iop.c

linux-2.6.15.6

/*
 *	Functions to handle I2O controllers and I2O message handling
 *
 *	Copyright (C) 1999-2002	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/additions:
 *		Philipp Rumpf
 *		Juha Siev鋘en <[e-mail]>
 *		Auvo H鋕kinen <[e-mail]>
 *		Deepak Saxena <[e-mail]>
 *		Boji T Kannanthanam <[e-mail]>
 *		Alan Cox <[e-mail]>:
 *			Ported to Linux 2.5.
 *		Markus Lidel <[e-mail]>:
 *			Minor fixes for 2.6.
 */

#include <linux/module.h>
#include <linux/i2o.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include "core.h"

#define OSM_NAME	"i2o"
#define OSM_VERSION	"1.288"
#define OSM_DESCRIPTION	"I2O subsystem"

/* global I2O controller list */
LIST_HEAD(i2o_controllers);

/*
 * global I2O System Table. Contains information about all the IOPs in the
 * system. Used to inform IOPs about each others existence.
 */
static struct i2o_dma i2o_systab;

static int i2o_hrt_get(struct i2o_controller *c);

/**
 *	i2o_msg_nop - Returns a message which is not used
 *	@c: I2O controller from which the message was created
 *	@m: message which should be returned
 *
 *	If you fetch a message via i2o_msg_get, and can't use it, you must
 *	return the message with this function. Otherwise the message frame
 *	is lost.
 */
void i2o_msg_nop(struct i2o_controller *c, u32 m)
{
	struct i2o_message __iomem *msg = i2o_msg_in_to_virt(c, m);

	writel(THREE_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_UTIL_NOP << 24 | HOST_TID << 12 | ADAPTER_TID,
	       &msg->u.head[1]);
	writel(0, &msg->u.head[2]);
	writel(0, &msg->u.head[3]);
	i2o_msg_post(c, m);
};

/**
 *	i2o_msg_get_wait - obtain an I2O message from the IOP
 *	@c: I2O controller
 *	@msg: pointer to a I2O message pointer
 *	@wait: how long to wait until timeout
 *
 *	This function waits up to wait seconds for a message slot to be
 *	available.
 *
 *	On a success the message is returned and the pointer to the message is
 *	set in msg. The returned message is the physical page frame offset
 *	address from the read port (see the i2o spec). If no message is
 *	available returns I2O_QUEUE_EMPTY and msg is leaved untouched.
 */
u32 i2o_msg_get_wait(struct i2o_controller *c,
		     struct i2o_message __iomem ** msg, int wait)
{
	unsigned long timeout = jiffies + wait * HZ;
	u32 m;

	while ((m = i2o_msg_get(c, msg)) == I2O_QUEUE_EMPTY) {
		if (time_after(jiffies, timeout)) {
			osm_debug("%s: Timeout waiting for message frame.\n",
				  c->name);
			return I2O_QUEUE_EMPTY;
		}
		schedule_timeout_uninterruptible(1);
	}

	return m;
};

#if BITS_PER_LONG == 64
/**
 *      i2o_cntxt_list_add - Append a pointer to context list and return a id
 *	@c: controller to which the context list belong
 *	@ptr: pointer to add to the context list
 *
 *	Because the context field in I2O is only 32-bit large, on 64-bit the
 *	pointer is to large to fit in the context field. The i2o_cntxt_list
 *	functions therefore map pointers to context fields.
 *
 *	Returns context id > 0 on success or 0 on failure.
 */
u32 i2o_cntxt_list_add(struct i2o_controller * c, void *ptr)
{
	struct i2o_context_list_element *entry;
	unsigned long flags;

	if (!ptr)
		osm_err("%s: couldn't add NULL pointer to context list!\n",
			c->name);

	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
	if (!entry) {
		osm_err("%s: Could not allocate memory for context list element"
			"\n", c->name);
		return 0;
	}

	entry->ptr = ptr;
	entry->timestamp = jiffies;
	INIT_LIST_HEAD(&entry->list);

	spin_lock_irqsave(&c->context_list_lock, flags);

	if (unlikely(atomic_inc_and_test(&c->context_list_counter)))
		atomic_inc(&c->context_list_counter);

	entry->context = atomic_read(&c->context_list_counter);

	list_add(&entry->list, &c->context_list);

	spin_unlock_irqrestore(&c->context_list_lock, flags);

	osm_debug("%s: Add context to list %p -> %d\n", c->name, ptr, context);

	return entry->context;
};

/**
 *      i2o_cntxt_list_remove - Remove a pointer from the context list
 *	@c: controller to which the context list belong
 *	@ptr: pointer which should be removed from the context list
 *
 *	Removes a previously added pointer from the context list and returns
 *	the matching context id.
 *
 *	Returns context id on succes or 0 on failure.
 */
u32 i2o_cntxt_list_remove(struct i2o_controller * c, void *ptr)
{
	struct i2o_context_list_element *entry;
	u32 context = 0;
	unsigned long flags;

	spin_lock_irqsave(&c->context_list_lock, flags);
	list_for_each_entry(entry, &c->context_list, list)
	    if (entry->ptr == ptr) {
		list_del(&entry->list);
		context = entry->context;
		kfree(entry);
		break;
	}
	spin_unlock_irqrestore(&c->context_list_lock, flags);

	if (!context)
		osm_warn("%s: Could not remove nonexistent ptr %p\n", c->name,
			 ptr);

	osm_debug("%s: remove ptr from context list %d -> %p\n", c->name,
		  context, ptr);

	return context;
};

/**
 *      i2o_cntxt_list_get - Get a pointer from the context list and remove it
 *	@c: controller to which the context list belong
 *	@context: context id to which the pointer belong
 *
 *	Returns pointer to the matching context id on success or NULL on
 *	failure.
 */
void *i2o_cntxt_list_get(struct i2o_controller *c, u32 context)
{
	struct i2o_context_list_element *entry;
	unsigned long flags;
	void *ptr = NULL;

	spin_lock_irqsave(&c->context_list_lock, flags);
	list_for_each_entry(entry, &c->context_list, list)
	    if (entry->context == context) {
		list_del(&entry->list);
		ptr = entry->ptr;
		kfree(entry);
		break;
	}
	spin_unlock_irqrestore(&c->context_list_lock, flags);

	if (!ptr)
		osm_warn("%s: context id %d not found\n", c->name, context);

	osm_debug("%s: get ptr from context list %d -> %p\n", c->name, context,
		  ptr);

	return ptr;
};

/**
 *      i2o_cntxt_list_get_ptr - Get a context id from the context list
 *	@c: controller to which the context list belong
 *	@ptr: pointer to which the context id should be fetched
 *
 *	Returns context id which matches to the pointer on succes or 0 on
 *	failure.
 */
u32 i2o_cntxt_list_get_ptr(struct i2o_controller * c, void *ptr)
{
	struct i2o_context_list_element *entry;
	u32 context = 0;
	unsigned long flags;

	spin_lock_irqsave(&c->context_list_lock, flags);
	list_for_each_entry(entry, &c->context_list, list)
	    if (entry->ptr == ptr) {
		context = entry->context;
		break;
	}
	spin_unlock_irqrestore(&c->context_list_lock, flags);

	if (!context)
		osm_warn("%s: Could not find nonexistent ptr %p\n", c->name,
			 ptr);

	osm_debug("%s: get context id from context list %p -> %d\n", c->name,
		  ptr, context);

	return context;
};
#endif

/**
 *	i2o_iop_find - Find an I2O controller by id
 *	@unit: unit number of the I2O controller to search for
 *
 *	Lookup the I2O controller on the controller list.
 *
 *	Returns pointer to the I2O controller on success or NULL if not found.
 */
struct i2o_controller *i2o_find_iop(int unit)
{
	struct i2o_controller *c;

	list_for_each_entry(c, &i2o_controllers, list) {
		if (c->unit == unit)
			return c;
	}

	return NULL;
};

/**
 *	i2o_iop_find_device - Find a I2O device on an I2O controller
 *	@c: I2O controller where the I2O device hangs on
 *	@tid: TID of the I2O device to search for
 *
 *	Searches the devices of the I2O controller for a device with TID tid and
 *	returns it.
 *
 *	Returns a pointer to the I2O device if found, otherwise NULL.
 */
struct i2o_device *i2o_iop_find_device(struct i2o_controller *c, u16 tid)
{
	struct i2o_device *dev;

	list_for_each_entry(dev, &c->devices, list)
	    if (dev->lct_data.tid == tid)
		return dev;

	return NULL;
};

/**
 *	i2o_quiesce_controller - quiesce controller
 *	@c: controller
 *
 *	Quiesce an IOP. Causes IOP to make external operation quiescent
 *	(i2o 'READY' state). Internal operation of the IOP continues normally.
 *
 *	Returns 0 on success or negative error code on failure.
 */
static int i2o_iop_quiesce(struct i2o_controller *c)
{
	struct i2o_message __iomem *msg;
	u32 m;
	i2o_status_block *sb = c->status_block.virt;
	int rc;

	i2o_status_get(c);

	/* SysQuiesce discarded if IOP not in READY or OPERATIONAL state */
	if ((sb->iop_state != ADAPTER_STATE_READY) &&
	    (sb->iop_state != ADAPTER_STATE_OPERATIONAL))
		return 0;

	m = i2o_msg_get_wait(c, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return -ETIMEDOUT;

	writel(FOUR_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_SYS_QUIESCE << 24 | HOST_TID << 12 | ADAPTER_TID,
	       &msg->u.head[1]);

	/* Long timeout needed for quiesce if lots of devices */
	if ((rc = i2o_msg_post_wait(c, m, 240)))
		osm_info("%s: Unable to quiesce (status=%#x).\n", c->name, -rc);
	else
		osm_debug("%s: Quiesced.\n", c->name);

	i2o_status_get(c);	// Entered READY state

	return rc;
};

/**
 *	i2o_iop_enable - move controller from ready to OPERATIONAL
 *	@c: I2O controller
 *
 *	Enable IOP. This allows the IOP to resume external operations and
 *	reverses the effect of a quiesce. Returns zero or an error code if
 *	an error occurs.
 */
static int i2o_iop_enable(struct i2o_controller *c)
{
	struct i2o_message __iomem *msg;
	u32 m;
	i2o_status_block *sb = c->status_block.virt;
	int rc;

	i2o_status_get(c);

	/* Enable only allowed on READY state */
	if (sb->iop_state != ADAPTER_STATE_READY)
		return -EINVAL;

	m = i2o_msg_get_wait(c, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return -ETIMEDOUT;

	writel(FOUR_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_SYS_ENABLE << 24 | HOST_TID << 12 | ADAPTER_TID,
	       &msg->u.head[1]);

	/* How long of a timeout do we need? */
	if ((rc = i2o_msg_post_wait(c, m, 240)))
		osm_err("%s: Could not enable (status=%#x).\n", c->name, -rc);
	else
		osm_debug("%s: Enabled.\n", c->name);

	i2o_status_get(c);	// entered OPERATIONAL state

	return rc;
};

/**
 *	i2o_iop_quiesce_all - Quiesce all I2O controllers on the system
 *
 *	Quiesce all I2O controllers which are connected to the system.
 */
static inline void i2o_iop_quiesce_all(void)
{
	struct i2o_controller *c, *tmp;

	list_for_each_entry_safe(c, tmp, &i2o_controllers, list) {
		if (!c->no_quiesce)
			i2o_iop_quiesce(c);
	}
};

/**
 *	i2o_iop_enable_all - Enables all controllers on the system
 *
 *	Enables all I2O controllers which are connected to the system.
 */
static inline void i2o_iop_enable_all(void)
{
	struct i2o_controller *c, *tmp;

	list_for_each_entry_safe(c, tmp, &i2o_controllers, list)
	    i2o_iop_enable(c);
};

/**
 *	i2o_clear_controller - Bring I2O controller into HOLD state
 *	@c: controller
 *
 *	Clear an IOP to HOLD state, ie. terminate external operations, clear all
 *	input queues and prepare for a system restart. IOP's internal operation
 *	continues normally and the outbound queue is alive. The IOP is not
 *	expected to rebuild its LCT.
 *
 *	Returns 0 on success or negative error code on failure.
 */
static int i2o_iop_clear(struct i2o_controller *c)
{
	struct i2o_message __iomem *msg;
	u32 m;
	int rc;

	m = i2o_msg_get_wait(c, &msg, I2O_TIMEOUT_MESSAGE_GET);
	if (m == I2O_QUEUE_EMPTY)
		return -ETIMEDOUT;

	/* Quiesce all IOPs first */
	i2o_iop_quiesce_all();

	writel(FOUR_WORD_MSG_SIZE | SGL_OFFSET_0, &msg->u.head[0]);
	writel(I2O_CMD_ADAPTER_CLEAR << 24 | HOST_TID << 12 | ADAPTER_TID,
	       &msg->u.head[1]);

	if ((rc = i2o_msg_post_wait(c, m, 30)))
		osm_info("%s: Unable to clear (status=%#x).\n", c->name, -rc);
	else
		osm_debug("%s: Cleared.\n", c->name);

	/* Enable all IOPs */