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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_KASAN_H
#define __ASM_KASAN_H
#include <asm/pgtable.h>
#ifdef CONFIG_KASAN
#define KASAN_SHADOW_SCALE_SHIFT 3
#define KASAN_SHADOW_SIZE \
(_AC(1, UL) << (_REGION1_SHIFT - KASAN_SHADOW_SCALE_SHIFT))
#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
#define KASAN_SHADOW_START KASAN_SHADOW_OFFSET
#define KASAN_SHADOW_END (KASAN_SHADOW_START + KASAN_SHADOW_SIZE)
extern void kasan_early_init(void);
extern void kasan_copy_shadow_mapping(void);
extern void kasan_free_early_identity(void);
/*
* 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
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