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