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


/*
 * Copyright (c) 2001-2005 Jakub Jermar
 * Copyright (c) 2005 Sergey Bondari
 * Copyright (c) 2009 Martin Decky
 * 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
 */
 
#include <arch/types.h>
#include <mm/frame.h>
#include <mm/as.h>
#include <panic.h>
#include <debug.h>
#include <adt/list.h>
#include <synch/mutex.h>
#include <synch/condvar.h>
#include <arch/asm.h>
#include <arch.h>
#include <print.h>
#include <align.h>
#include <mm/slab.h>
#include <bitops.h>
#include <macros.h>
#include <config.h>
 
zones_t zones;
 
/*
 * Synchronization primitives used to sleep when there is no memory
 * available.
 */
mutex_t mem_avail_mtx;
condvar_t mem_avail_cv;
count_t mem_avail_req = 0;  /**< Number of frames requested. */
count_t mem_avail_gen = 0;  /**< Generation counter. */
 
/********************/
/* 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 bool frame_index_valid(zone_t *zone, index_t index)
{
    return (index < zone->count);
}
 
static inline index_t make_frame_index(zone_t *zone, frame_t *frame)
{
    return (frame - zone->frames);
}
 
/** Initialize frame structure.
 *
 * @param frame Frame structure to be initialized.
 *
 */
static void frame_initialize(frame_t *frame)
{
    frame->refcount = 1;
    frame->buddy_order = 0;
}
 
/*******************/
/* Zones functions */
/*******************/
 
/** Insert-sort zone into zones list.
 *
 * Assume interrupts are disabled and zones lock is
 * locked.
 *
 * @param base  Base frame of the newly inserted zone.
 * @param count Number of frames of the newly inserted zone.
 *
 * @return Zone number on success, -1 on error.
 *
 */
static count_t zones_insert_zone(pfn_t base, count_t count)
{
    if (zones.count + 1 == ZONES_MAX) {
        printf("Maximum zone count %u exceeded!\n", ZONES_MAX);
        return (count_t) -1;
    }
   
    count_t i;
    for (i = 0; i < zones.count; i++) {
        /* Check for overlap */
        if (overlaps(base, count,
            zones.info[i].base, zones.info[i].count)) {
            printf("Zones overlap!\n");
            return (count_t) -1;
        }
        if (base < zones.info[i].base)
            break;
    }
   
    /* Move other zones up */
    count_t j;
    for (j = zones.count; j > i; j--) {
        zones.info[j] = zones.info[j - 1];
        zones.info[j].buddy_system->data =
            (void *) &zones.info[j - 1];
    }
   
    zones.count++;
   
    return i;
}
 
/** Get total available frames.
 *
 * Assume interrupts are disabled and zones lock is
 * locked.
 *
 * @return Total number of available frames.
 *
 */
#ifdef CONFIG_DEBUG
static count_t total_frames_free(void)
{
    count_t total = 0;
    count_t i;
    for (i = 0; i < zones.count; i++)
        total += zones.info[i].free_count;
   
    return total;
}
#endif
 
/** Find a zone with a given frames.
 *
 * Assume interrupts are disabled and zones lock is
 * locked.
 *
 * @param frame Frame number contained in zone.
 * @param count Number of frames to look for.
 * @param hint  Used as zone hint.
 *
 * @return Zone index or -1 if not found.
 *
 */
count_t find_zone(pfn_t frame, count_t count, count_t hint)
{
    if (hint >= zones.count)
        hint = 0;
   
    count_t i = hint;
    do {
        if ((zones.info[i].base <= frame)
            && (zones.info[i].base + zones.info[i].count >= frame + count))
            return i;
       
        i++;
        if (i >= zones.count)
            i = 0;
    } while (i != hint);
   
    return (count_t) -1;
}
 
/** @return True if zone can allocate specified order */
static bool zone_can_alloc(zone_t *zone, uint8_t order)
{
    return (zone_flags_available(zone->flags)
        && buddy_system_can_alloc(zone->buddy_system, order));
}
 
/** Find a zone that can allocate order frames.
 *
 * Assume interrupts are disabled and zones lock is
 * locked.
 *
 * @param order Size (2^order) of free space we are trying to find.
 * @param flags Required flags of the target zone.
 * @param hind  Preferred zone.
 *
 */
static count_t find_free_zone(uint8_t order, zone_flags_t flags, count_t hint)
{
    if (hint >= zones.count)
        hint = 0;
   
    count_t i = hint;
    do {
        /*
         * Check whether the zone meets the search criteria.
         */
        if ((zones.info[i].flags & flags) == flags) {
            /*
             * Check if the zone has 2^order frames area available.
             */
            if (zone_can_alloc(&zones.info[i], order))
                return i;
        }
       
        i++;
        if (i >= zones.count)
            i = 0;
    } while (i != hint);
   
    return (count_t) -1;
}
 
/**************************/
/* 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 *buddy, link_t *child,
    uint8_t order)
{
    frame_t *frame = list_get_instance(child, frame_t, buddy_link);
    zone_t *zone = (zone_t *) buddy->data;
   
    index_t index = frame_index(zone, frame);
    do {
        if (zone->frames[index].buddy_order != order)
            return &zone->frames[index].buddy_link;
    } while (index-- > 0);
   
    return NULL;
}
 
/** Buddy system find_buddy implementation.
 *
 * @param buddy 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 *buddy, link_t *block)
{
    frame_t *frame = list_get_instance(block, frame_t, buddy_link);
    zone_t *zone = (zone_t *) buddy->data;
    ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame),
        frame->buddy_order));
   
    bool is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);
   
    index_t index;
    if (is_left) {
        index = (frame_index(zone, frame)) +
            (1 << frame->buddy_order);
    } else {    /* 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 buddy Buddy system.
 * @param block Block to bisect.
 *
 * @return Right block.
 *
 */
static link_t *zone_buddy_bisect(buddy_system_t *buddy, link_t *block)
{
    frame_t *frame_l = list_get_instance(block, frame_t, buddy_link);
    frame_t *frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));
   
    return &frame_r->buddy_link;
}
 
/** Buddy system coalesce implementation.
 *
 * @param buddy   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 *buddy, link_t *block_1,
    link_t *block_2)
{
    frame_t *frame1 = list_get_instance(block_1, frame_t, buddy_link);
    frame_t *frame2 = list_get_instance(block_2, frame_t, buddy_link);
   
    return ((frame1 < frame2) ? block_1 : block_2);
}
 
/** Buddy system set_order implementation.
 *
 * @param buddy Buddy system.
 * @param block Buddy system block.
 * @param order Order to set.
 *
 */
static void zone_buddy_set_order(buddy_system_t *buddy, link_t *block,
    uint8_t order)
{
    list_get_instance(block, frame_t, buddy_link)->buddy_order = order;
}
 
/** Buddy system get_order implementation.
 *
 * @param buddy Buddy system.
 * @param block Buddy system block.
 *
 * @return Order of block.
 *
 */
static uint8_t zone_buddy_get_order(buddy_system_t *buddy, link_t *block)
{
    return list_get_instance(block, frame_t, buddy_link)->buddy_order;
}
 
/** Buddy system mark_busy implementation.
 *
 * @param buddy Buddy system.
 * @param block Buddy system block.
 *
 */
static void zone_buddy_mark_busy(buddy_system_t *buddy, link_t * block)
{
    list_get_instance(block, frame_t, buddy_link)->refcount = 1;
}
 
/** Buddy system mark_available implementation.
 *
 * @param buddy Buddy system.
 * @param block Buddy system block.
 */
static void zone_buddy_mark_available(buddy_system_t *buddy, link_t *block)
{
    list_get_instance(block, frame_t, buddy_link)->refcount = 0;
}
 
static buddy_system_operations_t 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
};
 
/******************/
/* Zone functions */
/******************/
 
/** Allocate frame in particular zone.
 *
 * Assume zone is locked and is available for allocation.
 * 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)
{
    ASSERT(zone_flags_available(zone->flags));
   
    /* Allocate frames from zone buddy system */
    link_t *link = buddy_system_alloc(zone->buddy_system, order);
   
    ASSERT(link);
   
    /* Update zone information. */
    zone->free_count -= (1 << order);
    zone->busy_count += (1 << order);
   
    /* Frame will be actually a first frame of the block. */
    frame_t *frame = list_get_instance(link, frame_t, buddy_link);
   
    /* Get frame address */
    return make_frame_index(zone, frame);
}
 
/** Free frame from zone.
 *
 * Assume zone is locked and is available for deallocation.
 *
 * @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)
{
    ASSERT(zone_flags_available(zone->flags));
   
    frame_t *frame = &zone->frames[frame_idx];
   
    /* Remember frame order */
    uint8_t 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)
{
    ASSERT(zone_flags_available(zone->flags));
   
    frame_t *frame = zone_get_frame(zone, frame_idx);
    if (frame->refcount)
        return;
   
    link_t *link __attribute__ ((unused));
   
    link = buddy_system_alloc_block(zone->buddy_system,
        &frame->buddy_link);
   
    ASSERT(link);
    zone->free_count--;
}
 
/** Merge two zones.
 *
 * Expect buddy to point to space at least zone_conf_size large.
 * Assume z1 & z2 are locked and compatible and zones lock is
 * locked.
 *
 * @param z1     First zone to merge.
 * @param z2     Second zone to merge.
 * @param old_z1 Original date of the first zone.
 * @param buddy  Merged zone buddy.
 *
 */
static void zone_merge_internal(count_t z1, count_t z2, zone_t *old_z1, buddy_system_t *buddy)
{
    ASSERT(zone_flags_available(zones.info[z1].flags));
    ASSERT(zone_flags_available(zones.info[z2].flags));
    ASSERT(zones.info[z1].flags == zones.info[z2].flags);
    ASSERT(zones.info[z1].base < zones.info[z2].base);
    ASSERT(!overlaps(zones.info[z1].base, zones.info[z1].count,
        zones.info[z2].base, zones.info[z2].count));
   
    /* Difference between zone bases */
    pfn_t base_diff = zones.info[z2].base - zones.info[z1].base;
   
    zones.info[z1].count = base_diff + zones.info[z2].count;
    zones.info[z1].free_count += zones.info[z2].free_count;
    zones.info[z1].busy_count += zones.info[z2].busy_count;
    zones.info[z1].buddy_system = buddy;
   
    uint8_t order = fnzb(zones.info[z1].count);
    buddy_system_create(zones.info[z1].buddy_system, order,
        &zone_buddy_system_operations, (void *) &zones.info[z1]);
   
    zones.info[z1].frames =
        (frame_t *) ((uint8_t *) zones.info[z1].buddy_system
        + buddy_conf_size(order));
   
    /* This marks all frames busy */
    count_t i;
    for (i = 0; i < zones.info[z1].count; i++)
        frame_initialize(&zones.info[z1].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, clearing
     * 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 < old_z1->count; i++)
        zones.info[z1].frames[i] = old_z1->frames[i];
   
    for (i = 0; i < zones.info[z2].count; i++)
        zones.info[z1].frames[base_diff + i]
            = zones.info[z2].frames[i];
   
    i = 0;
    while (i < zones.info[z1].count) {
        if (zones.info[z1].frames[i].refcount) {
            /* Skip busy frames */
            i += 1 << zones.info[z1].frames[i].buddy_order;
        } else {
            /* Free frames, set refcount = 1
             * (all free frames have refcount == 0, we need not
             * to check the order)
             */
            zones.info[z1].frames[i].refcount = 1;
            zones.info[z1].frames[i].buddy_order = 0;
            i++;
        }
    }
   
    /* Add free blocks from the original zone z1 */
    while (zone_can_alloc(old_z1, 0)) {
        /* Allocate from the original zone */
        pfn_t frame_idx = zone_frame_alloc(old_z1, 0);
       
        /* Free the frame from the merged zone */
        frame_t *frame = &zones.info[z1].frames[frame_idx];
        frame->refcount = 0;
        buddy_system_free(zones.info[z1].buddy_system, &frame->buddy_link);
    }
   
    /* Add free blocks from the original zone z2 */
    while (zone_can_alloc(&zones.info[z2], 0)) {
        /* Allocate from the original zone */
        pfn_t frame_idx = zone_frame_alloc(&zones.info[z2], 0);
       
        /* Free the frame from the merged zone */
        frame_t *frame = &zones.info[z1].frames[base_diff + frame_idx];
        frame->refcount = 0;
        buddy_system_free(zones.info[z1].buddy_system, &frame->buddy_link);
    }
}
 
/** Return old configuration frames into the zone.
 *
 * We have two cases:
 * - The configuration data is outside the zone
 *   -> do nothing (perhaps call frame_free?)
 * - The configuration data was created by zone_create
 *   or updated by reduce_region -> free every frame
 *
 * @param znum  The actual zone where freeing should occur.
 * @param pfn   Old zone configuration frame.
 * @param count Old zone frame count.
 *
 */
static void return_config_frames(count_t znum, pfn_t pfn, count_t count)
{
    ASSERT(zone_flags_available(zones.info[znum].flags));
   
    count_t cframes = SIZE2FRAMES(zone_conf_size(count));
   
    if ((pfn < zones.info[znum].base)
        || (pfn >= zones.info[znum].base + zones.info[znum].count))
        return;
   
    frame_t *frame __attribute__ ((unused));
 
    frame = &zones.info[znum].frames[pfn - zones.info[znum].base];
    ASSERT(!frame->buddy_order);
   
    count_t i;
    for (i = 0; i < cframes; i++) {
        zones.info[znum].busy_count++;
        zone_frame_free(&zones.info[znum],
            pfn - zones.info[znum].base + i);
    }
}
 
/** Reduce allocated block to count of order 0 frames.
 *
 * The allocated block needs 2^order frames. Reduce all frames
 * in the 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 znum      Zone.
 * @param frame_idx Index the first frame of the block.
 * @param count     Allocated frames in block.
 *
 */
static void zone_reduce_region(count_t znum, pfn_t frame_idx, count_t count)
{
    ASSERT(zone_flags_available(zones.info[znum].flags));
    ASSERT(frame_idx + count < zones.info[znum].count);
   
    uint8_t order = zones.info[znum].frames[frame_idx].buddy_order;
    ASSERT((count_t) (1 << order) >= count);
   
    /* Reduce all blocks to order 0 */
    count_t i;
    for (i = 0; i < (count_t) (1 << order); i++) {
        frame_t *frame = &zones.info[znum].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 < (count_t) (1 << order); i++)
        zone_frame_free(&zones.info[znum], i + frame_idx);
}
 
/** Merge zones z1 and z2.
 *
 * The merged zones must be 2 zones with no zone existing in between
 * (which means that z2 = z1 + 1). Both zones must be available zones
 * with the same flags.
 *
 * 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 :-/
 *
 * The function uses
 *
 */
bool zone_merge(count_t z1, count_t z2)
{
    ipl_t ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
   
    bool ret = true;
   
    /* We can join only 2 zones with none existing inbetween,
     * the zones have to be available and with the same
     * set of flags
     */
    if ((z1 >= zones.count) || (z2 >= zones.count)
        || (z2 - z1 != 1)
        || (!zone_flags_available(zones.info[z1].flags))
        || (!zone_flags_available(zones.info[z2].flags))
        || (zones.info[z1].flags != zones.info[z2].flags)) {
        ret = false;
        goto errout;
    }
   
    pfn_t cframes = SIZE2FRAMES(zone_conf_size(
        zones.info[z2].base - zones.info[z1].base
        + zones.info[z2].count));
   
    uint8_t order;
    if (cframes == 1)
        order = 0;
    else
        order = fnzb(cframes - 1) + 1;
   
    /* Allocate merged zone data inside one of the zones */
    pfn_t pfn;
    if (zone_can_alloc(&zones.info[z1], order)) {
        pfn = zones.info[z1].base + zone_frame_alloc(&zones.info[z1], order);
    } else if (zone_can_alloc(&zones.info[z2], order)) {
        pfn = zones.info[z2].base + zone_frame_alloc(&zones.info[z2], order);
    } else {
        ret = false;
        goto errout;
    }
   
    /* Preserve original data from z1 */
    zone_t old_z1 = zones.info[z1];
    old_z1.buddy_system->data = (void *) &old_z1;
   
    /* Do zone merging */
    buddy_system_t *buddy = (buddy_system_t *) PA2KA(PFN2ADDR(pfn));
    zone_merge_internal(z1, z2, &old_z1, buddy);
   
    /* Free unneeded config frames */
    zone_reduce_region(z1, pfn - zones.info[z1].base, cframes);
   
    /* Subtract zone information from busy frames */
    zones.info[z1].busy_count -= cframes;
   
    /* Free old zone information */
    return_config_frames(z1,
        ADDR2PFN(KA2PA((uintptr_t) old_z1.frames)), old_z1.count);
    return_config_frames(z1,
        ADDR2PFN(KA2PA((uintptr_t) zones.info[z2].frames)),
        zones.info[z2].count);
   
    /* Move zones down */
    count_t i;
    for (i = z2 + 1; i < zones.count; i++) {
        zones.info[i - 1] = zones.info[i];
        zones.info[i - 1].buddy_system->data =
            (void *) &zones.info[i - 1];
    }
   
    zones.count--;
   
errout:
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
   
    return ret;
}
 
/** Merge all mergeable zones into one big zone.
 *
 * It is reasonable to do this on systems where
 * BIOS reports parts in chunks, so that we could
 * have 1 zone (it's faster).
 *
 */
void zone_merge_all(void)
{
    count_t i = 0;
    while (i < zones.count) {
        if (!zone_merge(i, i + 1))
            i++;
    }
}
 
/** Create new frame zone.
 *
 * @param zone  Zone to construct.
 * @param buddy Address of buddy system configuration information.
 * @param start Physical address of the first frame within the zone.
 * @param count Count of frames in zone.
 * @param flags Zone flags.
 *
 * @return Initialized zone.
 *
 */
static void zone_construct(zone_t *zone, buddy_system_t *buddy, pfn_t start, count_t count, zone_flags_t flags)
{
    zone->base = start;
    zone->count = count;
    zone->flags = flags;
    zone->free_count = count;
    zone->busy_count = 0;
    zone->buddy_system = buddy;
   
    if (zone_flags_available(flags)) {
        /*
         * Compute order for buddy system and initialize
         */
        uint8_t order = fnzb(count);
        buddy_system_create(zone->buddy_system, order,
            &zone_buddy_system_operations, (void *) zone);
       
        /* Allocate frames _after_ the confframe */
       
        /* Check sizes */
        zone->frames = (frame_t *) ((uint8_t *) zone->buddy_system +
            buddy_conf_size(order));
       
        count_t i;
        for (i = 0; i < count; i++)
            frame_initialize(&zone->frames[i]);
       
        /* Stuffing frames */
        for (i = 0; i < count; i++) {
            zone->frames[i].refcount = 0;
            buddy_system_free(zone->buddy_system, &zone->frames[i].buddy_link);
        }
    } else
        zone->frames = NULL;
}
 
/** 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)
{
    return (count * sizeof(frame_t) + buddy_conf_size(fnzb(count)));
}
 
/** 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.
 *
 */
count_t zone_create(pfn_t start, count_t count, pfn_t confframe, zone_flags_t flags)
{
    ipl_t ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
   
    if (zone_flags_available(flags)) {  /* Create available zone */
        /* Theoretically we could have NULL here, practically make sure
         * nobody tries to do that. If some platform requires, remove
         * the assert
         */
        ASSERT(confframe != NULL);
       
        /* If confframe is supposed to be inside our zone, then make sure
         * it does not span kernel & init
         */
        count_t confcount = SIZE2FRAMES(zone_conf_size(count));
        if ((confframe >= start) && (confframe < start + count)) {
            for (; confframe < start + count; confframe++) {
                uintptr_t 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.");
        }
       
        count_t znum = zones_insert_zone(start, count);
        if (znum == (count_t) -1) {
            spinlock_unlock(&zones.lock);
            interrupts_restore(ipl);
            return (count_t) -1;
        }
       
        buddy_system_t *buddy = (buddy_system_t *) PA2KA(PFN2ADDR(confframe));
        zone_construct(&zones.info[znum], buddy, start, count, flags);
       
        /* If confdata in zone, mark as unavailable */
        if ((confframe >= start) && (confframe < start + count)) {
            count_t i;
            for (i = confframe; i < confframe + confcount; i++)
                zone_mark_unavailable(&zones.info[znum],
                    i - zones.info[znum].base);
        }
       
        spinlock_unlock(&zones.lock);
        interrupts_restore(ipl);
       
        return znum;
    }
   
    /* Non-available zone */
    count_t znum = zones_insert_zone(start, count);
    if (znum == (count_t) -1) {
        spinlock_unlock(&zones.lock);
        interrupts_restore(ipl);
        return (count_t) -1;
    }
    zone_construct(&zones.info[znum], NULL, start, count, flags);
   
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
   
    return znum;
}
 
/*******************/
/* Frame functions */
/*******************/
 
/** Set parent of frame. */
void frame_set_parent(pfn_t pfn, void *data, count_t hint)
{
    ipl_t ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
   
    count_t znum = find_zone(pfn, 1, hint);
   
    ASSERT(znum != (count_t) -1);
   
    zone_get_frame(&zones.info[znum],
        pfn - zones.info[znum].base)->parent = data;
   
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
}
 
void *frame_get_parent(pfn_t pfn, count_t hint)
{
    ipl_t ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
   
    count_t znum = find_zone(pfn, 1, hint);
   
    ASSERT(znum != (count_t) -1);
   
    void *res = zone_get_frame(&zones.info[znum],
        pfn - zones.info[znum].base)->parent;
   
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
   
    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, frame_flags_t flags, count_t *pzone)
{
    count_t size = ((count_t) 1) << order;
    ipl_t ipl;
    count_t hint = pzone ? (*pzone) : 0;
   
loop:
    ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
   
    /*
     * First, find suitable frame zone.
     */
    count_t znum = find_free_zone(order,
        FRAME_TO_ZONE_FLAGS(flags), hint);
   
    /* If no memory, reclaim some slab memory,
       if it does not help, reclaim all */
    if ((znum == (count_t) -1) && (!(flags & FRAME_NO_RECLAIM))) {
        spinlock_unlock(&zones.lock);
        interrupts_restore(ipl);
       
        count_t freed = slab_reclaim(0);
       
        ipl = interrupts_disable();
        spinlock_lock(&zones.lock);
       
        if (freed > 0)
            znum = find_free_zone(order,
                FRAME_TO_ZONE_FLAGS(flags), hint);
       
        if (znum == (count_t) -1) {
            spinlock_unlock(&zones.lock);
            interrupts_restore(ipl);
           
            freed = slab_reclaim(SLAB_RECLAIM_ALL);
           
            ipl = interrupts_disable();
            spinlock_lock(&zones.lock);
           
            if (freed > 0)
                znum = find_free_zone(order,
                    FRAME_TO_ZONE_FLAGS(flags), hint);
        }
    }
   
    if (znum == (count_t) -1) {
        if (flags & FRAME_ATOMIC) {
            spinlock_unlock(&zones.lock);
            interrupts_restore(ipl);
            return NULL;
        }
       
#ifdef CONFIG_DEBUG
        count_t avail = total_frames_free();
#endif
       
        spinlock_unlock(&zones.lock);
        interrupts_restore(ipl);
       
        /*
         * Sleep until some frames are available again.
         */
       
#ifdef CONFIG_DEBUG
        printf("Thread %" PRIu64 " waiting for %" PRIc " frames, "
            "%" PRIc " available.\n", THREAD->tid, size, avail);
#endif
       
        mutex_lock(&mem_avail_mtx);
       
        if (mem_avail_req > 0)
            mem_avail_req = min(mem_avail_req, size);
        else
            mem_avail_req = size;
        count_t gen = mem_avail_gen;
       
        while (gen == mem_avail_gen)
            condvar_wait(&mem_avail_cv, &mem_avail_mtx);
       
        mutex_unlock(&mem_avail_mtx);
       
#ifdef CONFIG_DEBUG
        printf("Thread %" PRIu64 " woken up.\n", THREAD->tid);
#endif
       
        goto loop;
    }
   
    pfn_t pfn = zone_frame_alloc(&zones.info[znum], order)
        + zones.info[znum].base;
   
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
   
    if (pzone)
        *pzone = znum;
   
    if (flags & FRAME_KA)
        return (void *) PA2KA(PFN2ADDR(pfn));
   
    return (void *) PFN2ADDR(pfn);
}
 
/** 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 = interrupts_disable();
    spinlock_lock(&zones.lock);
   
    /*
     * First, find host frame zone for addr.
     */
    pfn_t pfn = ADDR2PFN(frame);
    count_t znum = find_zone(pfn, 1, NULL);
   
    ASSERT(znum != (count_t) -1);
   
    zone_frame_free(&zones.info[znum], pfn - zones.info[znum].base);
   
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
   
    /*
     * Signal that some memory has been freed.
     */
    mutex_lock(&mem_avail_mtx);
    if (mem_avail_req > 0)
        mem_avail_req--;
   
    if (mem_avail_req == 0) {
        mem_avail_gen++;
        condvar_broadcast(&mem_avail_cv);
    }
    mutex_unlock(&mem_avail_mtx);
}
 
/** 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 = interrupts_disable();
    spinlock_lock(&zones.lock);
   
    /*
     * First, find host frame zone for addr.
     */
    count_t znum = find_zone(pfn, 1, NULL);
   
    ASSERT(znum != (count_t) -1);
   
    zones.info[znum].frames[pfn - zones.info[znum].base].refcount++;
   
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
}
 
/** Mark given range unavailable in frame zones. */
void frame_mark_unavailable(pfn_t start, count_t count)
{
    ipl_t ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
   
    count_t i;
    for (i = 0; i < count; i++) {
        count_t znum = find_zone(start + i, 1, 0);
        if (znum == (count_t) -1)  /* PFN not found */
            continue;
       
        zone_mark_unavailable(&zones.info[znum],
            start + i - zones.info[znum].base);
    }
   
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
}
 
/** Initialize physical memory management. */
void frame_init(void)
{
    if (config.cpu_active == 1) {
        zones.count = 0;
        spinlock_initialize(&zones.lock, "zones.lock");
        mutex_initialize(&mem_avail_mtx, MUTEX_ACTIVE);
        condvar_initialize(&mem_avail_cv);
    }
   
    /* 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++) {
            pfn_t pfn = ADDR2PFN(KA2PA(init.tasks[i].addr));
            frame_mark_unavailable(pfn,
                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);
    }
}
 
/** Return total size of all zones. */
uint64_t zone_total_size(void)
{
    ipl_t ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
   
    uint64_t total = 0;
    count_t i;
    for (i = 0; i < zones.count; i++)
        total += (uint64_t) FRAMES2SIZE(zones.info[i].count);
   
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
   
    return total;
}
 
/** Prints list of zones. */
void zone_print_list(void)
{
#ifdef __32_BITS__
    printf("#  base address frames       flags    free frames  busy frames\n");
    printf("-- ------------ ------------ -------- ------------ ------------\n");
#endif
 
#ifdef __64_BITS__
    printf("#  base address          frames      flags    free frames  busy frames\n");
    printf("-- -------------------- ------------ -------- ------------ ------------\n");
#endif
   
    /*
     * Because printing may require allocation of memory, we may not hold
     * the frame allocator locks when printing zone statistics.  Therefore,
     * we simply gather the statistics under the protection of the locks and
     * print the statistics when the locks have been released.
     *
     * When someone adds/removes zones while we are printing the statistics,
     * we may end up with inaccurate output (e.g. a zone being skipped from
     * the listing).
     */
   
    count_t i;
    for (i = 0;; i++) {
        ipl_t ipl = interrupts_disable();
        spinlock_lock(&zones.lock);
       
        if (i >= zones.count) {
            spinlock_unlock(&zones.lock);
            interrupts_restore(ipl);
            break;
        }
       
        uintptr_t base = PFN2ADDR(zones.info[i].base);
        count_t count = zones.info[i].count;
        zone_flags_t flags = zones.info[i].flags;
        count_t free_count = zones.info[i].free_count;
        count_t busy_count = zones.info[i].busy_count;
       
        spinlock_unlock(&zones.lock);
        interrupts_restore(ipl);
       
        bool available = zone_flags_available(flags);
       
        printf("%-2" PRIc, i);
       
#ifdef __32_BITS__
        printf("   %10p", base);
#endif
       
#ifdef __64_BITS__
        printf("   %18p", base);
#endif
       
        printf(" %12" PRIc " %c%c%c      ", count,
            available ? 'A' : ' ',
            (flags & ZONE_RESERVED) ? 'R' : ' ',
            (flags & ZONE_FIRMWARE) ? 'F' : ' ');
       
        if (available)
            printf("%12" PRIc " %12" PRIc,
                free_count, busy_count);
       
        printf("\n");
    }
}
 
/** Prints zone details.
 *
 * @param num Zone base address or zone number.
 *
 */
void zone_print_one(count_t num)
{
    ipl_t ipl = interrupts_disable();
    spinlock_lock(&zones.lock);
    count_t znum = (count_t) -1;
   
    count_t i;
    for (i = 0; i < zones.count; i++) {
        if ((i == num) || (PFN2ADDR(zones.info[i].base) == num)) {
            znum = i;
            break;
        }
    }
   
    if (znum == (count_t) -1) {
        spinlock_unlock(&zones.lock);
        interrupts_restore(ipl);
        printf("Zone not found.\n");
        return;
    }
   
    uintptr_t base = PFN2ADDR(zones.info[i].base);
    zone_flags_t flags = zones.info[i].flags;
    count_t count = zones.info[i].count;
    count_t free_count = zones.info[i].free_count;
    count_t busy_count = zones.info[i].busy_count;
   
    spinlock_unlock(&zones.lock);
    interrupts_restore(ipl);
   
    bool available = zone_flags_available(flags);
   
    printf("Zone number:       %" PRIc "\n", znum);
    printf("Zone base address: %p\n", base);
    printf("Zone size:         %" PRIc " frames (%" PRIs " KiB)\n", count,
        SIZE2KB(FRAMES2SIZE(count)));
    printf("Zone flags:        %c%c%c\n",
        available ? 'A' : ' ',
        (flags & ZONE_RESERVED) ? 'R' : ' ',
        (flags & ZONE_FIRMWARE) ? 'F' : ' ');
   
    if (available) {
        printf("Allocated space:   %" PRIc " frames (%" PRIs " KiB)\n",
            busy_count, SIZE2KB(FRAMES2SIZE(busy_count)));
        printf("Available space:   %" PRIc " frames (%" PRIs " KiB)\n",
            free_count, SIZE2KB(FRAMES2SIZE(free_count)));
    }
}
 
/** @}
 */
 
Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/mm/frame.c @ 2696 – Rev 4048 → 4230
