// SPDX-License-Identifier: GPL-2.0

#define DISABLE_BRANCH_PROFILING

#include <linux/kasan.h>
#include <linux/memblock.h>
#include <linux/hugetlb.h>

#include <asm/pgalloc.h>

static int __init
kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
{
        pmd_t *pmd = pmd_off_k(k_start);
        unsigned long k_cur, k_next;

        for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++, block += SZ_4M) {
                pte_t *ptep;
                int i;

                k_next = pgd_addr_end(k_cur, k_end);
                if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
                        continue;

                ptep = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);
                if (!ptep)
                        return -ENOMEM;

                for (i = 0; i < PTRS_PER_PTE; i++) {
                        pte_t pte = pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block + i * PAGE_SIZE)), PAGE_KERNEL));

                        __set_pte_at(&init_mm, k_cur, ptep + i, pte, 1);
                }
                pmd_populate_kernel(&init_mm, pmd, ptep);
                *pmd = __pmd(pmd_val(*pmd) | _PMD_PAGE_8M);
        }
        return 0;
}

int __init kasan_init_region(void *start, size_t size)
{
        unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
        unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
        unsigned long k_cur;
        int ret;
        void *block;

        block = memblock_alloc(k_end - k_start, SZ_8M);
        if (!block)
                return -ENOMEM;

        if (IS_ALIGNED(k_start, SZ_8M)) {
                kasan_init_shadow_8M(k_start, ALIGN_DOWN(k_end, SZ_8M), block);
                k_cur = ALIGN_DOWN(k_end, SZ_8M);
                if (k_cur == k_end)
                        goto finish;
        } else {
                k_cur = k_start;
        }

        ret = kasan_init_shadow_page_tables(k_start, k_end);
        if (ret)
                return ret;

        for (; k_cur < k_end; k_cur += PAGE_SIZE) {
                pmd_t *pmd = pmd_off_k(k_cur);
                void *va = block + k_cur - k_start;
                pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);

                if (k_cur < ALIGN_DOWN(k_end, SZ_512K))
                        pte = pte_mkhuge(pte);

                __set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
        }
finish:
        flush_tlb_kernel_range(k_start, k_end);
        return 0;
}