sh: default to extended TLB support.

All SH-X2 and SH-X3 parts support an extended TLB mode, which has been
left as experimental since support was originally merged. Now that it's
had some time to stabilize and get some exposure to various platforms,
we can drop it as an option and default enable it across the board.

This is also good future proofing for newer parts that will drop support
for the legacy TLB mode completely.

This will also force 3-level page tables for all newer parts, which is
necessary both for the varying page sizes and larger memories.

Signed-off-by: Paul Mundt <[e-mail]>

arch/sh/include/asm/pgalloc.h

···
 extern pgd_t *pgd_alloc(struct mm_struct *);
 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
 
-#ifdef CONFIG_PGTABLE_LEVELS_3
+#if PAGETABLE_LEVELS > 2
 extern void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd);
 extern pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address);
 extern void pmd_free(struct mm_struct *mm, pmd_t *pmd);

arch/sh/include/asm/pgtable.h

···
 #ifndef __ASM_SH_PGTABLE_H
 #define __ASM_SH_PGTABLE_H
 
-#ifdef CONFIG_PGTABLE_LEVELS_3
+#ifdef CONFIG_X2TLB
 #include <asm/pgtable_pmd.h>
 #else
 #include <asm/pgtable_nopmd.h>

arch/sh/include/asm/pgtable_nopmd.h

···
 /*
  * traditional two-level paging structure
  */
+#define PAGETABLE_LEVELS	2
 
 /* PTE bits */
-#define PTE_MAGNITUDE	2	/* 32-bit PTEs */
+#define PTE_MAGNITUDE		2	/* 32-bit PTEs */
 
-#define PTE_SHIFT	PAGE_SHIFT
-#define PTE_BITS	(PTE_SHIFT - PTE_MAGNITUDE)
+#define PTE_SHIFT		PAGE_SHIFT
+#define PTE_BITS		(PTE_SHIFT - PTE_MAGNITUDE)
 
 /* PGD bits */
-#define PGDIR_SHIFT	(PTE_SHIFT + PTE_BITS)
+#define PGDIR_SHIFT		(PTE_SHIFT + PTE_BITS)
 
-#define PTRS_PER_PGD	(PAGE_SIZE / (1 << PTE_MAGNITUDE))
+#define PTRS_PER_PGD		(PAGE_SIZE / (1 << PTE_MAGNITUDE))
 #define USER_PTRS_PER_PGD	(TASK_SIZE/PGDIR_SIZE)
 
 #endif /* __ASM_SH_PGTABLE_NOPMD_H */

arch/sh/include/asm/pgtable_pmd.h

···
  * Some cores need a 3-level page table layout, for example when using
  * 64-bit PTEs and 4K pages.
  */
+#define PAGETABLE_LEVELS	3
 
-#define PTE_MAGNITUDE	3	/* 64-bit PTEs on extended mode SH-X2 TLB */
+#define PTE_MAGNITUDE		3	/* 64-bit PTEs on SH-X2 TLB */
 
 /* PGD bits */
-#define PGDIR_SHIFT	30
+#define PGDIR_SHIFT		30
 
 #define PTRS_PER_PGD		4
 #define USER_PTRS_PER_PGD	2

arch/sh/mm/Kconfig

···
 	  and allows systems to support up to 512MiB of system memory.
 
 config X2TLB
-	bool "Enable extended TLB mode"
-	depends on (CPU_SHX2 || CPU_SHX3) && MMU && EXPERIMENTAL
-	help
-	  Selecting this option will enable the extended mode of the SH-X2
-	  TLB. For legacy SH-X behaviour and interoperability, say N. For
-	  all of the fun new features and a willingless to submit bug reports,
-	  say Y.
+	def_bool y
+	depends on (CPU_SHX2 || CPU_SHX3) && MMU
 
 config VSYSCALL
 	bool "Support vsyscall page"
···
 	depends on MEMORY_HOTPLUG
 
 choice
-	prompt "Page table layout"
-	default PGTABLE_LEVELS_3 if X2TLB
-	default PGTABLE_LEVELS_2
-
-config PGTABLE_LEVELS_2
-       bool "2 Levels"
-       help
-         This is the default page table layout for all SuperH CPUs.
-
-config PGTABLE_LEVELS_3
-       bool "3 Levels"
-       depends on X2TLB
-       help
-         This enables a 3 level page table structure.
-
-endchoice
-
-choice
 	prompt "Kernel page size"
-	default PAGE_SIZE_8KB if X2TLB
 	default PAGE_SIZE_4KB
 
 config PAGE_SIZE_4KB
 	bool "4kB"
-	depends on !MMU || !X2TLB || PGTABLE_LEVELS_3
 	help
 	  This is the default page size used by all SuperH CPUs.
 

arch/sh/mm/pgtable.c

···
 #define PGALLOC_GFP GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO
 
 static struct kmem_cache *pgd_cachep;
-
-#ifdef CONFIG_PGTABLE_LEVELS_3
+#if PAGETABLE_LEVELS > 2
 static struct kmem_cache *pmd_cachep;
 #endif
 
···
 	pgd_cachep = kmem_cache_create("pgd_cache",
 				       PTRS_PER_PGD * (1<<PTE_MAGNITUDE),
 				       PAGE_SIZE, SLAB_PANIC, pgd_ctor);
-#ifdef CONFIG_PGTABLE_LEVELS_3
+#if PAGETABLE_LEVELS > 2
 	pmd_cachep = kmem_cache_create("pmd_cache",
 				       PTRS_PER_PMD * (1<<PTE_MAGNITUDE),
 				       PAGE_SIZE, SLAB_PANIC, NULL);
···
 	kmem_cache_free(pgd_cachep, pgd);
 }
 
-#ifdef CONFIG_PGTABLE_LEVELS_3
+#if PAGETABLE_LEVELS > 2
 void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 {
 	set_pud(pud, __pud((unsigned long)pmd));
···
 {
 	kmem_cache_free(pmd_cachep, pmd);
 }
-#endif /* CONFIG_PGTABLE_LEVELS_3 */
+#endif /* PAGETABLE_LEVELS > 2 */