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8#include "pstack.h"
9#include "debug.h"
10#include <linux/kernel.h>
11#include <linux/zalloc.h>
12#include <stdlib.h>
13#include <string.h>
14
15struct pstack {
16 unsigned short top;
17 unsigned short max_nr_entries;
18 void *entries[];
19};
20
21struct pstack *pstack__new(unsigned short max_nr_entries)
22{
23 struct pstack *pstack = zalloc((sizeof(*pstack) +
24 max_nr_entries * sizeof(void *)));
25 if (pstack != NULL)
26 pstack->max_nr_entries = max_nr_entries;
27 return pstack;
28}
29
30void pstack__delete(struct pstack *pstack)
31{
32 free(pstack);
33}
34
35bool pstack__empty(const struct pstack *pstack)
36{
37 return pstack->top == 0;
38}
39
40void pstack__remove(struct pstack *pstack, void *key)
41{
42 unsigned short i = pstack->top, last_index = pstack->top - 1;
43
44 while (i-- != 0) {
45 if (pstack->entries[i] == key) {
46 if (i < last_index)
47 memmove(pstack->entries + i,
48 pstack->entries + i + 1,
49 (last_index - i) * sizeof(void *));
50 --pstack->top;
51 return;
52 }
53 }
54 pr_err("%s: %p not on the pstack!\n", __func__, key);
55}
56
57void pstack__push(struct pstack *pstack, void *key)
58{
59 if (pstack->top == pstack->max_nr_entries) {
60 pr_err("%s: top=%d, overflow!\n", __func__, pstack->top);
61 return;
62 }
63 pstack->entries[pstack->top++] = key;
64}
65
66void *pstack__pop(struct pstack *pstack)
67{
68 void *ret;
69
70 if (pstack->top == 0) {
71 pr_err("%s: underflow!\n", __func__);
72 return NULL;
73 }
74
75 ret = pstack->entries[--pstack->top];
76 pstack->entries[pstack->top] = NULL;
77 return ret;
78}
79
80void *pstack__peek(struct pstack *pstack)
81{
82 if (pstack->top == 0)
83 return NULL;
84 return pstack->entries[pstack->top - 1];
85}
86
