diff options
| author | Vasily Gorbik <gor@linux.ibm.com> | 2020-10-05 13:53:36 +0200 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2020-11-09 11:20:59 +0100 |
| commit | 0c4ec024a481774df98910c79a4b3a105d1bb996 (patch) | |
| tree | fee5cfbcb8c2558986b7a5408a649f5de27a8cb8 /arch/s390/include | |
| parent | e385b550faf356db47234083c53e9841e8ec05c5 (diff) | |
s390/kasan: move memory needs estimation into a function
Also correct rounding downs in estimation calculations.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch/s390/include')
| -rw-r--r-- | arch/s390/include/asm/kasan.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/arch/s390/include/asm/kasan.h b/arch/s390/include/asm/kasan.h index eea62586e719..76f351bd6645 100644 --- a/arch/s390/include/asm/kasan.h +++ b/arch/s390/include/asm/kasan.h @@ -17,10 +17,36 @@ extern void kasan_early_init(void); extern void kasan_copy_shadow_mapping(void); extern void kasan_free_early_identity(void); extern unsigned long kasan_vmax; + +/* + * Estimate kasan memory requirements, which it will reserve + * at the very end of available physical memory. To estimate + * that, we take into account that kasan would require + * 1/8 of available physical memory (for shadow memory) + + * creating page tables for the whole memory + shadow memory + * region (1 + 1/8). To keep page tables estimates simple take + * the double of combined ptes size. + * + * physmem parameter has to be already adjusted if not entire physical memory + * would be used (e.g. due to effect of "mem=" option). + */ +static inline unsigned long kasan_estimate_memory_needs(unsigned long physmem) +{ + unsigned long kasan_needs; + unsigned long pages; + /* for shadow memory */ + kasan_needs = round_up(physmem / 8, PAGE_SIZE); + /* for paging structures */ + pages = DIV_ROUND_UP(physmem + kasan_needs, PAGE_SIZE); + kasan_needs += DIV_ROUND_UP(pages, _PAGE_ENTRIES) * _PAGE_TABLE_SIZE * 2; + + return kasan_needs; +} #else static inline void kasan_early_init(void) { } static inline void kasan_copy_shadow_mapping(void) { } static inline void kasan_free_early_identity(void) { } +static inline unsigned long kasan_estimate_memory_needs(unsigned long physmem) { return 0; } #endif #endif |