WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/mm/frame.c


/*
 * Copyright (C) 2001-2005 Jakub Jermar
 * Copyright (C) 2005 Sergey Bondari
 * 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.
 */
 
/**
 * @file    frame.c
 * @brief   Physical frame allocator.
 *
 * This file contains the physical frame allocator and memory zone management.
 * The frame allocator is built on top of the buddy allocator.
 *
 * @see buddy.c
 */
 
/*
 * Locking order
 *
 * In order to access particular zone, the process must first lock
 * the zones.lock, then lock the zone and then unlock the zones.lock.
 * This insures, that we can fiddle with the zones in runtime without
 * affecting the processes.
 *
 */
 
#include <typedefs.h>
#include <arch/types.h>
#include <mm/frame.h>
#include <mm/as.h>
#include <panic.h>
#include <debug.h>
#include <adt/list.h>
#include <synch/spinlock.h>
#include <arch/asm.h>
#include <arch.h>
#include <print.h>
#include <align.h>
#include <mm/slab.h>
#include <bitops.h>
#include <macros.h>
 
typedef struct {
    count_t refcount;   /**< tracking of shared frames  */
    __u8 buddy_order;   /**< buddy system block order */
    link_t buddy_link;  /**< link to the next free block inside one order */
    void *parent;           /**< If allocated by slab, this points there */
} frame_t;
 
typedef struct {
    SPINLOCK_DECLARE(lock); /**< this lock protects everything below */
    pfn_t base;     /**< frame_no of the first frame in the frames array */
    count_t count;          /**< Size of zone */
 
    frame_t *frames;    /**< array of frame_t structures in this zone */
    count_t free_count; /**< number of free frame_t structures */
    count_t busy_count; /**< number of busy frame_t structures */
   
    buddy_system_t * buddy_system; /**< buddy system for the zone */
    int flags;
} zone_t;
 
/*
 * The zoneinfo.lock must be locked when accessing zoneinfo structure.
 * Some of the attributes in zone_t structures are 'read-only'
 */
 
struct {
    SPINLOCK_DECLARE(lock);
    int count;
    zone_t *info[ZONES_MAX];
} zones;
 
 
/*********************************/
/* Helper functions */
static inline index_t frame_index(zone_t *zone, frame_t *frame)
{
    return (index_t)(frame - zone->frames);
}
static inline index_t frame_index_abs(zone_t *zone, frame_t *frame)
{
    return (index_t)(frame - zone->frames) + zone->base;
}
static inline int frame_index_valid(zone_t *zone, index_t index)
{
    return index >= 0 && index < zone->count;
}
 
/** Compute pfn_t from frame_t pointer & zone pointer */
static index_t make_frame_index(zone_t *zone, frame_t *frame)
{
    return frame - zone->frames;
}
 
/** Initialize frame structure
 *
 * Initialize frame structure.
 *
 * @param frame Frame structure to be initialized.
 */
static void frame_initialize(frame_t *frame)
{
    frame->refcount = 1;
    frame->buddy_order = 0;
}
 
/*************************************/
/* Zoneinfo functions */
 
/**
 * Insert-sort zone into zones list
 *
 * @param newzone New zone to be inserted into zone list
 * @return zone number on success, -1 on error
 */
static int zones_add_zone(zone_t *newzone)
{
    int i,j;
    ipl_t ipl;
    zone_t *z;
 
    ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
    /* Try to merge */
    if (zones.count + 1 == ZONES_MAX)
        panic("Maximum zone(%d) count exceeded.", ZONES_MAX);
    for (i = 0; i < zones.count; i++) {
        /* Check for overflow */
        z = zones.info[i];
        if (overlaps(newzone->base,newzone->count,
                 z->base, z->count)) {
            printf("Zones overlap!\n");
            return -1;
        }
        if (newzone->base < z->base)
            break;
    }
    /* Move other zones up */
    for (j = i;j < zones.count; j++)
        zones.info[j + 1] = zones.info[j];
    zones.info[i] = newzone;
    zones.count++;
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
 
    return i;
}
 
/**
 * Try to find a zone where can we find the frame
 *
 * @param frame Frame number contained in zone
 * @param pzone If not null, it is used as zone hint. Zone index
 *              is filled into the variable on success.
 * @return Pointer to LOCKED zone containing frame
 *
 * Assume interrupts disable
 */
static zone_t * find_zone_and_lock(pfn_t frame, int *pzone)
{
    int i;
    int hint = pzone ? *pzone : 0;
    zone_t *z;
   
    spinlock_lock(&zones.lock);
 
    if (hint >= zones.count || hint < 0)
        hint = 0;
   
    i = hint;
    do {
        z = zones.info[i];
        spinlock_lock(&z->lock);
        if (z->base <= frame && z->base + z->count > frame) {
            spinlock_unlock(&zones.lock); /* Unlock the global lock */
            if (pzone)
                *pzone = i;
            return z;
        }
        spinlock_unlock(&z->lock);
 
        i++;
        if (i >= zones.count)
            i = 0;
    } while(i != hint);
 
    spinlock_unlock(&zones.lock);
    return NULL;
}
 
/** @return True if zone can allocate specified order */
static int zone_can_alloc(zone_t *z, __u8 order)
{
    return buddy_system_can_alloc(z->buddy_system, order);
}
 
/**
 * Find AND LOCK zone that can allocate order frames
 *
 * Assume interrupts are disabled!!
 *
 * @param order Size (2^order) of free space we are trying to find
 * @param pzone Pointer to preferred zone or NULL, on return contains zone number
 */
static zone_t * find_free_zone_lock(__u8 order, int *pzone)
{
    int i;
    zone_t *z;
    int hint = pzone ? *pzone : 0;
   
    spinlock_lock(&zones.lock);
    if (hint >= zones.count)
        hint = 0;
    i = hint;
    do {
        z = zones.info[i];
       
        spinlock_lock(&z->lock);
 
        /* Check if the zone has 2^order frames area available  */
        if (zone_can_alloc(z, order)) {
            spinlock_unlock(&zones.lock);
            if (pzone)
                *pzone = i;
            return z;
        }
        spinlock_unlock(&z->lock);
        if (++i >= zones.count)
            i = 0;
    } while(i != hint);
    spinlock_unlock(&zones.lock);
    return NULL;
}
 
/********************************************/
/* Buddy system functions */
 
/** Buddy system find_block implementation
 *
 * Find block that is parent of current list.
 * That means go to lower addresses, until such block is found
 *
 * @param order - Order of parent must be different then this parameter!!
 */
static link_t *zone_buddy_find_block(buddy_system_t *b, link_t *child,
                     __u8 order)
{
    frame_t * frame;
    zone_t * zone;
    index_t index;
   
    frame = list_get_instance(child, frame_t, buddy_link);
    zone = (zone_t *) b->data;
 
    index = frame_index(zone, frame);
    do {
        if (zone->frames[index].buddy_order != order) {
            return &zone->frames[index].buddy_link;
        }
    } while(index-- > 0);
    return NULL;
}
 
static void zone_buddy_print_id(buddy_system_t *b, link_t *block)
{
    frame_t * frame;
    zone_t * zone;
    index_t index;
 
    frame = list_get_instance(block, frame_t, buddy_link);
    zone = (zone_t *) b->data;
    index = frame_index(zone, frame);
    printf("%zd", index);
}                    
 
/** 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
 */
static link_t * zone_buddy_find_buddy(buddy_system_t *b, link_t * block)
{
    frame_t * frame;
    zone_t * zone;
    index_t index;
    bool is_left, is_right;
 
    frame = list_get_instance(block, frame_t, buddy_link);
    zone = (zone_t *) b->data;
    ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame), frame->buddy_order));
   
    is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);
    is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);
 
    ASSERT(is_left ^ is_right);
    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
 */
static 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)
 */
static 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
 */
static 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
 */
static __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
 *
 */
static 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;
}
 
/** Buddy system mark_available implementation
 *
 * @param b Buddy system
 * @param block Buddy system block
 *
 */
static void zone_buddy_mark_available(buddy_system_t *b, link_t * block) {
    frame_t * frame;
    frame = list_get_instance(block, frame_t, buddy_link);
    frame->refcount = 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,
    .mark_available = zone_buddy_mark_available,
    .find_block = zone_buddy_find_block,
    .print_id = zone_buddy_print_id
};
 
/*************************************/
/* Zone functions */
 
/** Allocate frame in particular zone
 *
 * Assume zone is locked
 * Panics if allocation is impossible.
 *
 * @param zone  Zone to allocate from.
 * @param order Allocate exactly 2^order frames.
 *
 * @return Frame index in zone
 *
 */
static pfn_t zone_frame_alloc(zone_t *zone, __u8 order)
{
    pfn_t v;
    link_t *tmp;
    frame_t *frame;
 
    /* Allocate frames from zone buddy system */
    tmp = buddy_system_alloc(zone->buddy_system, order);
   
    ASSERT(tmp);
   
    /* Update zone information. */
    zone->free_count -= (1 << order);
    zone->busy_count += (1 << order);
 
    /* Frame will be actually a first frame of the block. */
    frame = list_get_instance(tmp, frame_t, buddy_link);
   
    /* get frame address */
    v = make_frame_index(zone, frame);
    return v;
}
 
/** Free frame from zone
 *
 * Assume zone is locked
 *
 * @param zone Pointer to zone from which the frame is to be freed
 * @param frame_idx Frame index relative to zone
 */
static void zone_frame_free(zone_t *zone, index_t frame_idx)
{
    frame_t *frame;
    __u8 order;
 
    frame = &zone->frames[frame_idx];
   
    /* remember frame order */
    order = frame->buddy_order;
 
    ASSERT(frame->refcount);
 
    if (!--frame->refcount) {
        buddy_system_free(zone->buddy_system, &frame->buddy_link);
   
        /* Update zone information. */
        zone->free_count += (1 << order);
        zone->busy_count -= (1 << order);
    }
}
 
/** Return frame from zone */
static frame_t * zone_get_frame(zone_t *zone, index_t frame_idx)
{
    ASSERT(frame_idx < zone->count);
    return &zone->frames[frame_idx];
}
 
/** Mark frame in zone unavailable to allocation */
static void zone_mark_unavailable(zone_t *zone, index_t frame_idx)
{
    frame_t *frame;
    link_t *link;
 
    frame = zone_get_frame(zone, frame_idx);
    if (frame->refcount)
        return;
    link = buddy_system_alloc_block(zone->buddy_system,
                    &frame->buddy_link);
    ASSERT(link);
    zone->free_count--;
}
 
/**
 * Join 2 zones
 *
 * Expect zone_t *z to point to space at least zone_conf_size large
 *
 * Assume z1 & z2 are locked
 *
 * @param z Target zone structure pointer
 * @param z1 Zone to merge
 * @param z2 Zone to merge
 */
 
static void _zone_merge(zone_t *z, zone_t *z1, zone_t *z2)
{
    __u8 max_order;
    int i, z2idx;
    pfn_t frame_idx;
    frame_t *frame;
 
    ASSERT(!overlaps(z1->base,z1->count,z2->base,z2->count));
    ASSERT(z1->base < z2->base);
 
    spinlock_initialize(&z->lock, "zone_lock");
    z->base = z1->base;
    z->count = z2->base+z2->count - z1->base;
    z->flags = z1->flags & z2->flags;
 
    z->free_count = z1->free_count + z2->free_count;
    z->busy_count = z1->busy_count + z2->busy_count;
   
    max_order = fnzb(z->count);
 
    z->buddy_system = (buddy_system_t *)&z[1];
    buddy_system_create(z->buddy_system, max_order,
                &zone_buddy_system_operations,
                (void *) z);
 
    z->frames = (frame_t *)((void *)z->buddy_system+buddy_conf_size(max_order));
    for (i = 0; i < z->count; i++) {
        /* This marks all frames busy */
        frame_initialize(&z->frames[i]);
    }
    /* Copy frames from both zones to preserve full frame orders,
     * parents etc. Set all free frames with refcount=0 to 1, because
     * we add all free frames to buddy allocator later again, clear
     * order to 0. Don't set busy frames with refcount=0, as they
     * will not be reallocated during merge and it would make later
     * problems with allocation/free.
     */
    for (i=0; i<z1->count; i++)
        z->frames[i] = z1->frames[i];
    for (i=0; i < z2->count; i++) {
        z2idx = i + (z2->base - z1->base);
        z->frames[z2idx] = z2->frames[i];
    }
    i = 0;
    while (i < z->count) {
        if (z->frames[i].refcount) {
            /* skip busy frames */
            i += 1 << z->frames[i].buddy_order;
        } else { /* Free frames, set refcount=1 */
            /* All free frames have refcount=0, we need not
             * to check the order */
            z->frames[i].refcount = 1;
            z->frames[i].buddy_order = 0;
            i++;
        }
    }
    /* Add free blocks from the 2 original zones */
    while (zone_can_alloc(z1, 0)) {
        frame_idx = zone_frame_alloc(z1, 0);
        frame = &z->frames[frame_idx];
        frame->refcount = 0;
        buddy_system_free(z->buddy_system, &frame->buddy_link);
    }
    while (zone_can_alloc(z2, 0)) {
        frame_idx = zone_frame_alloc(z2, 0);
        frame = &z->frames[frame_idx + (z2->base-z1->base)];
        frame->refcount = 0;
        buddy_system_free(z->buddy_system, &frame->buddy_link);
    }
}
 
/** Return old configuration frames into the zone
 *
 * We have several cases
 * - the conf. data is outside of zone -> exit, shall we call frame_free??
 * - the conf. data was created by zone_create or
 *   updated with reduce_region -> free every frame
 *
 * @param newzone The actual zone where freeing should occur
 * @param oldzone Pointer to old zone configuration data that should
 *                be freed from new zone
 */
static void return_config_frames(zone_t *newzone, zone_t *oldzone)
{
    pfn_t pfn;
    frame_t *frame;
    count_t cframes;
    int i;
 
    pfn = ADDR2PFN((__address)KA2PA(oldzone));
    cframes = SIZE2FRAMES(zone_conf_size(oldzone->count));
   
    if (pfn < newzone->base || pfn >= newzone->base + newzone->count)
        return;
 
    frame = &newzone->frames[pfn - newzone->base];
    ASSERT(!frame->buddy_order);
 
    for (i=0; i < cframes; i++) {
        newzone->busy_count++;
        zone_frame_free(newzone, pfn+i-newzone->base);
    }
}
 
/** Reduce allocated block to count of order 0 frames
 *
 * The allocated block need 2^order frames of space. Reduce all frames
 * in block to order 0 and free the unneeded frames. This means, that
 * when freeing the previously allocated block starting with frame_idx,
 * you have to free every frame.
 *
 * @param zone
 * @param frame_idx Index to block
 * @param count Allocated space in block
 */
static void zone_reduce_region(zone_t *zone, pfn_t frame_idx, count_t count)
{
    count_t i;
    __u8 order;
    frame_t *frame;
   
    ASSERT(frame_idx+count < zone->count);
 
    order = zone->frames[frame_idx].buddy_order;
    ASSERT((1 << order) >= count);
 
    /* Reduce all blocks to order 0 */
    for (i=0; i < (1 << order); i++) {
        frame = &zone->frames[i + frame_idx];
        frame->buddy_order = 0;
        if (! frame->refcount)
            frame->refcount = 1;
        ASSERT(frame->refcount == 1);
    }
    /* Free unneeded frames */
    for (i=count; i < (1 << order); i++) {
        zone_frame_free(zone, i + frame_idx);
    }
}
 
/** Merge zones z1 and z2
 *
 * - the zones must be 2 zones with no zone existing in between,
 *   which means that z2 = z1+1
 *
 * - When you create a new zone, the frame allocator configuration does
 *   not to be 2^order size. Once the allocator is running it is no longer
 *   possible, merged configuration data occupies more space :-/
 */
void zone_merge(int z1, int z2)
{
    ipl_t ipl;
    zone_t *zone1, *zone2, *newzone;
    int cframes;
    __u8 order;
    int i;
    pfn_t pfn;
 
    ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
 
    if (z1 < 0 || z1 >= zones.count || z2 < 0 || z2 >= zones.count)
        goto errout;
    /* We can join only 2 zones with none existing inbetween */
    if (z2-z1 != 1)
        goto errout;
 
    zone1 = zones.info[z1];
    zone2 = zones.info[z2];
    spinlock_lock(&zone1->lock);
    spinlock_lock(&zone2->lock);
 
    cframes = SIZE2FRAMES(zone_conf_size(zone2->base+zone2->count-zone1->base));
    if (cframes == 1)
        order = 0;
    else
        order = fnzb(cframes - 1) + 1;
 
    /* Allocate zonedata inside one of the zones */
    if (zone_can_alloc(zone1, order))
        pfn = zone1->base + zone_frame_alloc(zone1, order);
    else if (zone_can_alloc(zone2, order))
        pfn = zone2->base + zone_frame_alloc(zone2, order);
    else
        goto errout2;
 
    newzone = (zone_t *)PA2KA(PFN2ADDR(pfn));
 
    _zone_merge(newzone, zone1, zone2);
 
    /* Free unneeded config frames */
    zone_reduce_region(newzone, pfn - newzone->base,  cframes);
    /* Subtract zone information from busy frames */
    newzone->busy_count -= cframes;
 
    /* Replace existing zones in zoneinfo list */
    zones.info[z1] = newzone;
    for (i = z2 + 1; i < zones.count; i++)
        zones.info[i - 1] = zones.info[i];
    zones.count--;
 
    /* Free old zone information */
    return_config_frames(newzone, zone1);
    return_config_frames(newzone, zone2);
errout2:
    /* Nobody is allowed to enter to zone, so we are safe
     * to touch the spinlocks last time */
    spinlock_unlock(&zone1->lock);
    spinlock_unlock(&zone2->lock);
errout:
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
}
 
/**
 * Merge all zones into one big zone
 *
 * It is reasonable to do this on systems whose bios reports parts in chunks,
 * so that we could have 1 zone (it's faster).
 */
void zone_merge_all(void)
{
    int count = zones.count;
 
    while (zones.count > 1 && --count) {
        zone_merge(0,1);
        break;
    }
}
 
/** Create frame zone
 *
 * Create new frame zone.
 *
 * @param start Physical address of the first frame within the zone.
 * @param count Count of frames in zone
 * @param z Address of configuration information of zone
 * @param flags Zone flags.
 *
 * @return Initialized zone.
 */
static void zone_construct(pfn_t start, count_t count, zone_t *z, int flags)
{
    int i;
    __u8 max_order;
 
    spinlock_initialize(&z->lock, "zone_lock");
    z->base = start;
    z->count = count;
    z->flags = flags;
    z->free_count = count;
    z->busy_count = 0;
 
    /*
     * Compute order for buddy system, initialize
     */
    max_order = fnzb(count);
    z->buddy_system = (buddy_system_t *)&z[1];
   
    buddy_system_create(z->buddy_system, max_order,
                &zone_buddy_system_operations,
                (void *) z);
   
    /* Allocate frames _after_ the conframe */
    /* Check sizes */
    z->frames = (frame_t *)((void *)z->buddy_system+buddy_conf_size(max_order));
    for (i = 0; i<count; i++) {
        frame_initialize(&z->frames[i]);
    }
   
    /* Stuffing frames */
    for (i = 0; i < count; i++) {
        z->frames[i].refcount = 0;
        buddy_system_free(z->buddy_system, &z->frames[i].buddy_link);
    }
}
 
/** Compute configuration data size for zone
 *
 * @param count Size of zone in frames
 * @return Size of zone configuration info (in bytes)
 */
__address zone_conf_size(count_t count)
{
    int size = sizeof(zone_t) + count*sizeof(frame_t);
    int max_order;
 
    max_order = fnzb(count);
    size += buddy_conf_size(max_order);
    return size;
}
 
/** Create and add zone to system
 *
 * @param start First frame number (absolute)
 * @param count Size of zone in frames
 * @param confframe Where configuration frames are supposed to be.
 *                  Automatically checks, that we will not disturb the
 *                  kernel and possibly init.
 *                  If confframe is given _outside_ this zone, it is expected,
 *                  that the area is already marked BUSY and big enough
 *                  to contain zone_conf_size() amount of data.
 *                  If the confframe is inside the area, the zone free frame
 *                  information is modified not to include it.
 *
 * @return Zone number or -1 on error
 */
int zone_create(pfn_t start, count_t count, pfn_t confframe, int flags)
{
    zone_t *z;
    __address addr;
    count_t confcount;
    int i;
    int znum;
 
    /* Theoretically we could have here 0, practically make sure
     * nobody tries to do that. If some platform requires, remove
     * the assert
     */
    ASSERT(confframe);
    /* If conframe is supposed to be inside our zone, then make sure
     * it does not span kernel & init
     */
    confcount = SIZE2FRAMES(zone_conf_size(count));
    if (confframe >= start && confframe < start+count) {
        for (;confframe < start + count; confframe++) {
            addr = PFN2ADDR(confframe);
            if (overlaps(addr, PFN2ADDR(confcount), KA2PA(config.base), config.kernel_size))
                continue;
           
            bool overlap = false;
            count_t i;
            for (i = 0; i < init.cnt; i++)
                if (overlaps(addr, PFN2ADDR(confcount), KA2PA(init.tasks[i].addr), init.tasks[i].size)) {
                    overlap = true;
                    break;
                }
            if (overlap)
                continue;
           
            break;
        }
        if (confframe >= start + count)
            panic("Cannot find configuration data for zone.");
    }
 
    z = (zone_t *)PA2KA(PFN2ADDR(confframe));
    zone_construct(start, count, z, flags);
    znum = zones_add_zone(z);
    if (znum == -1)
        return -1;
 
    /* If confdata in zone, mark as unavailable */
    if (confframe >= start && confframe < start+count)
        for (i=confframe; i<confframe+confcount; i++) {
            zone_mark_unavailable(z, i - z->base);
        }
    return znum;
}
 
/***************************************/
/* Frame functions */
 
/** Set parent of frame */
void frame_set_parent(pfn_t pfn, void *data, int hint)
{
    zone_t *zone = find_zone_and_lock(pfn, &hint);
 
    ASSERT(zone);
 
    zone_get_frame(zone, pfn-zone->base)->parent = data;
    spinlock_unlock(&zone->lock);
}
 
void * frame_get_parent(pfn_t pfn, int hint)
{
    zone_t *zone = find_zone_and_lock(pfn, &hint);
    void *res;
 
    ASSERT(zone);
    res = zone_get_frame(zone, pfn - zone->base)->parent;
   
    spinlock_unlock(&zone->lock);
    return res;
}
 
/** Allocate power-of-two frames of physical memory.
 *
 * @param order  Allocate exactly 2^order frames.
 * @param flags  Flags for host zone selection and address processing.
 * @param status Allocation status (FRAME_OK on success), unused if NULL.
 * @param pzone  Preferred zone
 *
 * @return Allocated frame.
 *
 */
pfn_t frame_alloc_generic(__u8 order, int flags, int *status, int *pzone)
{
    ipl_t ipl;
    int freed;
    pfn_t v;
    zone_t *zone;
   
loop:
    ipl = interrupts_disable();
   
    /*
     * First, find suitable frame zone.
     */
    zone = find_free_zone_lock(order, pzone);
   
    /* If no memory, reclaim some slab memory,
       if it does not help, reclaim all */
    if (!zone && !(flags & FRAME_NO_RECLAIM)) {
        freed = slab_reclaim(0);
        if (freed)
            zone = find_free_zone_lock(order, pzone);
        if (!zone) {
            freed = slab_reclaim(SLAB_RECLAIM_ALL);
            if (freed)
                zone = find_free_zone_lock(order, pzone);
        }
    }
    if (!zone) {
        if (flags & FRAME_PANIC)
            panic("Can't allocate frame.\n");
       
        /*
         * TODO: Sleep until frames are available again.
         */
        interrupts_restore(ipl);
 
        if (flags & FRAME_ATOMIC) {
            ASSERT(status != NULL);
            if (status)
                *status = FRAME_NO_MEMORY;
            return NULL;
        }
       
        panic("Sleep not implemented.\n");
        goto loop;
    }
   
    v = zone_frame_alloc(zone, order);
    v += zone->base;
 
    spinlock_unlock(&zone->lock);
    interrupts_restore(ipl);
 
    if (status)
        *status = FRAME_OK;
    return v;
}
 
/** Free a frame.
 *
 * Find respective frame structure for supplied PFN.
 * Decrement frame reference count.
 * If it drops to zero, move the frame structure to free list.
 *
 * @param frame Frame number to be freed.
 */
void frame_free(pfn_t pfn)
{
    ipl_t ipl;
    zone_t *zone;
 
    ipl = interrupts_disable();
   
    /*
     * First, find host frame zone for addr.
     */
    zone = find_zone_and_lock(pfn,NULL);
    ASSERT(zone);
   
    zone_frame_free(zone, pfn-zone->base);
   
    spinlock_unlock(&zone->lock);
    interrupts_restore(ipl);
}
 
/** Add reference to frame.
 *
 * Find respective frame structure for supplied PFN and
 * increment frame reference count.
 *
 * @param frame Frame no to be freed.
 */
void frame_reference_add(pfn_t pfn)
{
    ipl_t ipl;
    zone_t *zone;
    frame_t *frame;
 
    ipl = interrupts_disable();
   
    /*
     * First, find host frame zone for addr.
     */
    zone = find_zone_and_lock(pfn,NULL);
    ASSERT(zone);
   
    frame = &zone->frames[pfn-zone->base];
    frame->refcount++;
   
    spinlock_unlock(&zone->lock);
    interrupts_restore(ipl);
}
 
/** Mark given range unavailable in frame zones */
void frame_mark_unavailable(pfn_t start, count_t count)
{
    int i;
    zone_t *zone;
    int prefzone = 0;
   
    for (i=0; i < count; i++) {
        zone = find_zone_and_lock(start+i,&prefzone);
        if (!zone) /* PFN not found */
            continue;
        zone_mark_unavailable(zone, start+i-zone->base);
 
        spinlock_unlock(&zone->lock);
    }
}
 
/** Initialize physical memory management
 *
 * Initialize physical memory managemnt.
 */
void frame_init(void)
{
    if (config.cpu_active == 1) {
        zones.count = 0;
        spinlock_initialize(&zones.lock,"zones_glob_lock");
    }
    /* Tell the architecture to create some memory */
    frame_arch_init();
    if (config.cpu_active == 1) {
        pfn_t firstframe = ADDR2PFN(KA2PA(config.base));
        pfn_t lastframe = ADDR2PFN(KA2PA(config.base+config.kernel_size));
        frame_mark_unavailable(firstframe,lastframe-firstframe+1);
       
        count_t i;
        for (i = 0; i < init.cnt; i++)
            frame_mark_unavailable(ADDR2PFN(KA2PA(init.tasks[i].addr)), SIZE2FRAMES(init.tasks[i].size));
 
        /* Black list first frame, as allocating NULL would
         * fail on some places */
        frame_mark_unavailable(0, 1);
    }
}
 
 
 
/** Prints list of zones
 *
 */
void zone_print_list(void) {
    zone_t *zone = NULL;
    int i;
    ipl_t ipl;
 
    ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
    printf("#  Base address\tFree Frames\tBusy Frames\n");
    printf("   ------------\t-----------\t-----------\n");
    for (i = 0; i < zones.count; i++) {
        zone = zones.info[i];
        spinlock_lock(&zone->lock);
        printf("%d: %.*p \t%10zd\t%10zd\n", i, sizeof(__address) * 2, PFN2ADDR(zone->base), zone->free_count, zone->busy_count);
        spinlock_unlock(&zone->lock);
    }
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
}
 
/** Prints zone details
 *
 * @param base Zone base address OR zone number
 */
void zone_print_one(int num) {
    zone_t *zone = NULL;
    ipl_t ipl;
    int i;
 
    ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
 
    for (i = 0; i < zones.count; i++) {
        if (i == num || PFN2ADDR(zones.info[i]->base) == num) {
            zone = zones.info[i];
            break;
        }
    }
    if (!zone) {
        printf("Zone not found.\n");
        goto out;
    }
   
    spinlock_lock(&zone->lock);
    printf("Memory zone information\n");
    printf("Zone base address: %#.*p\n", sizeof(__address) * 2, PFN2ADDR(zone->base));
    printf("Zone size: %zd frames (%zdK)\n", zone->count, ((zone->count) * FRAME_SIZE) >> 10);
    printf("Allocated space: %zd frames (%zdK)\n", zone->busy_count, (zone->busy_count * FRAME_SIZE) >> 10);
    printf("Available space: %zd (%zdK)\n", zone->free_count, (zone->free_count * FRAME_SIZE) >> 10);
    buddy_system_structure_print(zone->buddy_system, FRAME_SIZE);
   
    spinlock_unlock(&zone->lock);
out:
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
}
 
 

Rev 1599	Rev 1700
1	/*	1	/*
2	* Copyright (C) 2001-2005 Jakub Jermar	2	* Copyright (C) 2001-2005 Jakub Jermar
3	* Copyright (C) 2005 Sergey Bondari	3	* Copyright (C) 2005 Sergey Bondari
4	* All rights reserved.	4	* All rights reserved.
5	*	5	*
6	* Redistribution and use in source and binary forms, with or without	6	* Redistribution and use in source and binary forms, with or without
7	* modification, are permitted provided that the following conditions	7	* modification, are permitted provided that the following conditions
8	* are met:	8	* are met:
9	*	9	*
10	* - Redistributions of source code must retain the above copyright	10	* - Redistributions of source code must retain the above copyright
11	* notice, this list of conditions and the following disclaimer.	11	* notice, this list of conditions and the following disclaimer.
12	* - Redistributions in binary form must reproduce the above copyright	12	* - Redistributions in binary form must reproduce the above copyright
13	* notice, this list of conditions and the following disclaimer in the	13	* notice, this list of conditions and the following disclaimer in the
14	* documentation and/or other materials provided with the distribution.	14	* documentation and/or other materials provided with the distribution.
15	* - The name of the author may not be used to endorse or promote products	15	* - The name of the author may not be used to endorse or promote products
16	* derived from this software without specific prior written permission.	16	* derived from this software without specific prior written permission.
17	*	17	*
18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28	*/	28	*/
29		29
30	/**	30	/**
31	* @file frame.c	31	* @file frame.c
32	* @brief Physical frame allocator.	32	* @brief Physical frame allocator.
33	*	33	*
34	* This file contains the physical frame allocator and memory zone management.	34	* This file contains the physical frame allocator and memory zone management.
35	* The frame allocator is built on top of the buddy allocator.	35	* The frame allocator is built on top of the buddy allocator.
36	*	36	*
37	* @see buddy.c	37	* @see buddy.c
38	*/	38	*/
39		39
40	/*	40	/*
41	* Locking order	41	* Locking order
42	*	42	*
43	* In order to access particular zone, the process must first lock	43	* In order to access particular zone, the process must first lock
44	* the zones.lock, then lock the zone and then unlock the zones.lock.	44	* the zones.lock, then lock the zone and then unlock the zones.lock.
45	* This insures, that we can fiddle with the zones in runtime without	45	* This insures, that we can fiddle with the zones in runtime without
46	* affecting the processes.	46	* affecting the processes.
47	*	47	*
48	*/	48	*/
49		49
50	#include <typedefs.h>	50	#include <typedefs.h>
51	#include <arch/types.h>	51	#include <arch/types.h>
52	#include <mm/frame.h>	52	#include <mm/frame.h>
53	#include <mm/as.h>	53	#include <mm/as.h>
54	#include <panic.h>	54	#include <panic.h>
55	#include <debug.h>	55	#include <debug.h>
56	#include <adt/list.h>	56	#include <adt/list.h>
57	#include <synch/spinlock.h>	57	#include <synch/spinlock.h>
58	#include <arch/asm.h>	58	#include <arch/asm.h>
59	#include <arch.h>	59	#include <arch.h>
60	#include <print.h>	60	#include <print.h>
61	#include <align.h>	61	#include <align.h>
62	#include <mm/slab.h>	62	#include <mm/slab.h>
63	#include <bitops.h>	63	#include <bitops.h>
64	#include <macros.h>	64	#include <macros.h>
65		65
66	typedef struct {	66	typedef struct {
67	count_t refcount; /*< tracking of shared frames /	67	count_t refcount; /*< tracking of shared frames /
68	__u8 buddy_order; /*< buddy system block order /	68	__u8 buddy_order; /*< buddy system block order /
69	link_t buddy_link; /*< link to the next free block inside one order /	69	link_t buddy_link; /*< link to the next free block inside one order /
70	void parent; /< If allocated by slab, this points there /	70	void parent; /< If allocated by slab, this points there /
71	} frame_t;	71	} frame_t;
72		72
73	typedef struct {	73	typedef struct {
74	SPINLOCK_DECLARE(lock); /*< this lock protects everything below /	74	SPINLOCK_DECLARE(lock); /*< this lock protects everything below /
75	pfn_t base; /*< frame_no of the first frame in the frames array /	75	pfn_t base; /*< frame_no of the first frame in the frames array /
76	count_t count; /*< Size of zone /	76	count_t count; /*< Size of zone /
77		77
78	frame_t frames; /< array of frame_t structures in this zone /	78	frame_t frames; /< array of frame_t structures in this zone /
79	count_t free_count; /*< number of free frame_t structures /	79	count_t free_count; /*< number of free frame_t structures /
80	count_t busy_count; /*< number of busy frame_t structures /	80	count_t busy_count; /*< number of busy frame_t structures /
81		81
82	buddy_system_t * buddy_system; /*< buddy system for the zone /	82	buddy_system_t * buddy_system; /*< buddy system for the zone /
83	int flags;	83	int flags;
84	} zone_t;	84	} zone_t;
85		85
86	/*	86	/*
87	* The zoneinfo.lock must be locked when accessing zoneinfo structure.	87	* The zoneinfo.lock must be locked when accessing zoneinfo structure.
88	* Some of the attributes in zone_t structures are 'read-only'	88	* Some of the attributes in zone_t structures are 'read-only'
89	*/	89	*/
90		90
91	struct {	91	struct {
92	SPINLOCK_DECLARE(lock);	92	SPINLOCK_DECLARE(lock);
93	int count;	93	int count;
94	zone_t *info[ZONES_MAX];	94	zone_t *info[ZONES_MAX];
95	} zones;	95	} zones;
96		96
97		97
98	/*********************************/	98	/*********************************/
99	/* Helper functions */	99	/* Helper functions */
100	static inline index_t frame_index(zone_t zone, frame_t frame)	100	static inline index_t frame_index(zone_t zone, frame_t frame)
101	{	101	{
102	return (index_t)(frame - zone->frames);	102	return (index_t)(frame - zone->frames);
103	}	103	}
104	static inline index_t frame_index_abs(zone_t zone, frame_t frame)	104	static inline index_t frame_index_abs(zone_t zone, frame_t frame)
105	{	105	{
106	return (index_t)(frame - zone->frames) + zone->base;	106	return (index_t)(frame - zone->frames) + zone->base;
107	}	107	}
108	static inline int frame_index_valid(zone_t *zone, index_t index)	108	static inline int frame_index_valid(zone_t *zone, index_t index)
109	{	109	{
110	return index >= 0 && index < zone->count;	110	return index >= 0 && index < zone->count;
111	}	111	}
112		112
113	/** Compute pfn_t from frame_t pointer & zone pointer */	113	/** Compute pfn_t from frame_t pointer & zone pointer */
114	static index_t make_frame_index(zone_t zone, frame_t frame)	114	static index_t make_frame_index(zone_t zone, frame_t frame)
115	{	115	{
116	return frame - zone->frames;	116	return frame - zone->frames;
117	}	117	}
118		118
119	/** Initialize frame structure	119	/** Initialize frame structure
120	*	120	*
121	* Initialize frame structure.	121	* Initialize frame structure.
122	*	122	*
123	* @param frame Frame structure to be initialized.	123	* @param frame Frame structure to be initialized.
124	*/	124	*/
125	static void frame_initialize(frame_t *frame)	125	static void frame_initialize(frame_t *frame)
126	{	126	{
127	frame->refcount = 1;	127	frame->refcount = 1;
128	frame->buddy_order = 0;	128	frame->buddy_order = 0;
129	}	129	}
130		130
131	/*************************************/	131	/*************************************/
132	/* Zoneinfo functions */	132	/* Zoneinfo functions */
133		133
134	/**	134	/**
135	* Insert-sort zone into zones list	135	* Insert-sort zone into zones list
136	*	136	*
137	* @param newzone New zone to be inserted into zone list	137	* @param newzone New zone to be inserted into zone list
138	* @return zone number on success, -1 on error	138	* @return zone number on success, -1 on error
139	*/	139	*/
140	static int zones_add_zone(zone_t *newzone)	140	static int zones_add_zone(zone_t *newzone)
141	{	141	{
142	int i,j;	142	int i,j;
143	ipl_t ipl;	143	ipl_t ipl;
144	zone_t *z;	144	zone_t *z;
145		145
146	ipl = interrupts_disable();	146	ipl = interrupts_disable();
147	spinlock_lock(&zones.lock);	147	spinlock_lock(&zones.lock);
148	/* Try to merge */	148	/* Try to merge */
149	if (zones.count + 1 == ZONES_MAX)	149	if (zones.count + 1 == ZONES_MAX)
150	panic("Maximum zone(%d) count exceeded.", ZONES_MAX);	150	panic("Maximum zone(%d) count exceeded.", ZONES_MAX);
151	for (i = 0; i < zones.count; i++) {	151	for (i = 0; i < zones.count; i++) {
152	/* Check for overflow */	152	/* Check for overflow */
153	z = zones.info[i];	153	z = zones.info[i];
154	if (overlaps(newzone->base,newzone->count,	154	if (overlaps(newzone->base,newzone->count,
155	z->base, z->count)) {	155	z->base, z->count)) {
156	printf("Zones overlap!\n");	156	printf("Zones overlap!\n");
157	return -1;	157	return -1;
158	}	158	}
159	if (newzone->base < z->base)	159	if (newzone->base < z->base)
160	break;	160	break;
161	}	161	}
162	/* Move other zones up */	162	/* Move other zones up */
163	for (j = i;j < zones.count; j++)	163	for (j = i;j < zones.count; j++)
164	zones.info[j + 1] = zones.info[j];	164	zones.info[j + 1] = zones.info[j];
165	zones.info[i] = newzone;	165	zones.info[i] = newzone;
166	zones.count++;	166	zones.count++;
167	spinlock_unlock(&zones.lock);	167	spinlock_unlock(&zones.lock);
168	interrupts_restore(ipl);	168	interrupts_restore(ipl);
169		169
170	return i;	170	return i;
171	}	171	}
172		172
173	/**	173	/**
174	* Try to find a zone where can we find the frame	174	* Try to find a zone where can we find the frame
175	*	175	*
176	* @param frame Frame number contained in zone	176	* @param frame Frame number contained in zone
177	* @param pzone If not null, it is used as zone hint. Zone index	177	* @param pzone If not null, it is used as zone hint. Zone index
178	* is filled into the variable on success.	178	* is filled into the variable on success.
179	* @return Pointer to LOCKED zone containing frame	179	* @return Pointer to LOCKED zone containing frame
180	*	180	*
181	* Assume interrupts disable	181	* Assume interrupts disable
182	*/	182	*/
183	static zone_t * find_zone_and_lock(pfn_t frame, int *pzone)	183	static zone_t * find_zone_and_lock(pfn_t frame, int *pzone)
184	{	184	{
185	int i;	185	int i;
186	int hint = pzone ? *pzone : 0;	186	int hint = pzone ? *pzone : 0;
187	zone_t *z;	187	zone_t *z;
188		188
189	spinlock_lock(&zones.lock);	189	spinlock_lock(&zones.lock);
190		190
191	if (hint >= zones.count \|\| hint < 0)	191	if (hint >= zones.count \|\| hint < 0)
192	hint = 0;	192	hint = 0;
193		193
194	i = hint;	194	i = hint;
195	do {	195	do {
196	z = zones.info[i];	196	z = zones.info[i];
197	spinlock_lock(&z->lock);	197	spinlock_lock(&z->lock);
198	if (z->base <= frame && z->base + z->count > frame) {	198	if (z->base <= frame && z->base + z->count > frame) {
199	spinlock_unlock(&zones.lock); /* Unlock the global lock */	199	spinlock_unlock(&zones.lock); /* Unlock the global lock */
200	if (pzone)	200	if (pzone)
201	*pzone = i;	201	*pzone = i;
202	return z;	202	return z;
203	}	203	}
204	spinlock_unlock(&z->lock);	204	spinlock_unlock(&z->lock);
205		205
206	i++;	206	i++;
207	if (i >= zones.count)	207	if (i >= zones.count)
208	i = 0;	208	i = 0;
209	} while(i != hint);	209	} while(i != hint);
210		210
211	spinlock_unlock(&zones.lock);	211	spinlock_unlock(&zones.lock);
212	return NULL;	212	return NULL;
213	}	213	}
214		214
215	/** @return True if zone can allocate specified order */	215	/** @return True if zone can allocate specified order */
216	static int zone_can_alloc(zone_t *z, __u8 order)	216	static int zone_can_alloc(zone_t *z, __u8 order)
217	{	217	{
218	return buddy_system_can_alloc(z->buddy_system, order);	218	return buddy_system_can_alloc(z->buddy_system, order);
219	}	219	}
220		220
221	/**	221	/**
222	* Find AND LOCK zone that can allocate order frames	222	* Find AND LOCK zone that can allocate order frames
223	*	223	*
224	* Assume interrupts are disabled!!	224	* Assume interrupts are disabled!!
225	*	225	*
226	* @param order Size (2^order) of free space we are trying to find	226	* @param order Size (2^order) of free space we are trying to find
227	* @param pzone Pointer to preferred zone or NULL, on return contains zone number	227	* @param pzone Pointer to preferred zone or NULL, on return contains zone number
228	*/	228	*/
229	static zone_t * find_free_zone_lock(__u8 order, int *pzone)	229	static zone_t * find_free_zone_lock(__u8 order, int *pzone)
230	{	230	{
231	int i;	231	int i;
232	zone_t *z;	232	zone_t *z;
233	int hint = pzone ? *pzone : 0;	233	int hint = pzone ? *pzone : 0;
234		234
235	spinlock_lock(&zones.lock);	235	spinlock_lock(&zones.lock);
236	if (hint >= zones.count)	236	if (hint >= zones.count)
237	hint = 0;	237	hint = 0;
238	i = hint;	238	i = hint;
239	do {	239	do {
240	z = zones.info[i];	240	z = zones.info[i];
241		241
242	spinlock_lock(&z->lock);	242	spinlock_lock(&z->lock);
243		243
244	/* Check if the zone has 2^order frames area available */	244	/* Check if the zone has 2^order frames area available */
245	if (zone_can_alloc(z, order)) {	245	if (zone_can_alloc(z, order)) {
246	spinlock_unlock(&zones.lock);	246	spinlock_unlock(&zones.lock);
247	if (pzone)	247	if (pzone)
248	*pzone = i;	248	*pzone = i;
249	return z;	249	return z;
250	}	250	}
251	spinlock_unlock(&z->lock);	251	spinlock_unlock(&z->lock);
252	if (++i >= zones.count)	252	if (++i >= zones.count)
253	i = 0;	253	i = 0;
254	} while(i != hint);	254	} while(i != hint);
255	spinlock_unlock(&zones.lock);	255	spinlock_unlock(&zones.lock);
256	return NULL;	256	return NULL;
257	}	257	}
258		258
259	/********************************************/	259	/********************************************/
260	/* Buddy system functions */	260	/* Buddy system functions */
261		261
262	/** Buddy system find_block implementation	262	/** Buddy system find_block implementation
263	*	263	*
264	* Find block that is parent of current list.	264	* Find block that is parent of current list.
265	* That means go to lower addresses, until such block is found	265	* That means go to lower addresses, until such block is found
266	*	266	*
267	* @param order - Order of parent must be different then this parameter!!	267	* @param order - Order of parent must be different then this parameter!!
268	*/	268	*/
269	static link_t zone_buddy_find_block(buddy_system_t b, link_t *child,	269	static link_t zone_buddy_find_block(buddy_system_t b, link_t *child,
270	__u8 order)	270	__u8 order)
271	{	271	{
272	frame_t * frame;	272	frame_t * frame;
273	zone_t * zone;	273	zone_t * zone;
274	index_t index;	274	index_t index;
275		275
276	frame = list_get_instance(child, frame_t, buddy_link);	276	frame = list_get_instance(child, frame_t, buddy_link);
277	zone = (zone_t *) b->data;	277	zone = (zone_t *) b->data;
278		278
279	index = frame_index(zone, frame);	279	index = frame_index(zone, frame);
280	do {	280	do {
281	if (zone->frames[index].buddy_order != order) {	281	if (zone->frames[index].buddy_order != order) {
282	return &zone->frames[index].buddy_link;	282	return &zone->frames[index].buddy_link;
283	}	283	}
284	} while(index-- > 0);	284	} while(index-- > 0);
285	return NULL;	285	return NULL;
286	}	286	}
287		287
288	static void zone_buddy_print_id(buddy_system_t b, link_t block)	288	static void zone_buddy_print_id(buddy_system_t b, link_t block)
289	{	289	{
290	frame_t * frame;	290	frame_t * frame;
291	zone_t * zone;	291	zone_t * zone;
292	index_t index;	292	index_t index;
293		293
294	frame = list_get_instance(block, frame_t, buddy_link);	294	frame = list_get_instance(block, frame_t, buddy_link);
295	zone = (zone_t *) b->data;	295	zone = (zone_t *) b->data;
296	index = frame_index(zone, frame);	296	index = frame_index(zone, frame);
297	printf("%zd", index);	297	printf("%zd", index);
298	}	298	}
299		299
300	/** Buddy system find_buddy implementation	300	/** Buddy system find_buddy implementation
301	*	301	*
302	* @param b Buddy system.	302	* @param b Buddy system.
303	* @param block Block for which buddy should be found	303	* @param block Block for which buddy should be found
304	*	304	*
305	* @return Buddy for given block if found	305	* @return Buddy for given block if found
306	*/	306	*/
307	static link_t * zone_buddy_find_buddy(buddy_system_t b, link_t block)	307	static link_t * zone_buddy_find_buddy(buddy_system_t b, link_t block)
308	{	308	{
309	frame_t * frame;	309	frame_t * frame;
310	zone_t * zone;	310	zone_t * zone;
311	index_t index;	311	index_t index;
312	bool is_left, is_right;	312	bool is_left, is_right;
313		313
314	frame = list_get_instance(block, frame_t, buddy_link);	314	frame = list_get_instance(block, frame_t, buddy_link);
315	zone = (zone_t *) b->data;	315	zone = (zone_t *) b->data;
316	ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame), frame->buddy_order));	316	ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame), frame->buddy_order));
317		317
318	is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);	318	is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);
319	is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);	319	is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);
320		320
321	ASSERT(is_left ^ is_right);	321	ASSERT(is_left ^ is_right);
322	if (is_left) {	322	if (is_left) {
323	index = (frame_index(zone, frame)) + (1 << frame->buddy_order);	323	index = (frame_index(zone, frame)) + (1 << frame->buddy_order);
324	} else { // if (is_right)	324	} else { // if (is_right)
325	index = (frame_index(zone, frame)) - (1 << frame->buddy_order);	325	index = (frame_index(zone, frame)) - (1 << frame->buddy_order);
326	}	326	}
327		327
328	if (frame_index_valid(zone, index)) {	328	if (frame_index_valid(zone, index)) {
329	if (zone->frames[index].buddy_order == frame->buddy_order &&	329	if (zone->frames[index].buddy_order == frame->buddy_order &&
330	zone->frames[index].refcount == 0) {	330	zone->frames[index].refcount == 0) {
331	return &zone->frames[index].buddy_link;	331	return &zone->frames[index].buddy_link;
332	}	332	}
333	}	333	}
334		334
335	return NULL;	335	return NULL;
336	}	336	}
337		337
338	/** Buddy system bisect implementation	338	/** Buddy system bisect implementation
339	*	339	*
340	* @param b Buddy system.	340	* @param b Buddy system.
341	* @param block Block to bisect	341	* @param block Block to bisect
342	*	342	*
343	* @return right block	343	* @return right block
344	*/	344	*/
345	static link_t * zone_buddy_bisect(buddy_system_t b, link_t block) {	345	static link_t * zone_buddy_bisect(buddy_system_t b, link_t block) {
346	frame_t * frame_l, * frame_r;	346	frame_t * frame_l, * frame_r;
347		347
348	frame_l = list_get_instance(block, frame_t, buddy_link);	348	frame_l = list_get_instance(block, frame_t, buddy_link);
349	frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));	349	frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));
350		350
351	return &frame_r->buddy_link;	351	return &frame_r->buddy_link;
352	}	352	}
353		353
354	/** Buddy system coalesce implementation	354	/** Buddy system coalesce implementation
355	*	355	*
356	* @param b Buddy system.	356	* @param b Buddy system.
357	* @param block_1 First block	357	* @param block_1 First block
358	* @param block_2 First block's buddy	358	* @param block_2 First block's buddy
359	*	359	*
360	* @return Coalesced block (actually block that represents lower address)	360	* @return Coalesced block (actually block that represents lower address)
361	*/	361	*/
362	static link_t * zone_buddy_coalesce(buddy_system_t b, link_t block_1,	362	static link_t * zone_buddy_coalesce(buddy_system_t b, link_t block_1,
363	link_t * block_2)	363	link_t * block_2)
364	{	364	{
365	frame_t frame1, frame2;	365	frame_t frame1, frame2;
366		366
367	frame1 = list_get_instance(block_1, frame_t, buddy_link);	367	frame1 = list_get_instance(block_1, frame_t, buddy_link);
368	frame2 = list_get_instance(block_2, frame_t, buddy_link);	368	frame2 = list_get_instance(block_2, frame_t, buddy_link);
369		369
370	return frame1 < frame2 ? block_1 : block_2;	370	return frame1 < frame2 ? block_1 : block_2;
371	}	371	}
372		372
373	/** Buddy system set_order implementation	373	/** Buddy system set_order implementation
374	*	374	*
375	* @param b Buddy system.	375	* @param b Buddy system.
376	* @param block Buddy system block	376	* @param block Buddy system block
377	* @param order Order to set	377	* @param order Order to set
378	*/	378	*/
379	static void zone_buddy_set_order(buddy_system_t b, link_t block, __u8 order) {	379	static void zone_buddy_set_order(buddy_system_t b, link_t block, __u8 order) {
380	frame_t * frame;	380	frame_t * frame;
381	frame = list_get_instance(block, frame_t, buddy_link);	381	frame = list_get_instance(block, frame_t, buddy_link);
382	frame->buddy_order = order;	382	frame->buddy_order = order;
383	}	383	}
384		384
385	/** Buddy system get_order implementation	385	/** Buddy system get_order implementation
386	*	386	*
387	* @param b Buddy system.	387	* @param b Buddy system.
388	* @param block Buddy system block	388	* @param block Buddy system block
389	*	389	*
390	* @return Order of block	390	* @return Order of block
391	*/	391	*/
392	static __u8 zone_buddy_get_order(buddy_system_t b, link_t block) {	392	static __u8 zone_buddy_get_order(buddy_system_t b, link_t block) {
393	frame_t * frame;	393	frame_t * frame;
394	frame = list_get_instance(block, frame_t, buddy_link);	394	frame = list_get_instance(block, frame_t, buddy_link);
395	return frame->buddy_order;	395	return frame->buddy_order;
396	}	396	}
397		397
398	/** Buddy system mark_busy implementation	398	/** Buddy system mark_busy implementation
399	*	399	*
400	* @param b Buddy system	400	* @param b Buddy system
401	* @param block Buddy system block	401	* @param block Buddy system block
402	*	402	*
403	*/	403	*/
404	static void zone_buddy_mark_busy(buddy_system_t b, link_t block) {	404	static void zone_buddy_mark_busy(buddy_system_t b, link_t block) {
405	frame_t * frame;	405	frame_t * frame;
406		406
407	frame = list_get_instance(block, frame_t, buddy_link);	407	frame = list_get_instance(block, frame_t, buddy_link);
408	frame->refcount = 1;	408	frame->refcount = 1;
409	}	409	}
410		410
411	/** Buddy system mark_available implementation	411	/** Buddy system mark_available implementation
412	*	412	*
413	* @param b Buddy system	413	* @param b Buddy system
414	* @param block Buddy system block	414	* @param block Buddy system block
415	*	415	*
416	*/	416	*/
417	static void zone_buddy_mark_available(buddy_system_t b, link_t block) {	417	static void zone_buddy_mark_available(buddy_system_t b, link_t block) {
418	frame_t * frame;	418	frame_t * frame;
419	frame = list_get_instance(block, frame_t, buddy_link);	419	frame = list_get_instance(block, frame_t, buddy_link);
420	frame->refcount = 0;	420	frame->refcount = 0;
421	}	421	}
422		422
423	static struct buddy_system_operations zone_buddy_system_operations = {	423	static struct buddy_system_operations zone_buddy_system_operations = {
424	.find_buddy = zone_buddy_find_buddy,	424	.find_buddy = zone_buddy_find_buddy,
425	.bisect = zone_buddy_bisect,	425	.bisect = zone_buddy_bisect,
426	.coalesce = zone_buddy_coalesce,	426	.coalesce = zone_buddy_coalesce,
427	.set_order = zone_buddy_set_order,	427	.set_order = zone_buddy_set_order,
428	.get_order = zone_buddy_get_order,	428	.get_order = zone_buddy_get_order,
429	.mark_busy = zone_buddy_mark_busy,	429	.mark_busy = zone_buddy_mark_busy,
430	.mark_available = zone_buddy_mark_available,	430	.mark_available = zone_buddy_mark_available,
431	.find_block = zone_buddy_find_block,	431	.find_block = zone_buddy_find_block,
432	.print_id = zone_buddy_print_id	432	.print_id = zone_buddy_print_id
433	};	433	};
434		434
435	/*************************************/	435	/*************************************/
436	/* Zone functions */	436	/* Zone functions */
437		437
438	/** Allocate frame in particular zone	438	/** Allocate frame in particular zone
439	*	439	*
440	* Assume zone is locked	440	* Assume zone is locked
441	* Panics if allocation is impossible.	441	* Panics if allocation is impossible.
442	*	442	*
443	* @param zone Zone to allocate from.	443	* @param zone Zone to allocate from.
444	* @param order Allocate exactly 2^order frames.	444	* @param order Allocate exactly 2^order frames.
445	*	445	*
446	* @return Frame index in zone	446	* @return Frame index in zone
447	*	447	*
448	*/	448	*/
449	static pfn_t zone_frame_alloc(zone_t *zone, __u8 order)	449	static pfn_t zone_frame_alloc(zone_t *zone, __u8 order)
450	{	450	{
451	pfn_t v;	451	pfn_t v;
452	link_t *tmp;	452	link_t *tmp;
453	frame_t *frame;	453	frame_t *frame;
454		454
455	/* Allocate frames from zone buddy system */	455	/* Allocate frames from zone buddy system */
456	tmp = buddy_system_alloc(zone->buddy_system, order);	456	tmp = buddy_system_alloc(zone->buddy_system, order);
457		457
458	ASSERT(tmp);	458	ASSERT(tmp);
459		459
460	/* Update zone information. */	460	/* Update zone information. */
461	zone->free_count -= (1 << order);	461	zone->free_count -= (1 << order);
462	zone->busy_count += (1 << order);	462	zone->busy_count += (1 << order);
463		463
464	/* Frame will be actually a first frame of the block. */	464	/* Frame will be actually a first frame of the block. */
465	frame = list_get_instance(tmp, frame_t, buddy_link);	465	frame = list_get_instance(tmp, frame_t, buddy_link);
466		466
467	/* get frame address */	467	/* get frame address */
468	v = make_frame_index(zone, frame);	468	v = make_frame_index(zone, frame);
469	return v;	469	return v;
470	}	470	}
471		471
472	/** Free frame from zone	472	/** Free frame from zone
473	*	473	*
474	* Assume zone is locked	474	* Assume zone is locked
475	*	475	*
476	* @param zone Pointer to zone from which the frame is to be freed	476	* @param zone Pointer to zone from which the frame is to be freed
477	* @param frame_idx Frame index relative to zone	477	* @param frame_idx Frame index relative to zone
478	*/	478	*/
479	static void zone_frame_free(zone_t *zone, index_t frame_idx)	479	static void zone_frame_free(zone_t *zone, index_t frame_idx)
480	{	480	{
481	frame_t *frame;	481	frame_t *frame;
482	__u8 order;	482	__u8 order;
483		483
484	frame = &zone->frames[frame_idx];	484	frame = &zone->frames[frame_idx];
485		485
486	/* remember frame order */	486	/* remember frame order */
487	order = frame->buddy_order;	487	order = frame->buddy_order;
488		488
489	ASSERT(frame->refcount);	489	ASSERT(frame->refcount);
490		490
491	if (!--frame->refcount) {	491	if (!--frame->refcount) {
492	buddy_system_free(zone->buddy_system, &frame->buddy_link);	492	buddy_system_free(zone->buddy_system, &frame->buddy_link);
493		493
494	/* Update zone information. */	494	/* Update zone information. */
495	zone->free_count += (1 << order);	495	zone->free_count += (1 << order);
496	zone->busy_count -= (1 << order);	496	zone->busy_count -= (1 << order);
497	}	497	}
498	}	498	}
499		499
500	/** Return frame from zone */	500	/** Return frame from zone */

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(root)/kernel/trunk/generic/src/mm/frame.c – Rev 1599 → 1700