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// SPDX-License-Identifier: GPL-2.0
#include <linux/string.h>
#include <linux/elf.h>
#include <asm/boot_data.h>
#include <asm/sections.h>
#include <asm/cpu_mf.h>
#include <asm/setup.h>
#include <asm/kexec.h>
#include <asm/sclp.h>
#include <asm/diag.h>
#include <asm/uv.h>
#include "compressed/decompressor.h"
#include "boot.h"
extern char __boot_data_start[], __boot_data_end[];
extern char __boot_data_preserved_start[], __boot_data_preserved_end[];
unsigned long __bootdata_preserved(__kaslr_offset);
unsigned long __bootdata(ident_map_size);
/*
* Some code and data needs to stay below 2 GB, even when the kernel would be
* relocated above 2 GB, because it has to use 31 bit addresses.
* Such code and data is part of the .dma section, and its location is passed
* over to the decompressed / relocated kernel via the .boot.preserved.data
* section.
*/
extern char _sdma[], _edma[];
extern char _stext_dma[], _etext_dma[];
extern struct exception_table_entry _start_dma_ex_table[];
extern struct exception_table_entry _stop_dma_ex_table[];
unsigned long __bootdata_preserved(__sdma) = __pa(&_sdma);
unsigned long __bootdata_preserved(__edma) = __pa(&_edma);
unsigned long __bootdata_preserved(__stext_dma) = __pa(&_stext_dma);
unsigned long __bootdata_preserved(__etext_dma) = __pa(&_etext_dma);
struct exception_table_entry *
__bootdata_preserved(__start_dma_ex_table) = _start_dma_ex_table;
struct exception_table_entry *
__bootdata_preserved(__stop_dma_ex_table) = _stop_dma_ex_table;
int _diag210_dma(struct diag210 *addr);
int _diag26c_dma(void *req, void *resp, enum diag26c_sc subcode);
int _diag14_dma(unsigned long rx, unsigned long ry1, unsigned long subcode);
void _diag0c_dma(struct hypfs_diag0c_entry *entry);
void _diag308_reset_dma(void);
struct diag_ops __bootdata_preserved(diag_dma_ops) = {
.diag210 = _diag210_dma,
.diag26c = _diag26c_dma,
.diag14 = _diag14_dma,
.diag0c = _diag0c_dma,
.diag308_reset = _diag308_reset_dma
};
static struct diag210 _diag210_tmp_dma __section(".dma.data");
struct diag210 *__bootdata_preserved(__diag210_tmp_dma) = &_diag210_tmp_dma;
void error(char *x)
{
sclp_early_printk("\n\n");
sclp_early_printk(x);
sclp_early_printk("\n\n -- System halted");
disabled_wait();
}
static void setup_lpp(void)
{
S390_lowcore.current_pid = 0;
S390_lowcore.lpp = LPP_MAGIC;
if (test_facility(40))
lpp(&S390_lowcore.lpp);
}
#ifdef CONFIG_KERNEL_UNCOMPRESSED
unsigned long mem_safe_offset(void)
{
return vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size;
}
#endif
static void rescue_initrd(unsigned long addr)
{
if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
return;
if (!INITRD_START || !INITRD_SIZE)
return;
if (addr <= INITRD_START)
return;
memmove((void *)addr, (void *)INITRD_START, INITRD_SIZE);
INITRD_START = addr;
}
static void copy_bootdata(void)
{
if (__boot_data_end - __boot_data_start != vmlinux.bootdata_size)
error(".boot.data section size mismatch");
memcpy((void *)vmlinux.bootdata_off, __boot_data_start, vmlinux.bootdata_size);
if (__boot_data_preserved_end - __boot_data_preserved_start != vmlinux.bootdata_preserved_size)
error(".boot.preserved.data section size mismatch");
memcpy((void *)vmlinux.bootdata_preserved_off, __boot_data_preserved_start, vmlinux.bootdata_preserved_size);
}
static void handle_relocs(unsigned long offset)
{
Elf64_Rela *rela_start, *rela_end, *rela;
int r_type, r_sym, rc;
Elf64_Addr loc, val;
Elf64_Sym *dynsym;
rela_start = (Elf64_Rela *) vmlinux.rela_dyn_start;
rela_end = (Elf64_Rela *) vmlinux.rela_dyn_end;
dynsym = (Elf64_Sym *) vmlinux.dynsym_start;
for (rela = rela_start; rela < rela_end; rela++) {
loc = rela->r_offset + offset;
val = rela->r_addend;
r_sym = ELF64_R_SYM(rela->r_info);
if (r_sym) {
if (dynsym[r_sym].st_shndx != SHN_UNDEF)
val += dynsym[r_sym].st_value + offset;
} else {
/*
* 0 == undefined symbol table index (STN_UNDEF),
* used for R_390_RELATIVE, only add KASLR offset
*/
val += offset;
}
r_type = ELF64_R_TYPE(rela->r_info);
rc = arch_kexec_do_relocs(r_type, (void *) loc, val, 0);
if (rc)
error("Unknown relocation type");
}
}
/*
* Merge information from several sources into a single ident_map_size value.
* "ident_map_size" represents the upper limit of physical memory we may ever
* reach. It might not be all online memory, but also include standby (offline)
* memory. "ident_map_size" could be lower then actual standby or even online
* memory present, due to limiting factors. We should never go above this limit.
* It is the size of our identity mapping.
*
* Consider the following factors:
* 1. max_physmem_end - end of physical memory online or standby.
* Always <= end of the last online memory block (get_mem_detect_end()).
* 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the
* kernel is able to support.
* 3. "mem=" kernel command line option which limits physical memory usage.
* 4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as
* crash kernel.
* 5. "hsa" size which is a memory limit when the kernel is executed during
* zfcp/nvme dump.
*/
static void setup_ident_map_size(unsigned long max_physmem_end)
{
unsigned long hsa_size;
ident_map_size = max_physmem_end;
if (memory_limit)
ident_map_size = min(ident_map_size, memory_limit);
ident_map_size = min(ident_map_size, 1UL << MAX_PHYSMEM_BITS);
#ifdef CONFIG_CRASH_DUMP
if (OLDMEM_BASE) {
kaslr_enabled = 0;
ident_map_size = min(ident_map_size, OLDMEM_SIZE);
} else if (ipl_block_valid && is_ipl_block_dump()) {
kaslr_enabled = 0;
if (!sclp_early_get_hsa_size(&hsa_size) && hsa_size)
ident_map_size = min(ident_map_size, hsa_size);
}
#endif
}
/*
* This function clears the BSS section of the decompressed Linux kernel and NOT the decompressor's.
*/
static void clear_bss_section(void)
{
memset((void *)vmlinux.default_lma + vmlinux.image_size, 0, vmlinux.bss_size);
}
/*
* Set vmalloc area size to an 8th of (potential) physical memory
* size, unless size has been set by kernel command line parameter.
*/
static void setup_vmalloc_size(void)
{
unsigned long size;
if (vmalloc_size_set)
return;
size = round_up(ident_map_size / 8, _SEGMENT_SIZE);
vmalloc_size = max(size, vmalloc_size);
}
void startup_kernel(void)
{
unsigned long random_lma;
unsigned long safe_addr;
void *img;
setup_lpp();
store_ipl_parmblock();
safe_addr = mem_safe_offset();
safe_addr = read_ipl_report(safe_addr);
uv_query_info();
rescue_initrd(safe_addr);
sclp_early_read_info();
setup_boot_command_line();
parse_boot_command_line();
setup_ident_map_size(detect_memory());
setup_vmalloc_size();
random_lma = __kaslr_offset = 0;
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_enabled) {
random_lma = get_random_base(safe_addr);
if (random_lma) {
__kaslr_offset = random_lma - vmlinux.default_lma;
img = (void *)vmlinux.default_lma;
vmlinux.default_lma += __kaslr_offset;
vmlinux.entry += __kaslr_offset;
vmlinux.bootdata_off += __kaslr_offset;
vmlinux.bootdata_preserved_off += __kaslr_offset;
vmlinux.rela_dyn_start += __kaslr_offset;
vmlinux.rela_dyn_end += __kaslr_offset;
vmlinux.dynsym_start += __kaslr_offset;
}
}
if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) {
img = decompress_kernel();
memmove((void *)vmlinux.default_lma, img, vmlinux.image_size);
} else if (__kaslr_offset)
memcpy((void *)vmlinux.default_lma, img, vmlinux.image_size);
clear_bss_section();
copy_bootdata();
if (IS_ENABLED(CONFIG_RELOCATABLE))
handle_relocs(__kaslr_offset);
if (__kaslr_offset) {
/*
* Save KASLR offset for early dumps, before vmcore_info is set.
* Mark as uneven to distinguish from real vmcore_info pointer.
*/
S390_lowcore.vmcore_info = __kaslr_offset | 0x1UL;
/* Clear non-relocated kernel */
if (IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED))
memset(img, 0, vmlinux.image_size);
}
vmlinux.entry();
}
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