/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * ipmi_smi.h
 *
 * MontaVista IPMI system management interface
 *
 * Author: MontaVista Software, Inc.
 *         Corey Minyard <minyard@mvista.com>
 *         source@mvista.com
 *
 * Copyright 2002 MontaVista Software Inc.
 *
 */

#ifndef __LINUX_IPMI_SMI_H
#define __LINUX_IPMI_SMI_H

#include <linux/ipmi_msgdefs.h>
#include <linux/proc_fs.h>
#include <linux/platform_device.h>
#include <linux/ipmi.h>

struct device;

/*
 * This files describes the interface for IPMI system management interface
 * drivers to bind into the IPMI message handler.
 */

/* Structure for the low-level drivers. */
struct ipmi_smi;

/*
 * Flags for set_check_watch() below.  Tells if the SMI should be
 * waiting for watchdog timeouts, commands and/or messages.
 */
#define IPMI_WATCH_MASK_CHECK_MESSAGES  (1 << 0)
#define IPMI_WATCH_MASK_CHECK_WATCHDOG  (1 << 1)
#define IPMI_WATCH_MASK_CHECK_COMMANDS  (1 << 2)

/*
 * Messages to/from the lower layer.  The smi interface will take one
 * of these to send. After the send has occurred and a response has
 * been received, it will report this same data structure back up to
 * the upper layer.  If an error occurs, it should fill in the
 * response with an error code in the completion code location. When
 * asynchronous data is received, one of these is allocated, the
 * data_size is set to zero and the response holds the data from the
 * get message or get event command that the interface initiated.
 * Note that it is the interfaces responsibility to detect
 * asynchronous data and messages and request them from the
 * interface.
 */
struct ipmi_smi_msg {
        struct list_head link;

        long    msgid;
        void    *user_data;

        int           data_size;
        unsigned char data[IPMI_MAX_MSG_LENGTH];

        int           rsp_size;
        unsigned char rsp[IPMI_MAX_MSG_LENGTH];

        /*
         * Will be called when the system is done with the message
         * (presumably to free it).
         */
        void (*done)(struct ipmi_smi_msg *msg);
};

struct ipmi_smi_handlers {
        struct module *owner;

        /*
         * The low-level interface cannot start sending messages to
         * the upper layer until this function is called.  This may
         * not be NULL, the lower layer must take the interface from
         * this call.
         */
        int (*start_processing)(void            *send_info,
                                struct ipmi_smi *new_intf);

        /*
         * When called, the low-level interface should disable all
         * processing, it should be complete shut down when it returns.
         */
        void (*shutdown)(void *send_info);

        /*
         * Get the detailed private info of the low level interface and store
         * it into the structure of ipmi_smi_data. For example: the
         * ACPI device handle will be returned for the pnp_acpi IPMI device.
         */
        int (*get_smi_info)(void *send_info, struct ipmi_smi_info *data);

        /*
         * Called to enqueue an SMI message to be sent.  This
         * operation is not allowed to fail.  If an error occurs, it
         * should report back the error in a received message.  It may
         * do this in the current call context, since no write locks
         * are held when this is run.  Message are delivered one at
         * a time by the message handler, a new message will not be
         * delivered until the previous message is returned.
         */
        void (*sender)(void                *send_info,
                       struct ipmi_smi_msg *msg);

        /*
         * Called by the upper layer to request that we try to get
         * events from the BMC we are attached to.
         */
        void (*request_events)(void *send_info);

        /*
         * Called by the upper layer when some user requires that the
         * interface watch for received messages and watchdog
         * pretimeouts (basically do a "Get Flags", or not.  Used by
         * the SMI to know if it should watch for these.  This may be
         * NULL if the SMI does not implement it.  watch_mask is from
         * IPMI_WATCH_MASK_xxx above.  The interface should run slower
         * timeouts for just watchdog checking or faster timeouts when
         * waiting for the message queue.
         */
        void (*set_need_watch)(void *send_info, unsigned int watch_mask);

        /*
         * Called when flushing all pending messages.
         */
        void (*flush_messages)(void *send_info);

        /*
         * Called when the interface should go into "run to
         * completion" mode.  If this call sets the value to true, the
         * interface should make sure that all messages are flushed
         * out and that none are pending, and any new requests are run
         * to completion immediately.
         */
        void (*set_run_to_completion)(void *send_info, bool run_to_completion);

        /*
         * Called to poll for work to do.  This is so upper layers can
         * poll for operations during things like crash dumps.
         */
        void (*poll)(void *send_info);

        /*
         * Enable/disable firmware maintenance mode.  Note that this
         * is *not* the modes defined, this is simply an on/off
         * setting.  The message handler does the mode handling.  Note
         * that this is called from interrupt context, so it cannot
         * block.
         */
        void (*set_maintenance_mode)(void *send_info, bool enable);
};

struct ipmi_device_id {
        unsigned char device_id;
        unsigned char device_revision;
        unsigned char firmware_revision_1;
        unsigned char firmware_revision_2;
        unsigned char ipmi_version;
        unsigned char additional_device_support;
        unsigned int  manufacturer_id;
        unsigned int  product_id;
        unsigned char aux_firmware_revision[4];
        unsigned int  aux_firmware_revision_set : 1;
};

#define ipmi_version_major(v) ((v)->ipmi_version & 0xf)
#define ipmi_version_minor(v) ((v)->ipmi_version >> 4)

/*
 * Take a pointer to an IPMI response and extract device id information from
 * it. @netfn is in the IPMI_NETFN_ format, so may need to be shifted from
 * a SI response.
 */
static inline int ipmi_demangle_device_id(uint8_t netfn, uint8_t cmd,
                                          const unsigned char *data,
                                          unsigned int data_len,
                                          struct ipmi_device_id *id)
{
        if (data_len < 7)
                return -EINVAL;
        if (netfn != IPMI_NETFN_APP_RESPONSE || cmd != IPMI_GET_DEVICE_ID_CMD)
                /* Strange, didn't get the response we expected. */
                return -EINVAL;
        if (data[0] != 0)
                /* That's odd, it shouldn't be able to fail. */
                return -EINVAL;

        data++;
        data_len--;

        id->device_id = data[0];
        id->device_revision = data[1];
        id->firmware_revision_1 = data[2];
        id->firmware_revision_2 = data[3];
        id->ipmi_version = data[4];
        id->additional_device_support = data[5];
        if (data_len >= 11) {
                id->manufacturer_id = (data[6] | (data[7] << 8) |
                                       (data[8] << 16));
                id->product_id = data[9] | (data[10] << 8);
        } else {
                id->manufacturer_id = 0;
                id->product_id = 0;
        }
        if (data_len >= 15) {
                memcpy(id->aux_firmware_revision, data+11, 4);
                id->aux_firmware_revision_set = 1;
        } else
                id->aux_firmware_revision_set = 0;

        return 0;
}

/*
 * Add a low-level interface to the IPMI driver.  Note that if the
 * interface doesn't know its slave address, it should pass in zero.
 * The low-level interface should not deliver any messages to the
 * upper layer until the start_processing() function in the handlers
 * is called, and the lower layer must get the interface from that
 * call.
 */
int ipmi_register_smi(const struct ipmi_smi_handlers *handlers,
                      void                     *send_info,
                      struct device            *dev,
                      unsigned char            slave_addr);

/*
 * Remove a low-level interface from the IPMI driver.  This will
 * return an error if the interface is still in use by a user.
 */
void ipmi_unregister_smi(struct ipmi_smi *intf);

/*
 * The lower layer reports received messages through this interface.
 * The data_size should be zero if this is an asynchronous message.  If
 * the lower layer gets an error sending a message, it should format
 * an error response in the message response.
 */
void ipmi_smi_msg_received(struct ipmi_smi     *intf,
                           struct ipmi_smi_msg *msg);

/* The lower layer received a watchdog pre-timeout on interface. */
void ipmi_smi_watchdog_pretimeout(struct ipmi_smi *intf);

struct ipmi_smi_msg *ipmi_alloc_smi_msg(void);
static inline void ipmi_free_smi_msg(struct ipmi_smi_msg *msg)
{
        msg->done(msg);
}

#endif /* __LINUX_IPMI_SMI_H */