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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.     unsigned 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.     unsigned 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, unsigned int *pzone)
  189. {
  190.     unsigned int i;
  191.     unsigned 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.     unsigned int i;
  236.     zone_t *z;
  237.     unsigned 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.     unsigned int i;
  543.     int z2idx;
  544.     pfn_t frame_idx;
  545.     frame_t *frame;
  546.  
  547.     ASSERT(!overlaps(z1->base,z1->count,z2->base,z2->count));
  548.     ASSERT(z1->base < z2->base);
  549.  
  550.     spinlock_initialize(&z->lock, "zone_lock");
  551.     z->base = z1->base;
  552.     z->count = z2->base+z2->count - z1->base;
  553.     z->flags = z1->flags & z2->flags;
  554.  
  555.     z->free_count = z1->free_count + z2->free_count;
  556.     z->busy_count = z1->busy_count + z2->busy_count;
  557.    
  558.     max_order = fnzb(z->count);
  559.  
  560.     z->buddy_system = (buddy_system_t *)&z[1];
  561.     buddy_system_create(z->buddy_system, max_order,
  562.                 &zone_buddy_system_operations,
  563.                 (void *) z);
  564.  
  565.     z->frames = (frame_t *)((uint8_t *) z->buddy_system + buddy_conf_size(max_order));
  566.     for (i = 0; i < z->count; i++) {
  567.         /* This marks all frames busy */
  568.         frame_initialize(&z->frames[i]);
  569.     }
  570.     /* Copy frames from both zones to preserve full frame orders,
  571.      * parents etc. Set all free frames with refcount=0 to 1, because
  572.      * we add all free frames to buddy allocator later again, clear
  573.      * order to 0. Don't set busy frames with refcount=0, as they
  574.      * will not be reallocated during merge and it would make later
  575.      * problems with allocation/free.
  576.      */
  577.     for (i = 0; i < z1->count; i++)
  578.         z->frames[i] = z1->frames[i];
  579.     for (i = 0; i < z2->count; i++) {
  580.         z2idx = i + (z2->base - z1->base);
  581.         z->frames[z2idx] = z2->frames[i];
  582.     }
  583.     i = 0;
  584.     while (i < z->count) {
  585.         if (z->frames[i].refcount) {
  586.             /* skip busy frames */
  587.             i += 1 << z->frames[i].buddy_order;
  588.         } else { /* Free frames, set refcount=1 */
  589.             /* All free frames have refcount=0, we need not
  590.              * to check the order */
  591.             z->frames[i].refcount = 1;
  592.             z->frames[i].buddy_order = 0;
  593.             i++;
  594.         }
  595.     }
  596.     /* Add free blocks from the 2 original zones */
  597.     while (zone_can_alloc(z1, 0)) {
  598.         frame_idx = zone_frame_alloc(z1, 0);
  599.         frame = &z->frames[frame_idx];
  600.         frame->refcount = 0;
  601.         buddy_system_free(z->buddy_system, &frame->buddy_link);
  602.     }
  603.     while (zone_can_alloc(z2, 0)) {
  604.         frame_idx = zone_frame_alloc(z2, 0);
  605.         frame = &z->frames[frame_idx + (z2->base-z1->base)];
  606.         frame->refcount = 0;
  607.         buddy_system_free(z->buddy_system, &frame->buddy_link);
  608.     }
  609. }
  610.  
  611. /** Return old configuration frames into the zone
  612.  *
  613.  * We have several cases
  614.  * - the conf. data is outside of zone -> exit, shall we call frame_free??
  615.  * - the conf. data was created by zone_create or
  616.  *   updated with reduce_region -> free every frame
  617.  *
  618.  * @param newzone The actual zone where freeing should occur
  619.  * @param oldzone Pointer to old zone configuration data that should
  620.  *                be freed from new zone
  621.  */
  622. static void return_config_frames(zone_t *newzone, zone_t *oldzone)
  623. {
  624.     pfn_t pfn;
  625.     frame_t *frame;
  626.     count_t cframes;
  627.     unsigned int i;
  628.  
  629.     pfn = ADDR2PFN((uintptr_t)KA2PA(oldzone));
  630.     cframes = SIZE2FRAMES(zone_conf_size(oldzone->count));
  631.    
  632.     if (pfn < newzone->base || pfn >= newzone->base + newzone->count)
  633.         return;
  634.  
  635.     frame = &newzone->frames[pfn - newzone->base];
  636.     ASSERT(!frame->buddy_order);
  637.  
  638.     for (i = 0; i < cframes; i++) {
  639.         newzone->busy_count++;
  640.         zone_frame_free(newzone, pfn+i-newzone->base);
  641.     }
  642. }
  643.  
  644. /** Reduce allocated block to count of order 0 frames
  645.  *
  646.  * The allocated block need 2^order frames of space. Reduce all frames
  647.  * in block to order 0 and free the unneeded frames. This means, that
  648.  * when freeing the previously allocated block starting with frame_idx,
  649.  * you have to free every frame.
  650.  *
  651.  * @param zone
  652.  * @param frame_idx Index to block
  653.  * @param count Allocated space in block
  654.  */
  655. static void zone_reduce_region(zone_t *zone, pfn_t frame_idx, count_t count)
  656. {
  657.     count_t i;
  658.     uint8_t order;
  659.     frame_t *frame;
  660.    
  661.     ASSERT(frame_idx + count < zone->count);
  662.  
  663.     order = zone->frames[frame_idx].buddy_order;
  664.     ASSERT((count_t) (1 << order) >= count);
  665.  
  666.     /* Reduce all blocks to order 0 */
  667.     for (i = 0; i < (count_t) (1 << order); i++) {
  668.         frame = &zone->frames[i + frame_idx];
  669.         frame->buddy_order = 0;
  670.         if (! frame->refcount)
  671.             frame->refcount = 1;
  672.         ASSERT(frame->refcount == 1);
  673.     }
  674.     /* Free unneeded frames */
  675.     for (i = count; i < (count_t) (1 << order); i++) {
  676.         zone_frame_free(zone, i + frame_idx);
  677.     }
  678. }
  679.  
  680. /** Merge zones z1 and z2
  681.  *
  682.  * - the zones must be 2 zones with no zone existing in between,
  683.  *   which means that z2 = z1+1
  684.  *
  685.  * - When you create a new zone, the frame allocator configuration does
  686.  *   not to be 2^order size. Once the allocator is running it is no longer
  687.  *   possible, merged configuration data occupies more space :-/
  688.  */
  689. void zone_merge(unsigned int z1, unsigned int z2)
  690. {
  691.     ipl_t ipl;
  692.     zone_t *zone1, *zone2, *newzone;
  693.     unsigned int cframes;
  694.     uint8_t order;
  695.     unsigned int i;
  696.     pfn_t pfn;
  697.  
  698.     ipl = interrupts_disable();
  699.     spinlock_lock(&zones.lock);
  700.  
  701.     if (z1 < 0 || z1 >= zones.count || z2 < 0 || z2 >= zones.count)
  702.         goto errout;
  703.     /* We can join only 2 zones with none existing inbetween */
  704.     if (z2-z1 != 1)
  705.         goto errout;
  706.  
  707.     zone1 = zones.info[z1];
  708.     zone2 = zones.info[z2];
  709.     spinlock_lock(&zone1->lock);
  710.     spinlock_lock(&zone2->lock);
  711.  
  712.     cframes = SIZE2FRAMES(zone_conf_size(zone2->base+zone2->count-zone1->base));
  713.     if (cframes == 1)
  714.         order = 0;
  715.     else
  716.         order = fnzb(cframes - 1) + 1;
  717.  
  718.     /* Allocate zonedata inside one of the zones */
  719.     if (zone_can_alloc(zone1, order))
  720.         pfn = zone1->base + zone_frame_alloc(zone1, order);
  721.     else if (zone_can_alloc(zone2, order))
  722.         pfn = zone2->base + zone_frame_alloc(zone2, order);
  723.     else
  724.         goto errout2;
  725.  
  726.     newzone = (zone_t *) PA2KA(PFN2ADDR(pfn));
  727.  
  728.     _zone_merge(newzone, zone1, zone2);
  729.  
  730.     /* Free unneeded config frames */
  731.     zone_reduce_region(newzone, pfn - newzone->base,  cframes);
  732.     /* Subtract zone information from busy frames */
  733.     newzone->busy_count -= cframes;
  734.  
  735.     /* Replace existing zones in zoneinfo list */
  736.     zones.info[z1] = newzone;
  737.     for (i = z2 + 1; i < zones.count; i++)
  738.         zones.info[i - 1] = zones.info[i];
  739.     zones.count--;
  740.  
  741.     /* Free old zone information */
  742.     return_config_frames(newzone, zone1);
  743.     return_config_frames(newzone, zone2);
  744. errout2:
  745.     /* Nobody is allowed to enter to zone, so we are safe
  746.      * to touch the spinlocks last time */
  747.     spinlock_unlock(&zone1->lock);
  748.     spinlock_unlock(&zone2->lock);
  749. errout:
  750.     spinlock_unlock(&zones.lock);
  751.     interrupts_restore(ipl);
  752. }
  753.  
  754. /**
  755.  * Merge all zones into one big zone
  756.  *
  757.  * It is reasonable to do this on systems whose bios reports parts in chunks,
  758.  * so that we could have 1 zone (it's faster).
  759.  */
  760. void zone_merge_all(void)
  761. {
  762.     int count = zones.count;
  763.  
  764.     while (zones.count > 1 && --count) {
  765.         zone_merge(0,1);
  766.         break;
  767.     }
  768. }
  769.  
  770. /** Create frame zone
  771.  *
  772.  * Create new frame zone.
  773.  *
  774.  * @param start Physical address of the first frame within the zone.
  775.  * @param count Count of frames in zone
  776.  * @param z Address of configuration information of zone
  777.  * @param flags Zone flags.
  778.  *
  779.  * @return Initialized zone.
  780.  */
  781. static void zone_construct(pfn_t start, count_t count, zone_t *z, int flags)
  782. {
  783.     unsigned int i;
  784.     uint8_t max_order;
  785.  
  786.     spinlock_initialize(&z->lock, "zone_lock");
  787.     z->base = start;
  788.     z->count = count;
  789.     z->flags = flags;
  790.     z->free_count = count;
  791.     z->busy_count = 0;
  792.  
  793.     /*
  794.      * Compute order for buddy system, initialize
  795.      */
  796.     max_order = fnzb(count);
  797.     z->buddy_system = (buddy_system_t *)&z[1];
  798.    
  799.     buddy_system_create(z->buddy_system, max_order,
  800.                 &zone_buddy_system_operations,
  801.                 (void *) z);
  802.    
  803.     /* Allocate frames _after_ the conframe */
  804.     /* Check sizes */
  805.     z->frames = (frame_t *)((uint8_t *) z->buddy_system + buddy_conf_size(max_order));
  806.     for (i = 0; i < count; i++) {
  807.         frame_initialize(&z->frames[i]);
  808.     }
  809.    
  810.     /* Stuffing frames */
  811.     for (i = 0; i < count; i++) {
  812.         z->frames[i].refcount = 0;
  813.         buddy_system_free(z->buddy_system, &z->frames[i].buddy_link);
  814.     }
  815. }
  816.  
  817. /** Compute configuration data size for zone
  818.  *
  819.  * @param count Size of zone in frames
  820.  * @return Size of zone configuration info (in bytes)
  821.  */
  822. uintptr_t zone_conf_size(count_t count)
  823. {
  824.     int size = sizeof(zone_t) + count*sizeof(frame_t);
  825.     int max_order;
  826.  
  827.     max_order = fnzb(count);
  828.     size += buddy_conf_size(max_order);
  829.     return size;
  830. }
  831.  
  832. /** Create and add zone to system
  833.  *
  834.  * @param start First frame number (absolute)
  835.  * @param count Size of zone in frames
  836.  * @param confframe Where configuration frames are supposed to be.
  837.  *                  Automatically checks, that we will not disturb the
  838.  *                  kernel and possibly init.
  839.  *                  If confframe is given _outside_ this zone, it is expected,
  840.  *                  that the area is already marked BUSY and big enough
  841.  *                  to contain zone_conf_size() amount of data.
  842.  *                  If the confframe is inside the area, the zone free frame
  843.  *                  information is modified not to include it.
  844.  *
  845.  * @return Zone number or -1 on error
  846.  */
  847. int zone_create(pfn_t start, count_t count, pfn_t confframe, int flags)
  848. {
  849.     zone_t *z;
  850.     uintptr_t addr;
  851.     count_t confcount;
  852.     unsigned int i;
  853.     int znum;
  854.  
  855.     /* Theoretically we could have here 0, practically make sure
  856.      * nobody tries to do that. If some platform requires, remove
  857.      * the assert
  858.      */
  859.     ASSERT(confframe);
  860.     /* If conframe is supposed to be inside our zone, then make sure
  861.      * it does not span kernel & init
  862.      */
  863.     confcount = SIZE2FRAMES(zone_conf_size(count));
  864.     if (confframe >= start && confframe < start+count) {
  865.         for (;confframe < start + count; confframe++) {
  866.             addr = PFN2ADDR(confframe);
  867.             if (overlaps(addr, PFN2ADDR(confcount), KA2PA(config.base), config.kernel_size))
  868.                 continue;
  869.            
  870.             if (overlaps(addr, PFN2ADDR(confcount), KA2PA(config.stack_base), config.stack_size))
  871.                 continue;
  872.            
  873.             bool overlap = false;
  874.             count_t i;
  875.             for (i = 0; i < init.cnt; i++)
  876.                 if (overlaps(addr, PFN2ADDR(confcount), KA2PA(init.tasks[i].addr), init.tasks[i].size)) {
  877.                     overlap = true;
  878.                     break;
  879.                 }
  880.             if (overlap)
  881.                 continue;
  882.            
  883.             break;
  884.         }
  885.         if (confframe >= start + count)
  886.             panic("Cannot find configuration data for zone.");
  887.     }
  888.  
  889.     z = (zone_t *)PA2KA(PFN2ADDR(confframe));
  890.     zone_construct(start, count, z, flags);
  891.     znum = zones_add_zone(z);
  892.     if (znum == -1)
  893.         return -1;
  894.  
  895.     /* If confdata in zone, mark as unavailable */
  896.     if (confframe >= start && confframe < start + count)
  897.         for (i = confframe; i < confframe + confcount; i++) {
  898.             zone_mark_unavailable(z, i - z->base);
  899.         }
  900.     return znum;
  901. }
  902.  
  903. /***************************************/
  904. /* Frame functions */
  905.  
  906. /** Set parent of frame */
  907. void frame_set_parent(pfn_t pfn, void *data, unsigned int hint)
  908. {
  909.     zone_t *zone = find_zone_and_lock(pfn, &hint);
  910.  
  911.     ASSERT(zone);
  912.  
  913.     zone_get_frame(zone, pfn-zone->base)->parent = data;
  914.     spinlock_unlock(&zone->lock);
  915. }
  916.  
  917. void * frame_get_parent(pfn_t pfn, unsigned int hint)
  918. {
  919.     zone_t *zone = find_zone_and_lock(pfn, &hint);
  920.     void *res;
  921.  
  922.     ASSERT(zone);
  923.     res = zone_get_frame(zone, pfn - zone->base)->parent;
  924.    
  925.     spinlock_unlock(&zone->lock);
  926.     return res;
  927. }
  928.  
  929. /** Allocate power-of-two frames of physical memory.
  930.  *
  931.  * @param order  Allocate exactly 2^order frames.
  932.  * @param flags  Flags for host zone selection and address processing.
  933.  * @param pzone  Preferred zone
  934.  *
  935.  * @return Physical address of the allocated frame.
  936.  *
  937.  */
  938. void * frame_alloc_generic(uint8_t order, int flags, int *pzone)
  939. {
  940.     ipl_t ipl;
  941.     int freed;
  942.     pfn_t v;
  943.     zone_t *zone;
  944.    
  945. loop:
  946.     ipl = interrupts_disable();
  947.    
  948.     /*
  949.      * First, find suitable frame zone.
  950.      */
  951.     zone = find_free_zone_and_lock(order, pzone);
  952.    
  953.     /* If no memory, reclaim some slab memory,
  954.        if it does not help, reclaim all */
  955.     if (!zone && !(flags & FRAME_NO_RECLAIM)) {
  956.         freed = slab_reclaim(0);
  957.         if (freed)
  958.             zone = find_free_zone_and_lock(order, pzone);
  959.         if (!zone) {
  960.             freed = slab_reclaim(SLAB_RECLAIM_ALL);
  961.             if (freed)
  962.                 zone = find_free_zone_and_lock(order, pzone);
  963.         }
  964.     }
  965.     if (!zone) {
  966.         /*
  967.          * TODO: Sleep until frames are available again.
  968.          */
  969.         interrupts_restore(ipl);
  970.  
  971.         if (flags & FRAME_ATOMIC)
  972.             return 0;
  973.        
  974.         panic("Sleep not implemented.\n");
  975.         goto loop;
  976.     }
  977.    
  978.     v = zone_frame_alloc(zone, order);
  979.     v += zone->base;
  980.  
  981.     spinlock_unlock(&zone->lock);
  982.     interrupts_restore(ipl);
  983.  
  984.     if (flags & FRAME_KA)
  985.         return (void *)PA2KA(PFN2ADDR(v));
  986.     return (void *)PFN2ADDR(v);
  987. }
  988.  
  989. /** Free a frame.
  990.  *
  991.  * Find respective frame structure for supplied physical frame address.
  992.  * Decrement frame reference count.
  993.  * If it drops to zero, move the frame structure to free list.
  994.  *
  995.  * @param Frame Physical Address of of the frame to be freed.
  996.  */
  997. void frame_free(uintptr_t frame)
  998. {
  999.     ipl_t ipl;
  1000.     zone_t *zone;
  1001.     pfn_t pfn = ADDR2PFN(frame);
  1002.  
  1003.     ipl = interrupts_disable();
  1004.    
  1005.     /*
  1006.      * First, find host frame zone for addr.
  1007.      */
  1008.     zone = find_zone_and_lock(pfn,NULL);
  1009.     ASSERT(zone);
  1010.    
  1011.     zone_frame_free(zone, pfn-zone->base);
  1012.    
  1013.     spinlock_unlock(&zone->lock);
  1014.     interrupts_restore(ipl);
  1015. }
  1016.  
  1017. /** Add reference to frame.
  1018.  *
  1019.  * Find respective frame structure for supplied PFN and
  1020.  * increment frame reference count.
  1021.  *
  1022.  * @param pfn Frame number of the frame to be freed.
  1023.  */
  1024. void frame_reference_add(pfn_t pfn)
  1025. {
  1026.     ipl_t ipl;
  1027.     zone_t *zone;
  1028.     frame_t *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.     frame = &zone->frames[pfn-zone->base];
  1039.     frame->refcount++;
  1040.    
  1041.     spinlock_unlock(&zone->lock);
  1042.     interrupts_restore(ipl);
  1043. }
  1044.  
  1045. /** Mark given range unavailable in frame zones */
  1046. void frame_mark_unavailable(pfn_t start, count_t count)
  1047. {
  1048.     unsigned int i;
  1049.     zone_t *zone;
  1050.     unsigned int prefzone = 0;
  1051.    
  1052.     for (i = 0; i < count; i++) {
  1053.         zone = find_zone_and_lock(start + i, &prefzone);
  1054.         if (!zone) /* PFN not found */
  1055.             continue;
  1056.         zone_mark_unavailable(zone, start + i - zone->base);
  1057.  
  1058.         spinlock_unlock(&zone->lock);
  1059.     }
  1060. }
  1061.  
  1062. /** Initialize physical memory management
  1063.  *
  1064.  * Initialize physical memory managemnt.
  1065.  */
  1066. void frame_init(void)
  1067. {
  1068.     if (config.cpu_active == 1) {
  1069.         zones.count = 0;
  1070.         spinlock_initialize(&zones.lock, "zones.lock");
  1071.     }
  1072.     /* Tell the architecture to create some memory */
  1073.     frame_arch_init();
  1074.     if (config.cpu_active == 1) {
  1075.         frame_mark_unavailable(ADDR2PFN(KA2PA(config.base)), SIZE2FRAMES(config.kernel_size));
  1076.         frame_mark_unavailable(ADDR2PFN(KA2PA(config.stack_base)), SIZE2FRAMES(config.stack_size));
  1077.        
  1078.         count_t i;
  1079.         for (i = 0; i < init.cnt; i++)
  1080.             frame_mark_unavailable(ADDR2PFN(KA2PA(init.tasks[i].addr)), SIZE2FRAMES(init.tasks[i].size));
  1081.  
  1082.         if (ballocs.size)
  1083.             frame_mark_unavailable(ADDR2PFN(KA2PA(ballocs.base)), SIZE2FRAMES(ballocs.size));
  1084.  
  1085.         /* Black list first frame, as allocating NULL would
  1086.          * fail in some places */
  1087.         frame_mark_unavailable(0, 1);
  1088.     }
  1089. }
  1090.  
  1091.  
  1092.  
  1093. /** Prints list of zones
  1094.  *
  1095.  */
  1096. void zone_print_list(void) {
  1097.     zone_t *zone = NULL;
  1098.     unsigned int i;
  1099.     ipl_t ipl;
  1100.  
  1101.     ipl = interrupts_disable();
  1102.     spinlock_lock(&zones.lock);
  1103.     printf("#  base address free frames  busy frames\n");
  1104.     printf("-- ------------ ------------ ------------\n");
  1105.     for (i = 0; i < zones.count; i++) {
  1106.         zone = zones.info[i];
  1107.         spinlock_lock(&zone->lock);
  1108.         printf("%-2d %12p %12zd %12zd\n", i, PFN2ADDR(zone->base), zone->free_count, zone->busy_count);
  1109.         spinlock_unlock(&zone->lock);
  1110.     }
  1111.     spinlock_unlock(&zones.lock);
  1112.     interrupts_restore(ipl);
  1113. }
  1114.  
  1115. /** Prints zone details.
  1116.  *
  1117.  * @param num Zone base address or zone number.
  1118.  */
  1119. void zone_print_one(unsigned int num) {
  1120.     zone_t *zone = NULL;
  1121.     ipl_t ipl;
  1122.     unsigned int i;
  1123.  
  1124.     ipl = interrupts_disable();
  1125.     spinlock_lock(&zones.lock);
  1126.  
  1127.     for (i = 0; i < zones.count; i++) {
  1128.         if (i == num || PFN2ADDR(zones.info[i]->base) == num) {
  1129.             zone = zones.info[i];
  1130.             break;
  1131.         }
  1132.     }
  1133.     if (!zone) {
  1134.         printf("Zone not found.\n");
  1135.         goto out;
  1136.     }
  1137.    
  1138.     spinlock_lock(&zone->lock);
  1139.     printf("Memory zone information\n");
  1140.     printf("Zone base address: %#.*p\n", sizeof(uintptr_t) * 2, PFN2ADDR(zone->base));
  1141.     printf("Zone size: %zd frames (%zdK)\n", zone->count, ((zone->count) * FRAME_SIZE) >> 10);
  1142.     printf("Allocated space: %zd frames (%zdK)\n", zone->busy_count, (zone->busy_count * FRAME_SIZE) >> 10);
  1143.     printf("Available space: %zd frames (%zdK)\n", zone->free_count, (zone->free_count * FRAME_SIZE) >> 10);
  1144.     buddy_system_structure_print(zone->buddy_system, FRAME_SIZE);
  1145.    
  1146.     spinlock_unlock(&zone->lock);
  1147. out:
  1148.     spinlock_unlock(&zones.lock);
  1149.     interrupts_restore(ipl);
  1150. }
  1151.  
  1152. /** @}
  1153.  */
  1154.