[PATCH] i386 mm init cleanup part 2

The remaining cleanups are to switch to using pfn instead of vaddr, and
improve readability.

arch/i386/mm/init.c

@@ -181,22 +181,16 @@ unsigned long __PAGE_KERNEL = _PAGE_KERNEL;
 
 static void __init pagetable_init (void)
 {
-	unsigned long vaddr, end;
+	unsigned long vaddr, pfn;
 	pgd_t *pgd, *pgd_base;
 	int i, j, k;
 	pmd_t *pmd;
 	pte_t *pte, *pte_base;
 
-	/*
-	 * This can be zero as well - no problem, in that case we exit
-	 * the loops anyway due to the PTRS_PER_* conditions.
-	 */
-	end = (unsigned long)__va(max_low_pfn*PAGE_SIZE);
-
 	pgd_base = swapper_pg_dir;
 #if CONFIG_X86_PAE
 	for (i = 0; i < PTRS_PER_PGD; i++)
-		set_pgd(pgd_base + i, __pgd(1 + __pa(empty_zero_page)));
+		set_pgd(pgd_base + i, __pgd(__pa(empty_zero_page) | _PAGE_PRESENT));
 #endif
 	if (cpu_has_pse) {
 		set_in_cr4(X86_CR4_PSE);
@@ -207,41 +201,28 @@ static void __init pagetable_init (void)
 	}
 
 	i = __pgd_offset(PAGE_OFFSET);
+	pfn = 0;
 	pgd = pgd_base + i;
 
-	for (; i < PTRS_PER_PGD; pgd++, i++) {
-		vaddr = i*PGDIR_SIZE;
-		if (end && (vaddr >= end))
-			break;
+	for (; i < PTRS_PER_PGD && pfn < max_low_pfn; pgd++, i++) {
 #if CONFIG_X86_PAE
 		pmd = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
-		set_pgd(pgd, __pgd(__pa(pmd) + 0x1));
+		set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT));
 #else
-		pmd = (pmd_t *)pgd;
+		pmd = (pmd_t *) pgd;
 #endif
-		if (pmd != pmd_offset(pgd, 0))
-			BUG();
-		for (j = 0; j < PTRS_PER_PMD; pmd++, j++) {
-			vaddr = i*PGDIR_SIZE + j*PMD_SIZE;
-			if (end && (vaddr >= end))
-				break;
+		for (j = 0; j < PTRS_PER_PMD && pfn < max_low_pfn; pmd++, j++) {
 			if (cpu_has_pse) {
-				set_pmd(pmd, pfn_pmd(__pa(vaddr) >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
-				continue;
-			}
-
+				set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE));
+				pfn += PTRS_PER_PTE;
+			} else {
 				pte_base = pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 
-			for (k = 0; k < PTRS_PER_PTE; pte++, k++) {
-				vaddr = i*PGDIR_SIZE + j*PMD_SIZE + k*PAGE_SIZE;
-				if (end && (vaddr >= end))
-					break;
-				*pte = pfn_pte(__pa(vaddr) >> PAGE_SHIFT, PAGE_KERNEL);
-			}
-			set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte_base)));
-			if (pte_base != pte_offset_kernel(pmd, 0))
-				BUG();
+				for (k = 0; k < PTRS_PER_PTE && pfn < max_low_pfn; pte++, pfn++, k++)
+					set_pte(pte, pfn_pte(pfn, PAGE_KERNEL));
 
+				set_pmd(pmd, __pmd(__pa(pte_base) | _KERNPG_TABLE));
+			}
 		}
 	}