i2o_core.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

/*
 * Core I2O structure management 
 * 
 * (C) Copyright 1999   Red Hat Software 
 *
 * Written by Alan Cox, Building Number Three Ltd 
 * 
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License 
 * as published by the Free Software Foundation; either version 
 * 2 of the License, or (at your option) any later version.  
 * 
 * A lot of the I2O message side code from this is taken from the 
 * Red Creek RCPCI45 adapter driver by Red Creek Communications 
 * 
 * Fixes by: 
 *		Philipp Rumpf 
 *		Juha Siev鋘en <[e-mail]> 
 *		Auvo H鋕kinen <[e-mail]> 
 *		Deepak Saxena <[e-mail]> 
 *		Boji T Kannanthanam <[e-mail]>
 * 
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>

#include <linux/i2o.h>

#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/smp_lock.h>

#include <linux/bitops.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/tqueue.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <asm/semaphore.h>
#include <linux/completion.h>

#include <asm/io.h>
#include <linux/reboot.h>

#include "i2o_lan.h"

//#define DRIVERDEBUG

#ifdef DRIVERDEBUG
#define dprintk(s, args...) printk(s, ## args)
#else
#define dprintk(s, args...)
#endif

/* OSM table */
static struct i2o_handler *i2o_handlers[MAX_I2O_MODULES];

/* Controller list */
static struct i2o_controller *i2o_controllers[MAX_I2O_CONTROLLERS];
struct i2o_controller *i2o_controller_chain;
int i2o_num_controllers;

/* Initiator Context for Core message */
static int core_context;

/* Initialization && shutdown functions */
static void i2o_sys_init(void);
static void i2o_sys_shutdown(void);
static int i2o_reset_controller(struct i2o_controller *);
static int i2o_reboot_event(struct notifier_block *, unsigned long , void *);
static int i2o_online_controller(struct i2o_controller *);
static int i2o_init_outbound_q(struct i2o_controller *);
static int i2o_post_outbound_messages(struct i2o_controller *);

/* Reply handler */
static void i2o_core_reply(struct i2o_handler *, struct i2o_controller *,
			   struct i2o_message *);

/* Various helper functions */
static int i2o_lct_get(struct i2o_controller *);
static int i2o_lct_notify(struct i2o_controller *);
static int i2o_hrt_get(struct i2o_controller *);

static int i2o_build_sys_table(void);
static int i2o_systab_send(struct i2o_controller *c);

/* I2O core event handler */
static int i2o_core_evt(void *);
static int evt_pid;
static int evt_running;

/* Dynamic LCT update handler */
static int i2o_dyn_lct(void *);

void i2o_report_controller_unit(struct i2o_controller *, struct i2o_device *);

/*
 * I2O System Table.  Contains information about
 * all the IOPs in the system.  Used to inform IOPs
 * about each other's existence.
 *
 * sys_tbl_ver is the CurrentChangeIndicator that is
 * used by IOPs to track changes.
 */
static struct i2o_sys_tbl *sys_tbl;
static int sys_tbl_ind;
static int sys_tbl_len;

/*
 * This spin lock is used to keep a device from being
 * added and deleted concurrently across CPUs or interrupts.
 * This can occur when a user creates a device and immediatelly
 * deletes it before the new_dev_notify() handler is called.
 */
static spinlock_t i2o_dev_lock = SPIN_LOCK_UNLOCKED;

#ifdef MODULE
/* 
 * Function table to send to bus specific layers
 * See <include/linux/i2o.h> for explanation of this
 */
static struct i2o_core_func_table i2o_core_functions =
{
	i2o_install_controller,
	i2o_activate_controller,
	i2o_find_controller,
	i2o_unlock_controller,
	i2o_run_queue,
	i2o_delete_controller
};

#ifdef CONFIG_I2O_PCI_MODULE
extern int i2o_pci_core_attach(struct i2o_core_func_table *);
extern void i2o_pci_core_detach(void);
#endif /* CONFIG_I2O_PCI_MODULE */

#endif /* MODULE */

/*
 * Structures and definitions for synchronous message posting.
 * See i2o_post_wait() for description.
 */ 
struct i2o_post_wait_data
{
	int *status;		/* Pointer to status block on caller stack */
	int *complete;		/* Pointer to completion flag on caller stack */
	u32 id;			/* Unique identifier */
	wait_queue_head_t *wq;	/* Wake up for caller (NULL for dead) */
	struct i2o_post_wait_data *next;	/* Chain */
	void *mem[2];		/* Memory blocks to recover on failure path */
};
static struct i2o_post_wait_data *post_wait_queue;
static u32 post_wait_id;	// Unique ID for each post_wait
static spinlock_t post_wait_lock = SPIN_LOCK_UNLOCKED;
static void i2o_post_wait_complete(u32, int);

/* OSM descriptor handler */ 
static struct i2o_handler i2o_core_handler =
{
	(void *)i2o_core_reply,
	NULL,
	NULL,
	NULL,
	"I2O core layer",
	0,
	I2O_CLASS_EXECUTIVE
};

/*
 * Used when queueing a reply to be handled later
 */
 
struct reply_info
{
	struct i2o_controller *iop;
	u32 msg[MSG_FRAME_SIZE];
};
static struct reply_info evt_reply;
static struct reply_info events[I2O_EVT_Q_LEN];
static int evt_in;
static int evt_out;
static int evt_q_len;
#define MODINC(x,y) ((x) = ((x) + 1) % (y))

/*
 * I2O configuration spinlock. This isnt a big deal for contention
 * so we have one only
 */

static DECLARE_MUTEX(i2o_configuration_lock);

/* 
 * Event spinlock.  Used to keep event queue sane and from
 * handling multiple events simultaneously.
 */
static spinlock_t i2o_evt_lock = SPIN_LOCK_UNLOCKED;

/*
 * Semaphore used to synchronize event handling thread with 
 * interrupt handler.
 */
 
static DECLARE_MUTEX(evt_sem);
static DECLARE_COMPLETION(evt_dead);
static DECLARE_WAIT_QUEUE_HEAD(evt_wait);

static struct notifier_block i2o_reboot_notifier =
{
        i2o_reboot_event,
        NULL,
        0
};

/*
 *	Config options
 */

static int verbose;
MODULE_PARM(verbose, "i");

/*
 * I2O Core reply handler
 */
static void i2o_core_reply(struct i2o_handler *h, struct i2o_controller *c,
		    struct i2o_message *m)
{
	u32 *msg=(u32 *)m;
	u32 status;
	u32 context = msg[2];

	if (msg[0] & MSG_FAIL) // Fail bit is set
	{
		u32 *preserved_msg = (u32*)(c->mem_offset + msg[7]);

		i2o_report_status(KERN_INFO, "i2o_core", msg);
		i2o_dump_message(preserved_msg);

		/* If the failed request needs special treatment,
		 * it should be done here. */

                /* Release the preserved msg by resubmitting it as a NOP */

		preserved_msg[0] = cpu_to_le32(THREE_WORD_MSG_SIZE | SGL_OFFSET_0);
		preserved_msg[1] = cpu_to_le32(I2O_CMD_UTIL_NOP << 24 | HOST_TID << 12 | 0);
		preserved_msg[2] = 0;
		i2o_post_message(c, msg[7]);

		/* If reply to i2o_post_wait failed, return causes a timeout */

		return;
	}       

#ifdef DRIVERDEBUG
	i2o_report_status(KERN_INFO, "i2o_core", msg);
#endif

	if(msg[2]&0x80000000)	// Post wait message
	{
		if (msg[4] >> 24)
			status = (msg[4] & 0xFFFF);
		else
			status = I2O_POST_WAIT_OK;
	
		i2o_post_wait_complete(context, status);
		return;
	}

	if(m->function == I2O_CMD_UTIL_EVT_REGISTER)
	{
		memcpy(events[evt_in].msg, msg, (msg[0]>>16)<<2);
		events[evt_in].iop = c;

		spin_lock(&i2o_evt_lock);
		MODINC(evt_in, I2O_EVT_Q_LEN);
		if(evt_q_len == I2O_EVT_Q_LEN)
			MODINC(evt_out, I2O_EVT_Q_LEN);
		else
			evt_q_len++;
		spin_unlock(&i2o_evt_lock);

		up(&evt_sem);
		wake_up_interruptible(&evt_wait);
		return;
	}

	if(m->function == I2O_CMD_LCT_NOTIFY)
	{
		up(&c->lct_sem);
		return;
	}

	/*
	 * If this happens, we want to dump the message to the syslog so
	 * it can be sent back to the card manufacturer by the end user
	 * to aid in debugging.
	 * 
	 */
	printk(KERN_WARNING "%s: Unsolicited message reply sent to core!"
			"Message dumped to syslog\n", 
			c->name);
	i2o_dump_message(msg);

	return;
}

/**
 *	i2o_install_handler - install a message handler
 *	@h: Handler structure
 *
 *	Install an I2O handler - these handle the asynchronous messaging
 *	from the card once it has initialised. If the table of handlers is
 *	full then -ENOSPC is returned. On a success 0 is returned and the
 *	context field is set by the function. The structure is part of the
 *	system from this time onwards. It must not be freed until it has
 *	been uninstalled
 */
 
int i2o_install_handler(struct i2o_handler *h)
{
	int i;
	down(&i2o_configuration_lock);
	for(i=0;i<MAX_I2O_MODULES;i++)
	{
		if(i2o_handlers[i]==NULL)
		{
			h->context = i;
			i2o_handlers[i]=h;
			up(&i2o_configuration_lock);
			return 0;
		}
	}
	up(&i2o_configuration_lock);
	return -ENOSPC;
}

/**
 *	i2o_remove_handler - remove an i2o message handler
 *	@h: handler
 *
 *	Remove a message handler previously installed with i2o_install_handler.
 *	After this function returns the handler object can be freed or re-used
 */
 
int i2o_remove_handler(struct i2o_handler *h)
{
	i2o_handlers[h->context]=NULL;
	return 0;
}
	

/*
 *	Each I2O controller has a chain of devices on it.
 * Each device has a pointer to it's LCT entry to be used
 * for fun purposes.
 */

/**
 *	i2o_install_device	-	attach a device to a controller
 *	@c: controller
 *	@d: device
 * 	
 *	Add a new device to an i2o controller. This can be called from
 *	non interrupt contexts only. It adds the device and marks it as
 *	unclaimed. The device memory becomes part of the kernel and must
 *	be uninstalled before being freed or reused. Zero is returned
 *	on success.
 */
 
int i2o_install_device(struct i2o_controller *c, struct i2o_device *d)
{
	int i;

	down(&i2o_configuration_lock);
	d->controller=c;
	d->owner=NULL;
	d->next=c->devices;
	d->prev=NULL;
	if (c->devices != NULL)
		c->devices->prev=d;
	c->devices=d;
	*d->dev_name = 0;

	for(i = 0; i < I2O_MAX_MANAGERS; i++)
		d->managers[i] = NULL;

	up(&i2o_configuration_lock);
	return 0;
}

/* we need this version to call out of i2o_delete_controller */

int __i2o_delete_device(struct i2o_device *d)
{
	struct i2o_device **p;
	int i;

	p=&(d->controller->devices);

	/*
	 *	Hey we have a driver!
	 * Check to see if the driver wants us to notify it of 
	 * device deletion. If it doesn't we assume that it
	 * is unsafe to delete a device with an owner and 
	 * fail.
	 */
	if(d->owner)
	{
		if(d->owner->dev_del_notify)
		{
			dprintk(KERN_INFO "Device has owner, notifying\n");
			d->owner->dev_del_notify(d->controller, d);
			if(d->owner)
			{
				printk(KERN_WARNING 
					"Driver \"%s\" did not release device!\n", d->owner->name);
				return -EBUSY;
			}
		}
		else
			return -EBUSY;
	}

	/*
	 * Tell any other users who are talking to this device
	 * that it's going away.  We assume that everything works.
	 */
	for(i=0; i < I2O_MAX_MANAGERS; i++)
	{
		if(d->managers[i] && d->managers[i]->dev_del_notify)
			d->managers[i]->dev_del_notify(d->controller, d);
	}
	 			
	while(*p!=NULL)
	{
		if(*p==d)
		{
			/*
			 *	Destroy
			 */
			*p=d->next;
			kfree(d);
			return 0;
		}
		p=&((*p)->next);
	}
	printk(KERN_ERR "i2o_delete_device: passed invalid device.\n");
	return -EINVAL;
}

/**
 *	i2o_delete_device	-	remove an i2o device
 *	@d: device to remove
 *
 *	This function unhooks a device from a controller. The device
 *	will not be unhooked if it has an owner who does not wish to free
 *	it, or if the owner lacks a dev_del_notify function. In that case
 *	-EBUSY is returned. On success 0 is returned. Other errors cause
 *	negative errno values to be returned
 */
 
int i2o_delete_device(struct i2o_device *d)
{
	int ret;

	down(&i2o_configuration_lock);

	/*
	 *	Seek, locate
	 */

	ret = __i2o_delete_device(d);

	up(&i2o_configuration_lock);

	return ret;
}

/**
 *	i2o_install_controller	-	attach a controller
 *	@c: controller
 * 	
 *	Add a new controller to the i2o layer. This can be called from
 *	non interrupt contexts only. It adds the controller and marks it as
 *	unused with no devices. If the tables are full or memory allocations
 *	fail then a negative errno code is returned. On success zero is
 *	returned and the controller is bound to the system. The structure
 *	must not be freed or reused until being uninstalled.
 */
 
int i2o_install_controller(struct i2o_controller *c)
{
	int i;
	down(&i2o_configuration_lock);
	for(i=0;i<MAX_I2O_CONTROLLERS;i++)
	{
		if(i2o_controllers[i]==NULL)
		{
			c->dlct = (i2o_lct*)kmalloc(8192, GFP_KERNEL);
			if(c->dlct==NULL)
			{
				up(&i2o_configuration_lock);
				return -ENOMEM;
			}
			i2o_controllers[i]=c;
			c->devices = NULL;
			c->next=i2o_controller_chain;
			i2o_controller_chain=c;
			c->unit = i;
			c->page_frame = NULL;
			c->hrt = NULL;
			c->lct = NULL;
			c->status_block = NULL;
			sprintf(c->name, "i2o/iop%d", i);
			i2o_num_controllers++;
			init_MUTEX_LOCKED(&c->lct_sem);
			up(&i2o_configuration_lock);
			return 0;
		}
	}
	printk(KERN_ERR "No free i2o controller slots.\n");
	up(&i2o_configuration_lock);
	return -EBUSY;
}

/**
 *	i2o_delete_controller	- delete a controller
 *	@c: controller
 *	
 *	Remove an i2o controller from the system. If the controller or its
 *	devices are busy then -EBUSY is returned. On a failure a negative
 *	errno code is returned. On success zero is returned.
 */
  
int i2o_delete_controller(struct i2o_controller *c)
{
	struct i2o_controller **p;
	int users;
	char name[16];
	int stat;

	dprintk(KERN_INFO "Deleting controller %s\n", c->name);