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Commit 8ce837ce authored by Ard Biesheuvel's avatar Ard Biesheuvel
Browse files

arm64/mm: add create_pgd_mapping() to create private page tables 



For UEFI, we need to install the memory mappings used for Runtime Services
in a dedicated set of page tables. Add create_pgd_mapping(), which allows
us to allocate and install those page table entries early.

Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
Tested-by: default avatarLeif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
parent e1e1fdda

arch/arm64/include/asm/mmu.h

+3 −0
Original line number Diff line number Diff line
@@ -33,5 +33,8 @@ extern void __iomem *early_io_map(phys_addr_t phys, unsigned long virt); 
extern void init_mem_pgprot(void);

/* create an identity mapping for memory (or io if map_io is true) */

extern void create_id_mapping(phys_addr_t addr, phys_addr_t size, int map_io);

extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,

			       unsigned long virt, phys_addr_t size,

			       pgprot_t prot);



#endif

arch/arm64/include/asm/pgtable.h

+5 −0
Original line number Diff line number Diff line
@@ -264,6 +264,11 @@ static inline pmd_t pte_pmd(pte_t pte) 
	return __pmd(pte_val(pte));

}



static inline pgprot_t mk_sect_prot(pgprot_t prot)

{

	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);

}



/*

 * THP definitions.

 */

arch/arm64/mm/mmu.c

+22 −21
Original line number Diff line number Diff line
@@ -158,20 +158,10 @@ static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr, 


static void __init alloc_init_pmd(struct mm_struct *mm, pud_t *pud,

				  unsigned long addr, unsigned long end,

				  phys_addr_t phys, int map_io)

				  phys_addr_t phys, pgprot_t prot)

{

	pmd_t *pmd;

	unsigned long next;

	pmdval_t prot_sect;

	pgprot_t prot_pte;



	if (map_io) {

		prot_sect = PROT_SECT_DEVICE_nGnRE;

		prot_pte = __pgprot(PROT_DEVICE_nGnRE);

	} else {

		prot_sect = PROT_SECT_NORMAL_EXEC;

		prot_pte = PAGE_KERNEL_EXEC;

	}



	/*

	 * Check for initial section mappings in the pgd/pud and remove them.
@@ -187,7 +177,8 @@ static void __init alloc_init_pmd(struct mm_struct *mm, pud_t *pud, 
		/* try section mapping first */

		if (((addr | next | phys) & ~SECTION_MASK) == 0) {

			pmd_t old_pmd =*pmd;

			set_pmd(pmd, __pmd(phys | prot_sect));

			set_pmd(pmd, __pmd(phys |

					   pgprot_val(mk_sect_prot(prot))));

			/*

			 * Check for previous table entries created during

			 * boot (__create_page_tables) and flush them.
@@ -196,7 +187,7 @@ static void __init alloc_init_pmd(struct mm_struct *mm, pud_t *pud, 
				flush_tlb_all();

		} else {

			alloc_init_pte(pmd, addr, next, __phys_to_pfn(phys),

				       prot_pte);

				       prot);

		}

		phys += next - addr;

	} while (pmd++, addr = next, addr != end);
@@ -204,7 +195,7 @@ static void __init alloc_init_pmd(struct mm_struct *mm, pud_t *pud, 


static void __init alloc_init_pud(struct mm_struct *mm, pgd_t *pgd,

				  unsigned long addr, unsigned long end,

				  phys_addr_t phys, int map_io)

				  phys_addr_t phys, pgprot_t prot)

{

	pud_t *pud;

	unsigned long next;
@@ -222,10 +213,11 @@ static void __init alloc_init_pud(struct mm_struct *mm, pgd_t *pgd, 
		/*

		 * For 4K granule only, attempt to put down a 1GB block

		 */

		if (!map_io && (PAGE_SHIFT == 12) &&

		if ((PAGE_SHIFT == 12) &&

		    ((addr | next | phys) & ~PUD_MASK) == 0) {

			pud_t old_pud = *pud;

			set_pud(pud, __pud(phys | PROT_SECT_NORMAL_EXEC));

			set_pud(pud, __pud(phys |

					   pgprot_val(mk_sect_prot(prot))));



			/*

			 * If we have an old value for a pud, it will
@@ -240,7 +232,7 @@ static void __init alloc_init_pud(struct mm_struct *mm, pgd_t *pgd, 
				flush_tlb_all();

			}

		} else {

			alloc_init_pmd(mm, pud, addr, next, phys, map_io);

			alloc_init_pmd(mm, pud, addr, next, phys, prot);

		}

		phys += next - addr;

	} while (pud++, addr = next, addr != end);
@@ -252,7 +244,7 @@ static void __init alloc_init_pud(struct mm_struct *mm, pgd_t *pgd, 
 */

static void __init __create_mapping(struct mm_struct *mm, pgd_t *pgd,

				    phys_addr_t phys, unsigned long virt,

				    phys_addr_t size, int map_io)

				    phys_addr_t size, pgprot_t prot)

{

	unsigned long addr, length, end, next;
@@ -262,7 +254,7 @@ static void __init __create_mapping(struct mm_struct *mm, pgd_t *pgd, 
	end = addr + length;

	do {

		next = pgd_addr_end(addr, end);

		alloc_init_pud(mm, pgd, addr, next, phys, map_io);

		alloc_init_pud(mm, pgd, addr, next, phys, prot);

		phys += next - addr;

	} while (pgd++, addr = next, addr != end);

}
@@ -276,7 +268,7 @@ static void __init create_mapping(phys_addr_t phys, unsigned long virt, 
		return;

	}

	__create_mapping(&init_mm, pgd_offset_k(virt & PAGE_MASK), phys, virt,

			 size, 0);

			 size, PAGE_KERNEL_EXEC);

}



void __init create_id_mapping(phys_addr_t addr, phys_addr_t size, int map_io)
@@ -286,7 +278,16 @@ void __init create_id_mapping(phys_addr_t addr, phys_addr_t size, int map_io) 
		return;

	}

	__create_mapping(&init_mm, &idmap_pg_dir[pgd_index(addr)],

			 addr, addr, size, map_io);

			 addr, addr, size,

			 map_io ? __pgprot(PROT_DEVICE_nGnRE)

				: PAGE_KERNEL_EXEC);

}



void __init create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,

			       unsigned long virt, phys_addr_t size,

			       pgprot_t prot)

{

	__create_mapping(mm, pgd_offset(mm, virt), phys, virt, size, prot);

}



static void __init map_mem(void)