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: Will Deacon <will.deacon@arm.com>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index c2f006c..5fd40c4 100644 (file)
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -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

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 210d632..5907924 100644 (file)
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -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.
  */

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 7d5dfe2..3f3d5aa 100644 (file)
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -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)