WebSVN – HelenOS – Diff – /trunk/kernel/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.
 */
 
/** @addtogroup genericmm
 * @{
 */
 
/**
 * @file
 * @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  */
    uint8_t 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
 
 * Assume interrupts are disabled.
 
 * @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
 */
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, uint8_t 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_and_lock(uint8_t 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,
                     uint8_t 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, uint8_t 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 uint8_t 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, uint8_t 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;
    uint8_t 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)
{
    uint8_t 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((uintptr_t)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;
    uint8_t 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;
    uint8_t 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;
    uint8_t 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)
 */
uintptr_t 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;
    uintptr_t 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;
           
            if (overlaps(addr, PFN2ADDR(confcount), KA2PA(config.stack_base), config.stack_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 pzone  Preferred zone
 *
 * @return Physical address of the allocated frame.
 *
 */
void * frame_alloc_generic(uint8_t order, int flags, 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_and_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_and_lock(order, pzone);
        if (!zone) {
            freed = slab_reclaim(SLAB_RECLAIM_ALL);
            if (freed)
                zone = find_free_zone_and_lock(order, pzone);
        }
    }
    if (!zone) {
        /*
         * TODO: Sleep until frames are available again.
         */
        interrupts_restore(ipl);
 
        if (flags & FRAME_ATOMIC)
            return 0;
       
        panic("Sleep not implemented.\n");
        goto loop;
    }
   
    v = zone_frame_alloc(zone, order);
    v += zone->base;
 
    spinlock_unlock(&zone->lock);
    interrupts_restore(ipl);
 
    if (flags & FRAME_KA)
        return (void *)PA2KA(PFN2ADDR(v));
    return (void *)PFN2ADDR(v);
}
 
/** Free a frame.
 *
 * Find respective frame structure for supplied physical frame address.
 * Decrement frame reference count.
 * If it drops to zero, move the frame structure to free list.
 *
 * @param Frame Physical Address of of the frame to be freed.
 */
void frame_free(uintptr_t frame)
{
    ipl_t ipl;
    zone_t *zone;
    pfn_t pfn = ADDR2PFN(frame);
 
    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 pfn Frame number of the frame 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.lock");
    }
    /* Tell the architecture to create some memory */
    frame_arch_init();
    if (config.cpu_active == 1) {
        frame_mark_unavailable(ADDR2PFN(KA2PA(config.base)), SIZE2FRAMES(config.kernel_size));
        frame_mark_unavailable(ADDR2PFN(KA2PA(config.stack_base)), SIZE2FRAMES(config.stack_size));
       
        count_t i;
        for (i = 0; i < init.cnt; i++)
            frame_mark_unavailable(ADDR2PFN(KA2PA(init.tasks[i].addr)), SIZE2FRAMES(init.tasks[i].size));
 
        if (ballocs.size)
            frame_mark_unavailable(ADDR2PFN(KA2PA(ballocs.base)), SIZE2FRAMES(ballocs.size));
 
        /* Black list first frame, as allocating NULL would
         * fail in 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 free frames  busy frames\n");
    printf("-- ------------ ------------ ------------\n");
    for (i = 0; i < zones.count; i++) {
        zone = zones.info[i];
        spinlock_lock(&zone->lock);
        printf("%-2d %12p %12zd %12zd\n", i, PFN2ADDR(zone->base), zone->free_count, zone->busy_count);
        spinlock_unlock(&zone->lock);
    }
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
}
 
/** Prints zone details.
 *
 * @param num 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(uintptr_t) * 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 frames (%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 2059	Rev 2071
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	/** @addtogroup genericmm	30	/** @addtogroup genericmm
31	* @{	31	* @{
32	*/	32	*/
33		33
34	/**	34	/**
35	* @file	35	* @file
36	* @brief Physical frame allocator.	36	* @brief Physical frame allocator.
37	*	37	*
38	* This file contains the physical frame allocator and memory zone management.	38	* This file contains the physical frame allocator and memory zone management.
39	* The frame allocator is built on top of the buddy allocator.	39	* The frame allocator is built on top of the buddy allocator.
40	*	40	*
41	* @see buddy.c	41	* @see buddy.c
42	*/	42	*/
43		43
44	/*	44	/*
45	* Locking order	45	* Locking order
46	*	46	*
47	* In order to access particular zone, the process must first lock	47	* In order to access particular zone, the process must first lock
48	* the zones.lock, then lock the zone and then unlock the zones.lock.	48	* the zones.lock, then lock the zone and then unlock the zones.lock.
49	* This insures, that we can fiddle with the zones in runtime without	49	* This insures, that we can fiddle with the zones in runtime without
50	* affecting the processes.	50	* affecting the processes.
51	*	51	*
52	*/	52	*/
53		53
54	#include <typedefs.h>	54	#include <typedefs.h>
55	#include <arch/types.h>	55	#include <arch/types.h>
56	#include <mm/frame.h>	56	#include <mm/frame.h>
57	#include <mm/as.h>	57	#include <mm/as.h>
58	#include <panic.h>	58	#include <panic.h>
59	#include <debug.h>	59	#include <debug.h>
60	#include <adt/list.h>	60	#include <adt/list.h>
61	#include <synch/spinlock.h>	61	#include <synch/spinlock.h>
62	#include <arch/asm.h>	62	#include <arch/asm.h>
63	#include <arch.h>	63	#include <arch.h>
64	#include <print.h>	64	#include <print.h>
65	#include <align.h>	65	#include <align.h>
66	#include <mm/slab.h>	66	#include <mm/slab.h>
67	#include <bitops.h>	67	#include <bitops.h>
68	#include <macros.h>	68	#include <macros.h>
69		69
70	typedef struct {	70	typedef struct {
71	count_t refcount; /*< tracking of shared frames /	71	count_t refcount; /*< tracking of shared frames /
72	uint8_t buddy_order; /*< buddy system block order /	72	uint8_t buddy_order; /*< buddy system block order /
73	link_t buddy_link; /*< link to the next free block inside one order /	73	link_t buddy_link; /*< link to the next free block inside one order /
74	void parent; /< If allocated by slab, this points there /	74	void parent; /< If allocated by slab, this points there /
75	} frame_t;	75	} frame_t;
76		76
77	typedef struct {	77	typedef struct {
78	SPINLOCK_DECLARE(lock); /*< this lock protects everything below /	78	SPINLOCK_DECLARE(lock); /*< this lock protects everything below /
79	pfn_t base; /*< frame_no of the first frame in the frames array /	79	pfn_t base; /*< frame_no of the first frame in the frames array /
80	count_t count; /*< Size of zone /	80	count_t count; /*< Size of zone /
81		81
82	frame_t frames; /< array of frame_t structures in this zone /	82	frame_t frames; /< array of frame_t structures in this zone /
83	count_t free_count; /*< number of free frame_t structures /	83	count_t free_count; /*< number of free frame_t structures /
84	count_t busy_count; /*< number of busy frame_t structures /	84	count_t busy_count; /*< number of busy frame_t structures /
85		85
86	buddy_system_t buddy_system; /< buddy system for the zone /	86	buddy_system_t buddy_system; /< buddy system for the zone /
87	int flags;	87	int flags;
88	} zone_t;	88	} zone_t;
89		89
90	/*	90	/*
91	* The zoneinfo.lock must be locked when accessing zoneinfo structure.	91	* The zoneinfo.lock must be locked when accessing zoneinfo structure.
92	* Some of the attributes in zone_t structures are 'read-only'	92	* Some of the attributes in zone_t structures are 'read-only'
93	*/	93	*/
94		94
95	struct {	95	struct {
96	SPINLOCK_DECLARE(lock);	96	SPINLOCK_DECLARE(lock);
97	int count;	97	int count;
98	zone_t *info[ZONES_MAX];	98	zone_t *info[ZONES_MAX];
99	} zones;	99	} zones;
100		100
101		101
102	/*********************************/	102	/*********************************/
103	/* Helper functions */	103	/* Helper functions */
104	static inline index_t frame_index(zone_t zone, frame_t frame)	104	static inline index_t frame_index(zone_t zone, frame_t frame)
105	{	105	{
106	return (index_t)(frame - zone->frames);	106	return (index_t)(frame - zone->frames);
107	}	107	}
108	static inline index_t frame_index_abs(zone_t zone, frame_t frame)	108	static inline index_t frame_index_abs(zone_t zone, frame_t frame)
109	{	109	{
110	return (index_t)(frame - zone->frames) + zone->base;	110	return (index_t)(frame - zone->frames) + zone->base;
111	}	111	}
112	static inline int frame_index_valid(zone_t *zone, index_t index)	112	static inline int frame_index_valid(zone_t *zone, index_t index)
113	{	113	{
114	return index >= 0 && index < zone->count;	114	return index >= 0 && index < zone->count;
115	}	115	}
116		116
117	/** Compute pfn_t from frame_t pointer & zone pointer */	117	/** Compute pfn_t from frame_t pointer & zone pointer */
118	static index_t make_frame_index(zone_t zone, frame_t frame)	118	static index_t make_frame_index(zone_t zone, frame_t frame)
119	{	119	{
120	return frame - zone->frames;	120	return frame - zone->frames;
121	}	121	}
122		122
123	/** Initialize frame structure	123	/** Initialize frame structure
124	*	124	*
125	* Initialize frame structure.	125	* Initialize frame structure.
126	*	126	*
127	* @param frame Frame structure to be initialized.	127	* @param frame Frame structure to be initialized.
128	*/	128	*/
129	static void frame_initialize(frame_t *frame)	129	static void frame_initialize(frame_t *frame)
130	{	130	{
131	frame->refcount = 1;	131	frame->refcount = 1;
132	frame->buddy_order = 0;	132	frame->buddy_order = 0;
133	}	133	}
134		134
135	/*************************************/	135	/*************************************/
136	/* Zoneinfo functions */	136	/* Zoneinfo functions */
137		137
138	/**	138	/**
139	* Insert-sort zone into zones list	139	* Insert-sort zone into zones list
140	*	140	*
141	* @param newzone New zone to be inserted into zone list	141	* @param newzone New zone to be inserted into zone list
142	* @return zone number on success, -1 on error	142	* @return zone number on success, -1 on error
143	*/	143	*/
144	static int zones_add_zone(zone_t *newzone)	144	static int zones_add_zone(zone_t *newzone)
145	{	145	{
146	int i,j;	146	int i,j;
147	ipl_t ipl;	147	ipl_t ipl;
148	zone_t *z;	148	zone_t *z;
149		149
150	ipl = interrupts_disable();	150	ipl = interrupts_disable();
151	spinlock_lock(&zones.lock);	151	spinlock_lock(&zones.lock);
152	/* Try to merge */	152	/* Try to merge */
153	if (zones.count + 1 == ZONES_MAX)	153	if (zones.count + 1 == ZONES_MAX)
154	panic("Maximum zone(%d) count exceeded.", ZONES_MAX);	154	panic("Maximum zone(%d) count exceeded.", ZONES_MAX);
155	for (i = 0; i < zones.count; i++) {	155	for (i = 0; i < zones.count; i++) {
156	/* Check for overflow */	156	/* Check for overflow */
157	z = zones.info[i];	157	z = zones.info[i];
158	if (overlaps(newzone->base,newzone->count,	158	if (overlaps(newzone->base,newzone->count,
159	z->base, z->count)) {	159	z->base, z->count)) {
160	printf("Zones overlap!\n");	160	printf("Zones overlap!\n");
161	return -1;	161	return -1;
162	}	162	}
163	if (newzone->base < z->base)	163	if (newzone->base < z->base)
164	break;	164	break;
165	}	165	}
166	/* Move other zones up */	166	/* Move other zones up */
167	for (j = i;j < zones.count; j++)	167	for (j = i;j < zones.count; j++)
168	zones.info[j + 1] = zones.info[j];	168	zones.info[j + 1] = zones.info[j];
169	zones.info[i] = newzone;	169	zones.info[i] = newzone;
170	zones.count++;	170	zones.count++;
171	spinlock_unlock(&zones.lock);	171	spinlock_unlock(&zones.lock);
172	interrupts_restore(ipl);	172	interrupts_restore(ipl);
173		173
174	return i;	174	return i;
175	}	175	}
176		176
177	/**	177	/**
178	* Try to find a zone where can we find the frame	178	* Try to find a zone where can we find the frame
179		179
180	* Assume interrupts are disabled.	180	* Assume interrupts are disabled.
181		181
182	* @param frame Frame number contained in zone	182	* @param frame Frame number contained in zone
183	* @param pzone If not null, it is used as zone hint. Zone index	183	* @param pzone If not null, it is used as zone hint. Zone index
184	* is filled into the variable on success.	184	* is filled into the variable on success.
185	* @return Pointer to locked zone containing frame	185	* @return Pointer to locked zone containing frame
186	*/	186	*/
187	static zone_t * find_zone_and_lock(pfn_t frame, int *pzone)	187	static zone_t * find_zone_and_lock(pfn_t frame, int *pzone)
188	{	188	{
189	int i;	189	int i;
190	int hint = pzone ? *pzone : 0;	190	int hint = pzone ? *pzone : 0;
191	zone_t *z;	191	zone_t *z;
192		192
193	spinlock_lock(&zones.lock);	193	spinlock_lock(&zones.lock);
194		194
195	if (hint >= zones.count \|\| hint < 0)	195	if (hint >= zones.count \|\| hint < 0)
196	hint = 0;	196	hint = 0;
197		197
198	i = hint;	198	i = hint;
199	do {	199	do {
200	z = zones.info[i];	200	z = zones.info[i];
201	spinlock_lock(&z->lock);	201	spinlock_lock(&z->lock);
202	if (z->base <= frame && z->base + z->count > frame) {	202	if (z->base <= frame && z->base + z->count > frame) {
203	spinlock_unlock(&zones.lock); /* Unlock the global lock */	203	spinlock_unlock(&zones.lock); /* Unlock the global lock */
204	if (pzone)	204	if (pzone)
205	*pzone = i;	205	*pzone = i;
206	return z;	206	return z;
207	}	207	}
208	spinlock_unlock(&z->lock);	208	spinlock_unlock(&z->lock);
209		209
210	i++;	210	i++;
211	if (i >= zones.count)	211	if (i >= zones.count)
212	i = 0;	212	i = 0;
213	} while(i != hint);	213	} while(i != hint);
214		214
215	spinlock_unlock(&zones.lock);	215	spinlock_unlock(&zones.lock);
216	return NULL;	216	return NULL;
217	}	217	}
218		218
219	/** @return True if zone can allocate specified order */	219	/** @return True if zone can allocate specified order */
220	static int zone_can_alloc(zone_t *z, uint8_t order)	220	static int zone_can_alloc(zone_t *z, uint8_t order)
221	{	221	{
222	return buddy_system_can_alloc(z->buddy_system, order);	222	return buddy_system_can_alloc(z->buddy_system, order);
223	}	223	}
224		224
225	/** Find and lock zone that can allocate order frames.	225	/** Find and lock zone that can allocate order frames.
226	*	226	*
227	* Assume interrupts are disabled.	227	* Assume interrupts are disabled.
228	*	228	*
229	* @param order Size (2^order) of free space we are trying to find	229	* @param order Size (2^order) of free space we are trying to find
230	* @param pzone Pointer to preferred zone or NULL, on return contains zone number	230	* @param pzone Pointer to preferred zone or NULL, on return contains zone number
231	*/	231	*/
232	static zone_t * find_free_zone_and_lock(uint8_t order, int *pzone)	232	static zone_t * find_free_zone_and_lock(uint8_t order, int *pzone)
233	{	233	{
234	int i;	234	int i;
235	zone_t *z;	235	zone_t *z;
236	int hint = pzone ? *pzone : 0;	236	int hint = pzone ? *pzone : 0;
237		237
238	spinlock_lock(&zones.lock);	238	spinlock_lock(&zones.lock);
239	if (hint >= zones.count)	239	if (hint >= zones.count)
240	hint = 0;	240	hint = 0;
241	i = hint;	241	i = hint;
242	do {	242	do {
243	z = zones.info[i];	243	z = zones.info[i];
244		244
245	spinlock_lock(&z->lock);	245	spinlock_lock(&z->lock);
246		246
247	/* Check if the zone has 2^order frames area available */	247	/* Check if the zone has 2^order frames area available */
248	if (zone_can_alloc(z, order)) {	248	if (zone_can_alloc(z, order)) {
249	spinlock_unlock(&zones.lock);	249	spinlock_unlock(&zones.lock);
250	if (pzone)	250	if (pzone)
251	*pzone = i;	251	*pzone = i;
252	return z;	252	return z;
253	}	253	}
254	spinlock_unlock(&z->lock);	254	spinlock_unlock(&z->lock);
255	if (++i >= zones.count)	255	if (++i >= zones.count)
256	i = 0;	256	i = 0;
257	} while(i != hint);	257	} while(i != hint);
258	spinlock_unlock(&zones.lock);	258	spinlock_unlock(&zones.lock);
259	return NULL;	259	return NULL;
260	}	260	}
261		261
262	/**************************/	262	/**************************/
263	/* Buddy system functions */	263	/* Buddy system functions */
264	/**************************/	264	/**************************/
265		265
266	/** Buddy system find_block implementation	266	/** Buddy system find_block implementation
267	*	267	*
268	* Find block that is parent of current list.	268	* Find block that is parent of current list.
269	* That means go to lower addresses, until such block is found	269	* That means go to lower addresses, until such block is found
270	*	270	*
271	* @param order - Order of parent must be different then this parameter!!	271	* @param order - Order of parent must be different then this parameter!!
272	*/	272	*/
273	static link_t zone_buddy_find_block(buddy_system_t b, link_t *child,	273	static link_t zone_buddy_find_block(buddy_system_t b, link_t *child,
274	uint8_t order)	274	uint8_t order)
275	{	275	{
276	frame_t * frame;	276	frame_t * frame;
277	zone_t * zone;	277	zone_t * zone;
278	index_t index;	278	index_t index;
279		279
280	frame = list_get_instance(child, frame_t, buddy_link);	280	frame = list_get_instance(child, frame_t, buddy_link);
281	zone = (zone_t *) b->data;	281	zone = (zone_t *) b->data;
282		282
283	index = frame_index(zone, frame);	283	index = frame_index(zone, frame);
284	do {	284	do {
285	if (zone->frames[index].buddy_order != order) {	285	if (zone->frames[index].buddy_order != order) {
286	return &zone->frames[index].buddy_link;	286	return &zone->frames[index].buddy_link;
287	}	287	}
288	} while(index-- > 0);	288	} while(index-- > 0);
289	return NULL;	289	return NULL;
290	}	290	}
291		291
292	static void zone_buddy_print_id(buddy_system_t b, link_t block)	292	static void zone_buddy_print_id(buddy_system_t b, link_t block)
293	{	293	{
294	frame_t * frame;	294	frame_t * frame;
295	zone_t * zone;	295	zone_t * zone;
296	index_t index;	296	index_t index;
297		297
298	frame = list_get_instance(block, frame_t, buddy_link);	298	frame = list_get_instance(block, frame_t, buddy_link);
299	zone = (zone_t *) b->data;	299	zone = (zone_t *) b->data;
300	index = frame_index(zone, frame);	300	index = frame_index(zone, frame);
301	printf("%zd", index);	301	printf("%zd", index);
302	}	302	}
303		303
304	/** Buddy system find_buddy implementation	304	/** Buddy system find_buddy implementation
305	*	305	*
306	* @param b Buddy system.	306	* @param b Buddy system.
307	* @param block Block for which buddy should be found	307	* @param block Block for which buddy should be found
308	*	308	*
309	* @return Buddy for given block if found	309	* @return Buddy for given block if found
310	*/	310	*/
311	static link_t * zone_buddy_find_buddy(buddy_system_t b, link_t block)	311	static link_t * zone_buddy_find_buddy(buddy_system_t b, link_t block)
312	{	312	{
313	frame_t * frame;	313	frame_t * frame;
314	zone_t * zone;	314	zone_t * zone;
315	index_t index;	315	index_t index;
316	bool is_left, is_right;	316	bool is_left, is_right;
317		317
318	frame = list_get_instance(block, frame_t, buddy_link);	318	frame = list_get_instance(block, frame_t, buddy_link);
319	zone = (zone_t *) b->data;	319	zone = (zone_t *) b->data;
320	ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame), frame->buddy_order));	320	ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame), frame->buddy_order));
321		321
322	is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);	322	is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);
323	is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);	323	is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);
324		324
325	ASSERT(is_left ^ is_right);	325	ASSERT(is_left ^ is_right);
326	if (is_left) {	326	if (is_left) {
327	index = (frame_index(zone, frame)) + (1 << frame->buddy_order);	327	index = (frame_index(zone, frame)) + (1 << frame->buddy_order);
328	} else { /* if (is_right) */	328	} else { /* if (is_right) */
329	index = (frame_index(zone, frame)) - (1 << frame->buddy_order);	329	index = (frame_index(zone, frame)) - (1 << frame->buddy_order);
330	}	330	}
331		331
332	if (frame_index_valid(zone, index)) {	332	if (frame_index_valid(zone, index)) {
333	if (zone->frames[index].buddy_order == frame->buddy_order &&	333	if (zone->frames[index].buddy_order == frame->buddy_order &&
334	zone->frames[index].refcount == 0) {	334	zone->frames[index].refcount == 0) {
335	return &zone->frames[index].buddy_link;	335	return &zone->frames[index].buddy_link;
336	}	336	}
337	}	337	}
338		338
339	return NULL;	339	return NULL;
340	}	340	}
341		341
342	/** Buddy system bisect implementation	342	/** Buddy system bisect implementation
343	*	343	*
344	* @param b Buddy system.	344	* @param b Buddy system.
345	* @param block Block to bisect	345	* @param block Block to bisect
346	*	346	*
347	* @return right block	347	* @return right block
348	*/	348	*/
349	static link_t * zone_buddy_bisect(buddy_system_t b, link_t block) {	349	static link_t * zone_buddy_bisect(buddy_system_t b, link_t block) {
350	frame_t * frame_l, * frame_r;	350	frame_t * frame_l, * frame_r;
351		351
352	frame_l = list_get_instance(block, frame_t, buddy_link);	352	frame_l = list_get_instance(block, frame_t, buddy_link);
353	frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));	353	frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));
354		354
355	return &frame_r->buddy_link;	355	return &frame_r->buddy_link;
356	}	356	}
357		357
358	/** Buddy system coalesce implementation	358	/** Buddy system coalesce implementation
359	*	359	*
360	* @param b Buddy system.	360	* @param b Buddy system.
361	* @param block_1 First block	361	* @param block_1 First block
362	* @param block_2 First block's buddy	362	* @param block_2 First block's buddy
363	*	363	*
364	* @return Coalesced block (actually block that represents lower address)	364	* @return Coalesced block (actually block that represents lower address)
365	*/	365	*/
366	static link_t * zone_buddy_coalesce(buddy_system_t b, link_t block_1,	366	static link_t * zone_buddy_coalesce(buddy_system_t b, link_t block_1,
367	link_t * block_2)	367	link_t * block_2)
368	{	368	{
369	frame_t frame1, frame2;	369	frame_t frame1, frame2;
370		370
371	frame1 = list_get_instance(block_1, frame_t, buddy_link);	371	frame1 = list_get_instance(block_1, frame_t, buddy_link);
372	frame2 = list_get_instance(block_2, frame_t, buddy_link);	372	frame2 = list_get_instance(block_2, frame_t, buddy_link);
373		373
374	return frame1 < frame2 ? block_1 : block_2;	374	return frame1 < frame2 ? block_1 : block_2;
375	}	375	}
376		376
377	/** Buddy system set_order implementation	377	/** Buddy system set_order implementation
378	*	378	*
379	* @param b Buddy system.	379	* @param b Buddy system.
380	* @param block Buddy system block	380	* @param block Buddy system block
381	* @param order Order to set	381	* @param order Order to set
382	*/	382	*/
383	static void zone_buddy_set_order(buddy_system_t b, link_t block, uint8_t order) {	383	static void zone_buddy_set_order(buddy_system_t b, link_t block, uint8_t order) {
384	frame_t * frame;	384	frame_t * frame;
385	frame = list_get_instance(block, frame_t, buddy_link);	385	frame = list_get_instance(block, frame_t, buddy_link);
386	frame->buddy_order = order;	386	frame->buddy_order = order;
387	}	387	}
388		388
389	/** Buddy system get_order implementation	389	/** Buddy system get_order implementation
390	*	390	*
391	* @param b Buddy system.	391	* @param b Buddy system.
392	* @param block Buddy system block	392	* @param block Buddy system block
393	*	393	*
394	* @return Order of block	394	* @return Order of block
395	*/	395	*/
396	static uint8_t zone_buddy_get_order(buddy_system_t b, link_t block) {	396	static uint8_t zone_buddy_get_order(buddy_system_t b, link_t block) {
397	frame_t * frame;	397	frame_t * frame;
398	frame = list_get_instance(block, frame_t, buddy_link);	398	frame = list_get_instance(block, frame_t, buddy_link);
399	return frame->buddy_order;	399	return frame->buddy_order;
400	}	400	}
401		401
402	/** Buddy system mark_busy implementation	402	/** Buddy system mark_busy implementation
403	*	403	*
404	* @param b Buddy system	404	* @param b Buddy system
405	* @param block Buddy system block	405	* @param block Buddy system block
406	*	406	*
407	*/	407	*/
408	static void zone_buddy_mark_busy(buddy_system_t b, link_t block) {	408	static void zone_buddy_mark_busy(buddy_system_t b, link_t block) {
409	frame_t * frame;	409	frame_t * frame;
410		410
411	frame = list_get_instance(block, frame_t, buddy_link);	411	frame = list_get_instance(block, frame_t, buddy_link);
412	frame->refcount = 1;	412	frame->refcount = 1;
413	}	413	}
414		414
415	/** Buddy system mark_available implementation	415	/** Buddy system mark_available implementation
416	*	416	*
417	* @param b Buddy system	417	* @param b Buddy system
418	* @param block Buddy system block	418	* @param block Buddy system block
419	*	419	*
420	*/	420	*/
421	static void zone_buddy_mark_available(buddy_system_t b, link_t block) {	421	static void zone_buddy_mark_available(buddy_system_t b, link_t block) {
422	frame_t * frame;	422	frame_t * frame;
423	frame = list_get_instance(block, frame_t, buddy_link);	423	frame = list_get_instance(block, frame_t, buddy_link);
424	frame->refcount = 0;	424	frame->refcount = 0;
425	}	425	}
426		426
427	static struct buddy_system_operations zone_buddy_system_operations = {	427	static struct buddy_system_operations zone_buddy_system_operations = {
428	.find_buddy = zone_buddy_find_buddy,	428	.find_buddy = zone_buddy_find_buddy,
429	.bisect = zone_buddy_bisect,	429	.bisect = zone_buddy_bisect,
430	.coalesce = zone_buddy_coalesce,	430	.coalesce = zone_buddy_coalesce,
431	.set_order = zone_buddy_set_order,	431	.set_order = zone_buddy_set_order,
432	.get_order = zone_buddy_get_order,	432	.get_order = zone_buddy_get_order,
433	.mark_busy = zone_buddy_mark_busy,	433	.mark_busy = zone_buddy_mark_busy,
434	.mark_available = zone_buddy_mark_available,	434	.mark_available = zone_buddy_mark_available,
435	.find_block = zone_buddy_find_block,	435	.find_block = zone_buddy_find_block,
436	.print_id = zone_buddy_print_id	436	.print_id = zone_buddy_print_id
437	};	437	};
438		438
439	/******************/	439	/******************/
440	/* Zone functions */	440	/* Zone functions */
441	/******************/	441	/******************/
442		442
443	/** Allocate frame in particular zone	443	/** Allocate frame in particular zone
444	*	444	*
445	* Assume zone is locked	445	* Assume zone is locked
446	* Panics if allocation is impossible.	446	* Panics if allocation is impossible.
447	*	447	*
448	* @param zone Zone to allocate from.	448	* @param zone Zone to allocate from.
449	* @param order Allocate exactly 2^order frames.	449	* @param order Allocate exactly 2^order frames.
450	*	450	*
451	* @return Frame index in zone	451	* @return Frame index in zone
452	*	452	*
453	*/	453	*/
454	static pfn_t zone_frame_alloc(zone_t *zone, uint8_t order)	454	static pfn_t zone_frame_alloc(zone_t *zone, uint8_t order)
455	{	455	{
456	pfn_t v;	456	pfn_t v;
457	link_t *tmp;	457	link_t *tmp;
458	frame_t *frame;	458	frame_t *frame;
459		459
460	/* Allocate frames from zone buddy system */	460	/* Allocate frames from zone buddy system */
461	tmp = buddy_system_alloc(zone->buddy_system, order);	461	tmp = buddy_system_alloc(zone->buddy_system, order);
462		462
463	ASSERT(tmp);	463	ASSERT(tmp);
464		464
465	/* Update zone information. */	465	/* Update zone information. */
466	zone->free_count -= (1 << order);	466	zone->free_count -= (1 << order);
467	zone->busy_count += (1 << order);	467	zone->busy_count += (1 << order);
468		468
469	/* Frame will be actually a first frame of the block. */	469	/* Frame will be actually a first frame of the block. */
470	frame = list_get_instance(tmp, frame_t, buddy_link);	470	frame = list_get_instance(tmp, frame_t, buddy_link);
471		471
472	/* get frame address */	472	/* get frame address */
473	v = make_frame_index(zone, frame);	473	v = make_frame_index(zone, frame);
474	return v;	474	return v;
475	}	475	}
476		476
477	/** Free frame from zone	477	/** Free frame from zone
478	*	478	*
479	* Assume zone is locked	479	* Assume zone is locked
480	*	480	*
481	* @param zone Pointer to zone from which the frame is to be freed	481	* @param zone Pointer to zone from which the frame is to be freed
482	* @param frame_idx Frame index relative to zone	482	* @param frame_idx Frame index relative to zone
483	*/	483	*/
484	static void zone_frame_free(zone_t *zone, index_t frame_idx)	484	static void zone_frame_free(zone_t *zone, index_t frame_idx)
485	{	485	{
486	frame_t *frame;	486	frame_t *frame;
487	uint8_t order;	487	uint8_t order;
488		488
489	frame = &zone->frames[frame_idx];	489	frame = &zone->frames[frame_idx];
490		490
491	/* remember frame order */	491	/* remember frame order */
492	order = frame->buddy_order;	492	order = frame->buddy_order;
493		493
494	ASSERT(frame->refcount);	494	ASSERT(frame->refcount);
495		495
496	if (!--frame->refcount) {	496	if (!--frame->refcount) {
497	buddy_system_free(zone->buddy_system, &frame->buddy_link);	497	buddy_system_free(zone->buddy_system, &frame->buddy_link);
498		498
499	/* Update zone information. */	499	/* Update zone information. */
500	zone->free_count += (1 << order);	500	zone->free_count += (1 << order);

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(root)/trunk/kernel/generic/src/mm/frame.c – Rev 2059 → 2071