18f75582aSVasily Gorbik // SPDX-License-Identifier: GPL-2.0 28f75582aSVasily Gorbik #include <linux/string.h> 3805bc0bcSGerald Schaefer #include <linux/elf.h> 473045a08SVasily Gorbik #include <asm/boot_data.h> 5a80313ffSGerald Schaefer #include <asm/sections.h> 6d7e7fbbaSVasily Gorbik #include <asm/cpu_mf.h> 715426ca4SVasily Gorbik #include <asm/setup.h> 80c4f2623SVasily Gorbik #include <asm/kasan.h> 9805bc0bcSGerald Schaefer #include <asm/kexec.h> 107516fc11SVasily Gorbik #include <asm/sclp.h> 11a80313ffSGerald Schaefer #include <asm/diag.h> 125abb9351SVasily Gorbik #include <asm/uv.h> 134df29d2bSAlexander Gordeev #include <asm/abs_lowcore.h> 14edd4a866SHeiko Carstens #include "decompressor.h" 158f75582aSVasily Gorbik #include "boot.h" 16c5cf5054SAlexander Egorenkov #include "uv.h" 178f75582aSVasily Gorbik 18b2d24b97SGerald Schaefer unsigned long __bootdata_preserved(__kaslr_offset); 194df29d2bSAlexander Gordeev unsigned long __bootdata_preserved(__abs_lowcore); 202f0e8aaeSAlexander Gordeev unsigned long __bootdata_preserved(__memcpy_real_area); 21e3ec8e0fSAlexander Gordeev unsigned long __bootdata(__amode31_base); 220c4f2623SVasily Gorbik unsigned long __bootdata_preserved(VMALLOC_START); 230c4f2623SVasily Gorbik unsigned long __bootdata_preserved(VMALLOC_END); 240c4f2623SVasily Gorbik struct page *__bootdata_preserved(vmemmap); 250c4f2623SVasily Gorbik unsigned long __bootdata_preserved(vmemmap_size); 260c4f2623SVasily Gorbik unsigned long __bootdata_preserved(MODULES_VADDR); 270c4f2623SVasily Gorbik unsigned long __bootdata_preserved(MODULES_END); 2873045a08SVasily Gorbik unsigned long __bootdata(ident_map_size); 299f744abbSAlexander Egorenkov int __bootdata(is_full_image) = 1; 3084733284SAlexander Egorenkov struct initrd_data __bootdata(initrd_data); 31d1b52a43SVasily Gorbik 3217e89e13SSven Schnelle u64 __bootdata_preserved(stfle_fac_list[16]); 3317e89e13SSven Schnelle u64 __bootdata_preserved(alt_stfle_fac_list[16]); 34e9e7870fSAlexander Egorenkov struct oldmem_data __bootdata_preserved(oldmem_data); 3517e89e13SSven Schnelle 36*bd50b743SAlexander Gordeev struct machine_info machine; 37*bd50b743SAlexander Gordeev 387516fc11SVasily Gorbik void error(char *x) 397516fc11SVasily Gorbik { 407516fc11SVasily Gorbik sclp_early_printk("\n\n"); 417516fc11SVasily Gorbik sclp_early_printk(x); 427516fc11SVasily Gorbik sclp_early_printk("\n\n -- System halted"); 437516fc11SVasily Gorbik 4498587c2dSMartin Schwidefsky disabled_wait(); 457516fc11SVasily Gorbik } 467516fc11SVasily Gorbik 47*bd50b743SAlexander Gordeev static void detect_facilities(void) 48*bd50b743SAlexander Gordeev { 49*bd50b743SAlexander Gordeev if (test_facility(8)) { 50*bd50b743SAlexander Gordeev machine.has_edat1 = 1; 51*bd50b743SAlexander Gordeev __ctl_set_bit(0, 23); 52*bd50b743SAlexander Gordeev } 53*bd50b743SAlexander Gordeev if (test_facility(78)) 54*bd50b743SAlexander Gordeev machine.has_edat2 = 1; 55*bd50b743SAlexander Gordeev if (!noexec_disabled && test_facility(130)) { 56*bd50b743SAlexander Gordeev machine.has_nx = 1; 57*bd50b743SAlexander Gordeev __ctl_set_bit(0, 20); 58*bd50b743SAlexander Gordeev } 59*bd50b743SAlexander Gordeev } 60*bd50b743SAlexander Gordeev 61d7e7fbbaSVasily Gorbik static void setup_lpp(void) 62d7e7fbbaSVasily Gorbik { 63d7e7fbbaSVasily Gorbik S390_lowcore.current_pid = 0; 64d7e7fbbaSVasily Gorbik S390_lowcore.lpp = LPP_MAGIC; 65d7e7fbbaSVasily Gorbik if (test_facility(40)) 66d7e7fbbaSVasily Gorbik lpp(&S390_lowcore.lpp); 67d7e7fbbaSVasily Gorbik } 68d7e7fbbaSVasily Gorbik 6915426ca4SVasily Gorbik #ifdef CONFIG_KERNEL_UNCOMPRESSED 7015426ca4SVasily Gorbik unsigned long mem_safe_offset(void) 7115426ca4SVasily Gorbik { 7215426ca4SVasily Gorbik return vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size; 7315426ca4SVasily Gorbik } 7415426ca4SVasily Gorbik #endif 7515426ca4SVasily Gorbik 769641b8ccSMartin Schwidefsky static void rescue_initrd(unsigned long addr) 7715426ca4SVasily Gorbik { 7815426ca4SVasily Gorbik if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD)) 7915426ca4SVasily Gorbik return; 8084733284SAlexander Egorenkov if (!initrd_data.start || !initrd_data.size) 8115426ca4SVasily Gorbik return; 8284733284SAlexander Egorenkov if (addr <= initrd_data.start) 8315426ca4SVasily Gorbik return; 8484733284SAlexander Egorenkov memmove((void *)addr, (void *)initrd_data.start, initrd_data.size); 8584733284SAlexander Egorenkov initrd_data.start = addr; 8615426ca4SVasily Gorbik } 8715426ca4SVasily Gorbik 88d1b52a43SVasily Gorbik static void copy_bootdata(void) 89d1b52a43SVasily Gorbik { 90d1b52a43SVasily Gorbik if (__boot_data_end - __boot_data_start != vmlinux.bootdata_size) 91d1b52a43SVasily Gorbik error(".boot.data section size mismatch"); 92d1b52a43SVasily Gorbik memcpy((void *)vmlinux.bootdata_off, __boot_data_start, vmlinux.bootdata_size); 93bf9921a9SGerald Schaefer if (__boot_data_preserved_end - __boot_data_preserved_start != vmlinux.bootdata_preserved_size) 94bf9921a9SGerald Schaefer error(".boot.preserved.data section size mismatch"); 95bf9921a9SGerald Schaefer memcpy((void *)vmlinux.bootdata_preserved_off, __boot_data_preserved_start, vmlinux.bootdata_preserved_size); 96d1b52a43SVasily Gorbik } 97d1b52a43SVasily Gorbik 98805bc0bcSGerald Schaefer static void handle_relocs(unsigned long offset) 99805bc0bcSGerald Schaefer { 100805bc0bcSGerald Schaefer Elf64_Rela *rela_start, *rela_end, *rela; 101805bc0bcSGerald Schaefer int r_type, r_sym, rc; 102805bc0bcSGerald Schaefer Elf64_Addr loc, val; 103805bc0bcSGerald Schaefer Elf64_Sym *dynsym; 104805bc0bcSGerald Schaefer 105805bc0bcSGerald Schaefer rela_start = (Elf64_Rela *) vmlinux.rela_dyn_start; 106805bc0bcSGerald Schaefer rela_end = (Elf64_Rela *) vmlinux.rela_dyn_end; 107805bc0bcSGerald Schaefer dynsym = (Elf64_Sym *) vmlinux.dynsym_start; 108805bc0bcSGerald Schaefer for (rela = rela_start; rela < rela_end; rela++) { 109805bc0bcSGerald Schaefer loc = rela->r_offset + offset; 110ac49303dSGerald Schaefer val = rela->r_addend; 111805bc0bcSGerald Schaefer r_sym = ELF64_R_SYM(rela->r_info); 112ac49303dSGerald Schaefer if (r_sym) { 113ac49303dSGerald Schaefer if (dynsym[r_sym].st_shndx != SHN_UNDEF) 114ac49303dSGerald Schaefer val += dynsym[r_sym].st_value + offset; 115ac49303dSGerald Schaefer } else { 116ac49303dSGerald Schaefer /* 117ac49303dSGerald Schaefer * 0 == undefined symbol table index (STN_UNDEF), 118ac49303dSGerald Schaefer * used for R_390_RELATIVE, only add KASLR offset 119ac49303dSGerald Schaefer */ 120ac49303dSGerald Schaefer val += offset; 121ac49303dSGerald Schaefer } 122805bc0bcSGerald Schaefer r_type = ELF64_R_TYPE(rela->r_info); 123805bc0bcSGerald Schaefer rc = arch_kexec_do_relocs(r_type, (void *) loc, val, 0); 124805bc0bcSGerald Schaefer if (rc) 125805bc0bcSGerald Schaefer error("Unknown relocation type"); 126805bc0bcSGerald Schaefer } 127805bc0bcSGerald Schaefer } 128805bc0bcSGerald Schaefer 129980d5f9aSAlexander Egorenkov /* 13073045a08SVasily Gorbik * Merge information from several sources into a single ident_map_size value. 13173045a08SVasily Gorbik * "ident_map_size" represents the upper limit of physical memory we may ever 13273045a08SVasily Gorbik * reach. It might not be all online memory, but also include standby (offline) 13373045a08SVasily Gorbik * memory. "ident_map_size" could be lower then actual standby or even online 13473045a08SVasily Gorbik * memory present, due to limiting factors. We should never go above this limit. 13573045a08SVasily Gorbik * It is the size of our identity mapping. 13673045a08SVasily Gorbik * 13773045a08SVasily Gorbik * Consider the following factors: 13873045a08SVasily Gorbik * 1. max_physmem_end - end of physical memory online or standby. 13973045a08SVasily Gorbik * Always <= end of the last online memory block (get_mem_detect_end()). 14073045a08SVasily Gorbik * 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the 14173045a08SVasily Gorbik * kernel is able to support. 14273045a08SVasily Gorbik * 3. "mem=" kernel command line option which limits physical memory usage. 14373045a08SVasily Gorbik * 4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as 14473045a08SVasily Gorbik * crash kernel. 14573045a08SVasily Gorbik * 5. "hsa" size which is a memory limit when the kernel is executed during 14673045a08SVasily Gorbik * zfcp/nvme dump. 14773045a08SVasily Gorbik */ 14873045a08SVasily Gorbik static void setup_ident_map_size(unsigned long max_physmem_end) 14973045a08SVasily Gorbik { 15073045a08SVasily Gorbik unsigned long hsa_size; 15173045a08SVasily Gorbik 15273045a08SVasily Gorbik ident_map_size = max_physmem_end; 15373045a08SVasily Gorbik if (memory_limit) 15473045a08SVasily Gorbik ident_map_size = min(ident_map_size, memory_limit); 15573045a08SVasily Gorbik ident_map_size = min(ident_map_size, 1UL << MAX_PHYSMEM_BITS); 15673045a08SVasily Gorbik 15773045a08SVasily Gorbik #ifdef CONFIG_CRASH_DUMP 158e9e7870fSAlexander Egorenkov if (oldmem_data.start) { 15973045a08SVasily Gorbik kaslr_enabled = 0; 160e9e7870fSAlexander Egorenkov ident_map_size = min(ident_map_size, oldmem_data.size); 16173045a08SVasily Gorbik } else if (ipl_block_valid && is_ipl_block_dump()) { 16273045a08SVasily Gorbik kaslr_enabled = 0; 16373045a08SVasily Gorbik if (!sclp_early_get_hsa_size(&hsa_size) && hsa_size) 16473045a08SVasily Gorbik ident_map_size = min(ident_map_size, hsa_size); 16573045a08SVasily Gorbik } 16673045a08SVasily Gorbik #endif 16773045a08SVasily Gorbik } 16873045a08SVasily Gorbik 1690c4f2623SVasily Gorbik static void setup_kernel_memory_layout(void) 1700c4f2623SVasily Gorbik { 1719a39abb7SVasily Gorbik unsigned long vmemmap_start; 1720c4f2623SVasily Gorbik unsigned long rte_size; 1730c4f2623SVasily Gorbik unsigned long pages; 17457ad19bcSAlexander Gordeev unsigned long vmax; 1750c4f2623SVasily Gorbik 1760c4f2623SVasily Gorbik pages = ident_map_size / PAGE_SIZE; 1770c4f2623SVasily Gorbik /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */ 1780c4f2623SVasily Gorbik vmemmap_size = SECTION_ALIGN_UP(pages) * sizeof(struct page); 1790c4f2623SVasily Gorbik 1800c4f2623SVasily Gorbik /* choose kernel address space layout: 4 or 3 levels. */ 1819a39abb7SVasily Gorbik vmemmap_start = round_up(ident_map_size, _REGION3_SIZE); 1820c4f2623SVasily Gorbik if (IS_ENABLED(CONFIG_KASAN) || 1830c4f2623SVasily Gorbik vmalloc_size > _REGION2_SIZE || 1849a39abb7SVasily Gorbik vmemmap_start + vmemmap_size + vmalloc_size + MODULES_LEN > 1859a39abb7SVasily Gorbik _REGION2_SIZE) { 18657ad19bcSAlexander Gordeev vmax = _REGION1_SIZE; 1879a39abb7SVasily Gorbik rte_size = _REGION2_SIZE; 1889a39abb7SVasily Gorbik } else { 18957ad19bcSAlexander Gordeev vmax = _REGION2_SIZE; 1909a39abb7SVasily Gorbik rte_size = _REGION3_SIZE; 1919a39abb7SVasily Gorbik } 1920c4f2623SVasily Gorbik /* 1930c4f2623SVasily Gorbik * forcing modules and vmalloc area under the ultravisor 1940c4f2623SVasily Gorbik * secure storage limit, so that any vmalloc allocation 1950c4f2623SVasily Gorbik * we do could be used to back secure guest storage. 1960c4f2623SVasily Gorbik */ 19757ad19bcSAlexander Gordeev vmax = adjust_to_uv_max(vmax); 1980c4f2623SVasily Gorbik #ifdef CONFIG_KASAN 1990c4f2623SVasily Gorbik /* force vmalloc and modules below kasan shadow */ 20057ad19bcSAlexander Gordeev vmax = min(vmax, KASAN_SHADOW_START); 2010c4f2623SVasily Gorbik #endif 2022f0e8aaeSAlexander Gordeev __memcpy_real_area = round_down(vmax - PAGE_SIZE, PAGE_SIZE); 2032f0e8aaeSAlexander Gordeev __abs_lowcore = round_down(__memcpy_real_area - ABS_LOWCORE_MAP_SIZE, 2042f0e8aaeSAlexander Gordeev sizeof(struct lowcore)); 2054df29d2bSAlexander Gordeev MODULES_END = round_down(__abs_lowcore, _SEGMENT_SIZE); 2060c4f2623SVasily Gorbik MODULES_VADDR = MODULES_END - MODULES_LEN; 2070c4f2623SVasily Gorbik VMALLOC_END = MODULES_VADDR; 2080c4f2623SVasily Gorbik 2099a39abb7SVasily Gorbik /* allow vmalloc area to occupy up to about 1/2 of the rest virtual space left */ 2109a39abb7SVasily Gorbik vmalloc_size = min(vmalloc_size, round_down(VMALLOC_END / 2, _REGION3_SIZE)); 2110c4f2623SVasily Gorbik VMALLOC_START = VMALLOC_END - vmalloc_size; 2120c4f2623SVasily Gorbik 2139a39abb7SVasily Gorbik /* split remaining virtual space between 1:1 mapping & vmemmap array */ 2149a39abb7SVasily Gorbik pages = VMALLOC_START / (PAGE_SIZE + sizeof(struct page)); 2150c4f2623SVasily Gorbik pages = SECTION_ALIGN_UP(pages); 2169a39abb7SVasily Gorbik /* keep vmemmap_start aligned to a top level region table entry */ 2179a39abb7SVasily Gorbik vmemmap_start = round_down(VMALLOC_START - pages * sizeof(struct page), rte_size); 2189a39abb7SVasily Gorbik /* vmemmap_start is the future VMEM_MAX_PHYS, make sure it is within MAX_PHYSMEM */ 2199a39abb7SVasily Gorbik vmemmap_start = min(vmemmap_start, 1UL << MAX_PHYSMEM_BITS); 2209a39abb7SVasily Gorbik /* make sure identity map doesn't overlay with vmemmap */ 2219a39abb7SVasily Gorbik ident_map_size = min(ident_map_size, vmemmap_start); 2220c4f2623SVasily Gorbik vmemmap_size = SECTION_ALIGN_UP(ident_map_size / PAGE_SIZE) * sizeof(struct page); 2239a39abb7SVasily Gorbik /* make sure vmemmap doesn't overlay with vmalloc area */ 2249a39abb7SVasily Gorbik VMALLOC_START = max(vmemmap_start + vmemmap_size, VMALLOC_START); 2259a39abb7SVasily Gorbik vmemmap = (struct page *)vmemmap_start; 2260c4f2623SVasily Gorbik } 2270c4f2623SVasily Gorbik 22873045a08SVasily Gorbik /* 229980d5f9aSAlexander Egorenkov * This function clears the BSS section of the decompressed Linux kernel and NOT the decompressor's. 230980d5f9aSAlexander Egorenkov */ 2312e83e0ebSVasily Gorbik static void clear_bss_section(void) 2322e83e0ebSVasily Gorbik { 2332e83e0ebSVasily Gorbik memset((void *)vmlinux.default_lma + vmlinux.image_size, 0, vmlinux.bss_size); 2342e83e0ebSVasily Gorbik } 2352e83e0ebSVasily Gorbik 23690178c19SHeiko Carstens /* 23790178c19SHeiko Carstens * Set vmalloc area size to an 8th of (potential) physical memory 23890178c19SHeiko Carstens * size, unless size has been set by kernel command line parameter. 23990178c19SHeiko Carstens */ 24090178c19SHeiko Carstens static void setup_vmalloc_size(void) 24190178c19SHeiko Carstens { 24290178c19SHeiko Carstens unsigned long size; 24390178c19SHeiko Carstens 24490178c19SHeiko Carstens if (vmalloc_size_set) 24590178c19SHeiko Carstens return; 24673045a08SVasily Gorbik size = round_up(ident_map_size / 8, _SEGMENT_SIZE); 24790178c19SHeiko Carstens vmalloc_size = max(size, vmalloc_size); 24890178c19SHeiko Carstens } 24990178c19SHeiko Carstens 250e8f06683SAlexander Gordeev static void offset_vmlinux_info(unsigned long offset) 251e8f06683SAlexander Gordeev { 252e8f06683SAlexander Gordeev vmlinux.default_lma += offset; 253e8f06683SAlexander Gordeev *(unsigned long *)(&vmlinux.entry) += offset; 254e8f06683SAlexander Gordeev vmlinux.bootdata_off += offset; 255e8f06683SAlexander Gordeev vmlinux.bootdata_preserved_off += offset; 256e8f06683SAlexander Gordeev vmlinux.rela_dyn_start += offset; 257e8f06683SAlexander Gordeev vmlinux.rela_dyn_end += offset; 258e8f06683SAlexander Gordeev vmlinux.dynsym_start += offset; 259e8f06683SAlexander Gordeev } 260e8f06683SAlexander Gordeev 261e3ec8e0fSAlexander Gordeev static unsigned long reserve_amode31(unsigned long safe_addr) 262e3ec8e0fSAlexander Gordeev { 263e3ec8e0fSAlexander Gordeev __amode31_base = PAGE_ALIGN(safe_addr); 264e3ec8e0fSAlexander Gordeev return safe_addr + vmlinux.amode31_size; 265e3ec8e0fSAlexander Gordeev } 266e3ec8e0fSAlexander Gordeev 2678f75582aSVasily Gorbik void startup_kernel(void) 2688f75582aSVasily Gorbik { 269b2d24b97SGerald Schaefer unsigned long random_lma; 2709641b8ccSMartin Schwidefsky unsigned long safe_addr; 271369f91c3SVasily Gorbik void *img; 2728f75582aSVasily Gorbik 273*bd50b743SAlexander Gordeev detect_facilities(); 274*bd50b743SAlexander Gordeev 27584733284SAlexander Egorenkov initrd_data.start = parmarea.initrd_start; 27684733284SAlexander Egorenkov initrd_data.size = parmarea.initrd_size; 277e9e7870fSAlexander Egorenkov oldmem_data.start = parmarea.oldmem_base; 278e9e7870fSAlexander Egorenkov oldmem_data.size = parmarea.oldmem_size; 27984733284SAlexander Egorenkov 280d7e7fbbaSVasily Gorbik setup_lpp(); 28149698745SVasily Gorbik store_ipl_parmblock(); 2829641b8ccSMartin Schwidefsky safe_addr = mem_safe_offset(); 283e3ec8e0fSAlexander Gordeev safe_addr = reserve_amode31(safe_addr); 2849641b8ccSMartin Schwidefsky safe_addr = read_ipl_report(safe_addr); 2859641b8ccSMartin Schwidefsky uv_query_info(); 2869641b8ccSMartin Schwidefsky rescue_initrd(safe_addr); 2879641b8ccSMartin Schwidefsky sclp_early_read_info(); 28849698745SVasily Gorbik setup_boot_command_line(); 289b5e80459SVasily Gorbik parse_boot_command_line(); 29042c89439SAlexander Egorenkov sanitize_prot_virt_host(); 29173045a08SVasily Gorbik setup_ident_map_size(detect_memory()); 29290178c19SHeiko Carstens setup_vmalloc_size(); 2930c4f2623SVasily Gorbik setup_kernel_memory_layout(); 294b2d24b97SGerald Schaefer 295b2d24b97SGerald Schaefer if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_enabled) { 296b2d24b97SGerald Schaefer random_lma = get_random_base(safe_addr); 297b2d24b97SGerald Schaefer if (random_lma) { 298b2d24b97SGerald Schaefer __kaslr_offset = random_lma - vmlinux.default_lma; 299b2d24b97SGerald Schaefer img = (void *)vmlinux.default_lma; 300e8f06683SAlexander Gordeev offset_vmlinux_info(__kaslr_offset); 301b2d24b97SGerald Schaefer } 302b2d24b97SGerald Schaefer } 303b2d24b97SGerald Schaefer 3048f75582aSVasily Gorbik if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) { 305369f91c3SVasily Gorbik img = decompress_kernel(); 306369f91c3SVasily Gorbik memmove((void *)vmlinux.default_lma, img, vmlinux.image_size); 307b2d24b97SGerald Schaefer } else if (__kaslr_offset) 308b2d24b97SGerald Schaefer memcpy((void *)vmlinux.default_lma, img, vmlinux.image_size); 309b2d24b97SGerald Schaefer 3102e83e0ebSVasily Gorbik clear_bss_section(); 311d1b52a43SVasily Gorbik copy_bootdata(); 312b2d24b97SGerald Schaefer handle_relocs(__kaslr_offset); 313b2d24b97SGerald Schaefer 314b2d24b97SGerald Schaefer if (__kaslr_offset) { 315a9f2f686SGerald Schaefer /* 316a9f2f686SGerald Schaefer * Save KASLR offset for early dumps, before vmcore_info is set. 317a9f2f686SGerald Schaefer * Mark as uneven to distinguish from real vmcore_info pointer. 318a9f2f686SGerald Schaefer */ 319a9f2f686SGerald Schaefer S390_lowcore.vmcore_info = __kaslr_offset | 0x1UL; 320b2d24b97SGerald Schaefer /* Clear non-relocated kernel */ 321b2d24b97SGerald Schaefer if (IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) 322b2d24b97SGerald Schaefer memset(img, 0, vmlinux.image_size); 323b2d24b97SGerald Schaefer } 324369f91c3SVasily Gorbik vmlinux.entry(); 3258f75582aSVasily Gorbik } 326