arch/parisc/mm/fixmap.c

   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 }