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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: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
David Hildenbrand 2023-01-13 18:10:10 +01:00 committed by Andrew Morton
parent ad464ff2c0
commit ed4154067a
3 changed files with 104 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
arch/m68k/include/asm/mcf_pgtable.h
View File

@ -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))

38
arch/m68k/include/asm/motorola_pgtable.h
View File

@ -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 */

39
arch/m68k/include/asm/sun3_pgtable.h
View File

@ -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 */