From ed4154067a086c44608b08f55cceb2688b661750 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 13 Jan 2023 18:10:10 +0100 Subject: [PATCH] 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 Cc: Geert Uytterhoeven Cc: Greg Ungerer Signed-off-by: Andrew Morton --- arch/m68k/include/asm/mcf_pgtable.h | 36 ++++++++++++++++++++++++++--- arch/m68k/include/asm/motorola_pgtable.h | 38 ++++++++++++++++++++++++++++--- arch/m68k/include/asm/sun3_pgtable.h | 39 +++++++++++++++++++++++++++++--- 3 files changed, 104 insertions(+), 9 deletions(-) diff --git a/arch/m68k/include/asm/mcf_pgtable.h b/arch/m68k/include/asm/mcf_pgtable.h index b619b22823f8..3f8f4d0e66dd 100644 --- a/arch/m68k/include/asm/mcf_pgtable.h +++ b/arch/m68k/include/asm/mcf_pgtable.h @@ -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)) diff --git a/arch/m68k/include/asm/motorola_pgtable.h b/arch/m68k/include/asm/motorola_pgtable.h index 562b54e09850..c1782563e793 100644 --- a/arch/m68k/include/asm/motorola_pgtable.h +++ b/arch/m68k/include/asm/motorola_pgtable.h @@ -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 */ diff --git a/arch/m68k/include/asm/sun3_pgtable.h b/arch/m68k/include/asm/sun3_pgtable.h index 90d57e537eb1..dbfc9703b15d 100644 --- a/arch/m68k/include/asm/sun3_pgtable.h +++ b/arch/m68k/include/asm/sun3_pgtable.h @@ -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 */ -- 2.11.0