arch/riscv/mm/pgtable.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <asm/pgalloc.h>
   4 #include <linux/gfp.h>
   5 #include <linux/kernel.h>
   6 #include <linux/pgtable.h>
   7
   8 int ptep_set_access_flags(struct vm_area_struct *vma,
   9                           unsigned long address, pte_t *ptep,
  10                           pte_t entry, int dirty)
  11 {
  12         asm goto(ALTERNATIVE("nop", "j %l[svvptc]", 0, RISCV_ISA_EXT_SVVPTC, 1)
  13                  : : : : svvptc);
  14
  15         if (!pte_same(ptep_get(ptep), entry))
  16                 __set_pte_at(vma->vm_mm, ptep, entry);
  17         /*
  18          * update_mmu_cache will unconditionally execute, handling both
  19          * the case that the PTE changed and the spurious fault case.
  20          */
  21         return true;
  22
  23 svvptc:
  24         if (!pte_same(ptep_get(ptep), entry)) {
  25                 __set_pte_at(vma->vm_mm, ptep, entry);
  26                 /* Here only not svadu is impacted */
  27                 flush_tlb_page(vma, address);
  28                 return true;
  29         }
  30
  31         return false;
  32 }
  33
  34 int ptep_test_and_clear_young(struct vm_area_struct *vma,
  35                               unsigned long address,
  36                               pte_t *ptep)
  37 {
  38         if (!pte_young(ptep_get(ptep)))
  39                 return 0;
  40         return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
  41 }
  42 EXPORT_SYMBOL_GPL(ptep_test_and_clear_young);
  43
  44 #ifdef CONFIG_64BIT
  45 pud_t *pud_offset(p4d_t *p4d, unsigned long address)
  46 {
  47         if (pgtable_l4_enabled)
  48                 return p4d_pgtable(p4dp_get(p4d)) + pud_index(address);
  49
  50         return (pud_t *)p4d;
  51 }
  52
  53 p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
  54 {
  55         if (pgtable_l5_enabled)
  56                 return pgd_pgtable(pgdp_get(pgd)) + p4d_index(address);
  57
  58         return (p4d_t *)pgd;
  59 }
  60 #endif
  61
  62 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
  63 int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
  64 {
  65         return 0;
  66 }
  67
  68 void p4d_clear_huge(p4d_t *p4d)
  69 {
  70 }
  71
  72 int pud_set_huge(pud_t *pud, phys_addr_t phys, pgprot_t prot)
  73 {
  74         pud_t new_pud = pfn_pud(__phys_to_pfn(phys), prot);
  75
  76         set_pud(pud, new_pud);
  77         return 1;
  78 }
  79
  80 int pud_clear_huge(pud_t *pud)
  81 {
  82         if (!pud_leaf(pudp_get(pud)))
  83                 return 0;
  84         pud_clear(pud);
  85         return 1;
  86 }
  87
  88 int pud_free_pmd_page(pud_t *pud, unsigned long addr)
  89 {
  90         pmd_t *pmd = pud_pgtable(pudp_get(pud));
  91         int i;
  92
  93         pud_clear(pud);
  94
  95         flush_tlb_kernel_range(addr, addr + PUD_SIZE);
  96
  97         for (i = 0; i < PTRS_PER_PMD; i++) {
  98                 if (!pmd_none(pmd[i])) {
  99                         pte_t *pte = (pte_t *)pmd_page_vaddr(pmd[i]);
 100
 101                         pte_free_kernel(NULL, pte);
 102                 }
 103         }
 104
 105         pmd_free(NULL, pmd);
 106
 107         return 1;
 108 }
 109
 110 int pmd_set_huge(pmd_t *pmd, phys_addr_t phys, pgprot_t prot)
 111 {
 112         pmd_t new_pmd = pfn_pmd(__phys_to_pfn(phys), prot);
 113
 114         set_pmd(pmd, new_pmd);
 115         return 1;
 116 }
 117
 118 int pmd_clear_huge(pmd_t *pmd)
 119 {
 120         if (!pmd_leaf(pmdp_get(pmd)))
 121                 return 0;
 122         pmd_clear(pmd);
 123         return 1;
 124 }
 125
 126 int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
 127 {
 128         pte_t *pte = (pte_t *)pmd_page_vaddr(pmdp_get(pmd));
 129
 130         pmd_clear(pmd);
 131
 132         flush_tlb_kernel_range(addr, addr + PMD_SIZE);
 133         pte_free_kernel(NULL, pte);
 134         return 1;
 135 }
 136
 137 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
 138 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 139 pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
 140                                         unsigned long address, pmd_t *pmdp)
 141 {
 142         pmd_t pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
 143
 144         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 145         VM_BUG_ON(pmd_trans_huge(pmdp_get(pmdp)));
 146         /*
 147          * When leaf PTE entries (regular pages) are collapsed into a leaf
 148          * PMD entry (huge page), a valid non-leaf PTE is converted into a
 149          * valid leaf PTE at the level 1 page table.  Since the sfence.vma
 150          * forms that specify an address only apply to leaf PTEs, we need a
 151          * global flush here.  collapse_huge_page() assumes these flushes are
 152          * eager, so just do the fence here.
 153          */
 154         flush_tlb_mm(vma->vm_mm);
 155         return pmd;
 156 }
 157 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */