sh: Reworked swap cache entry encoding for SH-X2 MMU.

extern void update_mmu_cache(struct vm_area_struct * vma,

			     unsigned long address, pte_t pte);

/* Encode and de-code a swap entry */

/*

 * Encode and de-code a swap entry

 *

 * Constraints:

 *	_PAGE_FILE at bit 0

 *	_PAGE_PRESENT at bit 8

 *	_PAGE_PROTNONE at bit 9

 *

 * For the normal case, we encode the swap type into bits 0:7 and the

 * swap offset into bits 10:30. For the 64-bit PTE case, we keep the

 * preserved bits in the low 32-bits and use the upper 32 as the swap

 * offset (along with a 5-bit type), following the same approach as x86

 * PAE. This keeps the logic quite simple, and allows for a full 32

 * PTE_FILE_MAX_BITS, as opposed to the 29-bits we're constrained with

 * in the pte_low case.

 *

 * As is evident by the Alpha code, if we ever get a 64-bit unsigned

 * long (swp_entry_t) to match up with the 64-bit PTEs, this all becomes

 * much cleaner..

 *

 * NOTE: We should set ZEROs at the position of _PAGE_PRESENT

 *       and _PAGE_PROTNONE bits

 */

#ifdef CONFIG_X2TLB

#define __swp_type(x)			((x).val & 0x1f)

#define __swp_offset(x)			((x).val >> 5)

#define __swp_entry(type, offset)	((swp_entry_t){ (type) | (offset) << 5})

#define __pte_to_swp_entry(pte)		((swp_entry_t){ (pte).pte_high })

#define __swp_entry_to_pte(x)		((pte_t){ 0, (x).val })

/*

 * Encode and decode a nonlinear file mapping entry

 */

#define pte_to_pgoff(pte)		((pte).pte_high)

#define pgoff_to_pte(off)		((pte_t) { _PAGE_FILE, (off) })

#define PTE_FILE_MAX_BITS		32

#else

#define __swp_type(x)			((x).val & 0xff)

#define __swp_offset(x)			((x).val >> 10)

#define __swp_entry(type, offset) ((swp_entry_t) { (type) | ((offset) << 10) })

#define __swp_entry(type, offset)	((swp_entry_t){(type) | (offset) <<10)})

#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 1 })

#define __swp_entry_to_pte(x)		((pte_t) { (x).val << 1 })

#define PTE_FILE_MAX_BITS	29

#define pte_to_pgoff(pte)	(pte_val(pte) >> 1)

#define pgoff_to_pte(off)	((pte_t) { ((off) << 1) | _PAGE_FILE })

#endif

typedef pte_t *pte_addr_t;