[MIPS] Fix swap entry for MIPS32 36-bit physical address

With 64-bit physical address enabled, 'swapon' was causing kernel oops on
Alchemy CPUs (MIPS32) because of the swap entry type field corrupting the
_PAGE_FILE bit in 'pte_low' field. So, switch to storing the swap entry in
'pte_high' field using all its bits except _PAGE_GLOBAL and _PAGE_VALID which
gives 25 bits for the swap entry offset.
    
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Sergei Shtylyov 2006-05-27 20:43:04 +04:00 committed by Ralf Baechle
parent 79e0bc3725
commit 6ebba0e2f5
1 changed files with 15 additions and 3 deletions

View File

@ -191,10 +191,17 @@ pfn_pte(unsigned long pfn, pgprot_t prot)
#else
/* Swap entries must have VALID and GLOBAL bits cleared. */
#define __swp_type(x) (((x).val >> 8) & 0x1f)
#define __swp_offset(x) ((x).val >> 13)
#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
#define __swp_type(x) (((x).val >> 2) & 0x1f)
#define __swp_offset(x) ((x).val >> 7)
#define __swp_entry(type,offset) \
((swp_entry_t) { ((type) << 8) | ((offset) << 13) })
((swp_entry_t) { ((type) << 2) | ((offset) << 7) })
#else
#define __swp_type(x) (((x).val >> 8) & 0x1f)
#define __swp_offset(x) ((x).val >> 13)
#define __swp_entry(type,offset) \
((swp_entry_t) { ((type) << 8) | ((offset) << 13) })
#endif /* defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32) */
/*
* Bits 0, 1, 2, 7 and 8 are taken, split up the 27 bits of offset
@ -218,7 +225,12 @@ pfn_pte(unsigned long pfn, pgprot_t prot)
#endif
#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
#define __pte_to_swp_entry(pte) ((swp_entry_t) { (pte).pte_high })
#define __swp_entry_to_pte(x) ((pte_t) { 0, (x).val })
#else
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
#endif
#endif /* _ASM_PGTABLE_32_H */