/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * ipmi.h
 *
 * MontaVista IPMI interface
 *
 * Author: MontaVista Software, Inc.
 *         Corey Minyard <minyard@mvista.com>
 *         source@mvista.com
 *
 * Copyright 2002 MontaVista Software Inc.
 *
 */
#ifndef __LINUX_IPMI_H
#define __LINUX_IPMI_H

#include <uapi/linux/ipmi.h>

#include <linux/list.h>
#include <linux/proc_fs.h>
#include <linux/acpi.h> /* For acpi_handle */

struct module;
struct device;

/*
 * Opaque type for a IPMI message user.  One of these is needed to
 * send and receive messages.
 */
struct ipmi_user;

/*
 * Stuff coming from the receive interface comes as one of these.
 * They are allocated, the receiver must free them with
 * ipmi_free_recv_msg() when done with the message.  The link is not
 * used after the message is delivered, so the upper layer may use the
 * link to build a linked list, if it likes.
 */
struct ipmi_recv_msg {
	struct list_head link;

	/*
	 * The type of message as defined in the "Receive Types"
	 * defines above.
	 */
	int              recv_type;

	struct ipmi_user *user;
	struct ipmi_addr addr;
	long             msgid;
	struct kernel_ipmi_msg  msg;

	/*
	 * The user_msg_data is the data supplied when a message was
	 * sent, if this is a response to a sent message.  If this is
	 * not a response to a sent message, then user_msg_data will
	 * be NULL.  If the user above is NULL, then this will be the
	 * intf.
	 */
	void             *user_msg_data;

	/*
	 * Call this when done with the message.  It will presumably free
	 * the message and do any other necessary cleanup.
	 */
	void (*done)(struct ipmi_recv_msg *msg);

	/*
	 * Place-holder for the data, don't make any assumptions about
	 * the size or existence of this, since it may change.
	 */
	unsigned char   msg_data[IPMI_MAX_MSG_LENGTH];
};

#define INIT_IPMI_RECV_MSG(done_handler) \
{					\
	.done = done_handler		\
}

/* Allocate and free the receive message. */
void ipmi_free_recv_msg(struct ipmi_recv_msg *msg);

struct ipmi_user_hndl {
	/*
	 * Routine type to call when a message needs to be routed to
	 * the upper layer.  This will be called with some locks held,
	 * the only IPMI routines that can be called are ipmi_request
	 * and the alloc/free operations.  The handler_data is the
	 * variable supplied when the receive handler was registered.
	 */
	void (*ipmi_recv_hndl)(struct ipmi_recv_msg *msg,
			       void                 *user_msg_data);

	/*
	 * Called when the interface detects a watchdog pre-timeout.  If
	 * this is NULL, it will be ignored for the user.  Note that you
	 * can't do any IPMI calls from here, it's called with locks held.
	 */
	void (*ipmi_watchdog_pretimeout)(void *handler_data);

	/*
	 * If not NULL, called at panic time after the interface has
	 * been set up to handle run to completion.
	 */
	void (*ipmi_panic_handler)(void *handler_data);

	/*
	 * Called when the interface has been removed.  After this returns
	 * the user handle will be invalid.  The interface may or may
	 * not be usable when this is called, but it will return errors
	 * if it is not usable.
	 */
	void (*shutdown)(void *handler_data);
};

/* Create a new user of the IPMI layer on the given interface number. */
int ipmi_create_user(unsigned int          if_num,
		     const struct ipmi_user_hndl *handler,
		     void                  *handler_data,
		     struct ipmi_user      **user);

/*
 * Destroy the given user of the IPMI layer.  Note that after this
 * function returns, the system is guaranteed to not call any
 * callbacks for the user.  Thus as long as you destroy all the users
 * before you unload a module, you will be safe.  And if you destroy
 * the users before you destroy the callback structures, it should be
 * safe, too.
 */
void ipmi_destroy_user(struct ipmi_user *user);

/* Get the IPMI version of the BMC we are talking to. */
int ipmi_get_version(struct ipmi_user *user,
		     unsigned char *major,
		     unsigned char *minor);

/*
 * Set and get the slave address and LUN that we will use for our
 * source messages.  Note that this affects the interface, not just
 * this user, so it will affect all users of this interface.  This is
 * so some initialization code can come in and do the OEM-specific
 * things it takes to determine your address (if not the BMC) and set
 * it for everyone else.  Note that each channel can have its own
 * address.
 */
int ipmi_set_my_address(struct ipmi_user *user,
			unsigned int  channel,
			unsigned char address);
int ipmi_get_my_address(struct ipmi_user *user,
			unsigned int  channel,
			unsigned char *address);
int ipmi_set_my_LUN(struct ipmi_user *user,
		    unsigned int  channel,
		    unsigned char LUN);
int ipmi_get_my_LUN(struct ipmi_user *user,
		    unsigned int  channel,
		    unsigned char *LUN);

/*
 * Like ipmi_request, but lets you specify the number of retries and
 * the retry time.  The retries is the number of times the message
 * will be resent if no reply is received.  If set to -1, the default
 * value will be used.  The retry time is the time in milliseconds
 * between retries.  If set to zero, the default value will be
 * used.
 *
 * Don't use this unless you *really* have to.  It's primarily for the
 * IPMI over LAN converter; since the LAN stuff does its own retries,
 * it makes no sense to do it here.  However, this can be used if you
 * have unusual requirements.
 */
int ipmi_request_settime(struct ipmi_user *user,
			 struct ipmi_addr *addr,
			 long             msgid,
			 struct kernel_ipmi_msg  *msg,
			 void             *user_msg_data,
			 int              priority,
			 int              max_retries,
			 unsigned int     retry_time_ms);

/*
 * Like ipmi_request, but with messages supplied.  This will not
 * allocate any memory, and the messages may be statically allocated
 * (just make sure to do the "done" handling on them).  Note that this
 * is primarily for the watchdog timer, since it should be able to
 * send messages even if no memory is available.  This is subject to
 * change as the system changes, so don't use it unless you REALLY
 * have to.
 */
int ipmi_request_supply_msgs(struct ipmi_user     *user,
			     struct ipmi_addr     *addr,
			     long                 msgid,
			     struct kernel_ipmi_msg *msg,
			     void                 *user_msg_data,
			     void                 *supplied_smi,
			     struct ipmi_recv_msg *supplied_recv,
			     int                  priority);

/*
 * Poll the IPMI interface for the user.  This causes the IPMI code to
 * do an immediate check for information from the driver and handle
 * anything that is immediately pending.  This will not block in any
 * way.  This is useful if you need to spin waiting for something to
 * happen in the IPMI driver.
 */
void ipmi_poll_interface(struct ipmi_user *user);

/*
 * When commands come in to the SMS, the user can register to receive
 * them.  Only one user can be listening on a specific netfn/cmd/chan tuple
 * at a time, you will get an EBUSY error if the command is already
 * registered.  If a command is received that does not have a user
 * registered, the driver will automatically return the proper
 * error.  Channels are specified as a bitfield, use IPMI_CHAN_ALL to
 * mean all channels.
 */
int ipmi_register_for_cmd(struct ipmi_user *user,
			  unsigned char netfn,
			  unsigned char cmd,
			  unsigned int  chans);
int ipmi_unregister_for_cmd(struct ipmi_user *user,
			    unsigned char netfn,
			    unsigned char cmd,
			    unsigned int  chans);

/*
 * Go into a mode where the driver will not autonomously attempt to do
 * things with the interface.  It will still respond to attentions and
 * interrupts, and it will expect that commands will complete.  It
 * will not automatcially check for flags, events, or things of that
 * nature.
 *
 * This is primarily used for firmware upgrades.  The idea is that
 * when you go into firmware upgrade mode, you do this operation
 * and the driver will not attempt to do anything but what you tell
 * it or what the BMC asks for.
 *
 * Note that if you send a command that resets the BMC, the driver
 * will still expect a response from that command.  So the BMC should
 * reset itself *after* the response is sent.  Resetting before the
 * response is just silly.
 *
 * If in auto maintenance mode, the driver will automatically go into
 * maintenance mode for 30 seconds if it sees a cold reset, a warm
 * reset, or a firmware NetFN.  This means that code that uses only
 * firmware NetFN commands to do upgrades will work automatically
 * without change, assuming it sends a message every 30 seconds or
 * less.
 *
 * See the IPMI_MAINTENANCE_MODE_xxx defines for what the mode means.
 */
int ipmi_get_maintenance_mode(struct ipmi_user *user);
int ipmi_set_maintenance_mode(struct ipmi_user *user, int mode);

/*
 * When the user is created, it will not receive IPMI events by
 * default.  The user must set this to TRUE to get incoming events.
 * The first user that sets this to TRUE will receive all events that
 * have been queued while no one was waiting for events.
 */
int ipmi_set_gets_events(struct ipmi_user *user, bool val);

/*
 * Called when a new SMI is registered.  This will also be called on
 * every existing interface when a new watcher is registered with
 * ipmi_smi_watcher_register().
 */
struct ipmi_smi_watcher {
	struct list_head link;

	/*
	 * You must set the owner to the current module, if you are in
	 * a module (generally just set it to "THIS_MODULE").
	 */
	struct module *owner;

	/*
	 * These two are called with read locks held for the interface
	 * the watcher list.  So you can add and remove users from the
	 * IPMI interface, send messages, etc., but you cannot add
	 * or remove SMI watchers or SMI interfaces.
	 */
	void (*new_smi)(int if_num, struct device *dev);
	void (*smi_gone)(int if_num);
};

int ipmi_smi_watcher_register(struct ipmi_smi_watcher *watcher);
int ipmi_smi_watcher_unregister(struct ipmi_smi_watcher *watcher);

/*
 * The following are various helper functions for dealing with IPMI
 * addresses.
 */

/* Return the maximum length of an IPMI address given it's type. */
unsigned int ipmi_addr_length(int addr_type);

/* Validate that the given IPMI address is valid. */
int ipmi_validate_addr(struct ipmi_addr *addr, int len);

/*
 * How did the IPMI driver find out about the device?
 */
enum ipmi_addr_src {
	SI_INVALID = 0, SI_HOTMOD, SI_HARDCODED, SI_SPMI, SI_ACPI, SI_SMBIOS,
	SI_PCI,	SI_DEVICETREE, SI_PLATFORM, SI_LAST
};
const char *ipmi_addr_src_to_str(enum ipmi_addr_src src);

union ipmi_smi_info_union {
#ifdef CONFIG_ACPI
	/*
	 * the acpi_info element is defined for the SI_ACPI
	 * address type
	 */
	struct {
		acpi_handle acpi_handle;
	} acpi_info;
#endif
};

struct ipmi_smi_info {
	enum ipmi_addr_src addr_src;

	/*
	 * Base device for the interface.  Don't forget to put this when
	 * you are done.
	 */
	struct device *dev;

	/*
	 * The addr_info provides more detailed info for some IPMI
	 * devices, depending on the addr_src.  Currently only SI_ACPI
	 * info is provided.
	 */
	union ipmi_smi_info_union addr_info;
};

/* This is to get the private info of struct ipmi_smi */
extern int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data);

#define GET_DEVICE_ID_MAX_RETRY		5

/* Helper function for computing the IPMB checksum of some data. */
unsigned char ipmb_checksum(unsigned char *data, int size);

/*
 * For things that must send messages at panic time, like the IPMI watchdog
 * driver that extends the reset time on a panic, use this to send messages
 * from panic context.  Note that this puts the driver into a mode that
 * only works at panic time, so only use it then.
 */
void ipmi_panic_request_and_wait(struct ipmi_user *user,
				 struct ipmi_addr *addr,
				 struct kernel_ipmi_msg *msg);

#endif /* __LINUX_IPMI_H */
