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  1. /*
  2.  * Copyright (C) 2006 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. #include <stdlib.h>
  30. #include <unistd.h>
  31. #include <string.h>
  32. #include <ddi.h>
  33. #include <sysinfo.h>
  34. #include <align.h>
  35. #include <as.h>
  36. #include <ipc/fb.h>
  37. #include <ipc/ipc.h>
  38. #include <ipc/ns.h>
  39. #include <ipc/services.h>
  40. #include <kernel/errno.h>
  41.  
  42.  
  43. #include <as.h>
  44. #include <libc.h>
  45. #include <unistd.h>
  46. #include <align.h>
  47.  
  48. /** Create address space area.
  49.  *
  50.  * @param address Virtual address where to place new address space area.
  51.  * @param size Size of the area.
  52.  * @param flags Flags describing type of the area.
  53.  *
  54.  * @return address on success, (void *) -1 otherwise.
  55.  */
  56. void *as_area_create(void *address, size_t size, int flags)
  57. {
  58.     return (void *) __SYSCALL3(SYS_AS_AREA_CREATE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
  59. }
  60.  
  61. /** Resize address space area.
  62.  *
  63.  * @param address Virtual address pointing into already existing address space area.
  64.  * @param size New requested size of the area.
  65.  * @param flags Currently unused.
  66.  *
  67.  * @return Zero on success or a code from @ref errno.h on failure.
  68.  */
  69. int as_area_resize(void *address, size_t size, int flags)
  70. {
  71.     return __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
  72. }
  73.  
  74. /** Destroy address space area.
  75.  *
  76.  * @param address Virtual address pointing into the address space area being destroyed.
  77.  *
  78.  * @return Zero on success or a code from @ref errno.h on failure.
  79.  */
  80. int as_area_destroy(void *address)
  81. {
  82.     return __SYSCALL1(SYS_AS_AREA_DESTROY, (sysarg_t ) address);
  83. }
  84.  
  85. static size_t heapsize = 0;
  86. static size_t maxheapsize = (size_t)(-1);
  87.  
  88. static void * last_allocated = 0;
  89.  
  90. /* Start of heap linker symbol */
  91. extern char _heap;
  92.  
  93. /** Sbrk emulation
  94.  *
  95.  * @param size New area that should be allocated or negative,
  96.                if it should be shrinked
  97.  * @return Pointer to newly allocated area
  98.  */
  99. void *sbrk(ssize_t incr)
  100. {
  101.     int rc;
  102.     void *res;
  103.     /* Check for invalid values */
  104.     if (incr < 0 && -incr > heapsize)
  105.         return NULL;
  106.     /* Check for too large value */
  107.     if (incr > 0 && incr+heapsize < heapsize)
  108.         return NULL;
  109.     /* Check for too small values */
  110.     if (incr < 0 && incr+heapsize > heapsize)
  111.         return NULL;
  112.     /* Check for user limit */
  113.     if ((maxheapsize!=(size_t)(-1)) && (heapsize + incr)>maxheapsize) return NULL;
  114.  
  115.     rc = as_area_resize(&_heap, heapsize + incr,0);
  116.     if (rc != 0)
  117.         return NULL;
  118.    
  119.     /* Compute start of new area */
  120.     res = (void *)&_heap + heapsize;
  121.  
  122.     heapsize += incr;
  123.  
  124.     return res;
  125. }
  126.  
  127. /** Set maximum heap size and return pointer just after the heap */
  128. void *set_maxheapsize(size_t mhs)
  129. {
  130.     maxheapsize=mhs;
  131.     /* Return pointer to area not managed by sbrk */
  132.     return (void *)&_heap + maxheapsize;
  133.  
  134. }
  135.  
  136. /** Return pointer to some unmapped area, where fits new as_area
  137.  *
  138.  * TODO: make some first_fit/... algorithm, we are now just incrementing
  139.  *       the pointer to last area
  140.  */
  141. void * as_get_mappable_page(size_t sz)
  142. {
  143.     void *res;
  144.  
  145.     /* Set heapsize to some meaningful value */
  146.     if (maxheapsize == -1)
  147.         set_maxheapsize(ALIGN_UP(USER_ADDRESS_SPACE_SIZE_ARCH>>1,PAGE_SIZE));
  148.     if (!last_allocated)
  149.         last_allocated = ALIGN_UP((void *)&_heap + maxheapsize, PAGE_SIZE);
  150.    
  151.     sz = ALIGN_UP(sz, PAGE_SIZE);
  152.     res = last_allocated;
  153.     last_allocated += sz;
  154.  
  155.     return res;
  156. }
  157.