root/arch/parisc/mm/fixmap.c

DEFINITIONS

1. set_fixmap
2. clear_fixmap

   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 }