_err("Unable to send ATCA, IPMI error 0x%x\n", rv);

        return;
}

static int ipmi_atca_detect(struct ipmi_user *user)
{
        struct ipmi_system_interface_addr smi_addr;
        struct kernel_ipmi_msg            send_msg;
        int                               rv;
        unsigned char                     data[1];

        /*
         * Configure IPMI address for local access
         */
        smi_addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
        smi_addr.channel = IPMI_BMC_CHANNEL;
        smi_addr.lun = 0;

        /*
         * Use get address info to check and see if we are ATCA
         */
        send_msg.netfn = IPMI_NETFN_ATCA;
        send_msg.cmd = IPMI_ATCA_GET_ADDR_INFO_CMD;
        data[0] = IPMI_PICMG_ID;
        send_msg.data = data;
        send_msg.data_len = sizeof(data);
        rv = ipmi_request_wait_for_response(user,
                                            (struct ipmi_addr *) &smi_addr,
                                            &send_msg);

        pr_info("ATCA Detect mfg 0x%X prod 0x%X\n", mfg_id, prod_id);
        if ((mfg_id == IPMI_MOTOROLA_MANUFACTURER_ID)
            && (prod_id == IPMI_MOTOROLA_PPS_IPMC_PRODUCT_ID)) {
                pr_info("Installing Pigeon Point Systems Poweroff Hook\n");
                atca_oem_poweroff_hook = pps_poweroff_atca;
        }
        return !rv;
}

static void ipmi_poweroff_atca(struct ipmi_user *user)
{
        struct ipmi_system_interface_addr smi_addr;
        struct kernel_ipmi_msg            send_msg;
        int                               rv;
        unsigned char                     data[4];

        /*
         * Configure IPMI address for local access
         */
        smi_addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
        smi_addr.channel = IPMI_BMC_CHANNEL;
        smi_addr.lun = 0;

        pr_info("Powering down via ATCA power command\n");

        /*
         * Power down
         */
        send_msg.netfn = IPMI_NETFN_ATCA;
        send_msg.cmd = IPMI_ATCA_SET_POWER_CMD;
        data[0] = IPMI_PICMG_ID;
        data[1] = 0; /* FRU id */
        data[2] = 0; /* Power Level */
        data[3] = 0; /* Don't change saved presets */
        send_msg.data = data;
        send_msg.data_len = sizeof(data);
        rv = ipmi_request_in_rc_mode(user,
                                     (struct ipmi_addr *) &smi_addr,
                                     &send_msg);
        /*
         * At this point, the system may be shutting down, and most
         * serial drivers (if used) will have interrupts turned off
         * it may be better to ignore IPMI_UNKNOWN_ERR_COMPLETION_CODE
         * return code
         */
        if (rv && rv != IPMI_UNKNOWN_ERR_COMPLETION_CODE) {
                pr_err("Unable to send ATCA powerdown message, IPMI error 0x%x\n",
                       rv);
                goto out;
        }

        if (atca_oem_poweroff_hook)
                atca_oem_poweroff_hook(user);
 out:
        return;
}

/*
 * CPI1 Support
 */

#define IPMI_NETFN_OEM_1                                0xf8
#define OEM_GRP_CMD_SET_RESET_STATE             0x84
#define OEM_GRP_CMD_SET_POWER_STATE             0x82
#define IPMI_NETFN_OEM_8                                0xf8
#define OEM_GRP_CMD_REQUEST_HOTSWAP_CTRL        0x80
#define OEM_GRP_CMD_GET_SLOT_GA                 0xa3
#define IPMI_NETFN_SENSOR_EVT                   0x10
#define IPMI_CMD_GET_EVENT_RECEIVER             0x01

#define IPMI_CPI1_PRODUCT_ID            0x000157
#define IPMI_CPI1_MANUFACTURER_ID       0x0108

static int ipmi_cpi1_detect(struct ipmi_user *user)
{
        return ((mfg_id == IPMI_CPI1_MANUFACTURER_ID)
                && (prod_id == IPMI_CPI1_PRODUCT_ID));
}

static void ipmi_poweroff_cpi1(struct ipmi_user *user)
{
        struct ipmi_system_interface_addr smi_addr;
        struct ipmi_ipmb_addr             ipmb_addr;
        struct kernel_ipmi_msg            send_msg;
        int                               rv;
        unsigned char                     data[1];
        int                               slot;
        unsigned char                     hotswap_ipmb;
        unsigned char                     aer_addr;
        unsigned char                     aer_lun;

        /*
         * Configure IPMI address for local access
         */
        smi_addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
        smi_addr.channel = IPMI_BMC_CHANNEL;
        smi_addr.lun = 0;

        pr_info("Powering down via CPI1 power command\n");

        /*
         * Get IPMI ipmb address
         */
        send_msg.netfn = IPMI_NETFN_OEM_8 >> 2;
        send_msg.cmd = OEM_GRP_CMD_GET_SLOT_GA;
        send_msg.data = NULL;
        send_msg.data_len = 0;
        rv = ipmi_request_in_rc_mode(user,
                                     (struct ipmi_addr *) &smi_addr,
                                     &send_msg);
        if (rv)
                goto out;
        slot = halt_recv_msg.msg.data[1];
        hotswap_ipmb = (slot > 9) ? (0xb0 + 2 * slot) : (0xae + 2 * slot);

        /*
         * Get active event receiver
         */
        send_msg.netfn = IPMI_NETFN_SENSOR_EVT >> 2;
        send_msg.cmd = IPMI_CMD_GET_EVENT_RECEIVER;
        send_msg.data = NULL;
        send_msg.data_len = 0;
        rv = ipmi_request_in_rc_mode(user,
                                     (struct ipmi_addr *) &smi_addr,
                                     &send_msg);
        if (rv)
                goto out;
        aer_addr = halt_recv_msg.msg.data[1];
        aer_lun = halt_recv_msg.msg.data[2];

        /*
         * Setup IPMB address target instead of local target
         */
        ipmb_addr.addr_type = IPMI_IPMB_ADDR_TYPE;
        ipmb_addr.channel = 0;
        ipmb_addr.slave_addr = aer_addr;
        ipmb_addr.lun = aer_lun;

        /*
         * Send request hotswap control to remove blade from dpv
         */
        send_msg.netfn = IPMI_NETFN_OEM_8 >> 2;
        send_msg.cmd = OEM_GRP_CMD_REQUEST_HOTSWAP_CTRL;
        send_msg.data = &hotswap_ipmb;
        send_msg.data_len = 1;
        ipmi_request_in_rc_mode(user,
                                (struct ipmi_addr *) &ipmb_addr,
                                &send_msg);

        /*
         * Set reset asserted
         */
        send_msg.netfn = IPMI_NETFN_OEM_1 >> 2;
        send_msg.cmd = OEM_GRP_CMD_SET_RESET_STATE;
        send_msg.data = data;
        data[0] = 1; /* Reset asserted state */
        send_msg.data_len = 1;
        rv = ipmi_request_in_rc_mode(user,
                                     (struct ipmi_addr *) &smi_addr,
                                     &send_msg);
        if (rv)
                goto out;

        /*
         * Power down
         */
        send_msg.netfn = IPMI_NETFN_OEM_1 >> 2;
        send_msg.cmd = OEM_GRP_CMD_SET_POWER_STATE;
        send_msg.data = data;
        data[0] = 1; /* Power down state */
        send_msg.data_len = 1;
        rv = ipmi_request_in_rc_mode(user,
                                     (struct ipmi_addr *) &smi_addr,
                                     &send_msg);
        if (rv)
                goto out;

 out:
        return;
}

/*
 * ipmi_dell_chassis_detect()
 * Dell systems with IPMI < 1.5 don't set the chassis capability bit
 * but they can handle a chassis poweroff or powercycle command.
 */

#define DELL_IANA_MFR_ID {0xA2, 0x02, 0x00}
static int ipmi_dell_chassis_detect(struct ipmi_user *user)
{
        const char ipmi_version_major = ipmi_version & 0xF;
        const char ipmi_version_minor = (ipmi_version >> 4) & 0xF;
        const char mfr[3] = DELL_IANA_MFR_ID;
        if (!memcmp(mfr, &mfg_id, sizeof(mfr)) &&
            ipmi_version_major <= 1 &&
            ipmi_version_minor < 5)
                return 1;
        return 0;
}

/*
 * ipmi_hp_chassis_detect()
 * HP PA-RISC servers rp3410/rp3440, the C8000 workstation and the rx2600 and
 * zx6000 machines support IPMI vers 1 and don't set the chassis capability bit
 * but they can handle a chassis poweroff or powercycle command.
 */

#define HP_IANA_MFR_ID 0x0b
#define HP_BMC_PROD_ID 0x8201
static int ipmi_hp_chassis_detect(struct ipmi_user *user)
{
        if (mfg_id == HP_IANA_MFR_ID
                && prod_id == HP_BMC_PROD_ID
                && ipmi_version == 1)
                return 1;
        return 0;
}

/*
 * Standard chassis support
 */

#define IPMI_NETFN_CHASSIS_REQUEST      0
#define IPMI_CHASSIS_CONTROL_CMD        0x02

static int ipmi_chassis_detect(struct ipmi_user *user)
{
        /* Chassis support, use it. */
        return (capabilities & 0x80);
}

static void ipmi_poweroff_chassis(struct ipmi_user *user)
{
        struct ipmi_system_interface_addr smi_addr;
        struct kernel_ipmi_msg            send_msg;
        int                               rv;
        unsigned char                     data[1];

        /*
         * Configure IPMI address for local access
         */
        smi_addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
        smi_addr.channel = IPMI_BMC_CHANNEL;
        smi_addr.lun = 0;

 powercyclefailed:
        pr_info("Powering %s via IPMI chassis control command\n",
                (poweroff_powercycle ? "cycle" : "down"));

        /*
         * Power down
         */
        send_msg.netfn = IPMI_NETFN_CHASSIS_REQUEST;
        send_msg.cmd = IPMI_CHASSIS_CONTROL_CMD;
        if (poweroff_powercycle)
                data[0] = IPMI_CHASSIS_POWER_CYCLE;
        else
                data[0] = IPMI_CHASSIS_POWER_DOWN;
        send_msg.data = data;
        send_msg.data_len = sizeof(data);
        rv = ipmi_request_in_rc_mode(user,
                                     (struct ipmi_addr *) &smi_addr,
                                     &send_msg);
        if (rv) {
                if (poweroff_powercycle) {
                        /* power cycle failed, default to power down */
                        pr_err("Unable to send chassis power cycle message, IPMI error 0x%x\n",
                               rv);
                        poweroff_powercycle = 0;
                        goto powercyclefailed;
                }

                pr_err("Unable to send chassis power down message, IPMI error 0x%x\n",
                       rv);
        }
}


/* Table of possible power off functions. */
struct poweroff_function {
        char *platform_type;
        int  (*detect)(struct ipmi_user *user);
        void (*poweroff_func)(struct ipmi_user *user);
};

static struct poweroff_function poweroff_functions[] = {
        { .platform_type        = "ATCA",
          .detect               = ipmi_atca_detect,
          .poweroff_func        = ipmi_poweroff_atca },
        { .platform_type        = "CPI1",
          .detect               = ipmi_cpi1_detect,
          .poweroff_func        = ipmi_poweroff_cpi1 },
        { .platform_type        = "chassis",
          .detect               = ipmi_dell_chassis_detect,
          .poweroff_func        = ipmi_poweroff_chassis },
        { .platform_type        = "chassis",
          .detect               = ipmi_hp_chassis_detect,
          .poweroff_func        = ipmi_poweroff_chassis },
        /* Chassis should generally be last, other things should override
           it. */
        { .platform_type        = "chassis",
          .detect               = ipmi_chassis_detect,
          .poweroff_func        = ipmi_poweroff_chassis },
};
#define NUM_PO_FUNCS ARRAY_SIZE(poweroff_functions)


/* Called on a powerdown request. */
static void ipmi_poweroff_function(void)
{
        if (!ready)
                return;

        /* Use run-to-completion mode, since interrupts may be off. */
        specific_poweroff_func(ipmi_user);
}

/* Wait for an IPMI interface to be installed, the first one installed
   will be grabbed by this code and used to perform the powerdown. */
static void ipmi_po_new_smi(int if_num, struct device *device)
{
        struct ipmi_system_interface_addr smi_addr;
        struct kernel_ipmi_msg            send_msg;
        int                               rv;
        int                               i;

        if (ready)
                return;

        if ((ifnum_to_use >= 0) && (ifnum_to_use != if_num))
                return;

        rv = ipmi_create_user(if_num, &ipmi_poweroff_handler, NULL,
                              &ipmi_user);
        if (rv) {
                pr_err("could not create IPMI user, error %d\n", rv);
                return;
        }

        ipmi_ifnum = if_num;

        /*
         * Do a get device ide and store some results, since this is
         * used by several functions.
         */
        smi_addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
        smi_addr.channel = IPMI_BMC_CHANNEL;
        smi_addr.lun = 0;

        send_msg.netfn = IPMI_NETFN_APP_REQUEST;
        send_msg.cmd = IPMI_GET_DEVICE_ID_CMD;
        send_msg.data = NULL;
        send_msg.data_len = 0;
        rv = ipmi_request_wait_for_response(ipmi_user,
                                            (struct ipmi_addr *) &smi_addr,
                                            &send_msg);
        if (rv) {
                pr_err("Unable to send IPMI get device id info, IPMI error 0x%x\n",
                       rv);
                goto out_err;
        }

        if (halt_recv_msg.msg.data_len < 12) {
                pr_err("(chassis) IPMI get device id info too short, was %d bytes, needed %d bytes\n",
                       halt_recv_msg.msg.data_len, 12);
                goto out_err;
        }

        mfg_id = (halt_recv_msg.msg.data[7]
                  | (halt_recv_msg.msg.data[8] << 8)
                  | (halt_recv_msg.msg.data[9] << 16));
        prod_id = (halt_recv_msg.msg.data[10]
                   | (halt_recv_msg.msg.data[11] << 8));
        capabilities = halt_recv_msg.msg.data[6];
        ipmi_version = halt_recv_msg.msg.data[5];


        /* Scan for a poweroff method */
        for (i = 0; i < NUM_PO_FUNCS; i++) {
                if (poweroff_functions[i].detect(ipmi_user))
                        goto found;
        }

 out_err:
        pr_err("Unable to find a poweroff function that will work, giving up\n");
        ipmi_destroy_user(ipmi_user);
        return;

 found:
        pr_info("Found a %s style poweroff function\n",
                poweroff_functions[i].platform_type);
        specific_poweroff_func = poweroff_functions[i].poweroff_func;
        old_poweroff_func = pm_power_off;
        pm_power_off = ipmi_poweroff_function;
        ready = 1;
}

static void ipmi_po_smi_gone(int if_num)
{
        if (!ready)
                return;

        if (ipmi_ifnum != if_num)
                return;

        ready = 0;
        ipmi_destroy_user(ipmi_user);
        pm_power_off = old_poweroff_func;
}

static struct ipmi_smi_watcher smi_watcher = {
        .owner    = THIS_MODULE,
        .new_smi  = ipmi_po_new_smi,
        .smi_gone = ipmi_po_smi_gone
};


#ifdef CONFIG_PROC_FS
#include <linux/sysctl.h>

static const struct ctl_table ipmi_table[] = {
        { .procname     = "poweroff_powercycle",
          .data         = &poweroff_powercycle,
          .maxlen       = sizeof(poweroff_powercycle),
          .mode         = 0644,
          .proc_handler = proc_dointvec },
};

static struct ctl_table_header *ipmi_table_header;
#endif /* CONFIG_PROC_FS */

/*
 * Startup and shutdown functions.
 */
static int __init ipmi_poweroff_init(void)
{
        int rv;

        pr_info("Copyright (C) 2004 MontaVista Software - IPMI Powerdown via sys_reboot\n");

        if (poweroff_powercycle)
                pr_info("Power cycle is enabled\n");

#ifdef CONFIG_PROC_FS
        ipmi_table_header = register_sysctl("dev/ipmi", ipmi_table);
        if (!ipmi_table_header) {
                pr_err("Unable to register powercycle sysctl\n");
                rv = -ENOMEM;
                goto out_err;
        }
#endif

        rv = ipmi_smi_watcher_register(&smi_watcher);

#ifdef CONFIG_PROC_FS
        if (rv) {
                unregister_sysctl_table(ipmi_table_header);
                pr_err("Unable to register SMI watcher: %d\n", rv);
                goto out_err;
        }

 out_err:
#endif
        return rv;
}

#ifdef MODULE
static void __exit ipmi_poweroff_cleanup(void)
{
#ifdef CONFIG_PROC_FS
        unregister_sysctl_table(ipmi_table_header);
#endif

        ipmi_smi_watcher_unregister(&smi_watcher);

        if (ready) {
                ipmi_destroy_user(ipmi_user);
                pm_power_off = old_poweroff_func;
        }
}
module_exit(ipmi_poweroff_cleanup);
#endif

module_init(ipmi_poweroff_init);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
MODULE_DESCRIPTION("IPMI Poweroff extension to sys_reboot");