Commit ed415406 authored by David Hildenbrand's avatar David Hildenbrand Committed by Andrew Morton
Browse files

m68k/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE 

Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the
type.  Generic MM currently only uses 5 bits for the type
(MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused.

While at it, make sure for sun3 that the valid bit never gets set by
properly masking it off and mask the type in __swp_entry().

Link: https://lkml.kernel.org/r/20230113171026.582290-11-david@redhat.com


Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent ad464ff2

arch/m68k/include/asm/mcf_pgtable.h

+33 −3
Original line number Diff line number Diff line
@@ -46,6 +46,9 @@ 
#define _CACHEMASK040		(~0x060)

#define _PAGE_GLOBAL040		0x400   /* 68040 global bit, used for kva descs */



/* We borrow bit 7 to store the exclusive marker in swap PTEs. */

#define _PAGE_SWP_EXCLUSIVE	0x080



/*

 * Externally used page protection values.

 */
@@ -254,15 +257,42 @@ static inline pte_t pte_mkcache(pte_t pte) 
extern pgd_t kernel_pg_dir[PTRS_PER_PGD];



/*

 * Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e))

 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that

 * are !pte_none() && !pte_present().

 *

 * Format of swap PTEs:

 *

 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1

 *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0

 *   <------------------ offset -------------> 0 0 0 E <-- type --->

 *

 *   E is the exclusive marker that is not stored in swap entries.

 */

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

#define __swp_type(x)		((x).val & 0x7f)

#define __swp_offset(x)		((x).val >> 11)

#define __swp_entry(typ, off)	((swp_entry_t) { (typ) | \

#define __swp_entry(typ, off)	((swp_entry_t) { ((typ) & 0x7f) | \

					(off << 11) })

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

#define __swp_entry_to_pte(x)	(__pte((x).val))



#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE

static inline int pte_swp_exclusive(pte_t pte)

{

	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;

}



static inline pte_t pte_swp_mkexclusive(pte_t pte)

{

	pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;

	return pte;

}



static inline pte_t pte_swp_clear_exclusive(pte_t pte)

{

	pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;

	return pte;

}



#define pmd_pfn(pmd)		(pmd_val(pmd) >> PAGE_SHIFT)

#define pmd_page(pmd)		(pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))

arch/m68k/include/asm/motorola_pgtable.h

+35 −3
Original line number Diff line number Diff line
@@ -41,6 +41,9 @@ 


#define _PAGE_PROTNONE	0x004



/* We borrow bit 11 to store the exclusive marker in swap PTEs. */

#define _PAGE_SWP_EXCLUSIVE	0x800



#ifndef __ASSEMBLY__



/* This is the cache mode to be used for pages containing page descriptors for
@@ -169,12 +172,41 @@ static inline pte_t pte_mkcache(pte_t pte) 
#define swapper_pg_dir kernel_pg_dir

extern pgd_t kernel_pg_dir[128];



/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */

#define __swp_type(x)		(((x).val >> 4) & 0xff)

/*

 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that

 * are !pte_none() && !pte_present().

 *

 * Format of swap PTEs:

 *

 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1

 *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0

 *   <----------------- offset ------------> E <-- type ---> 0 0 0 0

 *

 *   E is the exclusive marker that is not stored in swap entries.

 */

#define __swp_type(x)		(((x).val >> 4) & 0x7f)

#define __swp_offset(x)		((x).val >> 12)

#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 4) | ((offset) << 12) })

#define __swp_entry(type, offset) ((swp_entry_t) { (((type) & 0x7f) << 4) | ((offset) << 12) })

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

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



#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE

static inline int pte_swp_exclusive(pte_t pte)

{

	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;

}



static inline pte_t pte_swp_mkexclusive(pte_t pte)

{

	pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;

	return pte;

}



static inline pte_t pte_swp_clear_exclusive(pte_t pte)

{

	pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;

	return pte;

}



#endif	/* !__ASSEMBLY__ */

#endif /* _MOTOROLA_PGTABLE_H */

arch/m68k/include/asm/sun3_pgtable.h

+36 −3
Original line number Diff line number Diff line
@@ -71,6 +71,9 @@ 
#define SUN3_PMD_MASK	(0x0000003F)

#define SUN3_PMD_MAGIC	(0x0000002B)



/* We borrow bit 6 to store the exclusive marker in swap PTEs. */

#define _PAGE_SWP_EXCLUSIVE	0x040



#ifndef __ASSEMBLY__



/*
@@ -152,12 +155,42 @@ static inline pte_t pte_mkcache(pte_t pte) { return pte; } 
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];

extern pgd_t kernel_pg_dir[PTRS_PER_PGD];



/* Macros to (de)construct the fake PTEs representing swap pages. */

#define __swp_type(x)		((x).val & 0x7F)

/*

 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that

 * are !pte_none() && !pte_present().

 *

 * Format of swap PTEs:

 *

 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1

 *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0

 *   0 <--------------------- offset ----------------> E <- type -->

 *

 *   E is the exclusive marker that is not stored in swap entries.

 */

#define __swp_type(x)		((x).val & 0x3f)

#define __swp_offset(x)		(((x).val) >> 7)

#define __swp_entry(type,offset) ((swp_entry_t) { ((type) | ((offset) << 7)) })

#define __swp_entry(type, offset) ((swp_entry_t) { (((type) & 0x3f) | \

						   (((offset) << 7) & ~SUN3_PAGE_VALID)) })

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

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



#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE

static inline int pte_swp_exclusive(pte_t pte)

{

	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;

}



static inline pte_t pte_swp_mkexclusive(pte_t pte)

{

	pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;

	return pte;

}



static inline pte_t pte_swp_clear_exclusive(pte_t pte)

{

	pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;

	return pte;

}



#endif	/* !__ASSEMBLY__ */

#endif	/* !_SUN3_PGTABLE_H */