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