1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * KFENCE support for LoongArch.
4 *
5 * Author: Enze Li <lienze@kylinos.cn>
6 * Copyright (C) 2022-2023 KylinSoft Corporation.
7 */
8
9#ifndef _ASM_LOONGARCH_KFENCE_H
10#define _ASM_LOONGARCH_KFENCE_H
11
12#include <linux/kfence.h>
13#include <asm/pgtable.h>
14#include <asm/tlb.h>
15
16static inline bool arch_kfence_init_pool(void)
17{
18	int err;
19	char *kfence_pool = __kfence_pool;
20	struct vm_struct *area;
21
22	area = __get_vm_area_caller(KFENCE_POOL_SIZE, VM_IOREMAP,
23				    KFENCE_AREA_START, KFENCE_AREA_END,
24				    __builtin_return_address(0));
25	if (!area)
26		return false;
27
28	__kfence_pool = (char *)area->addr;
29	err = ioremap_page_range((unsigned long)__kfence_pool,
30				 (unsigned long)__kfence_pool + KFENCE_POOL_SIZE,
31				 virt_to_phys((void *)kfence_pool), PAGE_KERNEL);
32	if (err) {
33		free_vm_area(area);
34		__kfence_pool = kfence_pool;
35		return false;
36	}
37
38	return true;
39}
40
41/* Protect the given page and flush TLB. */
42static inline bool kfence_protect_page(unsigned long addr, bool protect)
43{
44	pte_t *pte = virt_to_kpte(addr);
45
46	if (WARN_ON(!pte) || pte_none(*pte))
47		return false;
48
49	if (protect)
50		set_pte(pte, __pte(pte_val(*pte) & ~(_PAGE_VALID | _PAGE_PRESENT)));
51	else
52		set_pte(pte, __pte(pte_val(*pte) | (_PAGE_VALID | _PAGE_PRESENT)));
53
54	preempt_disable();
55	local_flush_tlb_one(addr);
56	preempt_enable();
57
58	return true;
59}
60
61#endif /* _ASM_LOONGARCH_KFENCE_H */
62