1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2014, The Linux Foundation. All rights reserved.
  4 */
  5#include <linux/mm.h>
  6#include <linux/module.h>
  7
  8#include <asm/tlbflush.h>
  9#include <asm/set_memory.h>
 10
 11struct page_change_data {
 12	pgprot_t set_mask;
 13	pgprot_t clear_mask;
 14};
 15
 16static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
 17{
 18	struct page_change_data *cdata = data;
 19	pte_t pte = *ptep;
 20
 21	pte = clear_pte_bit(pte, cdata->clear_mask);
 22	pte = set_pte_bit(pte, cdata->set_mask);
 23
 24	set_pte_ext(ptep, pte, 0);
 25	return 0;
 26}
 27
 28static bool range_in_range(unsigned long start, unsigned long size,
 29	unsigned long range_start, unsigned long range_end)
 30{
 31	return start >= range_start && start < range_end &&
 32		size <= range_end - start;
 33}
 34
 35/*
 36 * This function assumes that the range is mapped with PAGE_SIZE pages.
 37 */
 38static int __change_memory_common(unsigned long start, unsigned long size,
 39				pgprot_t set_mask, pgprot_t clear_mask)
 40{
 41	struct page_change_data data;
 42	int ret;
 43
 44	data.set_mask = set_mask;
 45	data.clear_mask = clear_mask;
 46
 47	ret = apply_to_page_range(&init_mm, start, size, change_page_range,
 48				  &data);
 49
 50	flush_tlb_kernel_range(start, start + size);
 51	return ret;
 52}
 53
 54static int change_memory_common(unsigned long addr, int numpages,
 55				pgprot_t set_mask, pgprot_t clear_mask)
 56{
 57	unsigned long start = addr & PAGE_MASK;
 58	unsigned long end = PAGE_ALIGN(addr) + numpages * PAGE_SIZE;
 59	unsigned long size = end - start;
 60
 61	WARN_ON_ONCE(start != addr);
 62
 63	if (!size)
 64		return 0;
 65
 66	if (!range_in_range(start, size, MODULES_VADDR, MODULES_END) &&
 67	    !range_in_range(start, size, VMALLOC_START, VMALLOC_END))
 68		return -EINVAL;
 69
 70	return __change_memory_common(start, size, set_mask, clear_mask);
 71}
 72
 73int set_memory_ro(unsigned long addr, int numpages)
 74{
 75	return change_memory_common(addr, numpages,
 76					__pgprot(L_PTE_RDONLY),
 77					__pgprot(0));
 78}
 79
 80int set_memory_rw(unsigned long addr, int numpages)
 81{
 82	return change_memory_common(addr, numpages,
 83					__pgprot(0),
 84					__pgprot(L_PTE_RDONLY));
 85}
 86
 87int set_memory_nx(unsigned long addr, int numpages)
 88{
 89	return change_memory_common(addr, numpages,
 90					__pgprot(L_PTE_XN),
 91					__pgprot(0));
 92}
 93
 94int set_memory_x(unsigned long addr, int numpages)
 95{
 96	return change_memory_common(addr, numpages,
 97					__pgprot(0),
 98					__pgprot(L_PTE_XN));
 99}
100
101int set_memory_valid(unsigned long addr, int numpages, int enable)
102{
103	if (enable)
104		return __change_memory_common(addr, PAGE_SIZE * numpages,
105					      __pgprot(L_PTE_VALID),
106					      __pgprot(0));
107	else
108		return __change_memory_common(addr, PAGE_SIZE * numpages,
109					      __pgprot(0),
110					      __pgprot(L_PTE_VALID));
111}