1 /* subr_rmap.c 3.3 06/24/80 */ 2 3 #include "../h/param.h" 4 #include "../h/systm.h" 5 #include "../h/map.h" 6 #include "../h/dir.h" 7 #include "../h/user.h" 8 #include "../h/proc.h" 9 #include "../h/mtpr.h" 10 #include "../h/text.h" 11 12 /* 13 * Allocate 'size' units from the given 14 * map. Return the base of the allocated 15 * space. 16 * In a map, the addresses are increasing and the 17 * list is terminated by a 0 size. 18 * The swap map unit is 512 bytes. 19 * Algorithm is first-fit. 20 */ 21 malloc(mp, size) 22 struct map *mp; 23 { 24 register int a; 25 register struct map *bp; 26 swblk_t first, rest; 27 28 if (size <= 0 || mp == swapmap && size > DMMAX) 29 panic("malloc"); 30 for (bp=mp; bp->m_size; bp++) { 31 if (bp->m_size >= size) { 32 if (mp == swapmap && 33 (first = DMMAX - bp->m_addr%DMMAX) < bp->m_size) { 34 if (bp->m_size - first < size) 35 continue; 36 a = bp->m_addr + first; 37 rest = bp->m_size - first - size; 38 bp->m_size = first; 39 if (rest) 40 mfree(swapmap, rest, a+size); 41 return (a); 42 } 43 a = bp->m_addr; 44 bp->m_addr += size; 45 if ((bp->m_size -= size) == 0) { 46 do { 47 bp++; 48 (bp-1)->m_addr = bp->m_addr; 49 } while ((bp-1)->m_size = bp->m_size); 50 } 51 if (mp == swapmap && a % CLSIZE) 52 panic("malloc swapmap"); 53 return(a); 54 } 55 } 56 return(0); 57 } 58 59 /* 60 * Free the previously allocated space aa 61 * of size units into the specified map. 62 * Sort aa into map and combine on 63 * one or both ends if possible. 64 */ 65 mfree(mp, size, a) 66 struct map *mp; 67 register int size, a; 68 { 69 register struct map *bp; 70 register int t; 71 72 if (a <= 0) 73 panic("mfree addr"); 74 if (size <= 0) 75 panic("mfree size"); 76 bp = mp; 77 for (; bp->m_addr<=a && bp->m_size!=0; bp++) 78 continue; 79 if (bp>mp && (bp-1)->m_addr+(bp-1)->m_size > a) 80 panic("mfree begov"); 81 if (a+size > bp->m_addr && bp->m_size) 82 panic("mfree endov"); 83 if (bp>mp && (bp-1)->m_addr+(bp-1)->m_size == a) { 84 (bp-1)->m_size += size; 85 if (a+size == bp->m_addr) { 86 (bp-1)->m_size += bp->m_size; 87 while (bp->m_size) { 88 bp++; 89 (bp-1)->m_addr = bp->m_addr; 90 (bp-1)->m_size = bp->m_size; 91 } 92 } 93 } else { 94 if (a+size == bp->m_addr && bp->m_size) { 95 bp->m_addr -= size; 96 bp->m_size += size; 97 } else if (size) { 98 do { 99 t = bp->m_addr; 100 bp->m_addr = a; 101 a = t; 102 t = bp->m_size; 103 bp->m_size = size; 104 bp++; 105 } while (size = t); 106 } 107 } 108 if ((mp == kernelmap) && kmapwnt) { 109 kmapwnt = 0; 110 wakeup((caddr_t)kernelmap); 111 } 112 } 113