From af94002bda1d94f667706b6369ca1e718f32a072 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Wed, 13 Jan 2021 15:28:16 +0800 Subject: csky: Fixup swapon Current csky's swappon is broken by wrong swap PTE entry format. Now redesign the new format for abiv1 & abiv2 and make swappon + zram work properly on csky machines. C-SKY PTE has VALID, DIRTY to emulate PRESENT, READ, WRITE, EXEC attributes. GLOBAL bit is shared by two pages in the same tlb entry. So we need to keep GLOBAL, VALID, PRESENT zero in swp_pte. To distinguish PAGE_NONE and swp_pte, we need to use an additional bit (abiv1 is _PAGE_READ, abiv2 is _PAGE_WRITE). Signed-off-by: Guo Ren Cc: Arnd Bergmann --- arch/csky/abiv1/inc/abi/pgtable-bits.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'arch/csky/abiv1') diff --git a/arch/csky/abiv1/inc/abi/pgtable-bits.h b/arch/csky/abiv1/inc/abi/pgtable-bits.h index 6583333b2b0c..50ebe9c28095 100644 --- a/arch/csky/abiv1/inc/abi/pgtable-bits.h +++ b/arch/csky/abiv1/inc/abi/pgtable-bits.h @@ -24,6 +24,28 @@ #define _CACHE_CACHED _PAGE_CACHE #define _CACHE_UNCACHED _PAGE_UNCACHE +#define _PAGE_PROT_NONE _PAGE_READ + +/* + * Encode and decode a swap entry + * + * Format of swap PTE: + * bit 0: _PAGE_PRESENT (zero) + * bit 1: _PAGE_READ (zero) + * bit 2 - 5: swap type[0 - 3] + * bit 6: _PAGE_GLOBAL (zero) + * bit 7: _PAGE_VALID (zero) + * bit 8: swap type[4] + * bit 9 - 31: swap offset + */ +#define __swp_type(x) ((((x).val >> 2) & 0xf) | \ + (((x).val >> 4) & 0x10)) +#define __swp_offset(x) ((x).val >> 9) +#define __swp_entry(type, offset) ((swp_entry_t) { \ + ((type & 0xf) << 2) | \ + ((type & 0x10) << 4) | \ + ((offset) << 9)}) + #define HAVE_ARCH_UNMAPPED_AREA #endif /* __ASM_CSKY_PGTABLE_BITS_H */ -- cgit v1.2.3-59-g8ed1b