ARM: pgtable: use conventional page table code for identity mappings

Remove some knowledge of our 2-level page table layout from the
identity mapping code - we assume that a step size of PGDIR_SIZE will
allow us to step over all entries.  While this is true today, it won't
be true in the near future.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index 034124d..5729944 100644 (file)
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -4,33 +4,49 @@
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 
+static void idmap_add_pmd(pgd_t *pgd, unsigned long addr, unsigned long end,
+       unsigned long prot)
+{
+       pmd_t *pmd = pmd_offset(pgd, addr);
+
+       addr = (addr & PMD_MASK) | prot;
+       pmd[0] = __pmd(addr);
+       addr += SECTION_SIZE;
+       pmd[1] = __pmd(addr);
+       flush_pmd_entry(pmd);
+}
+
 void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)
 {
-       unsigned long prot;
+       unsigned long prot, next;
 
        prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE;
        if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
                prot |= PMD_BIT4;
 
-       for (addr &= PGDIR_MASK; addr < end;) {
-               pmd_t *pmd = pmd_offset(pgd + pgd_index(addr), addr);
-               pmd[0] = __pmd(addr | prot);
-               addr += SECTION_SIZE;
-               pmd[1] = __pmd(addr | prot);
-               addr += SECTION_SIZE;
-               flush_pmd_entry(pmd);
-       }
+       pgd += pgd_index(addr);
+       do {
+               next = pgd_addr_end(addr, end);
+               idmap_add_pmd(pgd, addr, next, prot);
+       } while (pgd++, addr = next, addr != end);
 }
 
 #ifdef CONFIG_SMP
+static void idmap_del_pmd(pgd_t *pgd, unsigned long addr, unsigned long end)
+{
+       pmd_t *pmd = pmd_offset(pgd, addr);
+       pmd_clear(pmd);
+}
+
 void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end)
 {
-       for (addr &= PGDIR_MASK; addr < end; addr += PGDIR_SIZE) {
-               pmd_t *pmd = pmd_offset(pgd + pgd_index(addr), addr);
-               pmd[0] = __pmd(0);
-               pmd[1] = __pmd(0);
-               clean_pmd_entry(pmd);
-       }
+       unsigned long next;
+
+       pgd += pgd_index(addr);
+       do {
+               next = pgd_addr_end(addr, end);
+               idmap_del_pmd(pgd, addr, next);
+       } while (pgd++, addr = next, addr != end);
 }
 #endif