/*
 *	Adaptec AAC series RAID controller driver
 *	(c) Copyright 2001 Red Hat Inc.
 *
 * based on the old aacraid driver that is..
 * Adaptec aacraid device driver for Linux.
 *
 * Copyright (c) 2000-2010 Adaptec, Inc.
 *               2010-2015 PMC-Sierra, Inc. (aacraid@pmc-sierra.com)
 *		 2016-2017 Microsemi Corp. (aacraid@microsemi.com)
 *
 * 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, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Module Name:
 *  dpcsup.c
 *
 * Abstract: All DPC processing routines for the cyclone board occur here.
 *
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <linux/blkdev.h>
#include <linux/semaphore.h>

#include "aacraid.h"

/**
 *	aac_response_normal	-	Handle command replies
 *	@q: Queue to read from
 *
 *	This DPC routine will be run when the adapter interrupts us to let us
 *	know there is a response on our normal priority queue. We will pull off
 *	all QE there are and wake up all the waiters before exiting. We will
 *	take a spinlock out on the queue before operating on it.
 */

unsigned int aac_response_normal(struct aac_queue * q)
{
	struct aac_dev * dev = q->dev;
	struct aac_entry *entry;
	struct hw_fib * hwfib;
	struct fib * fib;
	int consumed = 0;
	unsigned long flags, mflags;

	spin_lock_irqsave(q->lock, flags);
	/*
	 *	Keep pulling response QEs off the response queue and waking
	 *	up the waiters until there are no more QEs. We then return
	 *	back to the system. If no response was requesed we just
	 *	deallocate the Fib here and continue.
	 */
	while(aac_consumer_get(dev, q, &entry))
	{
		int fast;
		u32 index = le32_to_cpu(entry->addr);
		fast = index & 0x01;
		fib = &dev->fibs[index >> 2];
		hwfib = fib->hw_fib_va;
		
		aac_consumer_free(dev, q, HostNormRespQueue);
		/*
		 *	Remove this fib from the Outstanding I/O queue.
		 *	But only if it has not already been timed out.
		 *
		 *	If the fib has been timed out already, then just 
		 *	continue. The caller has already been notified that
		 *	the fib timed out.
		 */
		atomic_dec(&dev->queues->queue[AdapNormCmdQueue].numpending);

		if (unlikely(fib->flags & FIB_CONTEXT_FLAG_TIMED_OUT)) {
			spin_unlock_irqrestore(q->lock, flags);
			aac_fib_complete(fib);
			aac_fib_free(fib);
			spin_lock_irqsave(q->lock, flags);
			continue;
		}
		spin_unlock_irqrestore(q->lock, flags);

		if (fast) {
			/*
			 *	Doctor the fib
			 */
			*(__le32 *)hwfib->data = cpu_to_le32(ST_OK);
			hwfib->header.XferState |= cpu_to_le32(AdapterProcessed);
			fib->flags |= FIB_CONTEXT_FLAG_FASTRESP;
		}

		FIB_COUNTER_INCREMENT(aac_config.FibRecved);

		if (hwfib->header.Command == cpu_to_le16(NuFileSystem))
		{
			__le32 *pstatus = (__le32 *)hwfib->data;
			if (*pstatus & cpu_to_le32(0xffff0000))
				*pstatus = cpu_to_le32(ST_OK);
		}
		if (hwfib->header.XferState & cpu_to_le32(NoResponseExpected | Async)) 
		{
	        	if (hwfib->header.XferState & cpu_to_le32(NoResponseExpected))
				FIB_COUNTER_INCREMENT(aac_config.NoResponseRecved);
			else 
				FIB_COUNTER_INCREMENT(aac_config.AsyncRecved);
			/*
			 *	NOTE:  we cannot touch the fib after this
			 *	    call, because it may have been deallocated.
			 */
			fib->callback(fib->callback_data, fib);
		} else {
			unsigned long flagv;
			spin_lock_irqsave(&fib->event_lock, flagv);
			if (!fib->done) {
				fib->done = 1;
				up(&fib->event_wait);
			}
			spin_unlock_irqrestore(&fib->event_lock, flagv);

			spin_lock_irqsave(&dev->manage_lock, mflags);
			dev->management_fib_count--;
			spin_unlock_irqrestore(&dev->manage_lock, mflags);

			FIB_COUNTER_INCREMENT(aac_config.NormalRecved);
			if (fib->done == 2) {
				spin_lock_irqsave(&fib->event_lock, flagv);
				fib->done = 0;
				spin_unlock_irqrestore(&fib->event_lock, flagv);
				aac_fib_complete(fib);
				aac_fib_free(fib);
			}
		}
		consumed++;
		spin_lock_irqsave(q->lock, flags);
	}

	if (consumed > aac_config.peak_fibs)
		aac_config.peak_fibs = consumed;
	if (consumed == 0) 
		aac_config.zero_fibs++;

	spin_unlock_irqrestore(q->lock, flags);
	return 0;
}


/**
 *	aac_command_normal	-	handle commands
 *	@q: queue to process
 *
 *	This DPC routine will be queued when the adapter interrupts us to 
 *	let us know there is a command on our normal priority queue. We will 
 *	pull off all QE there are and wake up all the waiters before exiting.
 *	We will take a spinlock out on the queue before operating on it.
 */
 
unsigned int aac_command_normal(struct aac_queue *q)
{
	struct aac_dev * dev = q->dev;
	struct aac_entry *entry;
	unsigned long flags;

	spin_lock_irqsave(q->lock, flags);

	/*
	 *	Keep pulling response QEs off the response queue and waking
	 *	up the waiters until there are no more QEs. We then return
	 *	back to the system.
	 */
	while(aac_consumer_get(dev, q, &entry))
	{
		struct fib fibctx;
		struct hw_fib * hw_fib;
		u32 index;
		struct fib *fib = &fibctx;
		
		index = le32_to_cpu(entry->addr) / sizeof(struct hw_fib);
		hw_fib = &dev->aif_base_va[index];
		
		/*
		 *	Allocate a FIB at all costs. For non queued stuff
		 *	we can just use the stack so we are happy. We need
		 *	a fib object in order to manage the linked lists
		 */
		if (dev->aif_thread)
			if((fib = kmalloc(sizeof(struct fib), GFP_ATOMIC)) == NULL)
				fib = &fibctx;
		
		memset(fib, 0, sizeof(struct fib));
		INIT_LIST_HEAD(&fib->fiblink);
		fib->type = FSAFS_NTC_FIB_CONTEXT;
		fib->size = sizeof(struct fib);
		fib->hw_fib_va = hw_fib;
		fib->data = hw_fib->data;
		fib->dev = dev;
		
				
		if (dev->aif_thread && fib != &fibctx) {
		        list_add_tail(&fib->fiblink, &q->cmdq);
	 	        aac_consumer_free(dev, q, HostNormCmdQueue);
		        wake_up_interruptible(&q->cmdready);
		} else {
	 	        aac_consumer_free(dev, q, HostNormCmdQueue);
			spin_unlock_irqrestore(q->lock, flags);
			/*
			 *	Set the status of this FIB
			 */
			*(__le32 *)hw_fib->data = cpu_to_le32(ST_OK);
			aac_fib_adapter_complete(fib, sizeof(u32));
			spin_lock_irqsave(q->lock, flags);
		}		
	}
	spin_unlock_irqrestore(q->lock, flags);
	return 0;
}

/*
 *
 * aac_aif_callback
 * @context: the context set in the fib - here it is scsi cmd
 * @fibptr: pointer to the fib
 *
 * Handles the AIFs - new method (SRC)
 *
 */

static void aac_aif_callback(void *context, struct fib * fibptr)
{
	struct fib *fibctx;
	struct aac_dev *dev;
	struct aac_aifcmd *cmd;
	int status;

	fibctx = (struct fib *)context;
	BUG_ON(fibptr == NULL);
	dev = fibptr->dev;

	if ((fibptr->hw_fib_va->header.XferState &
	    cpu_to_le32(NoMoreAifDataAvailable)) ||
		dev->sa_firmware) {
		aac_fib_complete(fibptr);
		aac_fib_free(fibptr);
		return;
	}

	aac_intr_normal(dev, 0, 1, 0, fibptr->hw_fib_va);

	aac_fib_init(fibctx);
	cmd = (struct aac_aifcmd *) fib_data(fibctx);
	cmd->command = cpu_to_le32(AifReqEvent);

	status = aac_fib_send(AifRequest,
		fibctx,
		sizeof(struct hw_fib)-sizeof(struct aac_fibhdr),
		FsaNormal,
		0, 1,
		(fib_callback)aac_aif_callback, fibctx);
}


/**
 *	aac_intr_normal	-	Handle command replies
 *	@dev: Device
 *	@index: completion reference
 *
 *	This DPC routine will be run when the adapter interrupts us to let us
 *	know there is a response on our normal priority queue. We will pull off
 *	all QE there are and wake up all the waiters before exiting.
 */
unsigned int aac_intr_normal(struct aac_dev *dev, u32 index, int isAif,
	int isFastResponse, struct hw_fib *aif_fib)
{
	unsigned long mflags;
	dprintk((KERN_INFO "aac_intr_normal(%p,%x)\n", dev, index));
	if (isAif == 1) {	/* AIF - common */
		struct hw_fib * hw_fib;
		struct fib * fib;
		struct aac_queue *q = &dev->queues->queue[HostNormCmdQueue];
		unsigned long flags;

		/*
		 *	Allocate a FIB. For non queued stuff we can just use
		 * the stack so we are happy. We need a fib object in order to
		 * manage the linked lists.
		 */
		if ((!dev->aif_thread)
		 || (!(fib = kzalloc(sizeof(struct fib),GFP_ATOMIC))))
			return 1;
		if (!(hw_fib = kzalloc(sizeof(struct hw_fib),GFP_ATOMIC))) {
			kfree (fib);
			return 1;
		}
		if (dev->sa_firmware) {
			fib->hbacmd_size = index;	/* store event type */
		} else if (aif_fib != NULL) {
			memcpy(hw_fib, aif_fib, sizeof(struct hw_fib));
		} else {
			memcpy(hw_fib, (struct hw_fib *)
				(((uintptr_t)(dev->regs.sa)) + index),
				sizeof(struct hw_fib));
		}
		INIT_LIST_HEAD(&fib->fiblink);
		fib->type = FSAFS_NTC_FIB_CONTEXT;
		fib->size = sizeof(struct fib);
		fib->hw_fib_va = hw_fib;
		fib->data = hw_fib->data;
		fib->dev = dev;
	
		spin_lock_irqsave(q->lock, flags);
		list_add_tail(&fib->fiblink, &q->cmdq);
	        wake_up_interruptible(&q->cmdready);
		spin_unlock_irqrestore(q->lock, flags);
		return 1;
	} else if (isAif == 2) {	/* AIF - new (SRC) */
		struct fib *fibctx;
		struct aac_aifcmd *cmd;

		fibctx = aac_fib_alloc(dev);
		if (!fibctx)
			return 1;
		aac_fib_init(fibctx);

		cmd = (struct aac_aifcmd *) fib_data(fibctx);
		cmd->command = cpu_to_le32(AifReqEvent);

		return aac_fib_send(AifRequest,
			fibctx,
			sizeof(struct hw_fib)-sizeof(struct aac_fibhdr),
			FsaNormal,
			0, 1,
			(fib_callback)aac_aif_callback, fibctx);
	} else {
		struct fib *fib = &dev->fibs[index];
		int start_callback = 0;

		/*
		 *	Remove this fib from the Outstanding I/O queue.
		 *	But only if it has not already been timed out.
		 *
		 *	If the fib has been timed out already, then just 
		 *	continue. The caller has already been notified that
		 *	the fib timed out.
		 */
		atomic_dec(&dev->queues->queue[AdapNormCmdQueue].numpending);

		if (unlikely(fib->flags & FIB_CONTEXT_FLAG_TIMED_OUT)) {
			aac_fib_complete(fib);
			aac_fib_free(fib);
			return 0;
		}

		FIB_COUNTER_INCREMENT(aac_config.FibRecved);

		if (fib->flags & FIB_CONTEXT_FLAG_NATIVE_HBA) {

			if (isFastResponse)
				fib->flags |= FIB_CONTEXT_FLAG_FASTRESP;

			if (fib->callback) {
				start_callback = 1;
			} else {
				unsigned long flagv;
				int complete = 0;

				dprintk((KERN_INFO "event_wait up\n"));
				spin_lock_irqsave(&fib->event_lock, flagv);
				if (fib->done == 2) {
					fib->done = 1;
					complete = 1;
				} else {
					fib->done = 1;
					up(&fib->event_wait);
				}
				spin_unlock_irqrestore(&fib->event_lock, flagv);

				spin_lock_irqsave(&dev->manage_lock, mflags);
				dev->management_fib_count--;
				spin_unlock_irqrestore(&dev->manage_lock,
					mflags);

				FIB_COUNTER_INCREMENT(aac_config.NativeRecved);
				if (complete)
					aac_fib_complete(fib);
			}
		} else {
			struct hw_fib *hwfib = fib->hw_fib_va;

			if (isFastResponse) {
				/* Doctor the fib */
				*(__le32 *)hwfib->data = cpu_to_le32(ST_OK);
				hwfib->header.XferState |=
					cpu_to_le32(AdapterProcessed);
				fib->flags |= FIB_CONTEXT_FLAG_FASTRESP;
			}

			if (hwfib->header.Command ==
				cpu_to_le16(NuFileSystem)) {
				__le32 *pstatus = (__le32 *)hwfib->data;

				if (*pstatus & cpu_to_le32(0xffff0000))
					*pstatus = cpu_to_le32(ST_OK);
			}
			if (hwfib->header.XferState &
				cpu_to_le32(NoResponseExpected | Async)) {
				if (hwfib->header.XferState & cpu_to_le32(
					NoResponseExpected))
					FIB_COUNTER_INCREMENT(
						aac_config.NoResponseRecved);
				else
					FIB_COUNTER_INCREMENT(
						aac_config.AsyncRecved);
				start_callback = 1;
			} else {
				unsigned long flagv;
				int complete = 0;

				dprintk((KERN_INFO "event_wait up\n"));
				spin_lock_irqsave(&fib->event_lock, flagv);
				if (fib->done == 2) {
					fib->done = 1;
					complete = 1;
				} else {
					fib->done = 1;
					up(&fib->event_wait);
				}
				spin_unlock_irqrestore(&fib->event_lock, flagv);

				spin_lock_irqsave(&dev->manage_lock, mflags);
				dev->management_fib_count--;
				spin_unlock_irqrestore(&dev->manage_lock,
					mflags);

				FIB_COUNTER_INCREMENT(aac_config.NormalRecved);
				if (complete)
					aac_fib_complete(fib);
			}
		}


		if (start_callback) {
			/*
			 * NOTE:  we cannot touch the fib after this
			 *  call, because it may have been deallocated.
			 */
			if (likely(fib->callback && fib->callback_data)) {
				fib->callback(fib->callback_data, fib);
			} else {
				aac_fib_complete(fib);
				aac_fib_free(fib);
			}

		}
		return 0;
	}
}