xref: /linux/arch/parisc/mm/fixmap.c (revision b8d312aa075f33282565467662c4628dae0a2aff)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * fixmaps for parisc
4  *
5  * Copyright (c) 2019 Sven Schnelle <svens@stackframe.org>
6  */
7 
8 #include <linux/kprobes.h>
9 #include <linux/mm.h>
10 #include <asm/cacheflush.h>
11 #include <asm/fixmap.h>
12 
13 void notrace set_fixmap(enum fixed_addresses idx, phys_addr_t phys)
14 {
15 	unsigned long vaddr = __fix_to_virt(idx);
16 	pgd_t *pgd = pgd_offset_k(vaddr);
17 	pmd_t *pmd = pmd_offset(pgd, vaddr);
18 	pte_t *pte;
19 
20 	if (pmd_none(*pmd))
21 		pmd = pmd_alloc(NULL, pgd, vaddr);
22 
23 	pte = pte_offset_kernel(pmd, vaddr);
24 	if (pte_none(*pte))
25 		pte = pte_alloc_kernel(pmd, vaddr);
26 
27 	set_pte_at(&init_mm, vaddr, pte, __mk_pte(phys, PAGE_KERNEL_RWX));
28 	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
29 }
30 
31 void notrace clear_fixmap(enum fixed_addresses idx)
32 {
33 	unsigned long vaddr = __fix_to_virt(idx);
34 	pgd_t *pgd = pgd_offset_k(vaddr);
35 	pmd_t *pmd = pmd_offset(pgd, vaddr);
36 	pte_t *pte = pte_offset_kernel(pmd, vaddr);
37 
38 	if (WARN_ON(pte_none(*pte)))
39 		return;
40 
41 	pte_clear(&init_mm, vaddr, pte);
42 
43 	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
44 }
45