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