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  1. /*
  2.  * Copyright (c) 2001-2005 Jakub Jermar
  3.  * Copyright (c) 2005 Sergey Bondari
  4.  * All rights reserved.
  5.  *
  6.  * Redistribution and use in source and binary forms, with or without
  7.  * modification, are permitted provided that the following conditions
  8.  * are met:
  9.  *
  10.  * - Redistributions of source code must retain the above copyright
  11.  *   notice, this list of conditions and the following disclaimer.
  12.  * - Redistributions in binary form must reproduce the above copyright
  13.  *   notice, this list of conditions and the following disclaimer in the
  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
  16.  *   derived from this software without specific prior written permission.
  17.  *
  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
  20.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  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
  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
  27.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28.  */
  29.  
  30. /** @addtogroup genericmm
  31.  * @{
  32.  */
  33.  
  34. /**
  35.  * @file
  36.  * @brief   Physical frame allocator.
  37.  *
  38.  * This file contains the physical frame allocator and memory zone management.
  39.  * The frame allocator is built on top of the buddy allocator.
  40.  *
  41.  * @see buddy.c
  42.  */
  43.  
  44. /*
  45.  * Locking order
  46.  *
  47.  * In order to access particular zone, the process must first lock
  48.  * the zones.lock, then lock the zone and then unlock the zones.lock.
  49.  * This insures, that we can fiddle with the zones in runtime without
  50.  * affecting the processes.
  51.  *
  52.  */
  53.  
  54. #include <arch/types.h>
  55. #include <mm/frame.h>
  56. #include <mm/as.h>
  57. #include <panic.h>
  58. #include <debug.h>
  59. #include <adt/list.h>
  60. #include <synch/spinlock.h>
  61. #include <arch/asm.h>
  62. #include <arch.h>
  63. #include <print.h>
  64. #include <align.h>
  65. #include <mm/slab.h>
  66. #include <bitops.h>
  67. #include <macros.h>
  68. #include <config.h>
  69.  
  70. typedef struct {
  71.     count_t refcount;   /**< tracking of shared frames  */
  72.     uint8_t buddy_order;    /**< buddy system block order */
  73.     link_t buddy_link;  /**< link to the next free block inside one
  74.                      order */
  75.     void *parent;           /**< If allocated by slab, this points there */
  76. } frame_t;
  77.  
  78. typedef struct {
  79.     SPINLOCK_DECLARE(lock); /**< this lock protects everything below */
  80.     pfn_t base;     /**< frame_no of the first frame in the frames
  81.                      array */
  82.     count_t count;          /**< Size of zone */
  83.  
  84.     frame_t *frames;    /**< array of frame_t structures in this
  85.                      zone */
  86.     count_t free_count; /**< number of free frame_t structures */
  87.     count_t busy_count; /**< number of busy frame_t structures */
  88.    
  89.     buddy_system_t *buddy_system; /**< buddy system for the zone */
  90.     int flags;
  91. } zone_t;
  92.  
  93. /*
  94.  * The zoneinfo.lock must be locked when accessing zoneinfo structure.
  95.  * Some of the attributes in zone_t structures are 'read-only'
  96.  */
  97.  
  98. typedef struct {
  99.     SPINLOCK_DECLARE(lock);
  100.     unsigned int count;
  101.     zone_t *info[ZONES_MAX];
  102. } zones_t;
  103.  
  104. static zones_t zones;
  105.  
  106.  
  107. /********************/
  108. /* Helper functions */
  109. /********************/
  110.  
  111. static inline index_t frame_index(zone_t *zone, frame_t *frame)
  112. {
  113.     return (index_t) (frame - zone->frames);
  114. }
  115.  
  116. static inline index_t frame_index_abs(zone_t *zone, frame_t *frame)
  117. {
  118.     return (index_t) (frame - zone->frames) + zone->base;
  119. }
  120.  
  121. static inline int frame_index_valid(zone_t *zone, index_t index)
  122. {
  123.     return (index < zone->count);
  124. }
  125.  
  126. /** Compute pfn_t from frame_t pointer & zone pointer */
  127. static index_t make_frame_index(zone_t *zone, frame_t *frame)
  128. {
  129.     return (frame - zone->frames);
  130. }
  131.  
  132. /** Initialize frame structure
  133.  *
  134.  * Initialize frame structure.
  135.  *
  136.  * @param frame Frame structure to be initialized.
  137.  */
  138. static void frame_initialize(frame_t *frame)
  139. {
  140.     frame->refcount = 1;
  141.     frame->buddy_order = 0;
  142. }
  143.  
  144. /**********************/
  145. /* Zoneinfo functions */
  146. /**********************/
  147.  
  148. /**
  149.  * Insert-sort zone into zones list
  150.  *
  151.  * @param newzone New zone to be inserted into zone list
  152.  * @return zone number on success, -1 on error
  153.  */
  154. static int zones_add_zone(zone_t *newzone)
  155. {
  156.     unsigned int i, j;
  157.     ipl_t ipl;
  158.     zone_t *z;
  159.  
  160.     ipl = interrupts_disable();
  161.     spinlock_lock(&zones.lock);
  162.    
  163.     /* Try to merge */
  164.     if (zones.count + 1 == ZONES_MAX) {
  165.         printf("Maximum zone count %u exceeded!\n", ZONES_MAX);
  166.         spinlock_unlock(&zones.lock);
  167.         interrupts_restore(ipl);
  168.         return -1;
  169.     }
  170.    
  171.     for (i = 0; i < zones.count; i++) {
  172.         /* Check for overflow */
  173.         z = zones.info[i];
  174.         if (overlaps(newzone->base, newzone->count, z->base, z->count)) {
  175.             printf("Zones overlap!\n");
  176.             return -1;
  177.         }
  178.         if (newzone->base < z->base)
  179.             break;
  180.     }
  181.    
  182.     /* Move other zones up */
  183.     for (j = i; j < zones.count; j++)
  184.         zones.info[j + 1] = zones.info[j];
  185.    
  186.     zones.info[i] = newzone;
  187.     zones.count++;
  188.    
  189.     spinlock_unlock(&zones.lock);
  190.     interrupts_restore(ipl);
  191.  
  192.     return i;
  193. }
  194.  
  195. /**
  196.  * Try to find a zone where can we find the frame
  197.  *
  198.  * Assume interrupts are disabled.
  199.  *
  200.  * @param frame Frame number contained in zone
  201.  * @param pzone If not null, it is used as zone hint. Zone index
  202.  *              is filled into the variable on success.
  203.  * @return Pointer to locked zone containing frame
  204.  */
  205. static zone_t * find_zone_and_lock(pfn_t frame, unsigned int *pzone)
  206. {
  207.     unsigned int i;
  208.     unsigned int hint = pzone ? *pzone : 0;
  209.     zone_t *z;
  210.    
  211.     spinlock_lock(&zones.lock);
  212.  
  213.     if (hint >= zones.count)
  214.         hint = 0;
  215.    
  216.     i = hint;
  217.     do {
  218.         z = zones.info[i];
  219.         spinlock_lock(&z->lock);
  220.         if (z->base <= frame && z->base + z->count > frame) {
  221.             /* Unlock the global lock */
  222.             spinlock_unlock(&zones.lock);
  223.             if (pzone)
  224.                 *pzone = i;
  225.             return z;
  226.         }
  227.         spinlock_unlock(&z->lock);
  228.  
  229.         i++;
  230.         if (i >= zones.count)
  231.             i = 0;
  232.     } while(i != hint);
  233.  
  234.     spinlock_unlock(&zones.lock);
  235.     return NULL;
  236. }
  237.  
  238. /** @return True if zone can allocate specified order */
  239. static int zone_can_alloc(zone_t *z, uint8_t order)
  240. {
  241.     return buddy_system_can_alloc(z->buddy_system, order);
  242. }
  243.  
  244. /** Find and lock zone that can allocate order frames.
  245.  *
  246.  * Assume interrupts are disabled.
  247.  *
  248.  * @param order Size (2^order) of free space we are trying to find
  249.  * @param pzone Pointer to preferred zone or NULL, on return contains zone
  250.  *      number
  251.  */
  252. static zone_t * find_free_zone_and_lock(uint8_t order, unsigned int *pzone)
  253. {
  254.     unsigned int i;
  255.     zone_t *z;
  256.     unsigned int hint = pzone ? *pzone : 0;
  257.    
  258.     spinlock_lock(&zones.lock);
  259.     if (hint >= zones.count)
  260.         hint = 0;
  261.     i = hint;
  262.     do {
  263.         z = zones.info[i];
  264.        
  265.         spinlock_lock(&z->lock);
  266.  
  267.         /* Check if the zone has 2^order frames area available  */
  268.         if (zone_can_alloc(z, order)) {
  269.             spinlock_unlock(&zones.lock);
  270.             if (pzone)
  271.                 *pzone = i;
  272.             return z;
  273.         }
  274.         spinlock_unlock(&z->lock);
  275.         if (++i >= zones.count)
  276.             i = 0;
  277.     } while(i != hint);
  278.     spinlock_unlock(&zones.lock);
  279.     return NULL;
  280. }
  281.  
  282. /**************************/
  283. /* Buddy system functions */
  284. /**************************/
  285.  
  286. /** Buddy system find_block implementation
  287.  *
  288.  * Find block that is parent of current list.
  289.  * That means go to lower addresses, until such block is found
  290.  *
  291.  * @param order - Order of parent must be different then this parameter!!
  292.  */
  293. static link_t *zone_buddy_find_block(buddy_system_t *b, link_t *child,
  294.     uint8_t order)
  295. {
  296.     frame_t *frame;
  297.     zone_t *zone;
  298.     index_t index;
  299.    
  300.     frame = list_get_instance(child, frame_t, buddy_link);
  301.     zone = (zone_t *) b->data;
  302.  
  303.     index = frame_index(zone, frame);
  304.     do {
  305.         if (zone->frames[index].buddy_order != order) {
  306.             return &zone->frames[index].buddy_link;
  307.         }
  308.     } while(index-- > 0);
  309.     return NULL;
  310. }
  311.  
  312. static void zone_buddy_print_id(buddy_system_t *b, link_t *block)
  313. {
  314.     frame_t *frame;
  315.     zone_t *zone;
  316.     index_t index;
  317.  
  318.     frame = list_get_instance(block, frame_t, buddy_link);
  319.     zone = (zone_t *) b->data;
  320.     index = frame_index(zone, frame);
  321.     printf("%" PRIi, index);
  322. }                    
  323.  
  324. /** Buddy system find_buddy implementation
  325.  *
  326.  * @param b Buddy system.
  327.  * @param block Block for which buddy should be found
  328.  *
  329.  * @return Buddy for given block if found
  330.  */
  331. static link_t *zone_buddy_find_buddy(buddy_system_t *b, link_t *block)
  332. {
  333.     frame_t *frame;
  334.     zone_t *zone;
  335.     index_t index;
  336.     bool is_left, is_right;
  337.  
  338.     frame = list_get_instance(block, frame_t, buddy_link);
  339.     zone = (zone_t *) b->data;
  340.     ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame),
  341.         frame->buddy_order));
  342.    
  343.     is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);
  344.     is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);
  345.  
  346.     ASSERT(is_left ^ is_right);
  347.     if (is_left) {
  348.         index = (frame_index(zone, frame)) + (1 << frame->buddy_order);
  349.     } else {    /* if (is_right) */
  350.         index = (frame_index(zone, frame)) - (1 << frame->buddy_order);
  351.     }
  352.    
  353.     if (frame_index_valid(zone, index)) {
  354.         if (zone->frames[index].buddy_order == frame->buddy_order &&
  355.             zone->frames[index].refcount == 0) {
  356.             return &zone->frames[index].buddy_link;
  357.         }
  358.     }
  359.  
  360.     return NULL;   
  361. }
  362.  
  363. /** Buddy system bisect implementation
  364.  *
  365.  * @param b Buddy system.
  366.  * @param block Block to bisect
  367.  *
  368.  * @return right block
  369.  */
  370. static link_t * zone_buddy_bisect(buddy_system_t *b, link_t *block) {
  371.     frame_t *frame_l, *frame_r;
  372.  
  373.     frame_l = list_get_instance(block, frame_t, buddy_link);
  374.     frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));
  375.    
  376.     return &frame_r->buddy_link;
  377. }
  378.  
  379. /** Buddy system coalesce implementation
  380.  *
  381.  * @param b Buddy system.
  382.  * @param block_1 First block
  383.  * @param block_2 First block's buddy
  384.  *
  385.  * @return Coalesced block (actually block that represents lower address)
  386.  */
  387. static link_t *zone_buddy_coalesce(buddy_system_t *b, link_t *block_1,
  388.     link_t *block_2)
  389. {
  390.     frame_t *frame1, *frame2;
  391.    
  392.     frame1 = list_get_instance(block_1, frame_t, buddy_link);
  393.     frame2 = list_get_instance(block_2, frame_t, buddy_link);
  394.    
  395.     return frame1 < frame2 ? block_1 : block_2;
  396. }
  397.  
  398. /** Buddy system set_order implementation
  399.  *
  400.  * @param b Buddy system.
  401.  * @param block Buddy system block
  402.  * @param order Order to set
  403.  */
  404. static void zone_buddy_set_order(buddy_system_t *b, link_t *block,
  405.     uint8_t order) {
  406.     frame_t *frame;
  407.     frame = list_get_instance(block, frame_t, buddy_link);
  408.     frame->buddy_order = order;
  409. }
  410.  
  411. /** Buddy system get_order implementation
  412.  *
  413.  * @param b Buddy system.
  414.  * @param block Buddy system block
  415.  *
  416.  * @return Order of block
  417.  */
  418. static uint8_t zone_buddy_get_order(buddy_system_t *b, link_t *block) {
  419.     frame_t *frame;
  420.     frame = list_get_instance(block, frame_t, buddy_link);
  421.     return frame->buddy_order;
  422. }
  423.  
  424. /** Buddy system mark_busy implementation
  425.  *
  426.  * @param b Buddy system
  427.  * @param block Buddy system block
  428.  *
  429.  */
  430. static void zone_buddy_mark_busy(buddy_system_t *b, link_t * block) {
  431.     frame_t * frame;
  432.  
  433.     frame = list_get_instance(block, frame_t, buddy_link);
  434.     frame->refcount = 1;
  435. }
  436.  
  437. /** Buddy system mark_available implementation
  438.  *
  439.  * @param b Buddy system
  440.  * @param block Buddy system block
  441.  *
  442.  */
  443. static void zone_buddy_mark_available(buddy_system_t *b, link_t *block) {
  444.     frame_t *frame;
  445.     frame = list_get_instance(block, frame_t, buddy_link);
  446.     frame->refcount = 0;
  447. }
  448.  
  449. static buddy_system_operations_t zone_buddy_system_operations = {
  450.     .find_buddy = zone_buddy_find_buddy,
  451.     .bisect = zone_buddy_bisect,
  452.     .coalesce = zone_buddy_coalesce,
  453.     .set_order = zone_buddy_set_order,
  454.     .get_order = zone_buddy_get_order,
  455.     .mark_busy = zone_buddy_mark_busy,
  456.     .mark_available = zone_buddy_mark_available,
  457.     .find_block = zone_buddy_find_block,
  458.     .print_id = zone_buddy_print_id
  459. };
  460.  
  461. /******************/
  462. /* Zone functions */
  463. /******************/
  464.  
  465. /** Allocate frame in particular zone
  466.  *
  467.  * Assume zone is locked
  468.  * Panics if allocation is impossible.
  469.  *
  470.  * @param zone  Zone to allocate from.
  471.  * @param order Allocate exactly 2^order frames.
  472.  *
  473.  * @return Frame index in zone
  474.  *
  475.  */
  476. static pfn_t zone_frame_alloc(zone_t *zone, uint8_t order)
  477. {
  478.     pfn_t v;
  479.     link_t *tmp;
  480.     frame_t *frame;
  481.  
  482.     /* Allocate frames from zone buddy system */
  483.     tmp = buddy_system_alloc(zone->buddy_system, order);
  484.    
  485.     ASSERT(tmp);
  486.    
  487.     /* Update zone information. */
  488.     zone->free_count -= (1 << order);
  489.     zone->busy_count += (1 << order);
  490.  
  491.     /* Frame will be actually a first frame of the block. */
  492.     frame = list_get_instance(tmp, frame_t, buddy_link);
  493.    
  494.     /* get frame address */
  495.     v = make_frame_index(zone, frame);
  496.     return v;
  497. }
  498.  
  499. /** Free frame from zone
  500.  *
  501.  * Assume zone is locked
  502.  *
  503.  * @param zone Pointer to zone from which the frame is to be freed
  504.  * @param frame_idx Frame index relative to zone
  505.  */
  506. static void zone_frame_free(zone_t *zone, index_t frame_idx)
  507. {
  508.     frame_t *frame;
  509.     uint8_t order;
  510.  
  511.     frame = &zone->frames[frame_idx];
  512.    
  513.     /* remember frame order */
  514.     order = frame->buddy_order;
  515.  
  516.     ASSERT(frame->refcount);
  517.  
  518.     if (!--frame->refcount) {
  519.         buddy_system_free(zone->buddy_system, &frame->buddy_link);
  520.    
  521.         /* Update zone information. */
  522.         zone->free_count += (1 << order);
  523.         zone->busy_count -= (1 << order);
  524.     }
  525. }
  526.  
  527. /** Return frame from zone */
  528. static frame_t * zone_get_frame(zone_t *zone, index_t frame_idx)
  529. {
  530.     ASSERT(frame_idx < zone->count);
  531.     return &zone->frames[frame_idx];
  532. }
  533.  
  534. /** Mark frame in zone unavailable to allocation */
  535. static void zone_mark_unavailable(zone_t *zone, index_t frame_idx)
  536. {
  537.     frame_t *frame;
  538.     link_t *link;
  539.  
  540.     frame = zone_get_frame(zone, frame_idx);
  541.     if (frame->refcount)
  542.         return;
  543.     link = buddy_system_alloc_block(zone->buddy_system,
  544.         &frame->buddy_link);
  545.     ASSERT(link);
  546.     zone->free_count--;
  547. }
  548.  
  549. /**
  550.  * Join 2 zones
  551.  *
  552.  * Expect zone_t *z to point to space at least zone_conf_size large
  553.  *
  554.  * Assume z1 & z2 are locked
  555.  *
  556.  * @param z Target zone structure pointer
  557.  * @param z1 Zone to merge
  558.  * @param z2 Zone to merge
  559.  */
  560. static void _zone_merge(zone_t *z, zone_t *z1, zone_t *z2)
  561. {
  562.     uint8_t max_order;
  563.     unsigned int i;
  564.     int z2idx;
  565.     pfn_t frame_idx;
  566.     frame_t *frame;
  567.  
  568.     ASSERT(!overlaps(z1->base, z1->count, z2->base, z2->count));
  569.     ASSERT(z1->base < z2->base);
  570.  
  571.     spinlock_initialize(&z->lock, "zone_lock");
  572.     z->base = z1->base;
  573.     z->count = z2->base + z2->count - z1->base;
  574.     z->flags = z1->flags & z2->flags;
  575.  
  576.     z->free_count = z1->free_count + z2->free_count;
  577.     z->busy_count = z1->busy_count + z2->busy_count;
  578.    
  579.     max_order = fnzb(z->count);
  580.  
  581.     z->buddy_system = (buddy_system_t *) &z[1];
  582.     buddy_system_create(z->buddy_system, max_order,
  583.         &zone_buddy_system_operations, (void *) z);
  584.  
  585.     z->frames = (frame_t *)((uint8_t *) z->buddy_system +
  586.         buddy_conf_size(max_order));
  587.     for (i = 0; i < z->count; i++) {
  588.         /* This marks all frames busy */
  589.         frame_initialize(&z->frames[i]);
  590.     }
  591.     /* Copy frames from both zones to preserve full frame orders,
  592.      * parents etc. Set all free frames with refcount=0 to 1, because
  593.      * we add all free frames to buddy allocator later again, clear
  594.      * order to 0. Don't set busy frames with refcount=0, as they
  595.      * will not be reallocated during merge and it would make later
  596.      * problems with allocation/free.
  597.      */
  598.     for (i = 0; i < z1->count; i++)
  599.         z->frames[i] = z1->frames[i];
  600.     for (i = 0; i < z2->count; i++) {
  601.         z2idx = i + (z2->base - z1->base);
  602.         z->frames[z2idx] = z2->frames[i];
  603.     }
  604.     i = 0;
  605.     while (i < z->count) {
  606.         if (z->frames[i].refcount) {
  607.             /* skip busy frames */
  608.             i += 1 << z->frames[i].buddy_order;
  609.         } else { /* Free frames, set refcount=1 */
  610.             /* All free frames have refcount=0, we need not
  611.              * to check the order */
  612.             z->frames[i].refcount = 1;
  613.             z->frames[i].buddy_order = 0;
  614.             i++;
  615.         }
  616.     }
  617.     /* Add free blocks from the 2 original zones */
  618.     while (zone_can_alloc(z1, 0)) {
  619.         frame_idx = zone_frame_alloc(z1, 0);
  620.         frame = &z->frames[frame_idx];
  621.         frame->refcount = 0;
  622.         buddy_system_free(z->buddy_system, &frame->buddy_link);
  623.     }
  624.     while (zone_can_alloc(z2, 0)) {
  625.         frame_idx = zone_frame_alloc(z2, 0);
  626.         frame = &z->frames[frame_idx + (z2->base - z1->base)];
  627.         frame->refcount = 0;
  628.         buddy_system_free(z->buddy_system, &frame->buddy_link);
  629.     }
  630. }
  631.  
  632. /** Return old configuration frames into the zone
  633.  *
  634.  * We have several cases
  635.  * - the conf. data is outside of zone -> exit, shall we call frame_free??
  636.  * - the conf. data was created by zone_create or
  637.  *   updated with reduce_region -> free every frame
  638.  *
  639.  * @param newzone The actual zone where freeing should occur
  640.  * @param oldzone Pointer to old zone configuration data that should
  641.  *                be freed from new zone
  642.  */
  643. static void return_config_frames(zone_t *newzone, zone_t *oldzone)
  644. {
  645.     pfn_t pfn;
  646.     frame_t *frame;
  647.     count_t cframes;
  648.     unsigned int i;
  649.  
  650.     pfn = ADDR2PFN((uintptr_t)KA2PA(oldzone));
  651.     cframes = SIZE2FRAMES(zone_conf_size(oldzone->count));
  652.    
  653.     if (pfn < newzone->base || pfn >= newzone->base + newzone->count)
  654.         return;
  655.  
  656.     frame = &newzone->frames[pfn - newzone->base];
  657.     ASSERT(!frame->buddy_order);
  658.  
  659.     for (i = 0; i < cframes; i++) {
  660.         newzone->busy_count++;
  661.         zone_frame_free(newzone, pfn+i-newzone->base);
  662.     }
  663. }
  664.  
  665. /** Reduce allocated block to count of order 0 frames
  666.  *
  667.  * The allocated block need 2^order frames of space. Reduce all frames
  668.  * in block to order 0 and free the unneeded frames. This means, that
  669.  * when freeing the previously allocated block starting with frame_idx,
  670.  * you have to free every frame.
  671.  *
  672.  * @param zone
  673.  * @param frame_idx Index to block
  674.  * @param count Allocated space in block
  675.  */
  676. static void zone_reduce_region(zone_t *zone, pfn_t frame_idx, count_t count)
  677. {
  678.     count_t i;
  679.     uint8_t order;
  680.     frame_t *frame;
  681.    
  682.     ASSERT(frame_idx + count < zone->count);
  683.  
  684.     order = zone->frames[frame_idx].buddy_order;
  685.     ASSERT((count_t) (1 << order) >= count);
  686.  
  687.     /* Reduce all blocks to order 0 */
  688.     for (i = 0; i < (count_t) (1 << order); i++) {
  689.         frame = &zone->frames[i + frame_idx];
  690.         frame->buddy_order = 0;
  691.         if (!frame->refcount)
  692.             frame->refcount = 1;
  693.         ASSERT(frame->refcount == 1);
  694.     }
  695.     /* Free unneeded frames */
  696.     for (i = count; i < (count_t) (1 << order); i++) {
  697.         zone_frame_free(zone, i + frame_idx);
  698.     }
  699. }
  700.  
  701. /** Merge zones z1 and z2
  702.  *
  703.  * - the zones must be 2 zones with no zone existing in between,
  704.  *   which means that z2 = z1+1
  705.  *
  706.  * - When you create a new zone, the frame allocator configuration does
  707.  *   not to be 2^order size. Once the allocator is running it is no longer
  708.  *   possible, merged configuration data occupies more space :-/
  709.  */
  710. void zone_merge(unsigned int z1, unsigned int z2)
  711. {
  712.     ipl_t ipl;
  713.     zone_t *zone1, *zone2, *newzone;
  714.     unsigned int cframes;
  715.     uint8_t order;
  716.     unsigned int i;
  717.     pfn_t pfn;
  718.  
  719.     ipl = interrupts_disable();
  720.     spinlock_lock(&zones.lock);
  721.  
  722.     if ((z1 >= zones.count) || (z2 >= zones.count))
  723.         goto errout;
  724.     /* We can join only 2 zones with none existing inbetween */
  725.     if (z2-z1 != 1)
  726.         goto errout;
  727.  
  728.     zone1 = zones.info[z1];
  729.     zone2 = zones.info[z2];
  730.     spinlock_lock(&zone1->lock);
  731.     spinlock_lock(&zone2->lock);
  732.  
  733.     cframes = SIZE2FRAMES(zone_conf_size(zone2->base + zone2->count -
  734.         zone1->base));
  735.     if (cframes == 1)
  736.         order = 0;
  737.     else
  738.         order = fnzb(cframes - 1) + 1;
  739.  
  740.     /* Allocate zonedata inside one of the zones */
  741.     if (zone_can_alloc(zone1, order))
  742.         pfn = zone1->base + zone_frame_alloc(zone1, order);
  743.     else if (zone_can_alloc(zone2, order))
  744.         pfn = zone2->base + zone_frame_alloc(zone2, order);
  745.     else
  746.         goto errout2;
  747.  
  748.     newzone = (zone_t *) PA2KA(PFN2ADDR(pfn));
  749.  
  750.     _zone_merge(newzone, zone1, zone2);
  751.  
  752.     /* Free unneeded config frames */
  753.     zone_reduce_region(newzone, pfn - newzone->base,  cframes);
  754.     /* Subtract zone information from busy frames */
  755.     newzone->busy_count -= cframes;
  756.  
  757.     /* Replace existing zones in zoneinfo list */
  758.     zones.info[z1] = newzone;
  759.     for (i = z2 + 1; i < zones.count; i++)
  760.         zones.info[i - 1] = zones.info[i];
  761.     zones.count--;
  762.  
  763.     /* Free old zone information */
  764.     return_config_frames(newzone, zone1);
  765.     return_config_frames(newzone, zone2);
  766. errout2:
  767.     /* Nobody is allowed to enter to zone, so we are safe
  768.      * to touch the spinlocks last time */
  769.     spinlock_unlock(&zone1->lock);
  770.     spinlock_unlock(&zone2->lock);
  771. errout:
  772.     spinlock_unlock(&zones.lock);
  773.     interrupts_restore(ipl);
  774. }
  775.  
  776. /**
  777.  * Merge all zones into one big zone
  778.  *
  779.  * It is reasonable to do this on systems whose bios reports parts in chunks,
  780.  * so that we could have 1 zone (it's faster).
  781.  */
  782. void zone_merge_all(void)
  783. {
  784.     int count = zones.count;
  785.  
  786.     while (zones.count > 1 && --count) {
  787.         zone_merge(0,1);
  788.         break;
  789.     }
  790. }
  791.  
  792. /** Create frame zone
  793.  *
  794.  * Create new frame zone.
  795.  *
  796.  * @param start Physical address of the first frame within the zone.
  797.  * @param count Count of frames in zone
  798.  * @param z Address of configuration information of zone
  799.  * @param flags Zone flags.
  800.  *
  801.  * @return Initialized zone.
  802.  */
  803. static void zone_construct(pfn_t start, count_t count, zone_t *z, int flags)
  804. {
  805.     unsigned int i;
  806.     uint8_t max_order;
  807.  
  808.     spinlock_initialize(&z->lock, "zone_lock");
  809.     z->base = start;
  810.     z->count = count;
  811.     z->flags = flags;
  812.     z->free_count = count;
  813.     z->busy_count = 0;
  814.  
  815.     /*
  816.      * Compute order for buddy system, initialize
  817.      */
  818.     max_order = fnzb(count);
  819.     z->buddy_system = (buddy_system_t *)&z[1];
  820.    
  821.     buddy_system_create(z->buddy_system, max_order,
  822.                 &zone_buddy_system_operations,
  823.                 (void *) z);
  824.    
  825.     /* Allocate frames _after_ the conframe */
  826.     /* Check sizes */
  827.     z->frames = (frame_t *)((uint8_t *) z->buddy_system +
  828.         buddy_conf_size(max_order));
  829.     for (i = 0; i < count; i++) {
  830.         frame_initialize(&z->frames[i]);
  831.     }
  832.    
  833.     /* Stuffing frames */
  834.     for (i = 0; i < count; i++) {
  835.         z->frames[i].refcount = 0;
  836.         buddy_system_free(z->buddy_system, &z->frames[i].buddy_link);
  837.     }
  838. }
  839.  
  840. /** Compute configuration data size for zone
  841.  *
  842.  * @param count Size of zone in frames
  843.  * @return Size of zone configuration info (in bytes)
  844.  */
  845. uintptr_t zone_conf_size(count_t count)
  846. {
  847.     int size = sizeof(zone_t) + count * sizeof(frame_t);
  848.     int max_order;
  849.  
  850.     max_order = fnzb(count);
  851.     size += buddy_conf_size(max_order);
  852.     return size;
  853. }
  854.  
  855. /** Create and add zone to system
  856.  *
  857.  * @param start First frame number (absolute)
  858.  * @param count Size of zone in frames
  859.  * @param confframe Where configuration frames are supposed to be.
  860.  *                  Automatically checks, that we will not disturb the
  861.  *                  kernel and possibly init.
  862.  *                  If confframe is given _outside_ this zone, it is expected,
  863.  *                  that the area is already marked BUSY and big enough
  864.  *                  to contain zone_conf_size() amount of data.
  865.  *                  If the confframe is inside the area, the zone free frame
  866.  *                  information is modified not to include it.
  867.  *
  868.  * @return Zone number or -1 on error
  869.  */
  870. int zone_create(pfn_t start, count_t count, pfn_t confframe, int flags)
  871. {
  872.     zone_t *z;
  873.     uintptr_t addr;
  874.     count_t confcount;
  875.     unsigned int i;
  876.     int znum;
  877.  
  878.     /* Theoretically we could have here 0, practically make sure
  879.      * nobody tries to do that. If some platform requires, remove
  880.      * the assert
  881.      */
  882.     ASSERT(confframe);
  883.     /* If conframe is supposed to be inside our zone, then make sure
  884.      * it does not span kernel & init
  885.      */
  886.     confcount = SIZE2FRAMES(zone_conf_size(count));
  887.     if (confframe >= start && confframe < start+count) {
  888.         for (;confframe < start + count; confframe++) {
  889.             addr = PFN2ADDR(confframe);
  890.             if (overlaps(addr, PFN2ADDR(confcount),
  891.                 KA2PA(config.base), config.kernel_size))
  892.                 continue;
  893.            
  894.             if (overlaps(addr, PFN2ADDR(confcount),
  895.                 KA2PA(config.stack_base), config.stack_size))
  896.                 continue;
  897.            
  898.             bool overlap = false;
  899.             count_t i;
  900.             for (i = 0; i < init.cnt; i++)
  901.                 if (overlaps(addr, PFN2ADDR(confcount),
  902.                     KA2PA(init.tasks[i].addr),
  903.                     init.tasks[i].size)) {
  904.                     overlap = true;
  905.                     break;
  906.                 }
  907.             if (overlap)
  908.                 continue;
  909.            
  910.             break;
  911.         }
  912.         if (confframe >= start + count)
  913.             panic("Cannot find configuration data for zone.");
  914.     }
  915.  
  916.     z = (zone_t *) PA2KA(PFN2ADDR(confframe));
  917.     zone_construct(start, count, z, flags);
  918.     znum = zones_add_zone(z);
  919.     if (znum == -1)
  920.         return -1;
  921.  
  922.     /* If confdata in zone, mark as unavailable */
  923.     if (confframe >= start && confframe < start + count)
  924.         for (i = confframe; i < confframe + confcount; i++) {
  925.             zone_mark_unavailable(z, i - z->base);
  926.         }
  927.     return znum;
  928. }
  929.  
  930. /***************************************/
  931. /* Frame functions */
  932.  
  933. /** Set parent of frame */
  934. void frame_set_parent(pfn_t pfn, void *data, unsigned int hint)
  935. {
  936.     zone_t *zone = find_zone_and_lock(pfn, &hint);
  937.  
  938.     ASSERT(zone);
  939.  
  940.     zone_get_frame(zone, pfn-zone->base)->parent = data;
  941.     spinlock_unlock(&zone->lock);
  942. }
  943.  
  944. void *frame_get_parent(pfn_t pfn, unsigned int hint)
  945. {
  946.     zone_t *zone = find_zone_and_lock(pfn, &hint);
  947.     void *res;
  948.  
  949.     ASSERT(zone);
  950.     res = zone_get_frame(zone, pfn - zone->base)->parent;
  951.    
  952.     spinlock_unlock(&zone->lock);
  953.     return res;
  954. }
  955.  
  956. /** Allocate power-of-two frames of physical memory.
  957.  *
  958.  * @param order  Allocate exactly 2^order frames.
  959.  * @param flags  Flags for host zone selection and address processing.
  960.  * @param pzone  Preferred zone
  961.  *
  962.  * @return Physical address of the allocated frame.
  963.  *
  964.  */
  965. void * frame_alloc_generic(uint8_t order, int flags, unsigned int *pzone)
  966. {
  967.     ipl_t ipl;
  968.     int freed;
  969.     pfn_t v;
  970.     zone_t *zone;
  971.    
  972. loop:
  973.     ipl = interrupts_disable();
  974.    
  975.     /*
  976.      * First, find suitable frame zone.
  977.      */
  978.     zone = find_free_zone_and_lock(order, pzone);
  979.    
  980.     /* If no memory, reclaim some slab memory,
  981.        if it does not help, reclaim all */
  982.     if (!zone && !(flags & FRAME_NO_RECLAIM)) {
  983.         freed = slab_reclaim(0);
  984.         if (freed)
  985.             zone = find_free_zone_and_lock(order, pzone);
  986.         if (!zone) {
  987.             freed = slab_reclaim(SLAB_RECLAIM_ALL);
  988.             if (freed)
  989.                 zone = find_free_zone_and_lock(order, pzone);
  990.         }
  991.     }
  992.     if (!zone) {
  993.         /*
  994.          * TODO: Sleep until frames are available again.
  995.          */
  996.         interrupts_restore(ipl);
  997.  
  998.         if (flags & FRAME_ATOMIC)
  999.             return 0;
  1000.        
  1001.         panic("Sleep not implemented.\n");
  1002.         goto loop;
  1003.     }
  1004.    
  1005.     v = zone_frame_alloc(zone, order);
  1006.     v += zone->base;
  1007.  
  1008.     spinlock_unlock(&zone->lock);
  1009.     interrupts_restore(ipl);
  1010.  
  1011.     if (flags & FRAME_KA)
  1012.         return (void *)PA2KA(PFN2ADDR(v));
  1013.     return (void *)PFN2ADDR(v);
  1014. }
  1015.  
  1016. /** Free a frame.
  1017.  *
  1018.  * Find respective frame structure for supplied physical frame address.
  1019.  * Decrement frame reference count.
  1020.  * If it drops to zero, move the frame structure to free list.
  1021.  *
  1022.  * @param Frame Physical Address of of the frame to be freed.
  1023.  */
  1024. void frame_free(uintptr_t frame)
  1025. {
  1026.     ipl_t ipl;
  1027.     zone_t *zone;
  1028.     pfn_t pfn = ADDR2PFN(frame);
  1029.  
  1030.     ipl = interrupts_disable();
  1031.    
  1032.     /*
  1033.      * First, find host frame zone for addr.
  1034.      */
  1035.     zone = find_zone_and_lock(pfn,NULL);
  1036.     ASSERT(zone);
  1037.    
  1038.     zone_frame_free(zone, pfn-zone->base);
  1039.    
  1040.     spinlock_unlock(&zone->lock);
  1041.     interrupts_restore(ipl);
  1042. }
  1043.  
  1044. /** Add reference to frame.
  1045.  *
  1046.  * Find respective frame structure for supplied PFN and
  1047.  * increment frame reference count.
  1048.  *
  1049.  * @param pfn Frame number of the frame to be freed.
  1050.  */
  1051. void frame_reference_add(pfn_t pfn)
  1052. {
  1053.     ipl_t ipl;
  1054.     zone_t *zone;
  1055.     frame_t *frame;
  1056.  
  1057.     ipl = interrupts_disable();
  1058.    
  1059.     /*
  1060.      * First, find host frame zone for addr.
  1061.      */
  1062.     zone = find_zone_and_lock(pfn,NULL);
  1063.     ASSERT(zone);
  1064.    
  1065.     frame = &zone->frames[pfn-zone->base];
  1066.     frame->refcount++;
  1067.    
  1068.     spinlock_unlock(&zone->lock);
  1069.     interrupts_restore(ipl);
  1070. }
  1071.  
  1072. /** Mark given range unavailable in frame zones */
  1073. void frame_mark_unavailable(pfn_t start, count_t count)
  1074. {
  1075.     unsigned int i;
  1076.     zone_t *zone;
  1077.     unsigned int prefzone = 0;
  1078.    
  1079.     for (i = 0; i < count; i++) {
  1080.         zone = find_zone_and_lock(start + i, &prefzone);
  1081.         if (!zone) /* PFN not found */
  1082.             continue;
  1083.         zone_mark_unavailable(zone, start + i - zone->base);
  1084.  
  1085.         spinlock_unlock(&zone->lock);
  1086.     }
  1087. }
  1088.  
  1089. /** Initialize physical memory management
  1090.  *
  1091.  * Initialize physical memory managemnt.
  1092.  */
  1093. void frame_init(void)
  1094. {
  1095.     if (config.cpu_active == 1) {
  1096.         zones.count = 0;
  1097.         spinlock_initialize(&zones.lock, "zones.lock");
  1098.     }
  1099.     /* Tell the architecture to create some memory */
  1100.     frame_arch_init();
  1101.     if (config.cpu_active == 1) {
  1102.         frame_mark_unavailable(ADDR2PFN(KA2PA(config.base)),
  1103.             SIZE2FRAMES(config.kernel_size));
  1104.         frame_mark_unavailable(ADDR2PFN(KA2PA(config.stack_base)),
  1105.             SIZE2FRAMES(config.stack_size));
  1106.        
  1107.         count_t i;
  1108.         for (i = 0; i < init.cnt; i++) {
  1109.             pfn_t pfn = ADDR2PFN(KA2PA(init.tasks[i].addr));
  1110.             frame_mark_unavailable(pfn,
  1111.                 SIZE2FRAMES(init.tasks[i].size));
  1112.         }
  1113.  
  1114.         if (ballocs.size)
  1115.             frame_mark_unavailable(ADDR2PFN(KA2PA(ballocs.base)),
  1116.                 SIZE2FRAMES(ballocs.size));
  1117.  
  1118.         /* Black list first frame, as allocating NULL would
  1119.          * fail in some places */
  1120.         frame_mark_unavailable(0, 1);
  1121.     }
  1122. }
  1123.  
  1124.  
  1125. /** Return total size of all zones
  1126.  *
  1127.  */
  1128. uint64_t zone_total_size(void) {
  1129.     zone_t *zone = NULL;
  1130.     unsigned int i;
  1131.     ipl_t ipl;
  1132.     uint64_t total = 0;
  1133.  
  1134.     ipl = interrupts_disable();
  1135.     spinlock_lock(&zones.lock);
  1136.    
  1137.     for (i = 0; i < zones.count; i++) {
  1138.         zone = zones.info[i];
  1139.         spinlock_lock(&zone->lock);
  1140.         total += (uint64_t) FRAMES2SIZE(zone->count);
  1141.         spinlock_unlock(&zone->lock);
  1142.     }
  1143.    
  1144.     spinlock_unlock(&zones.lock);
  1145.     interrupts_restore(ipl);
  1146.    
  1147.     return total;
  1148. }
  1149.  
  1150.  
  1151.  
  1152. /** Prints list of zones
  1153.  *
  1154.  */
  1155. void zone_print_list(void) {
  1156.     zone_t *zone = NULL;
  1157.     unsigned int i;
  1158.     ipl_t ipl;
  1159.  
  1160.     ipl = interrupts_disable();
  1161.     spinlock_lock(&zones.lock);
  1162.  
  1163. #ifdef __32_BITS__ 
  1164.     printf("#  base address free frames  busy frames\n");
  1165.     printf("-- ------------ ------------ ------------\n");
  1166. #endif
  1167.  
  1168. #ifdef __64_BITS__
  1169.     printf("#  base address         free frames  busy frames\n");
  1170.     printf("-- -------------------- ------------ ------------\n");
  1171. #endif
  1172.    
  1173.     for (i = 0; i < zones.count; i++) {
  1174.         zone = zones.info[i];
  1175.         spinlock_lock(&zone->lock);
  1176.  
  1177. #ifdef __32_BITS__
  1178.         printf("%-2u   %10p %12" PRIc " %12" PRIc "\n", i, PFN2ADDR(zone->base),
  1179.             zone->free_count, zone->busy_count);
  1180. #endif
  1181.  
  1182. #ifdef __64_BITS__
  1183.         printf("%-2u   %18p %12" PRIc " %12" PRIc "\n", i, PFN2ADDR(zone->base),
  1184.             zone->free_count, zone->busy_count);
  1185. #endif
  1186.        
  1187.         spinlock_unlock(&zone->lock);
  1188.     }
  1189.    
  1190.     spinlock_unlock(&zones.lock);
  1191.     interrupts_restore(ipl);
  1192. }
  1193.  
  1194. /** Prints zone details.
  1195.  *
  1196.  * @param num Zone base address or zone number.
  1197.  */
  1198. void zone_print_one(unsigned int num) {
  1199.     zone_t *zone = NULL;
  1200.     ipl_t ipl;
  1201.     unsigned int i;
  1202.  
  1203.     ipl = interrupts_disable();
  1204.     spinlock_lock(&zones.lock);
  1205.  
  1206.     for (i = 0; i < zones.count; i++) {
  1207.         if ((i == num) || (PFN2ADDR(zones.info[i]->base) == num)) {
  1208.             zone = zones.info[i];
  1209.             break;
  1210.         }
  1211.     }
  1212.     if (!zone) {
  1213.         printf("Zone not found.\n");
  1214.         goto out;
  1215.     }
  1216.    
  1217.     spinlock_lock(&zone->lock);
  1218.     printf("Memory zone information\n");
  1219.     printf("Zone base address: %p\n", PFN2ADDR(zone->base));
  1220.     printf("Zone size: %" PRIc " frames (%" PRIs " KB)\n", zone->count,
  1221.         SIZE2KB(FRAMES2SIZE(zone->count)));
  1222.     printf("Allocated space: %" PRIc " frames (%" PRIs " KB)\n", zone->busy_count,
  1223.         SIZE2KB(FRAMES2SIZE(zone->busy_count)));
  1224.     printf("Available space: %" PRIc " frames (%" PRIs " KB)\n", zone->free_count,
  1225.         SIZE2KB(FRAMES2SIZE(zone->free_count)));
  1226.     buddy_system_structure_print(zone->buddy_system, FRAME_SIZE);
  1227.     spinlock_unlock(&zone->lock);
  1228.    
  1229. out:
  1230.     spinlock_unlock(&zones.lock);
  1231.     interrupts_restore(ipl);
  1232. }
  1233.  
  1234. /** @}
  1235.  */
  1236.  
  1237.