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// SPDX-License-Identifier: GPL-2.0-only
//
// Copyright (C) 2019 Jason Yan <yanaijie@huawei.com>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/stddef.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/memblock.h>
#include <asm/pgalloc.h>
#include <asm/prom.h>
#include <mm/mmu_decl.h>
static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size,
unsigned long kernel_sz)
{
/* return a fixed offset of 64M for now */
return SZ_64M;
}
/*
* To see if we need to relocate the kernel to a random offset
* void *dt_ptr - address of the device tree
* phys_addr_t size - size of the first memory block
*/
notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
{
unsigned long tlb_virt;
phys_addr_t tlb_phys;
unsigned long offset;
unsigned long kernel_sz;
kernel_sz = (unsigned long)_end - (unsigned long)_stext;
offset = kaslr_choose_location(dt_ptr, size, kernel_sz);
if (offset == 0)
return;
kernstart_virt_addr += offset;
kernstart_addr += offset;
is_second_reloc = 1;
if (offset >= SZ_64M) {
tlb_virt = round_down(kernstart_virt_addr, SZ_64M);
tlb_phys = round_down(kernstart_addr, SZ_64M);
/* Create kernel map to relocate in */
create_kaslr_tlb_entry(1, tlb_virt, tlb_phys);
}
/* Copy the kernel to it's new location and run */
memcpy((void *)kernstart_virt_addr, (void *)_stext, kernel_sz);
flush_icache_range(kernstart_virt_addr, kernstart_virt_addr + kernel_sz);
reloc_kernel_entry(dt_ptr, kernstart_virt_addr);
}
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