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
 *
 * @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 hint Start searching in zone 'hint'
 * @param lock Lock zone if true
 *
 * 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 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
 */
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
 */
 
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 unneded frames. This means, that
 * when freeing the block, you have to free every frame from block.
 *
 * @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));
    order = fnzb(cframes) + 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 size Size of the zone. Must be a multiple of FRAME_SIZE.
 * @param conffram Address of configuration frame
 * @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 */
__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 confframe Where configuration frame is supposed to be.
 *                  Always check, 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
 *
 * @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));
    }
}
 
 
 
/** 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 1248	Rev 1269
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	* @return zone number on success, -1 on error	137	* @return zone number on success, -1 on error
138	*/	138	*/
139	static int zones_add_zone(zone_t *newzone)	139	static int zones_add_zone(zone_t *newzone)
140	{	140	{
141	int i,j;	141	int i,j;
142	ipl_t ipl;	142	ipl_t ipl;
143	zone_t *z;	143	zone_t *z;
144		144
145	ipl = interrupts_disable();	145	ipl = interrupts_disable();
146	spinlock_lock(&zones.lock);	146	spinlock_lock(&zones.lock);
147	/* Try to merge */	147	/* Try to merge */
148	if (zones.count + 1 == ZONES_MAX)	148	if (zones.count + 1 == ZONES_MAX)
149	panic("Maximum zone(%d) count exceeded.", ZONES_MAX);	149	panic("Maximum zone(%d) count exceeded.", ZONES_MAX);
150	for (i = 0; i < zones.count; i++) {	150	for (i = 0; i < zones.count; i++) {
151	/* Check for overflow */	151	/* Check for overflow */
152	z = zones.info[i];	152	z = zones.info[i];
153	if (overlaps(newzone->base,newzone->count,	153	if (overlaps(newzone->base,newzone->count,
154	z->base, z->count)) {	154	z->base, z->count)) {
155	printf("Zones overlap!\n");	155	printf("Zones overlap!\n");
156	return -1;	156	return -1;
157	}	157	}
158	if (newzone->base < z->base)	158	if (newzone->base < z->base)
159	break;	159	break;
160	}	160	}
161	/* Move other zones up */	161	/* Move other zones up */
162	for (j = i;j < zones.count; j++)	162	for (j = i;j < zones.count; j++)
163	zones.info[j + 1] = zones.info[j];	163	zones.info[j + 1] = zones.info[j];
164	zones.info[i] = newzone;	164	zones.info[i] = newzone;
165	zones.count++;	165	zones.count++;
166	spinlock_unlock(&zones.lock);	166	spinlock_unlock(&zones.lock);
167	interrupts_restore(ipl);	167	interrupts_restore(ipl);
168		168
169	return i;	169	return i;
170	}	170	}
171		171
172	/**	172	/**
173	* Try to find a zone where can we find the frame	173	* Try to find a zone where can we find the frame
174	*	174	*
175	* @param hint Start searching in zone 'hint'	175	* @param hint Start searching in zone 'hint'
176	* @param lock Lock zone if true	176	* @param lock Lock zone if true
177	*	177	*
178	* Assume interrupts disable	178	* Assume interrupts disable
179	*/	179	*/
180	static zone_t * find_zone_and_lock(pfn_t frame, int *pzone)	180	static zone_t * find_zone_and_lock(pfn_t frame, int *pzone)
181	{	181	{
182	int i;	182	int i;
183	int hint = pzone ? *pzone : 0;	183	int hint = pzone ? *pzone : 0;
184	zone_t *z;	184	zone_t *z;
185		185
186	spinlock_lock(&zones.lock);	186	spinlock_lock(&zones.lock);
187		187
188	if (hint >= zones.count \|\| hint < 0)	188	if (hint >= zones.count \|\| hint < 0)
189	hint = 0;	189	hint = 0;
190		190
191	i = hint;	191	i = hint;
192	do {	192	do {
193	z = zones.info[i];	193	z = zones.info[i];
194	spinlock_lock(&z->lock);	194	spinlock_lock(&z->lock);
195	if (z->base <= frame && z->base + z->count > frame) {	195	if (z->base <= frame && z->base + z->count > frame) {
196	spinlock_unlock(&zones.lock); /* Unlock the global lock */	196	spinlock_unlock(&zones.lock); /* Unlock the global lock */
197	if (pzone)	197	if (pzone)
198	*pzone = i;	198	*pzone = i;
199	return z;	199	return z;
200	}	200	}
201	spinlock_unlock(&z->lock);	201	spinlock_unlock(&z->lock);
202		202
203	i++;	203	i++;
204	if (i >= zones.count)	204	if (i >= zones.count)
205	i = 0;	205	i = 0;
206	} while(i != hint);	206	} while(i != hint);
207		207
208	spinlock_unlock(&zones.lock);	208	spinlock_unlock(&zones.lock);
209	return NULL;	209	return NULL;
210	}	210	}
211		211
212	/** @return True if zone can allocate specified order */	212	/** @return True if zone can allocate specified order */
213	static int zone_can_alloc(zone_t *z, __u8 order)	213	static int zone_can_alloc(zone_t *z, __u8 order)
214	{	214	{
215	return buddy_system_can_alloc(z->buddy_system, order);	215	return buddy_system_can_alloc(z->buddy_system, order);
216	}	216	}
217		217
218	/**	218	/**
219	* Find AND LOCK zone that can allocate order frames	219	* Find AND LOCK zone that can allocate order frames
220	*	220	*
221	* Assume interrupts are disabled!!	221	* Assume interrupts are disabled!!
222	*	222	*
223	* @param pzone Pointer to preferred zone or NULL, on return contains zone number	223	* @param pzone Pointer to preferred zone or NULL, on return contains zone number
224	*/	224	*/
225	static zone_t * find_free_zone_lock(__u8 order, int *pzone)	225	static zone_t * find_free_zone_lock(__u8 order, int *pzone)
226	{	226	{
227	int i;	227	int i;
228	zone_t *z;	228	zone_t *z;
229	int hint = pzone ? *pzone : 0;	229	int hint = pzone ? *pzone : 0;
230		230
231	spinlock_lock(&zones.lock);	231	spinlock_lock(&zones.lock);
232	if (hint >= zones.count)	232	if (hint >= zones.count)
233	hint = 0;	233	hint = 0;
234	i = hint;	234	i = hint;
235	do {	235	do {
236	z = zones.info[i];	236	z = zones.info[i];
237		237
238	spinlock_lock(&z->lock);	238	spinlock_lock(&z->lock);
239		239
240	/* Check if the zone has 2^order frames area available */	240	/* Check if the zone has 2^order frames area available */
241	if (zone_can_alloc(z, order)) {	241	if (zone_can_alloc(z, order)) {
242	spinlock_unlock(&zones.lock);	242	spinlock_unlock(&zones.lock);
243	if (pzone)	243	if (pzone)
244	*pzone = i;	244	*pzone = i;
245	return z;	245	return z;
246	}	246	}
247	spinlock_unlock(&z->lock);	247	spinlock_unlock(&z->lock);
248	if (++i >= zones.count)	248	if (++i >= zones.count)
249	i = 0;	249	i = 0;
250	} while(i != hint);	250	} while(i != hint);
251	spinlock_unlock(&zones.lock);	251	spinlock_unlock(&zones.lock);
252	return NULL;	252	return NULL;
253	}	253	}
254		254
255	/********************************************/	255	/********************************************/
256	/* Buddy system functions */	256	/* Buddy system functions */
257		257
258	/** Buddy system find_block implementation	258	/** Buddy system find_block implementation
259	*	259	*
260	* Find block that is parent of current list.	260	* Find block that is parent of current list.
261	* That means go to lower addresses, until such block is found	261	* That means go to lower addresses, until such block is found
262	*	262	*
263	* @param order - Order of parent must be different then this parameter!!	263	* @param order - Order of parent must be different then this parameter!!
264	*/	264	*/
265	static link_t zone_buddy_find_block(buddy_system_t b, link_t *child,	265	static link_t zone_buddy_find_block(buddy_system_t b, link_t *child,
266	__u8 order)	266	__u8 order)
267	{	267	{
268	frame_t * frame;	268	frame_t * frame;
269	zone_t * zone;	269	zone_t * zone;
270	index_t index;	270	index_t index;
271		271
272	frame = list_get_instance(child, frame_t, buddy_link);	272	frame = list_get_instance(child, frame_t, buddy_link);
273	zone = (zone_t *) b->data;	273	zone = (zone_t *) b->data;
274		274
275	index = frame_index(zone, frame);	275	index = frame_index(zone, frame);
276	do {	276	do {
277	if (zone->frames[index].buddy_order != order) {	277	if (zone->frames[index].buddy_order != order) {
278	return &zone->frames[index].buddy_link;	278	return &zone->frames[index].buddy_link;
279	}	279	}
280	} while(index-- > 0);	280	} while(index-- > 0);
281	return NULL;	281	return NULL;
282	}	282	}
283		283
284	static void zone_buddy_print_id(buddy_system_t b, link_t block)	284	static void zone_buddy_print_id(buddy_system_t b, link_t block)
285	{	285	{
286	frame_t * frame;	286	frame_t * frame;
287	zone_t * zone;	287	zone_t * zone;
288	index_t index;	288	index_t index;
289		289
290	frame = list_get_instance(block, frame_t, buddy_link);	290	frame = list_get_instance(block, frame_t, buddy_link);
291	zone = (zone_t *) b->data;	291	zone = (zone_t *) b->data;
292	index = frame_index(zone, frame);	292	index = frame_index(zone, frame);
293	printf("%zd", index);	293	printf("%zd", index);
294	}	294	}
295		295
296	/** Buddy system find_buddy implementation	296	/** Buddy system find_buddy implementation
297	*	297	*
298	* @param b Buddy system.	298	* @param b Buddy system.
299	* @param block Block for which buddy should be found	299	* @param block Block for which buddy should be found
300	*	300	*
301	* @return Buddy for given block if found	301	* @return Buddy for given block if found
302	*/	302	*/
303	static link_t * zone_buddy_find_buddy(buddy_system_t b, link_t block)	303	static link_t * zone_buddy_find_buddy(buddy_system_t b, link_t block)
304	{	304	{
305	frame_t * frame;	305	frame_t * frame;
306	zone_t * zone;	306	zone_t * zone;
307	index_t index;	307	index_t index;
308	bool is_left, is_right;	308	bool is_left, is_right;
309		309
310	frame = list_get_instance(block, frame_t, buddy_link);	310	frame = list_get_instance(block, frame_t, buddy_link);
311	zone = (zone_t *) b->data;	311	zone = (zone_t *) b->data;
312	ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame), frame->buddy_order));	312	ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame), frame->buddy_order));
313		313
314	is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);	314	is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);
315	is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);	315	is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);
316		316
317	ASSERT(is_left ^ is_right);	317	ASSERT(is_left ^ is_right);
318	if (is_left) {	318	if (is_left) {
319	index = (frame_index(zone, frame)) + (1 << frame->buddy_order);	319	index = (frame_index(zone, frame)) + (1 << frame->buddy_order);
320	} else { // if (is_right)	320	} else { // if (is_right)
321	index = (frame_index(zone, frame)) - (1 << frame->buddy_order);	321	index = (frame_index(zone, frame)) - (1 << frame->buddy_order);
322	}	322	}
323		323
324	if (frame_index_valid(zone, index)) {	324	if (frame_index_valid(zone, index)) {
325	if (zone->frames[index].buddy_order == frame->buddy_order &&	325	if (zone->frames[index].buddy_order == frame->buddy_order &&
326	zone->frames[index].refcount == 0) {	326	zone->frames[index].refcount == 0) {
327	return &zone->frames[index].buddy_link;	327	return &zone->frames[index].buddy_link;
328	}	328	}
329	}	329	}
330		330
331	return NULL;	331	return NULL;
332	}	332	}
333		333
334	/** Buddy system bisect implementation	334	/** Buddy system bisect implementation
335	*	335	*
336	* @param b Buddy system.	336	* @param b Buddy system.
337	* @param block Block to bisect	337	* @param block Block to bisect
338	*	338	*
339	* @return right block	339	* @return right block
340	*/	340	*/
341	static link_t * zone_buddy_bisect(buddy_system_t b, link_t block) {	341	static link_t * zone_buddy_bisect(buddy_system_t b, link_t block) {
342	frame_t * frame_l, * frame_r;	342	frame_t * frame_l, * frame_r;
343		343
344	frame_l = list_get_instance(block, frame_t, buddy_link);	344	frame_l = list_get_instance(block, frame_t, buddy_link);
345	frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));	345	frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));
346		346
347	return &frame_r->buddy_link;	347	return &frame_r->buddy_link;
348	}	348	}
349		349
350	/** Buddy system coalesce implementation	350	/** Buddy system coalesce implementation
351	*	351	*
352	* @param b Buddy system.	352	* @param b Buddy system.
353	* @param block_1 First block	353	* @param block_1 First block
354	* @param block_2 First block's buddy	354	* @param block_2 First block's buddy
355	*	355	*
356	* @return Coalesced block (actually block that represents lower address)	356	* @return Coalesced block (actually block that represents lower address)
357	*/	357	*/
358	static link_t * zone_buddy_coalesce(buddy_system_t b, link_t block_1,	358	static link_t * zone_buddy_coalesce(buddy_system_t b, link_t block_1,
359	link_t * block_2)	359	link_t * block_2)
360	{	360	{
361	frame_t frame1, frame2;	361	frame_t frame1, frame2;
362		362
363	frame1 = list_get_instance(block_1, frame_t, buddy_link);	363	frame1 = list_get_instance(block_1, frame_t, buddy_link);
364	frame2 = list_get_instance(block_2, frame_t, buddy_link);	364	frame2 = list_get_instance(block_2, frame_t, buddy_link);
365		365
366	return frame1 < frame2 ? block_1 : block_2;	366	return frame1 < frame2 ? block_1 : block_2;
367	}	367	}
368		368
369	/** Buddy system set_order implementation	369	/** Buddy system set_order implementation
370	*	370	*
371	* @param b Buddy system.	371	* @param b Buddy system.
372	* @param block Buddy system block	372	* @param block Buddy system block
373	* @param order Order to set	373	* @param order Order to set
374	*/	374	*/
375	static void zone_buddy_set_order(buddy_system_t b, link_t block, __u8 order) {	375	static void zone_buddy_set_order(buddy_system_t b, link_t block, __u8 order) {
376	frame_t * frame;	376	frame_t * frame;
377	frame = list_get_instance(block, frame_t, buddy_link);	377	frame = list_get_instance(block, frame_t, buddy_link);
378	frame->buddy_order = order;	378	frame->buddy_order = order;
379	}	379	}
380		380
381	/** Buddy system get_order implementation	381	/** Buddy system get_order implementation
382	*	382	*
383	* @param b Buddy system.	383	* @param b Buddy system.
384	* @param block Buddy system block	384	* @param block Buddy system block
385	*	385	*
386	* @return Order of block	386	* @return Order of block
387	*/	387	*/
388	static __u8 zone_buddy_get_order(buddy_system_t b, link_t block) {	388	static __u8 zone_buddy_get_order(buddy_system_t b, link_t block) {
389	frame_t * frame;	389	frame_t * frame;
390	frame = list_get_instance(block, frame_t, buddy_link);	390	frame = list_get_instance(block, frame_t, buddy_link);
391	return frame->buddy_order;	391	return frame->buddy_order;
392	}	392	}
393		393
394	/** Buddy system mark_busy implementation	394	/** Buddy system mark_busy implementation
395	*	395	*
396	* @param b Buddy system	396	* @param b Buddy system
397	* @param block Buddy system block	397	* @param block Buddy system block
398	*	398	*
399	*/	399	*/
400	static void zone_buddy_mark_busy(buddy_system_t b, link_t block) {	400	static void zone_buddy_mark_busy(buddy_system_t b, link_t block) {
401	frame_t * frame;	401	frame_t * frame;
402		402
403	frame = list_get_instance(block, frame_t, buddy_link);	403	frame = list_get_instance(block, frame_t, buddy_link);
404	frame->refcount = 1;	404	frame->refcount = 1;
405	}	405	}
406		406
407	/** Buddy system mark_available implementation	407	/** Buddy system mark_available implementation
408	*	408	*
409	* @param b Buddy system	409	* @param b Buddy system
410	* @param block Buddy system block	410	* @param block Buddy system block
411	*	411	*
412	*/	412	*/
413	static void zone_buddy_mark_available(buddy_system_t b, link_t block) {	413	static void zone_buddy_mark_available(buddy_system_t b, link_t block) {
414	frame_t * frame;	414	frame_t * frame;
415	frame = list_get_instance(block, frame_t, buddy_link);	415	frame = list_get_instance(block, frame_t, buddy_link);
416	frame->refcount = 0;	416	frame->refcount = 0;
417	}	417	}
418		418
419	static struct buddy_system_operations zone_buddy_system_operations = {	419	static struct buddy_system_operations zone_buddy_system_operations = {
420	.find_buddy = zone_buddy_find_buddy,	420	.find_buddy = zone_buddy_find_buddy,
421	.bisect = zone_buddy_bisect,	421	.bisect = zone_buddy_bisect,
422	.coalesce = zone_buddy_coalesce,	422	.coalesce = zone_buddy_coalesce,
423	.set_order = zone_buddy_set_order,	423	.set_order = zone_buddy_set_order,
424	.get_order = zone_buddy_get_order,	424	.get_order = zone_buddy_get_order,
425	.mark_busy = zone_buddy_mark_busy,	425	.mark_busy = zone_buddy_mark_busy,
426	.mark_available = zone_buddy_mark_available,	426	.mark_available = zone_buddy_mark_available,
427	.find_block = zone_buddy_find_block,	427	.find_block = zone_buddy_find_block,
428	.print_id = zone_buddy_print_id	428	.print_id = zone_buddy_print_id
429	};	429	};
430		430
431	/*************************************/	431	/*************************************/
432	/* Zone functions */	432	/* Zone functions */
433		433
434	/** Allocate frame in particular zone	434	/** Allocate frame in particular zone
435	*	435	*
436	* Assume zone is locked	436	* Assume zone is locked
437	* Panics, if allocation is impossible.	437	* Panics if allocation is impossible.
-		438	*
-		439	* @param zone Zone to allocate from.
-		440	* @param order Allocate exactly 2^order frames.
438	*	441	*
439	* @return Frame index in zone	442	* @return Frame index in zone
-		443	*
440	*/	444	*/
441	static pfn_t zone_frame_alloc(zone_t *zone,__u8 order)	445	static pfn_t zone_frame_alloc(zone_t *zone, __u8 order)
442	{	446	{
443	pfn_t v;	447	pfn_t v;
444	link_t *tmp;	448	link_t *tmp;
445	frame_t *frame;	449	frame_t *frame;
446		450
447	/* Allocate frames from zone buddy system */	451	/* Allocate frames from zone buddy system */
448	tmp = buddy_system_alloc(zone->buddy_system, order);	452	tmp = buddy_system_alloc(zone->buddy_system, order);
449		453
450	ASSERT(tmp);	454	ASSERT(tmp);
451		455
452	/* Update zone information. */	456	/* Update zone information. */
453	zone->free_count -= (1 << order);	457	zone->free_count -= (1 << order);
454	zone->busy_count += (1 << order);	458	zone->busy_count += (1 << order);
455		459
456	/* Frame will be actually a first frame of the block. */	460	/* Frame will be actually a first frame of the block. */
457	frame = list_get_instance(tmp, frame_t, buddy_link);	461	frame = list_get_instance(tmp, frame_t, buddy_link);
458		462
459	/* get frame address */	463	/* get frame address */
460	v = make_frame_index(zone, frame);	464	v = make_frame_index(zone, frame);
461	return v;	465	return v;
462	}	466	}
463		467
464	/** Free frame from zone	468	/** Free frame from zone
465	*	469	*
466	* Assume zone is locked	470	* Assume zone is locked
467	*/	471	*/
468	static void zone_frame_free(zone_t *zone, index_t frame_idx)	472	static void zone_frame_free(zone_t *zone, index_t frame_idx)
469	{	473	{
470	frame_t *frame;	474	frame_t *frame;
471	__u8 order;	475	__u8 order;
472		476
473	frame = &zone->frames[frame_idx];	477	frame = &zone->frames[frame_idx];
474		478
475	/* remember frame order */	479	/* remember frame order */
476	order = frame->buddy_order;	480	order = frame->buddy_order;
477		481
478	ASSERT(frame->refcount);	482	ASSERT(frame->refcount);
479		483
480	if (!--frame->refcount) {	484	if (!--frame->refcount) {
481	buddy_system_free(zone->buddy_system, &frame->buddy_link);	485	buddy_system_free(zone->buddy_system, &frame->buddy_link);
482		486
483	/* Update zone information. */	487	/* Update zone information. */
484	zone->free_count += (1 << order);	488	zone->free_count += (1 << order);
485	zone->busy_count -= (1 << order);	489	zone->busy_count -= (1 << order);
486	}	490	}
487	}	491	}
488		492
489	/** Return frame from zone */	493	/** Return frame from zone */
490	static frame_t * zone_get_frame(zone_t *zone, index_t frame_idx)	494	static frame_t * zone_get_frame(zone_t *zone, index_t frame_idx)
491	{	495	{
492	ASSERT(frame_idx < zone->count);	496	ASSERT(frame_idx < zone->count);
493	return &zone->frames[frame_idx];	497	return &zone->frames[frame_idx];
494	}	498	}
495		499
496	/** Mark frame in zone unavailable to allocation */	500	/** Mark frame in zone unavailable to allocation */

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(root)/kernel/trunk/generic/src/mm/frame.c – Rev 1248 → 1269