lunaix-os/kernel/mm/cake.c

   1 /**
   2  * @file cake.c
   3  * @author Lunaixsky (zelong56@gmail.com)
   4  * @brief A simplified cake(slab) allocator.
   5  *          P.s. I call it cake as slab sounds more 'ridge' to me. :)
   6  * @version 0.1
   7  * @date 2022-07-02
   8  *
   9  * @copyright Copyright (c) 2022
  10  *
  11  */
  12
  13 #include <klibc/string.h>
  14 #include <lunaix/mm/cake.h>
  15 #include <lunaix/mm/pmm.h>
  16 #include <lunaix/mm/vmm.h>
  17 #include <lunaix/spike.h>
  18 #include <lunaix/syslog.h>
  19
  20 LOG_MODULE("CAKE")
  21
  22 #define CACHE_LINE_SIZE 128
  23
  24 struct cake_pile master_pile;
  25
  26 struct llist_header piles = { .next = &piles, .prev = &piles };
  27
  28 void*
  29 __alloc_cake(unsigned int cake_pg)
  30 {
  31     uintptr_t pa = pmm_alloc_cpage(KERNEL_PID, cake_pg, 0);
  32     if (!pa) {
  33         return NULL;
  34     }
  35     return vmm_vmap(pa, cake_pg * PG_SIZE, PG_PREM_RW);
  36 }
  37
  38 struct cake_s*
  39 __new_cake(struct cake_pile* pile)
  40 {
  41     struct cake_s* cake = __alloc_cake(pile->pg_per_cake);
  42
  43     if (!cake) {
  44         return NULL;
  45     }
  46
  47     int max_piece = pile->pieces_per_cake;
  48
  49     cake->first_piece = (void*)((uintptr_t)cake + pile->offset);
  50     cake->next_free = 0;
  51
  52     piece_index_t* free_list = cake->free_list;
  53     for (size_t i = 0; i < max_piece - 1; i++) {
  54         free_list[i] = i + 1;
  55     }
  56     free_list[max_piece - 1] = EO_FREE_PIECE;
  57
  58     llist_append(&pile->free, &cake->cakes);
  59
  60     return cake;
  61 }
  62
  63 void
  64 __init_pile(struct cake_pile* pile,
  65             char* name,
  66             unsigned int piece_size,
  67             unsigned int pg_per_cake,
  68             int options)
  69 {
  70     if (!pile) {
  71         return;
  72     }
  73
  74     unsigned int offset = sizeof(long);
  75
  76     // 默认每块儿蛋糕对齐到地址总线宽度
  77     if ((options & PILE_CACHELINE)) {
  78         // 对齐到128字节缓存行大小，主要用于DMA
  79         offset = CACHE_LINE_SIZE;
  80     }
  81
  82     piece_size = ROUNDUP(piece_size, offset);
  83     *pile = (struct cake_pile){ .piece_size = piece_size,
  84                                 .cakes_count = 1,
  85                                 .pieces_per_cake =
  86                                   (pg_per_cake * PG_SIZE) /
  87                                   (piece_size + sizeof(piece_index_t)),
  88                                 .pg_per_cake = pg_per_cake };
  89
  90     unsigned int free_list_size = pile->pieces_per_cake * sizeof(piece_index_t);
  91
  92     pile->offset = ROUNDUP(sizeof(struct cake_s) + free_list_size, offset);
  93     pile->pieces_per_cake -= ICEIL((pile->offset - free_list_size), piece_size);
  94
  95     strncpy(pile->pile_name, name, PILE_NAME_MAXLEN);
  96
  97     llist_init_head(&pile->free);
  98     llist_init_head(&pile->full);
  99     llist_init_head(&pile->partial);
 100     llist_append(&piles, &pile->piles);
 101 }
 102
 103 void
 104 cake_init()
 105 {
 106     __init_pile(&master_pile, "pinkamina", sizeof(master_pile), 1, 0);
 107 }
 108
 109 struct cake_pile*
 110 cake_new_pile(char* name,
 111               unsigned int piece_size,
 112               unsigned int pg_per_cake,
 113               int options)
 114 {
 115     struct cake_pile* pile = (struct cake_pile*)cake_grab(&master_pile);
 116
 117     __init_pile(pile, name, piece_size, pg_per_cake, options);
 118
 119     return pile;
 120 }
 121
 122 void*
 123 cake_grab(struct cake_pile* pile)
 124 {
 125     struct cake_s *pos, *n;
 126     if (!llist_empty(&pile->partial)) {
 127         pos = list_entry(pile->partial.next, typeof(*pos), cakes);
 128     } else if (llist_empty(&pile->free)) {
 129         pos = __new_cake(pile);
 130     } else {
 131         pos = list_entry(pile->free.next, typeof(*pos), cakes);
 132     }
 133
 134     if (!pos)
 135         return NULL;
 136
 137     piece_index_t found_index = pos->next_free;
 138     pos->next_free = pos->free_list[found_index];
 139     pos->used_pieces++;
 140     pile->alloced_pieces++;
 141
 142     llist_delete(&pos->cakes);
 143     if (pos->next_free == EO_FREE_PIECE) {
 144         llist_append(&pile->full, &pos->cakes);
 145     } else {
 146         llist_append(&pile->partial, &pos->cakes);
 147     }
 148
 149     return (void*)((uintptr_t)pos->first_piece +
 150                    found_index * pile->piece_size);
 151 }
 152
 153 int
 154 cake_release(struct cake_pile* pile, void* area)
 155 {
 156     piece_index_t piece_index;
 157     struct cake_s *pos, *n;
 158     struct llist_header* hdrs[2] = { &pile->full, &pile->partial };
 159
 160     for (size_t i = 0; i < 2; i++) {
 161         llist_for_each(pos, n, hdrs[i], cakes)
 162         {
 163             if (pos->first_piece > area) {
 164                 continue;
 165             }
 166             piece_index =
 167               (uintptr_t)(area - pos->first_piece) / pile->piece_size;
 168             if (piece_index < pile->pieces_per_cake) {
 169                 goto found;
 170             }
 171         }
 172     }
 173
 174     return 0;
 175
 176 found:
 177     pos->free_list[piece_index] = pos->next_free;
 178     pos->next_free = piece_index;
 179     pos->used_pieces--;
 180     pile->alloced_pieces--;
 181
 182     llist_delete(&pos->cakes);
 183     if (!pos->used_pieces) {
 184         llist_append(&pile->free, &pos->cakes);
 185     } else {
 186         llist_append(&pile->partial, &pos->cakes);
 187     }
 188
 189     return 1;
 190 }
 191
 192 void
 193 cake_stats()
 194 {
 195     kprintf(KDEBUG "<name> <cake> <pg/c> <p/c> <alloced>\n");
 196
 197     struct cake_pile *pos, *n;
 198     llist_for_each(pos, n, &piles, piles)
 199     {
 200         kprintf("%s %d %d %d %d\n",
 201                 pos->pile_name,
 202                 pos->cakes_count,
 203                 pos->pg_per_cake,
 204                 pos->pieces_per_cake,
 205                 pos->alloced_pieces);
 206     }
 207 }