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