1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright(c) 2019-2020 Broadcom 3 * All rights reserved. 4 */ 5 6 #include <stdio.h> 7 #include <stdlib.h> 8 #include <stdbool.h> 9 #include <stdint.h> 10 #include <errno.h> 11 #include "stack.h" 12 13 #define STACK_EMPTY -1 14 15 /* Initialize stack 16 */ 17 int 18 stack_init(int num_entries, uint32_t *items, struct stack *st) 19 { 20 if (items == NULL || st == NULL) 21 return -EINVAL; 22 23 st->max = num_entries; 24 st->top = STACK_EMPTY; 25 st->items = items; 26 27 return 0; 28 } 29 30 /* Return the size of the stack 31 */ 32 int32_t 33 stack_size(struct stack *st) 34 { 35 return st->top + 1; 36 } 37 38 /* Check if the stack is empty 39 */ 40 bool 41 stack_is_empty(struct stack *st) 42 { 43 return st->top == STACK_EMPTY; 44 } 45 46 /* Check if the stack is full 47 */ 48 bool 49 stack_is_full(struct stack *st) 50 { 51 return st->top == st->max - 1; 52 } 53 54 /* Add element x to the stack 55 */ 56 int 57 stack_push(struct stack *st, uint32_t x) 58 { 59 if (stack_is_full(st)) 60 return -EOVERFLOW; 61 62 /* add an element and increments the top index 63 */ 64 st->items[++st->top] = x; 65 66 return 0; 67 } 68 69 /* Pop top element x from the stack and return 70 * in user provided location. 71 */ 72 int 73 stack_pop(struct stack *st, uint32_t *x) 74 { 75 if (stack_is_empty(st)) 76 return -ENOENT; 77 78 *x = st->items[st->top]; 79 st->top--; 80 81 return 0; 82 } 83 84 /* Dump the stack 85 */ 86 void stack_dump(struct stack *st) 87 { 88 int i, j; 89 90 printf("top=%d\n", st->top); 91 printf("max=%d\n", st->max); 92 93 if (st->top == -1) { 94 printf("stack is empty\n"); 95 return; 96 } 97 98 for (i = 0; i < st->max + 7 / 8; i++) { 99 printf("item[%d] 0x%08x", i, st->items[i]); 100 101 for (j = 0; j < 7; j++) { 102 if (i++ < st->max - 1) 103 printf(" 0x%08x", st->items[i]); 104 } 105 printf("\n"); 106 } 107 } 108