xref: /openbmc/linux/arch/parisc/mm/fixmap.c (revision 9ac17575)
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 	p4d_t *p4d = p4d_offset(pgd, vaddr);
18 	pud_t *pud = pud_offset(p4d, vaddr);
19 	pmd_t *pmd = pmd_offset(pud, vaddr);
20 	pte_t *pte;
21 
22 	if (pmd_none(*pmd))
23 		pmd = pmd_alloc(NULL, pud, vaddr);
24 
25 	pte = pte_offset_kernel(pmd, vaddr);
26 	if (pte_none(*pte))
27 		pte = pte_alloc_kernel(pmd, vaddr);
28 
29 	set_pte_at(&init_mm, vaddr, pte, __mk_pte(phys, PAGE_KERNEL_RWX));
30 	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
31 }
32 
33 void notrace clear_fixmap(enum fixed_addresses idx)
34 {
35 	unsigned long vaddr = __fix_to_virt(idx);
36 	pgd_t *pgd = pgd_offset_k(vaddr);
37 	p4d_t *p4d = p4d_offset(pgd, vaddr);
38 	pud_t *pud = pud_offset(p4d, vaddr);
39 	pmd_t *pmd = pmd_offset(pud, vaddr);
40 	pte_t *pte = pte_offset_kernel(pmd, vaddr);
41 
42 	if (WARN_ON(pte_none(*pte)))
43 		return;
44 
45 	pte_clear(&init_mm, vaddr, pte);
46 
47 	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
48 }
49