Subversion Repositories HelenOS

Rev

Rev 1568 | Rev 1700 | Go to most recent revision | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  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. /**
  31.  * @file    frame.c
  32.  * @brief   Physical frame allocator.
  33.  *
  34.  * This file contains the physical frame allocator and memory zone management.
  35.  * The frame allocator is built on top of the buddy allocator.
  36.  *
  37.  * @see buddy.c
  38.  */
  39.  
  40. /*
  41.  * Locking order
  42.  *
  43.  * In order to access particular zone, the process must first lock
  44.  * the zones.lock, then lock the zone and then unlock the zones.lock.
  45.  * This insures, that we can fiddle with the zones in runtime without
  46.  * affecting the processes.
  47.  *
  48.  */
  49.  
  50. #include <typedefs.h>
  51. #include <arch/types.h>
  52. #include <mm/frame.h>
  53. #include <mm/as.h>
  54. #include <panic.h>
  55. #include <debug.h>
  56. #include <adt/list.h>
  57. #include <synch/spinlock.h>
  58. #include <arch/asm.h>
  59. #include <arch.h>
  60. #include <print.h>
  61. #include <align.h>
  62. #include <mm/slab.h>
  63. #include <bitops.h>
  64. #include <macros.h>
  65.  
  66. typedef struct {
  67.     count_t refcount;   /**< tracking of shared frames  */
  68.     __u8 buddy_order;   /**< buddy system block order */
  69.     link_t buddy_link;  /**< link to the next free block inside one order */
  70.     void *parent;           /**< If allocated by slab, this points there */
  71. } frame_t;
  72.  
  73. typedef struct {
  74.     SPINLOCK_DECLARE(lock); /**< this lock protects everything below */
  75.     pfn_t base;     /**< frame_no of the first frame in the frames array */
  76.     count_t count;          /**< Size of zone */
  77.  
  78.     frame_t *frames;    /**< array of frame_t structures in this zone */
  79.     count_t free_count; /**< number of free frame_t structures */
  80.     count_t busy_count; /**< number of busy frame_t structures */
  81.    
  82.     buddy_system_t * buddy_system; /**< buddy system for the zone */
  83.     int flags;
  84. } zone_t;
  85.  
  86. /*
  87.  * The zoneinfo.lock must be locked when accessing zoneinfo structure.
  88.  * Some of the attributes in zone_t structures are 'read-only'
  89.  */
  90.  
  91. struct {
  92.     SPINLOCK_DECLARE(lock);
  93.     int count;
  94.     zone_t *info[ZONES_MAX];
  95. } zones;
  96.  
  97.  
  98. /*********************************/
  99. /* Helper functions */
  100. static inline index_t frame_index(zone_t *zone, frame_t *frame)
  101. {
  102.     return (index_t)(frame - zone->frames);
  103. }
  104. static inline index_t frame_index_abs(zone_t *zone, frame_t *frame)
  105. {
  106.     return (index_t)(frame - zone->frames) + zone->base;
  107. }
  108. static inline int frame_index_valid(zone_t *zone, index_t index)
  109. {
  110.     return index >= 0 && index < zone->count;
  111. }
  112.  
  113. /** Compute pfn_t from frame_t pointer & zone pointer */
  114. static index_t make_frame_index(zone_t *zone, frame_t *frame)
  115. {
  116.     return frame - zone->frames;
  117. }
  118.  
  119. /** Initialize frame structure
  120.  *
  121.  * Initialize frame structure.
  122.  *
  123.  * @param frame Frame structure to be initialized.
  124.  */
  125. static void frame_initialize(frame_t *frame)
  126. {
  127.     frame->refcount = 1;
  128.     frame->buddy_order = 0;
  129. }
  130.  
  131. /*************************************/
  132. /* Zoneinfo functions */
  133.  
  134. /**
  135.  * Insert-sort zone into zones list
  136.  *
  137.  * @param newzone New zone to be inserted into zone list
  138.  * @return zone number on success, -1 on error
  139.  */
  140. static int zones_add_zone(zone_t *newzone)
  141. {
  142.     int i,j;
  143.     ipl_t ipl;
  144.     zone_t *z;
  145.  
  146.     ipl = interrupts_disable();
  147.     spinlock_lock(&zones.lock);
  148.     /* Try to merge */
  149.     if (zones.count + 1 == ZONES_MAX)
  150.         panic("Maximum zone(%d) count exceeded.", ZONES_MAX);
  151.     for (i = 0; i < zones.count; i++) {
  152.         /* Check for overflow */
  153.         z = zones.info[i];
  154.         if (overlaps(newzone->base,newzone->count,
  155.                  z->base, z->count)) {
  156.             printf("Zones overlap!\n");
  157.             return -1;
  158.         }
  159.         if (newzone->base < z->base)
  160.             break;
  161.     }
  162.     /* Move other zones up */
  163.     for (j = i;j < zones.count; j++)
  164.         zones.info[j + 1] = zones.info[j];
  165.     zones.info[i] = newzone;
  166.     zones.count++;
  167.     spinlock_unlock(&zones.lock);
  168.     interrupts_restore(ipl);
  169.  
  170.     return i;
  171. }
  172.  
  173. /**
  174.  * Try to find a zone where can we find the frame
  175.  *
  176.  * @param frame Frame number contained in zone
  177.  * @param pzone If not null, it is used as zone hint. Zone index
  178.  *              is filled into the variable on success.
  179.  * @return Pointer to LOCKED zone containing frame
  180.  *
  181.  * Assume interrupts disable
  182.  */
  183. static zone_t * find_zone_and_lock(pfn_t frame, int *pzone)
  184. {
  185.     int i;
  186.     int hint = pzone ? *pzone : 0;
  187.     zone_t *z;
  188.    
  189.     spinlock_lock(&zones.lock);
  190.  
  191.     if (hint >= zones.count || hint < 0)
  192.         hint = 0;
  193.    
  194.     i = hint;
  195.     do {
  196.         z = zones.info[i];
  197.         spinlock_lock(&z->lock);
  198.         if (z->base <= frame && z->base + z->count > frame) {
  199.             spinlock_unlock(&zones.lock); /* Unlock the global lock */
  200.             if (pzone)
  201.                 *pzone = i;
  202.             return z;
  203.         }
  204.         spinlock_unlock(&z->lock);
  205.  
  206.         i++;
  207.         if (i >= zones.count)
  208.             i = 0;
  209.     } while(i != hint);
  210.  
  211.     spinlock_unlock(&zones.lock);
  212.     return NULL;
  213. }
  214.  
  215. /** @return True if zone can allocate specified order */
  216. static int zone_can_alloc(zone_t *z, __u8 order)
  217. {
  218.     return buddy_system_can_alloc(z->buddy_system, order);
  219. }
  220.  
  221. /**
  222.  * Find AND LOCK zone that can allocate order frames
  223.  *
  224.  * Assume interrupts are disabled!!
  225.  *
  226.  * @param order Size (2^order) of free space we are trying to find
  227.  * @param pzone Pointer to preferred zone or NULL, on return contains zone number
  228.  */
  229. static zone_t * find_free_zone_lock(__u8 order, int *pzone)
  230. {
  231.     int i;
  232.     zone_t *z;
  233.     int hint = pzone ? *pzone : 0;
  234.    
  235.     spinlock_lock(&zones.lock);
  236.     if (hint >= zones.count)
  237.         hint = 0;
  238.     i = hint;
  239.     do {
  240.         z = zones.info[i];
  241.        
  242.         spinlock_lock(&z->lock);
  243.  
  244.         /* Check if the zone has 2^order frames area available  */
  245.         if (zone_can_alloc(z, order)) {
  246.             spinlock_unlock(&zones.lock);
  247.             if (pzone)
  248.                 *pzone = i;
  249.             return z;
  250.         }
  251.         spinlock_unlock(&z->lock);
  252.         if (++i >= zones.count)
  253.             i = 0;
  254.     } while(i != hint);
  255.     spinlock_unlock(&zones.lock);
  256.     return NULL;
  257. }
  258.  
  259. /********************************************/
  260. /* Buddy system functions */
  261.  
  262. /** Buddy system find_block implementation
  263.  *
  264.  * Find block that is parent of current list.
  265.  * That means go to lower addresses, until such block is found
  266.  *
  267.  * @param order - Order of parent must be different then this parameter!!
  268.  */
  269. static link_t *zone_buddy_find_block(buddy_system_t *b, link_t *child,
  270.                      __u8 order)
  271. {
  272.     frame_t * frame;
  273.     zone_t * zone;
  274.     index_t index;
  275.    
  276.     frame = list_get_instance(child, frame_t, buddy_link);
  277.     zone = (zone_t *) b->data;
  278.  
  279.     index = frame_index(zone, frame);
  280.     do {
  281.         if (zone->frames[index].buddy_order != order) {
  282.             return &zone->frames[index].buddy_link;
  283.         }
  284.     } while(index-- > 0);
  285.     return NULL;
  286. }
  287.  
  288. static void zone_buddy_print_id(buddy_system_t *b, link_t *block)
  289. {
  290.     frame_t * frame;
  291.     zone_t * zone;
  292.     index_t index;
  293.  
  294.     frame = list_get_instance(block, frame_t, buddy_link);
  295.     zone = (zone_t *) b->data;
  296.     index = frame_index(zone, frame);
  297.     printf("%zd", index);
  298. }                    
  299.  
  300. /** Buddy system find_buddy implementation
  301.  *
  302.  * @param b Buddy system.
  303.  * @param block Block for which buddy should be found
  304.  *
  305.  * @return Buddy for given block if found
  306.  */
  307. static link_t * zone_buddy_find_buddy(buddy_system_t *b, link_t * block)
  308. {
  309.     frame_t * frame;
  310.     zone_t * zone;
  311.     index_t index;
  312.     bool is_left, is_right;
  313.  
  314.     frame = list_get_instance(block, frame_t, buddy_link);
  315.     zone = (zone_t *) b->data;
  316.     ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame), frame->buddy_order));
  317.    
  318.     is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);
  319.     is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);
  320.  
  321.     ASSERT(is_left ^ is_right);
  322.     if (is_left) {
  323.         index = (frame_index(zone, frame)) + (1 << frame->buddy_order);
  324.     } else { // if (is_right)
  325.         index = (frame_index(zone, frame)) - (1 << frame->buddy_order);
  326.     }
  327.    
  328.     if (frame_index_valid(zone, index)) {
  329.         if (zone->frames[index].buddy_order == frame->buddy_order &&
  330.             zone->frames[index].refcount == 0) {
  331.             return &zone->frames[index].buddy_link;
  332.         }
  333.     }
  334.  
  335.     return NULL;   
  336. }
  337.  
  338. /** Buddy system bisect implementation
  339.  *
  340.  * @param b Buddy system.
  341.  * @param block Block to bisect
  342.  *
  343.  * @return right block
  344.  */
  345. static link_t * zone_buddy_bisect(buddy_system_t *b, link_t * block) {
  346.     frame_t * frame_l, * frame_r;
  347.  
  348.     frame_l = list_get_instance(block, frame_t, buddy_link);
  349.     frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));
  350.    
  351.     return &frame_r->buddy_link;
  352. }
  353.  
  354. /** Buddy system coalesce implementation
  355.  *
  356.  * @param b Buddy system.
  357.  * @param block_1 First block
  358.  * @param block_2 First block's buddy
  359.  *
  360.  * @return Coalesced block (actually block that represents lower address)
  361.  */
  362. static link_t * zone_buddy_coalesce(buddy_system_t *b, link_t * block_1,
  363.                     link_t * block_2)
  364. {
  365.     frame_t *frame1, *frame2;
  366.    
  367.     frame1 = list_get_instance(block_1, frame_t, buddy_link);
  368.     frame2 = list_get_instance(block_2, frame_t, buddy_link);
  369.    
  370.     return frame1 < frame2 ? block_1 : block_2;
  371. }
  372.  
  373. /** Buddy system set_order implementation
  374.  *
  375.  * @param b Buddy system.
  376.  * @param block Buddy system block
  377.  * @param order Order to set
  378.  */
  379. static void zone_buddy_set_order(buddy_system_t *b, link_t * block, __u8 order) {
  380.     frame_t * frame;
  381.     frame = list_get_instance(block, frame_t, buddy_link);
  382.     frame->buddy_order = order;
  383. }
  384.  
  385. /** Buddy system get_order implementation
  386.  *
  387.  * @param b Buddy system.
  388.  * @param block Buddy system block
  389.  *
  390.  * @return Order of block
  391.  */
  392. static __u8 zone_buddy_get_order(buddy_system_t *b, link_t * block) {
  393.     frame_t * frame;
  394.     frame = list_get_instance(block, frame_t, buddy_link);
  395.     return frame->buddy_order;
  396. }
  397.  
  398. /** Buddy system mark_busy implementation
  399.  *
  400.  * @param b Buddy system
  401.  * @param block Buddy system block
  402.  *
  403.  */
  404. static void zone_buddy_mark_busy(buddy_system_t *b, link_t * block) {
  405.     frame_t * frame;
  406.  
  407.     frame = list_get_instance(block, frame_t, buddy_link);
  408.     frame->refcount = 1;
  409. }
  410.  
  411. /** Buddy system mark_available implementation
  412.  *
  413.  * @param b Buddy system
  414.  * @param block Buddy system block
  415.  *
  416.  */
  417. static void zone_buddy_mark_available(buddy_system_t *b, link_t * block) {
  418.     frame_t * frame;
  419.     frame = list_get_instance(block, frame_t, buddy_link);
  420.     frame->refcount = 0;
  421. }
  422.  
  423. static struct buddy_system_operations  zone_buddy_system_operations = {
  424.     .find_buddy = zone_buddy_find_buddy,
  425.     .bisect = zone_buddy_bisect,
  426.     .coalesce = zone_buddy_coalesce,
  427.     .set_order = zone_buddy_set_order,
  428.     .get_order = zone_buddy_get_order,
  429.     .mark_busy = zone_buddy_mark_busy,
  430.     .mark_available = zone_buddy_mark_available,
  431.     .find_block = zone_buddy_find_block,
  432.     .print_id = zone_buddy_print_id
  433. };
  434.  
  435. /*************************************/
  436. /* Zone functions */
  437.  
  438. /** Allocate frame in particular zone
  439.  *
  440.  * Assume zone is locked
  441.  * Panics if allocation is impossible.
  442.  *
  443.  * @param zone  Zone to allocate from.
  444.  * @param order Allocate exactly 2^order frames.
  445.  *
  446.  * @return Frame index in zone
  447.  *
  448.  */
  449. static pfn_t zone_frame_alloc(zone_t *zone, __u8 order)
  450. {
  451.     pfn_t v;
  452.     link_t *tmp;
  453.     frame_t *frame;
  454.  
  455.     /* Allocate frames from zone buddy system */
  456.     tmp = buddy_system_alloc(zone->buddy_system, order);
  457.    
  458.     ASSERT(tmp);
  459.    
  460.     /* Update zone information. */
  461.     zone->free_count -= (1 << order);
  462.     zone->busy_count += (1 << order);
  463.  
  464.     /* Frame will be actually a first frame of the block. */
  465.     frame = list_get_instance(tmp, frame_t, buddy_link);
  466.    
  467.     /* get frame address */
  468.     v = make_frame_index(zone, frame);
  469.     return v;
  470. }
  471.  
  472. /** Free frame from zone
  473.  *
  474.  * Assume zone is locked
  475.  *
  476.  * @param zone Pointer to zone from which the frame is to be freed
  477.  * @param frame_idx Frame index relative to zone
  478.  */
  479. static void zone_frame_free(zone_t *zone, index_t frame_idx)
  480. {
  481.     frame_t *frame;
  482.     __u8 order;
  483.  
  484.     frame = &zone->frames[frame_idx];
  485.    
  486.     /* remember frame order */
  487.     order = frame->buddy_order;
  488.  
  489.     ASSERT(frame->refcount);
  490.  
  491.     if (!--frame->refcount) {
  492.         buddy_system_free(zone->buddy_system, &frame->buddy_link);
  493.    
  494.         /* Update zone information. */
  495.         zone->free_count += (1 << order);
  496.         zone->busy_count -= (1 << order);
  497.     }
  498. }
  499.  
  500. /** Return frame from zone */
  501. static frame_t * zone_get_frame(zone_t *zone, index_t frame_idx)
  502. {
  503.     ASSERT(frame_idx < zone->count);
  504.     return &zone->frames[frame_idx];
  505. }
  506.  
  507. /** Mark frame in zone unavailable to allocation */
  508. static void zone_mark_unavailable(zone_t *zone, index_t frame_idx)
  509. {
  510.     frame_t *frame;
  511.     link_t *link;
  512.  
  513.     frame = zone_get_frame(zone, frame_idx);
  514.     if (frame->refcount)
  515.         return;
  516.     link = buddy_system_alloc_block(zone->buddy_system,
  517.                     &frame->buddy_link);
  518.     ASSERT(link);
  519.     zone->free_count--;
  520. }
  521.  
  522. /**
  523.  * Join 2 zones
  524.  *
  525.  * Expect zone_t *z to point to space at least zone_conf_size large
  526.  *
  527.  * Assume z1 & z2 are locked
  528.  *
  529.  * @param z Target zone structure pointer
  530.  * @param z1 Zone to merge
  531.  * @param z2 Zone to merge
  532.  */
  533.  
  534. static void _zone_merge(zone_t *z, zone_t *z1, zone_t *z2)
  535. {
  536.     __u8 max_order;
  537.     int i, z2idx;
  538.     pfn_t frame_idx;
  539.     frame_t *frame;
  540.  
  541.     ASSERT(!overlaps(z1->base,z1->count,z2->base,z2->count));
  542.     ASSERT(z1->base < z2->base);
  543.  
  544.     spinlock_initialize(&z->lock, "zone_lock");
  545.     z->base = z1->base;
  546.     z->count = z2->base+z2->count - z1->base;
  547.     z->flags = z1->flags & z2->flags;
  548.  
  549.     z->free_count = z1->free_count + z2->free_count;
  550.     z->busy_count = z1->busy_count + z2->busy_count;
  551.    
  552.     max_order = fnzb(z->count);
  553.  
  554.     z->buddy_system = (buddy_system_t *)&z[1];
  555.     buddy_system_create(z->buddy_system, max_order,
  556.                 &zone_buddy_system_operations,
  557.                 (void *) z);
  558.  
  559.     z->frames = (frame_t *)((void *)z->buddy_system+buddy_conf_size(max_order));
  560.     for (i = 0; i < z->count; i++) {
  561.         /* This marks all frames busy */
  562.         frame_initialize(&z->frames[i]);
  563.     }
  564.     /* Copy frames from both zones to preserve full frame orders,
  565.      * parents etc. Set all free frames with refcount=0 to 1, because
  566.      * we add all free frames to buddy allocator later again, clear
  567.      * order to 0. Don't set busy frames with refcount=0, as they
  568.      * will not be reallocated during merge and it would make later
  569.      * problems with allocation/free.
  570.      */
  571.     for (i=0; i<z1->count; i++)
  572.         z->frames[i] = z1->frames[i];
  573.     for (i=0; i < z2->count; i++) {
  574.         z2idx = i + (z2->base - z1->base);
  575.         z->frames[z2idx] = z2->frames[i];
  576.     }
  577.     i = 0;
  578.     while (i < z->count) {
  579.         if (z->frames[i].refcount) {
  580.             /* skip busy frames */
  581.             i += 1 << z->frames[i].buddy_order;
  582.         } else { /* Free frames, set refcount=1 */
  583.             /* All free frames have refcount=0, we need not
  584.              * to check the order */
  585.             z->frames[i].refcount = 1;
  586.             z->frames[i].buddy_order = 0;
  587.             i++;
  588.         }
  589.     }
  590.     /* Add free blocks from the 2 original zones */
  591.     while (zone_can_alloc(z1, 0)) {
  592.         frame_idx = zone_frame_alloc(z1, 0);
  593.         frame = &z->frames[frame_idx];
  594.         frame->refcount = 0;
  595.         buddy_system_free(z->buddy_system, &frame->buddy_link);
  596.     }
  597.     while (zone_can_alloc(z2, 0)) {
  598.         frame_idx = zone_frame_alloc(z2, 0);
  599.         frame = &z->frames[frame_idx + (z2->base-z1->base)];
  600.         frame->refcount = 0;
  601.         buddy_system_free(z->buddy_system, &frame->buddy_link);
  602.     }
  603. }
  604.  
  605. /** Return old configuration frames into the zone
  606.  *
  607.  * We have several cases
  608.  * - the conf. data is outside of zone -> exit, shall we call frame_free??
  609.  * - the conf. data was created by zone_create or
  610.  *   updated with reduce_region -> free every frame
  611.  *
  612.  * @param newzone The actual zone where freeing should occur
  613.  * @param oldzone Pointer to old zone configuration data that should
  614.  *                be freed from new zone
  615.  */
  616. static void return_config_frames(zone_t *newzone, zone_t *oldzone)
  617. {
  618.     pfn_t pfn;
  619.     frame_t *frame;
  620.     count_t cframes;
  621.     int i;
  622.  
  623.     pfn = ADDR2PFN((__address)KA2PA(oldzone));
  624.     cframes = SIZE2FRAMES(zone_conf_size(oldzone->count));
  625.    
  626.     if (pfn < newzone->base || pfn >= newzone->base + newzone->count)
  627.         return;
  628.  
  629.     frame = &newzone->frames[pfn - newzone->base];
  630.     ASSERT(!frame->buddy_order);
  631.  
  632.     for (i=0; i < cframes; i++) {
  633.         newzone->busy_count++;
  634.         zone_frame_free(newzone, pfn+i-newzone->base);
  635.     }
  636. }
  637.  
  638. /** Reduce allocated block to count of order 0 frames
  639.  *
  640.  * The allocated block need 2^order frames of space. Reduce all frames
  641.  * in block to order 0 and free the unneeded frames. This means, that
  642.  * when freeing the previously allocated block starting with frame_idx,
  643.  * you have to free every frame.
  644.  *
  645.  * @param zone
  646.  * @param frame_idx Index to block
  647.  * @param count Allocated space in block
  648.  */
  649. static void zone_reduce_region(zone_t *zone, pfn_t frame_idx, count_t count)
  650. {
  651.     count_t i;
  652.     __u8 order;
  653.     frame_t *frame;
  654.    
  655.     ASSERT(frame_idx+count < zone->count);
  656.  
  657.     order = zone->frames[frame_idx].buddy_order;
  658.     ASSERT((1 << order) >= count);
  659.  
  660.     /* Reduce all blocks to order 0 */
  661.     for (i=0; i < (1 << order); i++) {
  662.         frame = &zone->frames[i + frame_idx];
  663.         frame->buddy_order = 0;
  664.         if (! frame->refcount)
  665.             frame->refcount = 1;
  666.         ASSERT(frame->refcount == 1);
  667.     }
  668.     /* Free unneeded frames */
  669.     for (i=count; i < (1 << order); i++) {
  670.         zone_frame_free(zone, i + frame_idx);
  671.     }
  672. }
  673.  
  674. /** Merge zones z1 and z2
  675.  *
  676.  * - the zones must be 2 zones with no zone existing in between,
  677.  *   which means that z2 = z1+1
  678.  *
  679.  * - When you create a new zone, the frame allocator configuration does
  680.  *   not to be 2^order size. Once the allocator is running it is no longer
  681.  *   possible, merged configuration data occupies more space :-/
  682.  */
  683. void zone_merge(int z1, int z2)
  684. {
  685.     ipl_t ipl;
  686.     zone_t *zone1, *zone2, *newzone;
  687.     int cframes;
  688.     __u8 order;
  689.     int i;
  690.     pfn_t pfn;
  691.  
  692.     ipl = interrupts_disable();
  693.     spinlock_lock(&zones.lock);
  694.  
  695.     if (z1 < 0 || z1 >= zones.count || z2 < 0 || z2 >= zones.count)
  696.         goto errout;
  697.     /* We can join only 2 zones with none existing inbetween */
  698.     if (z2-z1 != 1)
  699.         goto errout;
  700.  
  701.     zone1 = zones.info[z1];
  702.     zone2 = zones.info[z2];
  703.     spinlock_lock(&zone1->lock);
  704.     spinlock_lock(&zone2->lock);
  705.  
  706.     cframes = SIZE2FRAMES(zone_conf_size(zone2->base+zone2->count-zone1->base));
  707.     order = fnzb(cframes) + 1;
  708.  
  709.     /* Allocate zonedata inside one of the zones */
  710.     if (zone_can_alloc(zone1, order))
  711.         pfn = zone1->base + zone_frame_alloc(zone1, order);
  712.     else if (zone_can_alloc(zone2, order))
  713.         pfn = zone2->base + zone_frame_alloc(zone2, order);
  714.     else
  715.         goto errout2;
  716.  
  717.     newzone = (zone_t *)PA2KA(PFN2ADDR(pfn));
  718.  
  719.     _zone_merge(newzone, zone1, zone2);
  720.  
  721.     /* Free unneeded config frames */
  722.     zone_reduce_region(newzone, pfn - newzone->base,  cframes);
  723.     /* Subtract zone information from busy frames */
  724.     newzone->busy_count -= cframes;
  725.  
  726.     /* Replace existing zones in zoneinfo list */
  727.     zones.info[z1] = newzone;
  728.     for (i = z2 + 1; i < zones.count; i++)
  729.         zones.info[i - 1] = zones.info[i];
  730.     zones.count--;
  731.  
  732.     /* Free old zone information */
  733.     return_config_frames(newzone, zone1);
  734.     return_config_frames(newzone, zone2);
  735. errout2:
  736.     /* Nobody is allowed to enter to zone, so we are safe
  737.      * to touch the spinlocks last time */
  738.     spinlock_unlock(&zone1->lock);
  739.     spinlock_unlock(&zone2->lock);
  740. errout:
  741.     spinlock_unlock(&zones.lock);
  742.     interrupts_restore(ipl);
  743. }
  744.  
  745. /**
  746.  * Merge all zones into one big zone
  747.  *
  748.  * It is reasonable to do this on systems whose bios reports parts in chunks,
  749.  * so that we could have 1 zone (it's faster).
  750.  */
  751. void zone_merge_all(void)
  752. {
  753.     int count = zones.count;
  754.  
  755.     while (zones.count > 1 && --count) {
  756.         zone_merge(0,1);
  757.         break;
  758.     }
  759. }
  760.  
  761. /** Create frame zone
  762.  *
  763.  * Create new frame zone.
  764.  *
  765.  * @param start Physical address of the first frame within the zone.
  766.  * @param count Count of frames in zone
  767.  * @param z Address of configuration information of zone
  768.  * @param flags Zone flags.
  769.  *
  770.  * @return Initialized zone.
  771.  */
  772. static void zone_construct(pfn_t start, count_t count, zone_t *z, int flags)
  773. {
  774.     int i;
  775.     __u8 max_order;
  776.  
  777.     spinlock_initialize(&z->lock, "zone_lock");
  778.     z->base = start;
  779.     z->count = count;
  780.     z->flags = flags;
  781.     z->free_count = count;
  782.     z->busy_count = 0;
  783.  
  784.     /*
  785.      * Compute order for buddy system, initialize
  786.      */
  787.     max_order = fnzb(count);
  788.     z->buddy_system = (buddy_system_t *)&z[1];
  789.    
  790.     buddy_system_create(z->buddy_system, max_order,
  791.                 &zone_buddy_system_operations,
  792.                 (void *) z);
  793.    
  794.     /* Allocate frames _after_ the conframe */
  795.     /* Check sizes */
  796.     z->frames = (frame_t *)((void *)z->buddy_system+buddy_conf_size(max_order));
  797.     for (i = 0; i<count; i++) {
  798.         frame_initialize(&z->frames[i]);
  799.     }
  800.    
  801.     /* Stuffing frames */
  802.     for (i = 0; i < count; i++) {
  803.         z->frames[i].refcount = 0;
  804.         buddy_system_free(z->buddy_system, &z->frames[i].buddy_link);
  805.     }
  806. }
  807.  
  808. /** Compute configuration data size for zone
  809.  *
  810.  * @param count Size of zone in frames
  811.  * @return Size of zone configuration info (in bytes)
  812.  */
  813. __address zone_conf_size(count_t count)
  814. {
  815.     int size = sizeof(zone_t) + count*sizeof(frame_t);
  816.     int max_order;
  817.  
  818.     max_order = fnzb(count);
  819.     size += buddy_conf_size(max_order);
  820.     return size;
  821. }
  822.  
  823. /** Create and add zone to system
  824.  *
  825.  * @param start First frame number (absolute)
  826.  * @param count Size of zone in frames
  827.  * @param confframe Where configuration frames are supposed to be.
  828.  *                  Automatically checks, that we will not disturb the
  829.  *                  kernel and possibly init.
  830.  *                  If confframe is given _outside_ this zone, it is expected,
  831.  *                  that the area is already marked BUSY and big enough
  832.  *                  to contain zone_conf_size() amount of data.
  833.  *                  If the confframe is inside the area, the zone free frame
  834.  *                  information is modified not to include it.
  835.  *
  836.  * @return Zone number or -1 on error
  837.  */
  838. int zone_create(pfn_t start, count_t count, pfn_t confframe, int flags)
  839. {
  840.     zone_t *z;
  841.     __address addr;
  842.     count_t confcount;
  843.     int i;
  844.     int znum;
  845.  
  846.     /* Theoretically we could have here 0, practically make sure
  847.      * nobody tries to do that. If some platform requires, remove
  848.      * the assert
  849.      */
  850.     ASSERT(confframe);
  851.     /* If conframe is supposed to be inside our zone, then make sure
  852.      * it does not span kernel & init
  853.      */
  854.     confcount = SIZE2FRAMES(zone_conf_size(count));
  855.     if (confframe >= start && confframe < start+count) {
  856.         for (;confframe < start + count; confframe++) {
  857.             addr = PFN2ADDR(confframe);
  858.             if (overlaps(addr, PFN2ADDR(confcount), KA2PA(config.base), config.kernel_size))
  859.                 continue;
  860.            
  861.             bool overlap = false;
  862.             count_t i;
  863.             for (i = 0; i < init.cnt; i++)
  864.                 if (overlaps(addr, PFN2ADDR(confcount), KA2PA(init.tasks[i].addr), init.tasks[i].size)) {
  865.                     overlap = true;
  866.                     break;
  867.                 }
  868.             if (overlap)
  869.                 continue;
  870.            
  871.             break;
  872.         }
  873.         if (confframe >= start + count)
  874.             panic("Cannot find configuration data for zone.");
  875.     }
  876.  
  877.     z = (zone_t *)PA2KA(PFN2ADDR(confframe));
  878.     zone_construct(start, count, z, flags);
  879.     znum = zones_add_zone(z);
  880.     if (znum == -1)
  881.         return -1;
  882.  
  883.     /* If confdata in zone, mark as unavailable */
  884.     if (confframe >= start && confframe < start+count)
  885.         for (i=confframe; i<confframe+confcount; i++) {
  886.             zone_mark_unavailable(z, i - z->base);
  887.         }
  888.     return znum;
  889. }
  890.  
  891. /***************************************/
  892. /* Frame functions */
  893.  
  894. /** Set parent of frame */
  895. void frame_set_parent(pfn_t pfn, void *data, int hint)
  896. {
  897.     zone_t *zone = find_zone_and_lock(pfn, &hint);
  898.  
  899.     ASSERT(zone);
  900.  
  901.     zone_get_frame(zone, pfn-zone->base)->parent = data;
  902.     spinlock_unlock(&zone->lock);
  903. }
  904.  
  905. void * frame_get_parent(pfn_t pfn, int hint)
  906. {
  907.     zone_t *zone = find_zone_and_lock(pfn, &hint);
  908.     void *res;
  909.  
  910.     ASSERT(zone);
  911.     res = zone_get_frame(zone, pfn - zone->base)->parent;
  912.    
  913.     spinlock_unlock(&zone->lock);
  914.     return res;
  915. }
  916.  
  917. /** Allocate power-of-two frames of physical memory.
  918.  *
  919.  * @param order  Allocate exactly 2^order frames.
  920.  * @param flags  Flags for host zone selection and address processing.
  921.  * @param status Allocation status (FRAME_OK on success), unused if NULL.
  922.  * @param pzone  Preferred zone
  923.  *
  924.  * @return Allocated frame.
  925.  *
  926.  */
  927. pfn_t frame_alloc_generic(__u8 order, int flags, int *status, int *pzone)
  928. {
  929.     ipl_t ipl;
  930.     int freed;
  931.     pfn_t v;
  932.     zone_t *zone;
  933.    
  934. loop:
  935.     ipl = interrupts_disable();
  936.    
  937.     /*
  938.      * First, find suitable frame zone.
  939.      */
  940.     zone = find_free_zone_lock(order, pzone);
  941.    
  942.     /* If no memory, reclaim some slab memory,
  943.        if it does not help, reclaim all */
  944.     if (!zone && !(flags & FRAME_NO_RECLAIM)) {
  945.         freed = slab_reclaim(0);
  946.         if (freed)
  947.             zone = find_free_zone_lock(order, pzone);
  948.         if (!zone) {
  949.             freed = slab_reclaim(SLAB_RECLAIM_ALL);
  950.             if (freed)
  951.                 zone = find_free_zone_lock(order, pzone);
  952.         }
  953.     }
  954.     if (!zone) {
  955.         if (flags & FRAME_PANIC)
  956.             panic("Can't allocate frame.\n");
  957.        
  958.         /*
  959.          * TODO: Sleep until frames are available again.
  960.          */
  961.         interrupts_restore(ipl);
  962.  
  963.         if (flags & FRAME_ATOMIC) {
  964.             ASSERT(status != NULL);
  965.             if (status)
  966.                 *status = FRAME_NO_MEMORY;
  967.             return NULL;
  968.         }
  969.        
  970.         panic("Sleep not implemented.\n");
  971.         goto loop;
  972.     }
  973.    
  974.     v = zone_frame_alloc(zone, order);
  975.     v += zone->base;
  976.  
  977.     spinlock_unlock(&zone->lock);
  978.     interrupts_restore(ipl);
  979.  
  980.     if (status)
  981.         *status = FRAME_OK;
  982.     return v;
  983. }
  984.  
  985. /** Free a frame.
  986.  *
  987.  * Find respective frame structure for supplied PFN.
  988.  * Decrement frame reference count.
  989.  * If it drops to zero, move the frame structure to free list.
  990.  *
  991.  * @param frame Frame number to be freed.
  992.  */
  993. void frame_free(pfn_t pfn)
  994. {
  995.     ipl_t ipl;
  996.     zone_t *zone;
  997.  
  998.     ipl = interrupts_disable();
  999.    
  1000.     /*
  1001.      * First, find host frame zone for addr.
  1002.      */
  1003.     zone = find_zone_and_lock(pfn,NULL);
  1004.     ASSERT(zone);
  1005.    
  1006.     zone_frame_free(zone, pfn-zone->base);
  1007.    
  1008.     spinlock_unlock(&zone->lock);
  1009.     interrupts_restore(ipl);
  1010. }
  1011.  
  1012. /** Add reference to frame.
  1013.  *
  1014.  * Find respective frame structure for supplied PFN and
  1015.  * increment frame reference count.
  1016.  *
  1017.  * @param frame Frame no to be freed.
  1018.  */
  1019. void frame_reference_add(pfn_t pfn)
  1020. {
  1021.     ipl_t ipl;
  1022.     zone_t *zone;
  1023.     frame_t *frame;
  1024.  
  1025.     ipl = interrupts_disable();
  1026.    
  1027.     /*
  1028.      * First, find host frame zone for addr.
  1029.      */
  1030.     zone = find_zone_and_lock(pfn,NULL);
  1031.     ASSERT(zone);
  1032.    
  1033.     frame = &zone->frames[pfn-zone->base];
  1034.     frame->refcount++;
  1035.    
  1036.     spinlock_unlock(&zone->lock);
  1037.     interrupts_restore(ipl);
  1038. }
  1039.  
  1040. /** Mark given range unavailable in frame zones */
  1041. void frame_mark_unavailable(pfn_t start, count_t count)
  1042. {
  1043.     int i;
  1044.     zone_t *zone;
  1045.     int prefzone = 0;
  1046.    
  1047.     for (i=0; i < count; i++) {
  1048.         zone = find_zone_and_lock(start+i,&prefzone);
  1049.         if (!zone) /* PFN not found */
  1050.             continue;
  1051.         zone_mark_unavailable(zone, start+i-zone->base);
  1052.  
  1053.         spinlock_unlock(&zone->lock);
  1054.     }
  1055. }
  1056.  
  1057. /** Initialize physical memory management
  1058.  *
  1059.  * Initialize physical memory managemnt.
  1060.  */
  1061. void frame_init(void)
  1062. {
  1063.     if (config.cpu_active == 1) {
  1064.         zones.count = 0;
  1065.         spinlock_initialize(&zones.lock,"zones_glob_lock");
  1066.     }
  1067.     /* Tell the architecture to create some memory */
  1068.     frame_arch_init();
  1069.     if (config.cpu_active == 1) {
  1070.         pfn_t firstframe = ADDR2PFN(KA2PA(config.base));
  1071.         pfn_t lastframe = ADDR2PFN(KA2PA(config.base+config.kernel_size));
  1072.         frame_mark_unavailable(firstframe,lastframe-firstframe+1);
  1073.        
  1074.         count_t i;
  1075.         for (i = 0; i < init.cnt; i++)
  1076.             frame_mark_unavailable(ADDR2PFN(KA2PA(init.tasks[i].addr)), SIZE2FRAMES(init.tasks[i].size));
  1077.  
  1078.         /* Black list first frame, as allocating NULL would
  1079.          * fail on some places */
  1080.         frame_mark_unavailable(0, 1);
  1081.     }
  1082. }
  1083.  
  1084.  
  1085.  
  1086. /** Prints list of zones
  1087.  *
  1088.  */
  1089. void zone_print_list(void) {
  1090.     zone_t *zone = NULL;
  1091.     int i;
  1092.     ipl_t ipl;
  1093.  
  1094.     ipl = interrupts_disable();
  1095.     spinlock_lock(&zones.lock);
  1096.     printf("#  Base address\tFree Frames\tBusy Frames\n");
  1097.     printf("   ------------\t-----------\t-----------\n");
  1098.     for (i = 0; i < zones.count; i++) {
  1099.         zone = zones.info[i];
  1100.         spinlock_lock(&zone->lock);
  1101.         printf("%d: %.*p \t%10zd\t%10zd\n", i, sizeof(__address) * 2, PFN2ADDR(zone->base), zone->free_count, zone->busy_count);
  1102.         spinlock_unlock(&zone->lock);
  1103.     }
  1104.     spinlock_unlock(&zones.lock);
  1105.     interrupts_restore(ipl);
  1106. }
  1107.  
  1108. /** Prints zone details
  1109.  *
  1110.  * @param base Zone base address OR zone number
  1111.  */
  1112. void zone_print_one(int num) {
  1113.     zone_t *zone = NULL;
  1114.     ipl_t ipl;
  1115.     int i;
  1116.  
  1117.     ipl = interrupts_disable();
  1118.     spinlock_lock(&zones.lock);
  1119.  
  1120.     for (i = 0; i < zones.count; i++) {
  1121.         if (i == num || PFN2ADDR(zones.info[i]->base) == num) {
  1122.             zone = zones.info[i];
  1123.             break;
  1124.         }
  1125.     }
  1126.     if (!zone) {
  1127.         printf("Zone not found.\n");
  1128.         goto out;
  1129.     }
  1130.    
  1131.     spinlock_lock(&zone->lock);
  1132.     printf("Memory zone information\n");
  1133.     printf("Zone base address: %#.*p\n", sizeof(__address) * 2, PFN2ADDR(zone->base));
  1134.     printf("Zone size: %zd frames (%zdK)\n", zone->count, ((zone->count) * FRAME_SIZE) >> 10);
  1135.     printf("Allocated space: %zd frames (%zdK)\n", zone->busy_count, (zone->busy_count * FRAME_SIZE) >> 10);
  1136.     printf("Available space: %zd (%zdK)\n", zone->free_count, (zone->free_count * FRAME_SIZE) >> 10);
  1137.     buddy_system_structure_print(zone->buddy_system, FRAME_SIZE);
  1138.    
  1139.     spinlock_unlock(&zone->lock);
  1140. out:
  1141.     spinlock_unlock(&zones.lock);
  1142.     interrupts_restore(ipl);
  1143. }
  1144.  
  1145.