// SPDX-License-Identifier: GPL-2.0/* * Simple pointer stack * * (c) 2010 Arnaldo Carvalho de Melo <acme@redhat.com> */ #include "pstack.h"#include "debug.h"#include <linux/kernel.h>#include <linux/zalloc.h>#include <stdlib.h>#include <string.h> struct pstack {	unsigned short	top;	unsigned short	max_nr_entries;	void		*entries[0];}; struct pstack *pstack__new(unsigned short max_nr_entries){	struct pstack *pstack = zalloc((sizeof(*pstack) +				       max_nr_entries * sizeof(void *)));	if (pstack != NULL)		pstack->max_nr_entries = max_nr_entries;	return pstack;} void pstack__delete(struct pstack *pstack){	free(pstack);} bool pstack__empty(const struct pstack *pstack){	return pstack->top == 0;} void pstack__remove(struct pstack *pstack, void *key){	unsigned short i = pstack->top, last_index = pstack->top - 1; 	while (i-- != 0) {		if (pstack->entries[i] == key) {			if (i < last_index)				memmove(pstack->entries + i,					pstack->entries + i + 1,					(last_index - i) * sizeof(void *));			--pstack->top;			return;		}	}	pr_err("%s: %p not on the pstack!\n", __func__, key);} void pstack__push(struct pstack *pstack, void *key){	if (pstack->top == pstack->max_nr_entries) {		pr_err("%s: top=%d, overflow!\n", __func__, pstack->top);		return;	}	pstack->entries[pstack->top++] = key;} void *pstack__pop(struct pstack *pstack){	void *ret; 	if (pstack->top == 0) {		pr_err("%s: underflow!\n", __func__);		return NULL;	} 	ret = pstack->entries[--pstack->top];	pstack->entries[pstack->top] = NULL;	return ret;} void *pstack__peek(struct pstack *pstack){	if (pstack->top == 0)		return NULL;	return pstack->entries[pstack->top - 1];}