0c4f2623b9
Currently there are two separate places where kernel memory layout has to be known and adjusted: 1. early kasan setup. 2. paging setup later. Those 2 places had to be kept in sync and adjusted to reflect peculiar technical details of one another. With additional factors which influence kernel memory layout like ultravisor secure storage limit, complexity of keeping two things in sync grew up even more. Besides that if we look forward towards creating identity mapping and enabling DAT before jumping into uncompressed kernel - that would also require full knowledge of and control over kernel memory layout. So, de-duplicate and move kernel memory layout setup logic into the decompressor. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
52 lines
1.7 KiB
C
52 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __ASM_KASAN_H
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#define __ASM_KASAN_H
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#include <asm/pgtable.h>
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#ifdef CONFIG_KASAN
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#define KASAN_SHADOW_SCALE_SHIFT 3
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#define KASAN_SHADOW_SIZE \
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(_AC(1, UL) << (_REGION1_SHIFT - KASAN_SHADOW_SCALE_SHIFT))
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#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
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#define KASAN_SHADOW_START KASAN_SHADOW_OFFSET
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#define KASAN_SHADOW_END (KASAN_SHADOW_START + KASAN_SHADOW_SIZE)
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extern void kasan_early_init(void);
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extern void kasan_copy_shadow_mapping(void);
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extern void kasan_free_early_identity(void);
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/*
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* Estimate kasan memory requirements, which it will reserve
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* at the very end of available physical memory. To estimate
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* that, we take into account that kasan would require
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* 1/8 of available physical memory (for shadow memory) +
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* creating page tables for the whole memory + shadow memory
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* region (1 + 1/8). To keep page tables estimates simple take
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* the double of combined ptes size.
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*
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* physmem parameter has to be already adjusted if not entire physical memory
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* would be used (e.g. due to effect of "mem=" option).
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*/
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static inline unsigned long kasan_estimate_memory_needs(unsigned long physmem)
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{
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unsigned long kasan_needs;
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unsigned long pages;
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/* for shadow memory */
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kasan_needs = round_up(physmem / 8, PAGE_SIZE);
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/* for paging structures */
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pages = DIV_ROUND_UP(physmem + kasan_needs, PAGE_SIZE);
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kasan_needs += DIV_ROUND_UP(pages, _PAGE_ENTRIES) * _PAGE_TABLE_SIZE * 2;
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return kasan_needs;
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}
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#else
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static inline void kasan_early_init(void) { }
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static inline void kasan_copy_shadow_mapping(void) { }
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static inline void kasan_free_early_identity(void) { }
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static inline unsigned long kasan_estimate_memory_needs(unsigned long physmem) { return 0; }
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#endif
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#endif
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