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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/kasan.h>
- #include <asm/kexec.h>
- #include <asm/sclp.h>
- #include <asm/diag.h>
- #include <asm/uv.h>
- #include <asm/abs_lowcore.h>
- #include "decompressor.h"
- #include "boot.h"
- #include "uv.h"
- unsigned long __bootdata_preserved(__kaslr_offset);
- unsigned long __bootdata_preserved(__abs_lowcore);
- unsigned long __bootdata_preserved(__memcpy_real_area);
- unsigned long __bootdata(__amode31_base);
- unsigned long __bootdata_preserved(VMALLOC_START);
- unsigned long __bootdata_preserved(VMALLOC_END);
- struct page *__bootdata_preserved(vmemmap);
- unsigned long __bootdata_preserved(vmemmap_size);
- unsigned long __bootdata_preserved(MODULES_VADDR);
- unsigned long __bootdata_preserved(MODULES_END);
- unsigned long __bootdata(ident_map_size);
- int __bootdata(is_full_image) = 1;
- struct initrd_data __bootdata(initrd_data);
- u64 __bootdata_preserved(stfle_fac_list[16]);
- u64 __bootdata_preserved(alt_stfle_fac_list[16]);
- struct oldmem_data __bootdata_preserved(oldmem_data);
- 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 unsigned long rescue_initrd(unsigned long safe_addr)
- {
- if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
- return safe_addr;
- if (!initrd_data.start || !initrd_data.size)
- return safe_addr;
- if (initrd_data.start < safe_addr) {
- memmove((void *)safe_addr, (void *)initrd_data.start, initrd_data.size);
- initrd_data.start = safe_addr;
- }
- return initrd_data.start + initrd_data.size;
- }
- 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_data.start) {
- kaslr_enabled = 0;
- ident_map_size = min(ident_map_size, oldmem_data.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
- }
- static void setup_kernel_memory_layout(void)
- {
- unsigned long vmemmap_start;
- unsigned long rte_size;
- unsigned long pages;
- unsigned long vmax;
- pages = ident_map_size / PAGE_SIZE;
- /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
- vmemmap_size = SECTION_ALIGN_UP(pages) * sizeof(struct page);
- /* choose kernel address space layout: 4 or 3 levels. */
- vmemmap_start = round_up(ident_map_size, _REGION3_SIZE);
- if (IS_ENABLED(CONFIG_KASAN) ||
- vmalloc_size > _REGION2_SIZE ||
- vmemmap_start + vmemmap_size + vmalloc_size + MODULES_LEN >
- _REGION2_SIZE) {
- vmax = _REGION1_SIZE;
- rte_size = _REGION2_SIZE;
- } else {
- vmax = _REGION2_SIZE;
- rte_size = _REGION3_SIZE;
- }
- /*
- * forcing modules and vmalloc area under the ultravisor
- * secure storage limit, so that any vmalloc allocation
- * we do could be used to back secure guest storage.
- */
- vmax = adjust_to_uv_max(vmax);
- #ifdef CONFIG_KASAN
- /* force vmalloc and modules below kasan shadow */
- vmax = min(vmax, KASAN_SHADOW_START);
- #endif
- __memcpy_real_area = round_down(vmax - PAGE_SIZE, PAGE_SIZE);
- __abs_lowcore = round_down(__memcpy_real_area - ABS_LOWCORE_MAP_SIZE,
- sizeof(struct lowcore));
- MODULES_END = round_down(__abs_lowcore, _SEGMENT_SIZE);
- MODULES_VADDR = MODULES_END - MODULES_LEN;
- VMALLOC_END = MODULES_VADDR;
- /* allow vmalloc area to occupy up to about 1/2 of the rest virtual space left */
- vmalloc_size = min(vmalloc_size, round_down(VMALLOC_END / 2, _REGION3_SIZE));
- VMALLOC_START = VMALLOC_END - vmalloc_size;
- /* split remaining virtual space between 1:1 mapping & vmemmap array */
- pages = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
- pages = SECTION_ALIGN_UP(pages);
- /* keep vmemmap_start aligned to a top level region table entry */
- vmemmap_start = round_down(VMALLOC_START - pages * sizeof(struct page), rte_size);
- /* vmemmap_start is the future VMEM_MAX_PHYS, make sure it is within MAX_PHYSMEM */
- vmemmap_start = min(vmemmap_start, 1UL << MAX_PHYSMEM_BITS);
- /* make sure identity map doesn't overlay with vmemmap */
- ident_map_size = min(ident_map_size, vmemmap_start);
- vmemmap_size = SECTION_ALIGN_UP(ident_map_size / PAGE_SIZE) * sizeof(struct page);
- /* make sure vmemmap doesn't overlay with vmalloc area */
- VMALLOC_START = max(vmemmap_start + vmemmap_size, VMALLOC_START);
- vmemmap = (struct page *)vmemmap_start;
- }
- /*
- * 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);
- }
- static void offset_vmlinux_info(unsigned long offset)
- {
- vmlinux.default_lma += offset;
- *(unsigned long *)(&vmlinux.entry) += offset;
- vmlinux.bootdata_off += offset;
- vmlinux.bootdata_preserved_off += offset;
- vmlinux.rela_dyn_start += offset;
- vmlinux.rela_dyn_end += offset;
- vmlinux.dynsym_start += offset;
- }
- static unsigned long reserve_amode31(unsigned long safe_addr)
- {
- __amode31_base = PAGE_ALIGN(safe_addr);
- return safe_addr + vmlinux.amode31_size;
- }
- void startup_kernel(void)
- {
- unsigned long max_physmem_end;
- unsigned long random_lma;
- unsigned long safe_addr;
- void *img;
- initrd_data.start = parmarea.initrd_start;
- initrd_data.size = parmarea.initrd_size;
- oldmem_data.start = parmarea.oldmem_base;
- oldmem_data.size = parmarea.oldmem_size;
- setup_lpp();
- store_ipl_parmblock();
- safe_addr = mem_safe_offset();
- safe_addr = reserve_amode31(safe_addr);
- safe_addr = read_ipl_report(safe_addr);
- uv_query_info();
- safe_addr = rescue_initrd(safe_addr);
- sclp_early_read_info();
- setup_boot_command_line();
- parse_boot_command_line();
- sanitize_prot_virt_host();
- max_physmem_end = detect_memory(&safe_addr);
- setup_ident_map_size(max_physmem_end);
- setup_vmalloc_size();
- setup_kernel_memory_layout();
- 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;
- offset_vmlinux_info(__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();
- 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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