Subversion Repositories HelenOS

Rev

Rev 2128 | Rev 2725 | 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. /** @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. #include <config.h>
  69.  
  70. typedef struct {
  71.     count_t refcount;   /**< tracking of shared frames  */
  72.     uint8_t buddy_order;    /**< buddy system block order */
  73.     link_t buddy_link;  /**< link to the next free block inside one
  74.                      order */
  75.     void *parent;           /**< If allocated by slab, this points there */
  76. } frame_t;
  77.  
  78. typedef struct {
  79.     SPINLOCK_DECLARE(lock); /**< this lock protects everything below */
  80.     pfn_t base;     /**< frame_no of the first frame in the frames
  81.                      array */
  82.     count_t count;          /**< Size of zone */
  83.  
  84.     frame_t *frames;    /**< array of frame_t structures in this
  85.                      zone */
  86.     count_t free_count; /**< number of free frame_t structures */
  87.     count_t busy_count; /**< number of busy frame_t structures */
  88.    
  89.     buddy_system_t *buddy_system; /**< buddy system for the zone */
  90.     int flags;
  91. } zone_t;
  92.  
  93. /*
  94.  * The zoneinfo.lock must be locked when accessing zoneinfo structure.
  95.  * Some of the attributes in zone_t structures are 'read-only'
  96.  */
  97.  
  98. typedef struct {
  99.     SPINLOCK_DECLARE(lock);
  100.     unsigned int count;
  101.     zone_t *info[ZONES_MAX];
  102. } zones_t;
  103.  
  104. static zones_t zones;
  105.  
  106.  
  107. /*********************************/
  108. /* Helper functions */
  109. static inline index_t frame_index(zone_t *zone, frame_t *frame)
  110. {
  111.     return (index_t)(frame - zone->frames);
  112. }
  113. static inline index_t frame_index_abs(zone_t *zone, frame_t *frame)
  114. {
  115.     return (index_t)(frame - zone->frames) + zone->base;
  116. }
  117. static inline int frame_index_valid(zone_t *zone, index_t index)
  118. {
  119.     return index >= 0 && index < zone->count;
  120. }
  121.  
  122. /** Compute pfn_t from frame_t pointer & zone pointer */
  123. static index_t make_frame_index(zone_t *zone, frame_t *frame)
  124. {
  125.     return frame - zone->frames;
  126. }
  127.  
  128. /** Initialize frame structure
  129.  *
  130.  * Initialize frame structure.
  131.  *
  132.  * @param frame Frame structure to be initialized.
  133.  */
  134. static void frame_initialize(frame_t *frame)
  135. {
  136.     frame->refcount = 1;
  137.     frame->buddy_order = 0;
  138. }
  139.  
  140. /*************************************/
  141. /* Zoneinfo functions */
  142.  
  143. /**
  144.  * Insert-sort zone into zones list
  145.  *
  146.  * @param newzone New zone to be inserted into zone list
  147.  * @return zone number on success, -1 on error
  148.  */
  149. static int zones_add_zone(zone_t *newzone)
  150. {
  151.     unsigned int i, j;
  152.     ipl_t ipl;
  153.     zone_t *z;
  154.  
  155.     ipl = interrupts_disable();
  156.     spinlock_lock(&zones.lock);
  157.     /* Try to merge */
  158.     if (zones.count + 1 == ZONES_MAX)
  159.         panic("Maximum zone(%d) count exceeded.", ZONES_MAX);
  160.     for (i = 0; i < zones.count; i++) {
  161.         /* Check for overflow */
  162.         z = zones.info[i];
  163.         if (overlaps(newzone->base,newzone->count, z->base,
  164.             z->count)) {
  165.             printf("Zones overlap!\n");
  166.             return -1;
  167.         }
  168.         if (newzone->base < z->base)
  169.             break;
  170.     }
  171.     /* Move other zones up */
  172.     for (j = i; j < zones.count; j++)
  173.         zones.info[j + 1] = zones.info[j];
  174.     zones.info[i] = newzone;
  175.     zones.count++;
  176.     spinlock_unlock(&zones.lock);
  177.     interrupts_restore(ipl);
  178.  
  179.     return i;
  180. }
  181.  
  182. /**
  183.  * Try to find a zone where can we find the frame
  184.  
  185.  * Assume interrupts are disabled.
  186.  
  187.  * @param frame Frame number contained in zone
  188.  * @param pzone If not null, it is used as zone hint. Zone index
  189.  *              is filled into the variable on success.
  190.  * @return Pointer to locked zone containing frame
  191.  */
  192. static zone_t * find_zone_and_lock(pfn_t frame, unsigned int *pzone)
  193. {
  194.     unsigned int i;
  195.     unsigned int hint = pzone ? *pzone : 0;
  196.     zone_t *z;
  197.    
  198.     spinlock_lock(&zones.lock);
  199.  
  200.     if (hint >= zones.count || hint < 0)
  201.         hint = 0;
  202.    
  203.     i = hint;
  204.     do {
  205.         z = zones.info[i];
  206.         spinlock_lock(&z->lock);
  207.         if (z->base <= frame && z->base + z->count > frame) {
  208.             /* Unlock the global lock */
  209.             spinlock_unlock(&zones.lock);
  210.             if (pzone)
  211.                 *pzone = i;
  212.             return z;
  213.         }
  214.         spinlock_unlock(&z->lock);
  215.  
  216.         i++;
  217.         if (i >= zones.count)
  218.             i = 0;
  219.     } while(i != hint);
  220.  
  221.     spinlock_unlock(&zones.lock);
  222.     return NULL;
  223. }
  224.  
  225. /** @return True if zone can allocate specified order */
  226. static int zone_can_alloc(zone_t *z, uint8_t order)
  227. {
  228.     return buddy_system_can_alloc(z->buddy_system, order);
  229. }
  230.  
  231. /** Find and lock zone that can allocate order frames.
  232.  *
  233.  * Assume interrupts are disabled.
  234.  *
  235.  * @param order Size (2^order) of free space we are trying to find
  236.  * @param pzone Pointer to preferred zone or NULL, on return contains zone
  237.  *      number
  238.  */
  239. static zone_t * find_free_zone_and_lock(uint8_t order, unsigned int *pzone)
  240. {
  241.     unsigned int i;
  242.     zone_t *z;
  243.     unsigned int hint = pzone ? *pzone : 0;
  244.    
  245.     spinlock_lock(&zones.lock);
  246.     if (hint >= zones.count)
  247.         hint = 0;
  248.     i = hint;
  249.     do {
  250.         z = zones.info[i];
  251.        
  252.         spinlock_lock(&z->lock);
  253.  
  254.         /* Check if the zone has 2^order frames area available  */
  255.         if (zone_can_alloc(z, order)) {
  256.             spinlock_unlock(&zones.lock);
  257.             if (pzone)
  258.                 *pzone = i;
  259.             return z;
  260.         }
  261.         spinlock_unlock(&z->lock);
  262.         if (++i >= zones.count)
  263.             i = 0;
  264.     } while(i != hint);
  265.     spinlock_unlock(&zones.lock);
  266.     return NULL;
  267. }
  268.  
  269. /**************************/
  270. /* Buddy system functions */
  271. /**************************/
  272.  
  273. /** Buddy system find_block implementation
  274.  *
  275.  * Find block that is parent of current list.
  276.  * That means go to lower addresses, until such block is found
  277.  *
  278.  * @param order - Order of parent must be different then this parameter!!
  279.  */
  280. static link_t *zone_buddy_find_block(buddy_system_t *b, link_t *child,
  281.     uint8_t order)
  282. {
  283.     frame_t *frame;
  284.     zone_t *zone;
  285.     index_t index;
  286.    
  287.     frame = list_get_instance(child, frame_t, buddy_link);
  288.     zone = (zone_t *) b->data;
  289.  
  290.     index = frame_index(zone, frame);
  291.     do {
  292.         if (zone->frames[index].buddy_order != order) {
  293.             return &zone->frames[index].buddy_link;
  294.         }
  295.     } while(index-- > 0);
  296.     return NULL;
  297. }
  298.  
  299. static void zone_buddy_print_id(buddy_system_t *b, link_t *block)
  300. {
  301.     frame_t *frame;
  302.     zone_t *zone;
  303.     index_t index;
  304.  
  305.     frame = list_get_instance(block, frame_t, buddy_link);
  306.     zone = (zone_t *) b->data;
  307.     index = frame_index(zone, frame);
  308.     printf("%zd", index);
  309. }                    
  310.  
  311. /** Buddy system find_buddy implementation
  312.  *
  313.  * @param b Buddy system.
  314.  * @param block Block for which buddy should be found
  315.  *
  316.  * @return Buddy for given block if found
  317.  */
  318. static link_t *zone_buddy_find_buddy(buddy_system_t *b, link_t *block)
  319. {
  320.     frame_t *frame;
  321.     zone_t *zone;
  322.     index_t index;
  323.     bool is_left, is_right;
  324.  
  325.     frame = list_get_instance(block, frame_t, buddy_link);
  326.     zone = (zone_t *) b->data;
  327.     ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame),
  328.         frame->buddy_order));
  329.    
  330.     is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);
  331.     is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);
  332.  
  333.     ASSERT(is_left ^ is_right);
  334.     if (is_left) {
  335.         index = (frame_index(zone, frame)) + (1 << frame->buddy_order);
  336.     } else {    /* if (is_right) */
  337.         index = (frame_index(zone, frame)) - (1 << frame->buddy_order);
  338.     }
  339.    
  340.     if (frame_index_valid(zone, index)) {
  341.         if (zone->frames[index].buddy_order == frame->buddy_order &&
  342.             zone->frames[index].refcount == 0) {
  343.             return &zone->frames[index].buddy_link;
  344.         }
  345.     }
  346.  
  347.     return NULL;   
  348. }
  349.  
  350. /** Buddy system bisect implementation
  351.  *
  352.  * @param b Buddy system.
  353.  * @param block Block to bisect
  354.  *
  355.  * @return right block
  356.  */
  357. static link_t * zone_buddy_bisect(buddy_system_t *b, link_t *block) {
  358.     frame_t *frame_l, *frame_r;
  359.  
  360.     frame_l = list_get_instance(block, frame_t, buddy_link);
  361.     frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));
  362.    
  363.     return &frame_r->buddy_link;
  364. }
  365.  
  366. /** Buddy system coalesce implementation
  367.  *
  368.  * @param b Buddy system.
  369.  * @param block_1 First block
  370.  * @param block_2 First block's buddy
  371.  *
  372.  * @return Coalesced block (actually block that represents lower address)
  373.  */
  374. static link_t *zone_buddy_coalesce(buddy_system_t *b, link_t *block_1,
  375.     link_t *block_2)
  376. {
  377.     frame_t *frame1, *frame2;
  378.    
  379.     frame1 = list_get_instance(block_1, frame_t, buddy_link);
  380.     frame2 = list_get_instance(block_2, frame_t, buddy_link);
  381.    
  382.     return frame1 < frame2 ? block_1 : block_2;
  383. }
  384.  
  385. /** Buddy system set_order implementation
  386.  *
  387.  * @param b Buddy system.
  388.  * @param block Buddy system block
  389.  * @param order Order to set
  390.  */
  391. static void zone_buddy_set_order(buddy_system_t *b, link_t *block,
  392.     uint8_t order) {
  393.     frame_t *frame;
  394.     frame = list_get_instance(block, frame_t, buddy_link);
  395.     frame->buddy_order = order;
  396. }
  397.  
  398. /** Buddy system get_order implementation
  399.  *
  400.  * @param b Buddy system.
  401.  * @param block Buddy system block
  402.  *
  403.  * @return Order of block
  404.  */
  405. static uint8_t zone_buddy_get_order(buddy_system_t *b, link_t *block) {
  406.     frame_t *frame;
  407.     frame = list_get_instance(block, frame_t, buddy_link);
  408.     return frame->buddy_order;
  409. }
  410.  
  411. /** Buddy system mark_busy implementation
  412.  *
  413.  * @param b Buddy system
  414.  * @param block Buddy system block
  415.  *
  416.  */
  417. static void zone_buddy_mark_busy(buddy_system_t *b, link_t * block) {
  418.     frame_t * frame;
  419.  
  420.     frame = list_get_instance(block, frame_t, buddy_link);
  421.     frame->refcount = 1;
  422. }
  423.  
  424. /** Buddy system mark_available implementation
  425.  *
  426.  * @param b Buddy system
  427.  * @param block Buddy system block
  428.  *
  429.  */
  430. static void zone_buddy_mark_available(buddy_system_t *b, link_t *block) {
  431.     frame_t *frame;
  432.     frame = list_get_instance(block, frame_t, buddy_link);
  433.     frame->refcount = 0;
  434. }
  435.  
  436. static buddy_system_operations_t zone_buddy_system_operations = {
  437.     .find_buddy = zone_buddy_find_buddy,
  438.     .bisect = zone_buddy_bisect,
  439.     .coalesce = zone_buddy_coalesce,
  440.     .set_order = zone_buddy_set_order,
  441.     .get_order = zone_buddy_get_order,
  442.     .mark_busy = zone_buddy_mark_busy,
  443.     .mark_available = zone_buddy_mark_available,
  444.     .find_block = zone_buddy_find_block,
  445.     .print_id = zone_buddy_print_id
  446. };
  447.  
  448. /******************/
  449. /* Zone functions */
  450. /******************/
  451.  
  452. /** Allocate frame in particular zone
  453.  *
  454.  * Assume zone is locked
  455.  * Panics if allocation is impossible.
  456.  *
  457.  * @param zone  Zone to allocate from.
  458.  * @param order Allocate exactly 2^order frames.
  459.  *
  460.  * @return Frame index in zone
  461.  *
  462.  */
  463. static pfn_t zone_frame_alloc(zone_t *zone, uint8_t order)
  464. {
  465.     pfn_t v;
  466.     link_t *tmp;
  467.     frame_t *frame;
  468.  
  469.     /* Allocate frames from zone buddy system */
  470.     tmp = buddy_system_alloc(zone->buddy_system, order);
  471.    
  472.     ASSERT(tmp);
  473.    
  474.     /* Update zone information. */
  475.     zone->free_count -= (1 << order);
  476.     zone->busy_count += (1 << order);
  477.  
  478.     /* Frame will be actually a first frame of the block. */
  479.     frame = list_get_instance(tmp, frame_t, buddy_link);
  480.    
  481.     /* get frame address */
  482.     v = make_frame_index(zone, frame);
  483.     return v;
  484. }
  485.  
  486. /** Free frame from zone
  487.  *
  488.  * Assume zone is locked
  489.  *
  490.  * @param zone Pointer to zone from which the frame is to be freed
  491.  * @param frame_idx Frame index relative to zone
  492.  */
  493. static void zone_frame_free(zone_t *zone, index_t frame_idx)
  494. {
  495.     frame_t *frame;
  496.     uint8_t order;
  497.  
  498.     frame = &zone->frames[frame_idx];
  499.    
  500.     /* remember frame order */
  501.     order = frame->buddy_order;
  502.  
  503.     ASSERT(frame->refcount);
  504.  
  505.     if (!--frame->refcount) {
  506.         buddy_system_free(zone->buddy_system, &frame->buddy_link);
  507.    
  508.         /* Update zone information. */
  509.         zone->free_count += (1 << order);
  510.         zone->busy_count -= (1 << order);
  511.     }
  512. }
  513.  
  514. /** Return frame from zone */
  515. static frame_t * zone_get_frame(zone_t *zone, index_t frame_idx)
  516. {
  517.     ASSERT(frame_idx < zone->count);
  518.     return &zone->frames[frame_idx];
  519. }
  520.  
  521. /** Mark frame in zone unavailable to allocation */
  522. static void zone_mark_unavailable(zone_t *zone, index_t frame_idx)
  523. {
  524.     frame_t *frame;
  525.     link_t *link;
  526.  
  527.     frame = zone_get_frame(zone, frame_idx);
  528.     if (frame->refcount)
  529.         return;
  530.     link = buddy_system_alloc_block(zone->buddy_system,
  531.         &frame->buddy_link);
  532.     ASSERT(link);
  533.     zone->free_count--;
  534. }
  535.  
  536. /**
  537.  * Join 2 zones
  538.  *
  539.  * Expect zone_t *z to point to space at least zone_conf_size large
  540.  *
  541.  * Assume z1 & z2 are locked
  542.  *
  543.  * @param z Target zone structure pointer
  544.  * @param z1 Zone to merge
  545.  * @param z2 Zone to merge
  546.  */
  547. static void _zone_merge(zone_t *z, zone_t *z1, zone_t *z2)
  548. {
  549.     uint8_t max_order;
  550.     unsigned int i;
  551.     int z2idx;
  552.     pfn_t frame_idx;
  553.     frame_t *frame;
  554.  
  555.     ASSERT(!overlaps(z1->base, z1->count, z2->base, z2->count));
  556.     ASSERT(z1->base < z2->base);
  557.  
  558.     spinlock_initialize(&z->lock, "zone_lock");
  559.     z->base = z1->base;
  560.     z->count = z2->base + z2->count - z1->base;
  561.     z->flags = z1->flags & z2->flags;
  562.  
  563.     z->free_count = z1->free_count + z2->free_count;
  564.     z->busy_count = z1->busy_count + z2->busy_count;
  565.    
  566.     max_order = fnzb(z->count);
  567.  
  568.     z->buddy_system = (buddy_system_t *) &z[1];
  569.     buddy_system_create(z->buddy_system, max_order,
  570.         &zone_buddy_system_operations, (void *) z);
  571.  
  572.     z->frames = (frame_t *)((uint8_t *) z->buddy_system +
  573.         buddy_conf_size(max_order));
  574.     for (i = 0; i < z->count; i++) {
  575.         /* This marks all frames busy */
  576.         frame_initialize(&z->frames[i]);
  577.     }
  578.     /* Copy frames from both zones to preserve full frame orders,
  579.      * parents etc. Set all free frames with refcount=0 to 1, because
  580.      * we add all free frames to buddy allocator later again, clear
  581.      * order to 0. Don't set busy frames with refcount=0, as they
  582.      * will not be reallocated during merge and it would make later
  583.      * problems with allocation/free.
  584.      */
  585.     for (i = 0; i < z1->count; i++)
  586.         z->frames[i] = z1->frames[i];
  587.     for (i = 0; i < z2->count; i++) {
  588.         z2idx = i + (z2->base - z1->base);
  589.         z->frames[z2idx] = z2->frames[i];
  590.     }
  591.     i = 0;
  592.     while (i < z->count) {
  593.         if (z->frames[i].refcount) {
  594.             /* skip busy frames */
  595.             i += 1 << z->frames[i].buddy_order;
  596.         } else { /* Free frames, set refcount=1 */
  597.             /* All free frames have refcount=0, we need not
  598.              * to check the order */
  599.             z->frames[i].refcount = 1;
  600.             z->frames[i].buddy_order = 0;
  601.             i++;
  602.         }
  603.     }
  604.     /* Add free blocks from the 2 original zones */
  605.     while (zone_can_alloc(z1, 0)) {
  606.         frame_idx = zone_frame_alloc(z1, 0);
  607.         frame = &z->frames[frame_idx];
  608.         frame->refcount = 0;
  609.         buddy_system_free(z->buddy_system, &frame->buddy_link);
  610.     }
  611.     while (zone_can_alloc(z2, 0)) {
  612.         frame_idx = zone_frame_alloc(z2, 0);
  613.         frame = &z->frames[frame_idx + (z2->base - z1->base)];
  614.         frame->refcount = 0;
  615.         buddy_system_free(z->buddy_system, &frame->buddy_link);
  616.     }
  617. }
  618.  
  619. /** Return old configuration frames into the zone
  620.  *
  621.  * We have several cases
  622.  * - the conf. data is outside of zone -> exit, shall we call frame_free??
  623.  * - the conf. data was created by zone_create or
  624.  *   updated with reduce_region -> free every frame
  625.  *
  626.  * @param newzone The actual zone where freeing should occur
  627.  * @param oldzone Pointer to old zone configuration data that should
  628.  *                be freed from new zone
  629.  */
  630. static void return_config_frames(zone_t *newzone, zone_t *oldzone)
  631. {
  632.     pfn_t pfn;
  633.     frame_t *frame;
  634.     count_t cframes;
  635.     unsigned int i;
  636.  
  637.     pfn = ADDR2PFN((uintptr_t)KA2PA(oldzone));
  638.     cframes = SIZE2FRAMES(zone_conf_size(oldzone->count));
  639.    
  640.     if (pfn < newzone->base || pfn >= newzone->base + newzone->count)
  641.         return;
  642.  
  643.     frame = &newzone->frames[pfn - newzone->base];
  644.     ASSERT(!frame->buddy_order);
  645.  
  646.     for (i = 0; i < cframes; i++) {
  647.         newzone->busy_count++;
  648.         zone_frame_free(newzone, pfn+i-newzone->base);
  649.     }
  650. }
  651.  
  652. /** Reduce allocated block to count of order 0 frames
  653.  *
  654.  * The allocated block need 2^order frames of space. Reduce all frames
  655.  * in block to order 0 and free the unneeded frames. This means, that
  656.  * when freeing the previously allocated block starting with frame_idx,
  657.  * you have to free every frame.
  658.  *
  659.  * @param zone
  660.  * @param frame_idx Index to block
  661.  * @param count Allocated space in block
  662.  */
  663. static void zone_reduce_region(zone_t *zone, pfn_t frame_idx, count_t count)
  664. {
  665.     count_t i;
  666.     uint8_t order;
  667.     frame_t *frame;
  668.    
  669.     ASSERT(frame_idx + count < zone->count);
  670.  
  671.     order = zone->frames[frame_idx].buddy_order;
  672.     ASSERT((count_t) (1 << order) >= count);
  673.  
  674.     /* Reduce all blocks to order 0 */
  675.     for (i = 0; i < (count_t) (1 << order); i++) {
  676.         frame = &zone->frames[i + frame_idx];
  677.         frame->buddy_order = 0;
  678.         if (!frame->refcount)
  679.             frame->refcount = 1;
  680.         ASSERT(frame->refcount == 1);
  681.     }
  682.     /* Free unneeded frames */
  683.     for (i = count; i < (count_t) (1 << order); i++) {
  684.         zone_frame_free(zone, i + frame_idx);
  685.     }
  686. }
  687.  
  688. /** Merge zones z1 and z2
  689.  *
  690.  * - the zones must be 2 zones with no zone existing in between,
  691.  *   which means that z2 = z1+1
  692.  *
  693.  * - When you create a new zone, the frame allocator configuration does
  694.  *   not to be 2^order size. Once the allocator is running it is no longer
  695.  *   possible, merged configuration data occupies more space :-/
  696.  */
  697. void zone_merge(unsigned int z1, unsigned int z2)
  698. {
  699.     ipl_t ipl;
  700.     zone_t *zone1, *zone2, *newzone;
  701.     unsigned int cframes;
  702.     uint8_t order;
  703.     unsigned int i;
  704.     pfn_t pfn;
  705.  
  706.     ipl = interrupts_disable();
  707.     spinlock_lock(&zones.lock);
  708.  
  709.     if (z1 < 0 || z1 >= zones.count || z2 < 0 || z2 >= zones.count)
  710.         goto errout;
  711.     /* We can join only 2 zones with none existing inbetween */
  712.     if (z2-z1 != 1)
  713.         goto errout;
  714.  
  715.     zone1 = zones.info[z1];
  716.     zone2 = zones.info[z2];
  717.     spinlock_lock(&zone1->lock);
  718.     spinlock_lock(&zone2->lock);
  719.  
  720.     cframes = SIZE2FRAMES(zone_conf_size(zone2->base + zone2->count -
  721.         zone1->base));
  722.     if (cframes == 1)
  723.         order = 0;
  724.     else
  725.         order = fnzb(cframes - 1) + 1;
  726.  
  727.     /* Allocate zonedata inside one of the zones */
  728.     if (zone_can_alloc(zone1, order))
  729.         pfn = zone1->base + zone_frame_alloc(zone1, order);
  730.     else if (zone_can_alloc(zone2, order))
  731.         pfn = zone2->base + zone_frame_alloc(zone2, order);
  732.     else
  733.         goto errout2;
  734.  
  735.     newzone = (zone_t *) PA2KA(PFN2ADDR(pfn));
  736.  
  737.     _zone_merge(newzone, zone1, zone2);
  738.  
  739.     /* Free unneeded config frames */
  740.     zone_reduce_region(newzone, pfn - newzone->base,  cframes);
  741.     /* Subtract zone information from busy frames */
  742.     newzone->busy_count -= cframes;
  743.  
  744.     /* Replace existing zones in zoneinfo list */
  745.     zones.info[z1] = newzone;
  746.     for (i = z2 + 1; i < zones.count; i++)
  747.         zones.info[i - 1] = zones.info[i];
  748.     zones.count--;
  749.  
  750.     /* Free old zone information */
  751.     return_config_frames(newzone, zone1);
  752.     return_config_frames(newzone, zone2);
  753. errout2:
  754.     /* Nobody is allowed to enter to zone, so we are safe
  755.      * to touch the spinlocks last time */
  756.     spinlock_unlock(&zone1->lock);
  757.     spinlock_unlock(&zone2->lock);
  758. errout:
  759.     spinlock_unlock(&zones.lock);
  760.     interrupts_restore(ipl);
  761. }
  762.  
  763. /**
  764.  * Merge all zones into one big zone
  765.  *
  766.  * It is reasonable to do this on systems whose bios reports parts in chunks,
  767.  * so that we could have 1 zone (it's faster).
  768.  */
  769. void zone_merge_all(void)
  770. {
  771.     int count = zones.count;
  772.  
  773.     while (zones.count > 1 && --count) {
  774.         zone_merge(0,1);
  775.         break;
  776.     }
  777. }
  778.  
  779. /** Create frame zone
  780.  *
  781.  * Create new frame zone.
  782.  *
  783.  * @param start Physical address of the first frame within the zone.
  784.  * @param count Count of frames in zone
  785.  * @param z Address of configuration information of zone
  786.  * @param flags Zone flags.
  787.  *
  788.  * @return Initialized zone.
  789.  */
  790. static void zone_construct(pfn_t start, count_t count, zone_t *z, int flags)
  791. {
  792.     unsigned int i;
  793.     uint8_t max_order;
  794.  
  795.     spinlock_initialize(&z->lock, "zone_lock");
  796.     z->base = start;
  797.     z->count = count;
  798.     z->flags = flags;
  799.     z->free_count = count;
  800.     z->busy_count = 0;
  801.  
  802.     /*
  803.      * Compute order for buddy system, initialize
  804.      */
  805.     max_order = fnzb(count);
  806.     z->buddy_system = (buddy_system_t *)&z[1];
  807.    
  808.     buddy_system_create(z->buddy_system, max_order,
  809.                 &zone_buddy_system_operations,
  810.                 (void *) z);
  811.    
  812.     /* Allocate frames _after_ the conframe */
  813.     /* Check sizes */
  814.     z->frames = (frame_t *)((uint8_t *) z->buddy_system +
  815.         buddy_conf_size(max_order));
  816.     for (i = 0; i < count; i++) {
  817.         frame_initialize(&z->frames[i]);
  818.     }
  819.    
  820.     /* Stuffing frames */
  821.     for (i = 0; i < count; i++) {
  822.         z->frames[i].refcount = 0;
  823.         buddy_system_free(z->buddy_system, &z->frames[i].buddy_link);
  824.     }
  825. }
  826.  
  827. /** Compute configuration data size for zone
  828.  *
  829.  * @param count Size of zone in frames
  830.  * @return Size of zone configuration info (in bytes)
  831.  */
  832. uintptr_t zone_conf_size(count_t count)
  833. {
  834.     int size = sizeof(zone_t) + count*sizeof(frame_t);
  835.     int max_order;
  836.  
  837.     max_order = fnzb(count);
  838.     size += buddy_conf_size(max_order);
  839.     return size;
  840. }
  841.  
  842. /** Create and add zone to system
  843.  *
  844.  * @param start First frame number (absolute)
  845.  * @param count Size of zone in frames
  846.  * @param confframe Where configuration frames are supposed to be.
  847.  *                  Automatically checks, that we will not disturb the
  848.  *                  kernel and possibly init.
  849.  *                  If confframe is given _outside_ this zone, it is expected,
  850.  *                  that the area is already marked BUSY and big enough
  851.  *                  to contain zone_conf_size() amount of data.
  852.  *                  If the confframe is inside the area, the zone free frame
  853.  *                  information is modified not to include it.
  854.  *
  855.  * @return Zone number or -1 on error
  856.  */
  857. int zone_create(pfn_t start, count_t count, pfn_t confframe, int flags)
  858. {
  859.     zone_t *z;
  860.     uintptr_t addr;
  861.     count_t confcount;
  862.     unsigned int i;
  863.     int znum;
  864.  
  865.     /* Theoretically we could have here 0, practically make sure
  866.      * nobody tries to do that. If some platform requires, remove
  867.      * the assert
  868.      */
  869.     ASSERT(confframe);
  870.     /* If conframe is supposed to be inside our zone, then make sure
  871.      * it does not span kernel & init
  872.      */
  873.     confcount = SIZE2FRAMES(zone_conf_size(count));
  874.     if (confframe >= start && confframe < start+count) {
  875.         for (;confframe < start + count; confframe++) {
  876.             addr = PFN2ADDR(confframe);
  877.             if (overlaps(addr, PFN2ADDR(confcount),
  878.                 KA2PA(config.base), config.kernel_size))
  879.                 continue;
  880.            
  881.             if (overlaps(addr, PFN2ADDR(confcount),
  882.                 KA2PA(config.stack_base), config.stack_size))
  883.                 continue;
  884.            
  885.             bool overlap = false;
  886.             count_t i;
  887.             for (i = 0; i < init.cnt; i++)
  888.                 if (overlaps(addr, PFN2ADDR(confcount),
  889.                     KA2PA(init.tasks[i].addr),
  890.                     init.tasks[i].size)) {
  891.                     overlap = true;
  892.                     break;
  893.                 }
  894.             if (overlap)
  895.                 continue;
  896.            
  897.             break;
  898.         }
  899.         if (confframe >= start + count)
  900.             panic("Cannot find configuration data for zone.");
  901.     }
  902.  
  903.     z = (zone_t *)PA2KA(PFN2ADDR(confframe));
  904.     zone_construct(start, count, z, flags);
  905.     znum = zones_add_zone(z);
  906.     if (znum == -1)
  907.         return -1;
  908.  
  909.     /* If confdata in zone, mark as unavailable */
  910.     if (confframe >= start && confframe < start + count)
  911.         for (i = confframe; i < confframe + confcount; i++) {
  912.             zone_mark_unavailable(z, i - z->base);
  913.         }
  914.     return znum;
  915. }
  916.  
  917. /***************************************/
  918. /* Frame functions */
  919.  
  920. /** Set parent of frame */
  921. void frame_set_parent(pfn_t pfn, void *data, unsigned int hint)
  922. {
  923.     zone_t *zone = find_zone_and_lock(pfn, &hint);
  924.  
  925.     ASSERT(zone);
  926.  
  927.     zone_get_frame(zone, pfn-zone->base)->parent = data;
  928.     spinlock_unlock(&zone->lock);
  929. }
  930.  
  931. void *frame_get_parent(pfn_t pfn, unsigned int hint)
  932. {
  933.     zone_t *zone = find_zone_and_lock(pfn, &hint);
  934.     void *res;
  935.  
  936.     ASSERT(zone);
  937.     res = zone_get_frame(zone, pfn - zone->base)->parent;
  938.    
  939.     spinlock_unlock(&zone->lock);
  940.     return res;
  941. }
  942.  
  943. /** Allocate power-of-two frames of physical memory.
  944.  *
  945.  * @param order  Allocate exactly 2^order frames.
  946.  * @param flags  Flags for host zone selection and address processing.
  947.  * @param pzone  Preferred zone
  948.  *
  949.  * @return Physical address of the allocated frame.
  950.  *
  951.  */
  952. void * frame_alloc_generic(uint8_t order, int flags, unsigned int *pzone)
  953. {
  954.     ipl_t ipl;
  955.     int freed;
  956.     pfn_t v;
  957.     zone_t *zone;
  958.    
  959. loop:
  960.     ipl = interrupts_disable();
  961.    
  962.     /*
  963.      * First, find suitable frame zone.
  964.      */
  965.     zone = find_free_zone_and_lock(order, pzone);
  966.    
  967.     /* If no memory, reclaim some slab memory,
  968.        if it does not help, reclaim all */
  969.     if (!zone && !(flags & FRAME_NO_RECLAIM)) {
  970.         freed = slab_reclaim(0);
  971.         if (freed)
  972.             zone = find_free_zone_and_lock(order, pzone);
  973.         if (!zone) {
  974.             freed = slab_reclaim(SLAB_RECLAIM_ALL);
  975.             if (freed)
  976.                 zone = find_free_zone_and_lock(order, pzone);
  977.         }
  978.     }
  979.     if (!zone) {
  980.         /*
  981.          * TODO: Sleep until frames are available again.
  982.          */
  983.         interrupts_restore(ipl);
  984.  
  985.         if (flags & FRAME_ATOMIC)
  986.             return 0;
  987.        
  988.         panic("Sleep not implemented.\n");
  989.         goto loop;
  990.     }
  991.    
  992.     v = zone_frame_alloc(zone, order);
  993.     v += zone->base;
  994.  
  995.     spinlock_unlock(&zone->lock);
  996.     interrupts_restore(ipl);
  997.  
  998.     if (flags & FRAME_KA)
  999.         return (void *)PA2KA(PFN2ADDR(v));
  1000.     return (void *)PFN2ADDR(v);
  1001. }
  1002.  
  1003. /** Free a frame.
  1004.  *
  1005.  * Find respective frame structure for supplied physical frame address.
  1006.  * Decrement frame reference count.
  1007.  * If it drops to zero, move the frame structure to free list.
  1008.  *
  1009.  * @param Frame Physical Address of of the frame to be freed.
  1010.  */
  1011. void frame_free(uintptr_t frame)
  1012. {
  1013.     ipl_t ipl;
  1014.     zone_t *zone;
  1015.     pfn_t pfn = ADDR2PFN(frame);
  1016.  
  1017.     ipl = interrupts_disable();
  1018.    
  1019.     /*
  1020.      * First, find host frame zone for addr.
  1021.      */
  1022.     zone = find_zone_and_lock(pfn,NULL);
  1023.     ASSERT(zone);
  1024.    
  1025.     zone_frame_free(zone, pfn-zone->base);
  1026.    
  1027.     spinlock_unlock(&zone->lock);
  1028.     interrupts_restore(ipl);
  1029. }
  1030.  
  1031. /** Add reference to frame.
  1032.  *
  1033.  * Find respective frame structure for supplied PFN and
  1034.  * increment frame reference count.
  1035.  *
  1036.  * @param pfn Frame number of the frame to be freed.
  1037.  */
  1038. void frame_reference_add(pfn_t pfn)
  1039. {
  1040.     ipl_t ipl;
  1041.     zone_t *zone;
  1042.     frame_t *frame;
  1043.  
  1044.     ipl = interrupts_disable();
  1045.    
  1046.     /*
  1047.      * First, find host frame zone for addr.
  1048.      */
  1049.     zone = find_zone_and_lock(pfn,NULL);
  1050.     ASSERT(zone);
  1051.    
  1052.     frame = &zone->frames[pfn-zone->base];
  1053.     frame->refcount++;
  1054.    
  1055.     spinlock_unlock(&zone->lock);
  1056.     interrupts_restore(ipl);
  1057. }
  1058.  
  1059. /** Mark given range unavailable in frame zones */
  1060. void frame_mark_unavailable(pfn_t start, count_t count)
  1061. {
  1062.     unsigned int i;
  1063.     zone_t *zone;
  1064.     unsigned int prefzone = 0;
  1065.    
  1066.     for (i = 0; i < count; i++) {
  1067.         zone = find_zone_and_lock(start + i, &prefzone);
  1068.         if (!zone) /* PFN not found */
  1069.             continue;
  1070.         zone_mark_unavailable(zone, start + i - zone->base);
  1071.  
  1072.         spinlock_unlock(&zone->lock);
  1073.     }
  1074. }
  1075.  
  1076. /** Initialize physical memory management
  1077.  *
  1078.  * Initialize physical memory managemnt.
  1079.  */
  1080. void frame_init(void)
  1081. {
  1082.     if (config.cpu_active == 1) {
  1083.         zones.count = 0;
  1084.         spinlock_initialize(&zones.lock, "zones.lock");
  1085.     }
  1086.     /* Tell the architecture to create some memory */
  1087.     frame_arch_init();
  1088.     if (config.cpu_active == 1) {
  1089.         frame_mark_unavailable(ADDR2PFN(KA2PA(config.base)),
  1090.             SIZE2FRAMES(config.kernel_size));
  1091.         frame_mark_unavailable(ADDR2PFN(KA2PA(config.stack_base)),
  1092.             SIZE2FRAMES(config.stack_size));
  1093.        
  1094.         count_t i;
  1095.         for (i = 0; i < init.cnt; i++) {
  1096.             pfn_t pfn = ADDR2PFN(KA2PA(init.tasks[i].addr));
  1097.             frame_mark_unavailable(pfn,
  1098.                 SIZE2FRAMES(init.tasks[i].size));
  1099.         }
  1100.  
  1101.         if (ballocs.size)
  1102.             frame_mark_unavailable(ADDR2PFN(KA2PA(ballocs.base)),
  1103.                 SIZE2FRAMES(ballocs.size));
  1104.  
  1105.         /* Black list first frame, as allocating NULL would
  1106.          * fail in some places */
  1107.         frame_mark_unavailable(0, 1);
  1108.     }
  1109. }
  1110.  
  1111.  
  1112.  
  1113. /** Prints list of zones
  1114.  *
  1115.  */
  1116. void zone_print_list(void) {
  1117.     zone_t *zone = NULL;
  1118.     unsigned int i;
  1119.     ipl_t ipl;
  1120.  
  1121.     ipl = interrupts_disable();
  1122.     spinlock_lock(&zones.lock);
  1123.     printf("#  base address free frames  busy frames\n");
  1124.     printf("-- ------------ ------------ ------------\n");
  1125.     for (i = 0; i < zones.count; i++) {
  1126.         zone = zones.info[i];
  1127.         spinlock_lock(&zone->lock);
  1128.         printf("%-2d %12p %12zd %12zd\n", i, PFN2ADDR(zone->base),
  1129.             zone->free_count, zone->busy_count);
  1130.         spinlock_unlock(&zone->lock);
  1131.     }
  1132.     spinlock_unlock(&zones.lock);
  1133.     interrupts_restore(ipl);
  1134. }
  1135.  
  1136. /** Prints zone details.
  1137.  *
  1138.  * @param num Zone base address or zone number.
  1139.  */
  1140. void zone_print_one(unsigned int num) {
  1141.     zone_t *zone = NULL;
  1142.     ipl_t ipl;
  1143.     unsigned int i;
  1144.  
  1145.     ipl = interrupts_disable();
  1146.     spinlock_lock(&zones.lock);
  1147.  
  1148.     for (i = 0; i < zones.count; i++) {
  1149.         if (i == num || PFN2ADDR(zones.info[i]->base) == num) {
  1150.             zone = zones.info[i];
  1151.             break;
  1152.         }
  1153.     }
  1154.     if (!zone) {
  1155.         printf("Zone not found.\n");
  1156.         goto out;
  1157.     }
  1158.    
  1159.     spinlock_lock(&zone->lock);
  1160.     printf("Memory zone information\n");
  1161.     printf("Zone base address: %#.*p\n", sizeof(uintptr_t) * 2,
  1162.         PFN2ADDR(zone->base));
  1163.     printf("Zone size: %zd frames (%zdK)\n", zone->count,
  1164.         ((zone->count) * FRAME_SIZE) >> 10);
  1165.     printf("Allocated space: %zd frames (%zdK)\n", zone->busy_count,
  1166.         (zone->busy_count * FRAME_SIZE) >> 10);
  1167.     printf("Available space: %zd frames (%zdK)\n", zone->free_count,
  1168.         (zone->free_count * FRAME_SIZE) >> 10);
  1169.     buddy_system_structure_print(zone->buddy_system, FRAME_SIZE);
  1170.    
  1171.     spinlock_unlock(&zone->lock);
  1172. out:
  1173.     spinlock_unlock(&zones.lock);
  1174.     interrupts_restore(ipl);
  1175. }
  1176.  
  1177. /** @}
  1178.  */
  1179.  
  1180.