/*
* 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;
}