1 /* 2 * MMU enable and page table manipulation functions 3 * 4 * Copyright (C) 2014, Red Hat Inc, Andrew Jones <drjones@redhat.com> 5 * 6 * This work is licensed under the terms of the GNU LGPL, version 2. 7 */ 8 #include <asm/setup.h> 9 #include <asm/mmu.h> 10 11 pgd_t *mmu_idmap; 12 13 static bool mmu_on; 14 bool mmu_enabled(void) 15 { 16 return mmu_on; 17 } 18 19 extern void asm_mmu_enable(phys_addr_t pgtable); 20 void mmu_enable(pgd_t *pgtable) 21 { 22 asm_mmu_enable(__pa(pgtable)); 23 flush_tlb_all(); 24 mmu_on = true; 25 } 26 27 void mmu_set_range_ptes(pgd_t *pgtable, unsigned long virt_offset, 28 unsigned long phys_start, unsigned long phys_end, 29 pgprot_t prot) 30 { 31 unsigned long vaddr = virt_offset & PAGE_MASK; 32 unsigned long paddr = phys_start & PAGE_MASK; 33 unsigned long virt_end = phys_end - paddr + vaddr; 34 35 for (; vaddr < virt_end; vaddr += PAGE_SIZE, paddr += PAGE_SIZE) { 36 pgd_t *pgd = pgd_offset(pgtable, vaddr); 37 pud_t *pud = pud_alloc(pgd, vaddr); 38 pmd_t *pmd = pmd_alloc(pud, vaddr); 39 pte_t *pte = pte_alloc(pmd, vaddr); 40 41 pte_val(*pte) = paddr; 42 pte_val(*pte) |= PTE_TYPE_PAGE | PTE_AF | PTE_SHARED; 43 pte_val(*pte) |= pgprot_val(prot); 44 } 45 } 46 47 void mmu_set_range_sect(pgd_t *pgtable, unsigned long virt_offset, 48 unsigned long phys_start, unsigned long phys_end, 49 pgprot_t prot) 50 { 51 unsigned long vaddr = virt_offset & PGDIR_MASK; 52 unsigned long paddr = phys_start & PGDIR_MASK; 53 unsigned long virt_end = phys_end - paddr + vaddr; 54 55 for (; vaddr < virt_end; vaddr += PGDIR_SIZE, paddr += PGDIR_SIZE) { 56 pgd_t *pgd = pgd_offset(pgtable, vaddr); 57 pgd_val(*pgd) = paddr; 58 pgd_val(*pgd) |= PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S; 59 pgd_val(*pgd) |= pgprot_val(prot); 60 } 61 } 62 63 64 void mmu_init_io_sect(pgd_t *pgtable, unsigned long virt_offset) 65 { 66 mmu_set_range_sect(pgtable, virt_offset, 67 PHYS_IO_OFFSET, PHYS_IO_END, 68 __pgprot(PMD_SECT_UNCACHED | PMD_SECT_USER)); 69 } 70 71 void mmu_enable_idmap(void) 72 { 73 unsigned long phys_end = sizeof(long) == 8 || !(PHYS_END >> 32) 74 ? PHYS_END : 0xfffff000; 75 76 mmu_idmap = pgd_alloc(); 77 78 mmu_init_io_sect(mmu_idmap, PHYS_IO_OFFSET); 79 80 mmu_set_range_ptes(mmu_idmap, PHYS_OFFSET, 81 PHYS_OFFSET, phys_end, 82 __pgprot(PTE_WBWA | PTE_USER)); 83 84 mmu_enable(mmu_idmap); 85 } 86