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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>

#include <print.h>

#include <align.h>

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

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

region_t zone_blacklist[ZONE_BLACKLIST_SIZE];

count_t zone_blacklist_count = 0;

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,

	.mark_busy = zone_buddy_mark_busy,

};

/** Initialize physical memory management

 *

 * Initialize physical memory managemnt.

 */

void frame_init(void)

{

	if (config.cpu_active == 1) {

		zone_init();

		frame_region_not_free(KA2PA(config.base), config.kernel_size);

	}

	frame_arch_init();

}

/** Allocate power-of-two frames of physical memory.

 *

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

 * @param order Allocate exactly 2^order frames.

 *

 * @return Allocated frame.

 */

__address 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  */

		if (buddy_system_can_alloc(z->buddy_system, 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 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);

	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);

}

/** Mark frame region not free.

 *

 * Mark frame region not free.

 *

 * @param base Base address of non-available region.

 * @param size Size of non-available region.

 */

void frame_region_not_free(__address base, size_t size)

{

	index_t index;

	index = zone_blacklist_count++;

	/* Force base to the nearest lower address frame boundary. */

	base &= ~(FRAME_SIZE - 1);

	/* Align size to frame boundary. */

	size = ALIGN(size, FRAME_SIZE);

	ASSERT(zone_blacklist_count <= ZONE_BLACKLIST_SIZE);

	zone_blacklist[index].base = base;

	zone_blacklist[index].size = size;

}

/** Initialize zonekeeping

 *

 * Initialize zonekeeping.

 */

void zone_init(void)

{

	spinlock_initialize(&zone_head_lock);

	list_initialize(&zone_head);

}

void zone_create_in_region(__address base, size_t size) {

	int i;

	zone_t * z;

	__address s;

	size_t sz;

	ASSERT(base % FRAME_SIZE == 0);

	ASSERT(size % FRAME_SIZE == 0);

	if (!size)

		return;

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

		if (zone_blacklist[i].base >= base && zone_blacklist[i].base < base + size) {

			s = base; sz = zone_blacklist[i].base - base;

			ASSERT(base != s || sz != size);

			zone_create_in_region(s, sz);

			s = zone_blacklist[i].base + zone_blacklist[i].size;

			sz = (base + size) - (zone_blacklist[i].base + zone_blacklist[i].size);

			ASSERT(base != s || sz != size);

			zone_create_in_region(s, sz);

			return;

		}

	}

	z = zone_create(base, size, 0);

	if (!z) {

		panic("Cannot allocate zone (%dB).\n", size);

	}

	zone_attach(z);

}

/** 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;

	/* hack for bug #10 */

	// if (start == 0x100000) size -= (FRAME_SIZE * 256);

	// printf("ZONE_CREATE()   %X - %X (%d kbytes)			\n", start, start+size, size/1024);	

	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;

		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);

		}

		/*

		 * 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);

		/* Stuffing frames */

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

			z->frames[i].refcount = 0;

			buddy_system_free(z->buddy_system, &z->frames[i].buddy_link);	

		}

	}

	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 = 1;

	frame->buddy_order = 0;

}

/** 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;

	count_t index;

	bool is_left, is_right;

	frame = list_get_instance(block, frame_t, buddy_link);

	zone = (zone_t *) b->data;

	/* 

	 * (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));

	/*

	 * test left buddy

	 */

	if (is_left) {

		index = (FRAME_INDEX(zone, frame)) + (1 << frame->buddy_order);

	} else if (is_right) {

		index = (FRAME_INDEX(zone, frame)) - (1 << frame->buddy_order);

	}

	if (FRAME_INDEX_VALID(zone, index)) {

		if (	zone->frames[index].buddy_order == frame->buddy_order && 

			zone->frames[index].refcount == 0) {

			return &zone->frames[index].buddy_link;

		}

	}

	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_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;

}

/** Buddy system mark_busy implementation

 *

 * @param b Buddy system

 * @param block Buddy system block

 *

 */

void zone_buddy_mark_busy(buddy_system_t *b, link_t * block) {

	frame_t * frame;

	frame = list_get_instance(block, frame_t, buddy_link);

	frame->refcount = 1;

}