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/*

 * Copyright (C) 2001-2004 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include <typedefs.h>

#include <arch/types.h>

#include <mm/heap.h>

#include <mm/frame.h>

#include <mm/vm.h>

#include <panic.h>

#include <debug.h>

#include <list.h>

#include <synch/spinlock.h>

#include <arch/asm.h>

#include <arch.h>

spinlock_t zone_head_lock;       /**< this lock protects zone_head list */

link_t zone_head;                /**< list of all zones in the system */

static struct buddy_system_operations  zone_buddy_system_operations = {

	.find_buddy = zone_buddy_find_buddy,

	.bisect = zone_buddy_bisect,

	.coalesce = zone_buddy_coalesce,

	.set_order = zone_buddy_set_order,

	.get_order = zone_buddy_get_order,

};

/** Initialize physical memory management

 *

 * Initialize physical memory managemnt.

 */

void frame_init(void)

{

	if (config.cpu_active == 1) {

		zone_init();

	}

	frame_arch_init();

	if (config.cpu_active == 1) {

                frame_region_not_free(config.base, config.base + config.kernel_size + CONFIG_STACK_SIZE);

        }	

}

/** Allocate a frame

 *

 * Allocate a frame of physical memory.

 *

 * @param flags Flags for host zone selection and address processing.

 *

 * @return Allocated frame.

 */

__address frame_alloc(int flags)

{

	ipl_t ipl;

	link_t *cur, *tmp;

	zone_t *z;

	zone_t *zone = NULL;

	frame_t *frame = NULL;

	__address v;

loop:

	ipl = interrupts_disable();

	spinlock_lock(&zone_head_lock);

	/*

	 * First, find suitable frame zone.

	 */

	for (cur = zone_head.next; cur != &zone_head; cur = cur->next) {

		z = list_get_instance(cur, zone_t, link);

		spinlock_lock(&z->lock);

		/*

		 * Check if the zone has any free frames.

		 */

		if (z->free_count) {

			zone = z;

			break;

		}

		spinlock_unlock(&z->lock);

	}

	if (!zone) {

		if (flags & FRAME_PANIC)

			panic("Can't allocate frame.\n");

		/*

		 * TODO: Sleep until frames are available again.

		 */

		spinlock_unlock(&zone_head_lock);

		interrupts_restore(ipl);

		panic("Sleep not implemented.\n");

		goto loop;

	}

	tmp = zone->free_head.next;

	frame = list_get_instance(tmp, frame_t, link);

	frame->refcount++;

	list_remove(tmp);			/* remove frame from free_head */

	zone->free_count--;

	zone->busy_count++;

	//v = zone->base + (frame - zone->frames) * FRAME_SIZE;

	v = FRAME2ADDR(zone, frame);

	if (flags & FRAME_KA)

		v = PA2KA(v);

	spinlock_unlock(&zone->lock);

	spinlock_unlock(&zone_head_lock);

	interrupts_restore(ipl);

	return v;

}

/** Free a frame.

 *

 * Find respective frame structrue for supplied addr.

 * Decrement frame reference count.

 * If it drops to zero, move the frame structure to free list.

 *

 * @param addr Address of the frame to be freed. It must be a multiple of FRAME_SIZE.

 */

void frame_free(__address addr)

{

	ipl_t ipl;

	link_t *cur;

	zone_t *z;

	zone_t *zone = NULL;

	frame_t *frame;

	ASSERT(addr % FRAME_SIZE == 0);

	ipl = interrupts_disable();

	spinlock_lock(&zone_head_lock);

	/*

	 * First, find host frame zone for addr.

	 */

	for (cur = zone_head.next; cur != &zone_head; cur = cur->next) {

		z = list_get_instance(cur, zone_t, link);

		spinlock_lock(&z->lock);

		if (IS_KA(addr))

			addr = KA2PA(addr);

		/*

		 * Check if addr belongs to z.

		 */

		if ((addr >= z->base) && (addr <= z->base + (z->free_count + z->busy_count) * FRAME_SIZE)) {

			zone = z;

			break;

		}

		spinlock_unlock(&z->lock);

	}

	ASSERT(zone != NULL);

	frame = ADDR2FRAME(zone, addr);

	// frame = &zone->frames[(addr - zone->base)/FRAME_SIZE];

	ASSERT(frame->refcount);

	if (!--frame->refcount) {

		list_append(&frame->link, &zone->free_head);	/* append frame to free_head */

		zone->free_count++;

		zone->busy_count--;

	}

	spinlock_unlock(&zone->lock);	

	spinlock_unlock(&zone_head_lock);

	interrupts_restore(ipl);

}

/** Mark frame not free.

 *

 * Find respective frame structrue for supplied addr.

 * Increment frame reference count and remove the frame structure from free list.

 *

 * @param addr Address of the frame to be marked. It must be a multiple of FRAME_SIZE.

 */

void frame_not_free(__address addr)

{

	ipl_t ipl;

	link_t *cur;

	zone_t *z;

	zone_t *zone = NULL;

	frame_t *frame;

	ASSERT(addr % FRAME_SIZE == 0);

	ipl = interrupts_disable();

	spinlock_lock(&zone_head_lock);

	/*

	 * First, find host frame zone for addr.

	 */

	for (cur = zone_head.next; cur != &zone_head; cur = cur->next) {

		z = list_get_instance(cur, zone_t, link);

		spinlock_lock(&z->lock);

		if (IS_KA(addr))

			addr = KA2PA(addr);

		/*

		 * Check if addr belongs to z.

		 */

		if ((addr >= z->base) && (addr <= z->base + (z->free_count + z->busy_count) * FRAME_SIZE)) {

			zone = z;

			break;

		}

		spinlock_unlock(&z->lock);

	}

	ASSERT(zone != NULL);

	//frame = &zone->frames[(addr - zone->base)/FRAME_SIZE];

	frame = ADDR2FRAME(zone, addr);

	if (!frame->refcount) {

		frame->refcount++;

		list_remove(&frame->link);			/* remove frame from free_head */

		zone->free_count--;

		zone->busy_count++;

	}

	spinlock_unlock(&zone->lock);	

	spinlock_unlock(&zone_head_lock);

	interrupts_restore(ipl);

}

/** Mark frame region not free.

 *

 * Mark frame region not free.

 *

 * @param start First address.

 * @param stop Last address.

 */

void frame_region_not_free(__address start, __address stop)

{

        __address a;

        start /= FRAME_SIZE;

        stop /= FRAME_SIZE;

        for (a = start; a <= stop; a++)

                frame_not_free(a * FRAME_SIZE);

}

/** Initialize zonekeeping

 *

 * Initialize zonekeeping.

 */

void zone_init(void)

{

	spinlock_initialize(&zone_head_lock);

	list_initialize(&zone_head);

}

/** Create frame zone

 *

 * Create new frame zone.

 *

 * @param start Physical address of the first frame within the zone.

 * @param size Size of the zone. Must be a multiple of FRAME_SIZE.

 * @param flags Zone flags.

 *

 * @return Initialized zone.

 */

zone_t *zone_create(__address start, size_t size, int flags)

{

	zone_t *z;

	count_t cnt;

	int i;

	__u8 max_order;

	ASSERT(start % FRAME_SIZE == 0);

	ASSERT(size % FRAME_SIZE == 0);

	cnt = size / FRAME_SIZE;

	z = (zone_t *) early_malloc(sizeof(zone_t));

	if (z) {

		link_initialize(&z->link);

		spinlock_initialize(&z->lock);

		z->base = start;

		z->flags = flags;

		z->free_count = cnt;

		list_initialize(&z->free_head);

		z->busy_count = 0;

		z->frames = (frame_t *) early_malloc(cnt * sizeof(frame_t));

		if (!z->frames) {

			early_free(z);

			return NULL;

		}

		for (i = 0; i<cnt; i++) {

			frame_initialize(&z->frames[i], z);

			list_append(&z->frames[i].link, &z->free_head);

		}

		/*

		 * Create buddy system for the zone

		 */

		for (max_order = 0; cnt >> max_order; max_order++);

		z->buddy_system = buddy_system_create(max_order, &zone_buddy_system_operations, (void *) z);

	}

	return z;

}

/** Attach frame zone

 *

 * Attach frame zone to zone list.

 *

 * @param zone Zone to be attached.

 */

void zone_attach(zone_t *zone)

{

	ipl_t ipl;

	ipl = interrupts_disable();

	spinlock_lock(&zone_head_lock);

	list_append(&zone->link, &zone_head);

	spinlock_unlock(&zone_head_lock);

	interrupts_restore(ipl);

}

/** Initialize frame structure

 *

 * Initialize frame structure.

 *

 * @param frame Frame structure to be initialized.

 * @param zone Host frame zone.

 */

void frame_initialize(frame_t *frame, zone_t *zone)

{

	frame->refcount = 0;

	link_initialize(&frame->link);

}

/*

 * buddy system functions (under construction)

 * 

 */

/** Allocate 2^order frames

 *

 */

__address zone_buddy_frame_alloc(int flags, __u8 order) {

	ipl_t ipl;

	link_t *cur, *tmp;

	zone_t *z;

	zone_t *zone = NULL;

	frame_t *frame = NULL;

	__address v;

loop:

	ipl = interrupts_disable();

	spinlock_lock(&zone_head_lock);

	/*

	 * First, find suitable frame zone.

	 */

	for (cur = zone_head.next; cur != &zone_head; cur = cur->next) {

		z = list_get_instance(cur, zone_t, link);

		spinlock_lock(&z->lock);

		/*

		 * Check if the zone has 2^order frames area available

		 * TODO: Must check if buddy system has at least block in order >= given order

		 */

		if (z->free_count == (1 >> order)) { 

			zone = z;

			break;

		}

		spinlock_unlock(&z->lock);

	}

	if (!zone) {

		if (flags & FRAME_PANIC)

			panic("Can't allocate frame.\n");

		/*

		 * TODO: Sleep until frames are available again.

		 */

		spinlock_unlock(&zone_head_lock);

		interrupts_restore(ipl);

		panic("Sleep not implemented.\n");

		goto loop;

	}

	/* Allocate frames from zone buddy system */

	cur = buddy_system_alloc(zone->buddy_system, order);

	/* frame will be actually a first frame of the block */

	frame = list_get_instance(cur, frame_t, buddy_link);

	/* get frame address */

	v = FRAME2ADDR(zone, frame);

	if (flags & FRAME_KA)

		v = PA2KA(v);

	spinlock_unlock(&zone->lock);

	spinlock_unlock(&zone_head_lock);

	interrupts_restore(ipl);

	return v;

}

/** Free frame(s)

 *

 * @param addr Address of the frame(s) to be freed. It must be a multiple of FRAME_SIZE.

 */

void zone_buddy_frame_free(__address addr)

{

	ipl_t ipl;

	link_t *cur;

	zone_t *z;

	zone_t *zone = NULL;

	frame_t *frame;

	ASSERT(addr % FRAME_SIZE == 0);

	ipl = interrupts_disable();

	spinlock_lock(&zone_head_lock);

	/*

	 * First, find host frame zone for addr.

	 */

	for (cur = zone_head.next; cur != &zone_head; cur = cur->next) {

		z = list_get_instance(cur, zone_t, link);

		spinlock_lock(&z->lock);

		if (IS_KA(addr))

			addr = KA2PA(addr);

		/*

		 * Check if addr belongs to z.

		 */

		if ((addr >= z->base) && (addr <= z->base + (z->free_count + z->busy_count) * FRAME_SIZE)) {

			zone = z;

			break;

		}

		spinlock_unlock(&z->lock);

	}

	ASSERT(zone != NULL);

	frame = ADDR2FRAME(zone, addr);

	ASSERT(frame->refcount);

	if (!--frame->refcount) {

		buddy_system_free(zone->buddy_system, &frame->buddy_link);

	}

	spinlock_unlock(&zone->lock);	

	spinlock_unlock(&zone_head_lock);

	interrupts_restore(ipl);

}

/** Guess zone by frame instance address

 *

 * @param frame Frame

 *

 * @return Zone of given frame

 */

zone_t * get_zone_by_frame(frame_t * frame) {

	link_t * cur;

	zone_t * zone, *z;

	ASSERT(frame);

	/*

	 * First, find host frame zone for addr.

	 */

	for (cur = zone_head.next; cur != &zone_head; cur = cur->next) {

		z = list_get_instance(cur, zone_t, link);

		spinlock_lock(&z->lock);

		/*

		 * Check if frame address belongs to z.

		 */

		if ((frame >= z->frames) && (frame <= z->frames + (z->free_count + z->busy_count))) {

			zone = z;

			break;

		}

		spinlock_unlock(&z->lock);

	}

	ASSERT(zone);

	return zone;

}

/** Buddy system find_buddy implementation

 *

 * @param b Buddy system.

 * @param block Block for which buddy should be found

 *

 * @return Buddy for given block if found

 */

link_t * zone_buddy_find_buddy(buddy_system_t *b, link_t * block) {

	frame_t * frame, * f;

	zone_t * zone;

	link_t * cur;

	bool is_left, is_right;

	frame = list_get_instance(block, frame_t, buddy_link);

	zone = get_zone_by_frame(frame);

	/* 

	 * (FRAME_INDEX % 2^(ORDER+1)) == 0 ===> LEFT BUDDY 

	 * (FRAME_INDEX % 2^(ORDER+1)) == 2^(ORDER) ===> RIGHT BUDDY

	 */

	is_left = IS_BUDDY_LEFT_BLOCK(zone, frame);

	is_right = IS_BUDDY_RIGHT_BLOCK(zone, frame);

	ASSERT((is_left || is_right) && (!is_left || !is_right));

	for (cur = &zone->buddy_system->order[frame->buddy_order]; cur; cur = cur->next) {

		f = list_get_instance(cur, frame_t, buddy_link);

		ASSERT(f->buddy_order == frame->buddy_order);

		/* 

		 * if found frame is coherent with our frame from the left 

		 */

		if ((FRAME_INDEX(zone, f) + 1 >> frame->buddy_order == FRAME_INDEX(zone, frame)) && is_right) {

			return cur;

		}

		/* 

		 * if found frame is coherent with our frame from the right 

		 */

		if ((FRAME_INDEX(zone,f) - 1 >> frame->buddy_order == FRAME_INDEX(zone, frame)) && is_left) {

			return cur;

		}

	}

	return NULL;

}

/** Buddy system bisect implementation

 *

 * @param b Buddy system.

 * @param block Block to bisect

 *

 * @return right block

 */

link_t * zone_buddy_bisect(buddy_system_t *b, link_t * block) {

	frame_t * frame_l, * frame_r;

	frame_l = list_get_instance(block, frame_t, buddy_link);

	frame_r = (frame_t *) (&frame_l + (1>>frame_l->buddy_order-1));

	return &frame_r->buddy_link;

}

/** Buddy system coalesce implementation

 *

 * @param b Buddy system.

 * @param block_1 First block

 * @param block_2 First block's buddy

 *

 * @return Coalesced block (actually block that represents lower address)

 */

link_t * zone_buddy_coalesce(buddy_system_t *b, link_t * block_1, link_t * block_2) {

	frame_t * frame1, * frame2;

	frame1 = list_get_instance(block_1, frame_t, buddy_link);

	frame2 = list_get_instance(block_2, frame_t, buddy_link);

	return &frame1 < &frame2 ? block_1 : block_2;

}

/** Buddy system set_order implementation

 *

 * @param b Buddy system.

 * @param block Buddy system block

 * @param order Order to set

 */

void zone_buddy_set_order(buddy_system_t *b, link_t * block, __u8 order) {

	frame_t * frame;

	frame = list_get_instance(block, frame_t, buddy_link);

	frame->buddy_order = order;

}

/** Buddy system get_order implementation

 *

 * @param b Buddy system.

 * @param block Buddy system block

 *

 * @return Order of block

 */

__u8 zone_buddy_get_order(buddy_system_t *b, link_t * block) {

	frame_t * frame;

	frame = list_get_instance(block, frame_t, buddy_link);

	return frame->buddy_order;

}