1bb1520d5SAlexander Gordeev // SPDX-License-Identifier: GPL-2.0 2bb1520d5SAlexander Gordeev #include <linux/sched/task.h> 3bb1520d5SAlexander Gordeev #include <linux/pgtable.h> 4bb1520d5SAlexander Gordeev #include <asm/pgalloc.h> 5bb1520d5SAlexander Gordeev #include <asm/facility.h> 6bb1520d5SAlexander Gordeev #include <asm/sections.h> 7bb1520d5SAlexander Gordeev #include <asm/mem_detect.h> 8*8e9205d2SAlexander Gordeev #include <asm/maccess.h> 9bb1520d5SAlexander Gordeev #include "decompressor.h" 10bb1520d5SAlexander Gordeev #include "boot.h" 11bb1520d5SAlexander Gordeev 12bb1520d5SAlexander Gordeev #define init_mm (*(struct mm_struct *)vmlinux.init_mm_off) 13bb1520d5SAlexander Gordeev #define swapper_pg_dir vmlinux.swapper_pg_dir_off 14bb1520d5SAlexander Gordeev #define invalid_pg_dir vmlinux.invalid_pg_dir_off 15bb1520d5SAlexander Gordeev 16*8e9205d2SAlexander Gordeev /* 17*8e9205d2SAlexander Gordeev * Mimic virt_to_kpte() in lack of init_mm symbol. Skip pmd NULL check though. 18*8e9205d2SAlexander Gordeev */ 19*8e9205d2SAlexander Gordeev static inline pte_t *__virt_to_kpte(unsigned long va) 20*8e9205d2SAlexander Gordeev { 21*8e9205d2SAlexander Gordeev return pte_offset_kernel(pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va), va); 22*8e9205d2SAlexander Gordeev } 23*8e9205d2SAlexander Gordeev 24bb1520d5SAlexander Gordeev unsigned long __bootdata_preserved(s390_invalid_asce); 25bb1520d5SAlexander Gordeev unsigned long __bootdata(pgalloc_pos); 26bb1520d5SAlexander Gordeev unsigned long __bootdata(pgalloc_end); 27bb1520d5SAlexander Gordeev unsigned long __bootdata(pgalloc_low); 28bb1520d5SAlexander Gordeev 29e0e0a87bSAlexander Gordeev enum populate_mode { 30*8e9205d2SAlexander Gordeev POPULATE_NONE, 31e0e0a87bSAlexander Gordeev POPULATE_ONE2ONE, 32e0e0a87bSAlexander Gordeev }; 33e0e0a87bSAlexander Gordeev 34bb1520d5SAlexander Gordeev static void boot_check_oom(void) 35bb1520d5SAlexander Gordeev { 36bb1520d5SAlexander Gordeev if (pgalloc_pos < pgalloc_low) 37bb1520d5SAlexander Gordeev error("out of memory on boot\n"); 38bb1520d5SAlexander Gordeev } 39bb1520d5SAlexander Gordeev 40bb1520d5SAlexander Gordeev static void pgtable_populate_begin(unsigned long online_end) 41bb1520d5SAlexander Gordeev { 42bb1520d5SAlexander Gordeev unsigned long initrd_end; 43bb1520d5SAlexander Gordeev unsigned long kernel_end; 44bb1520d5SAlexander Gordeev 45bb1520d5SAlexander Gordeev kernel_end = vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size; 46bb1520d5SAlexander Gordeev pgalloc_low = round_up(kernel_end, PAGE_SIZE); 47bb1520d5SAlexander Gordeev if (IS_ENABLED(CONFIG_BLK_DEV_INITRD)) { 48bb1520d5SAlexander Gordeev initrd_end = round_up(initrd_data.start + initrd_data.size, _SEGMENT_SIZE); 49bb1520d5SAlexander Gordeev pgalloc_low = max(pgalloc_low, initrd_end); 50bb1520d5SAlexander Gordeev } 51bb1520d5SAlexander Gordeev 52bb1520d5SAlexander Gordeev pgalloc_end = round_down(online_end, PAGE_SIZE); 53bb1520d5SAlexander Gordeev pgalloc_pos = pgalloc_end; 54bb1520d5SAlexander Gordeev 55bb1520d5SAlexander Gordeev boot_check_oom(); 56bb1520d5SAlexander Gordeev } 57bb1520d5SAlexander Gordeev 58bb1520d5SAlexander Gordeev static void *boot_alloc_pages(unsigned int order) 59bb1520d5SAlexander Gordeev { 60bb1520d5SAlexander Gordeev unsigned long size = PAGE_SIZE << order; 61bb1520d5SAlexander Gordeev 62bb1520d5SAlexander Gordeev pgalloc_pos -= size; 63bb1520d5SAlexander Gordeev pgalloc_pos = round_down(pgalloc_pos, size); 64bb1520d5SAlexander Gordeev 65bb1520d5SAlexander Gordeev boot_check_oom(); 66bb1520d5SAlexander Gordeev 67bb1520d5SAlexander Gordeev return (void *)pgalloc_pos; 68bb1520d5SAlexander Gordeev } 69bb1520d5SAlexander Gordeev 70bb1520d5SAlexander Gordeev static void *boot_crst_alloc(unsigned long val) 71bb1520d5SAlexander Gordeev { 72bb1520d5SAlexander Gordeev unsigned long *table; 73bb1520d5SAlexander Gordeev 74bb1520d5SAlexander Gordeev table = boot_alloc_pages(CRST_ALLOC_ORDER); 75bb1520d5SAlexander Gordeev if (table) 76bb1520d5SAlexander Gordeev crst_table_init(table, val); 77bb1520d5SAlexander Gordeev return table; 78bb1520d5SAlexander Gordeev } 79bb1520d5SAlexander Gordeev 80bb1520d5SAlexander Gordeev static pte_t *boot_pte_alloc(void) 81bb1520d5SAlexander Gordeev { 82bb1520d5SAlexander Gordeev static void *pte_leftover; 83bb1520d5SAlexander Gordeev pte_t *pte; 84bb1520d5SAlexander Gordeev 85bb1520d5SAlexander Gordeev BUILD_BUG_ON(_PAGE_TABLE_SIZE * 2 != PAGE_SIZE); 86bb1520d5SAlexander Gordeev 87bb1520d5SAlexander Gordeev if (!pte_leftover) { 88bb1520d5SAlexander Gordeev pte_leftover = boot_alloc_pages(0); 89bb1520d5SAlexander Gordeev pte = pte_leftover + _PAGE_TABLE_SIZE; 90bb1520d5SAlexander Gordeev } else { 91bb1520d5SAlexander Gordeev pte = pte_leftover; 92bb1520d5SAlexander Gordeev pte_leftover = NULL; 93bb1520d5SAlexander Gordeev } 94bb1520d5SAlexander Gordeev memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE); 95bb1520d5SAlexander Gordeev return pte; 96bb1520d5SAlexander Gordeev } 97bb1520d5SAlexander Gordeev 98e0e0a87bSAlexander Gordeev static unsigned long _pa(unsigned long addr, enum populate_mode mode) 99e0e0a87bSAlexander Gordeev { 100e0e0a87bSAlexander Gordeev switch (mode) { 101*8e9205d2SAlexander Gordeev case POPULATE_NONE: 102*8e9205d2SAlexander Gordeev return -1; 103e0e0a87bSAlexander Gordeev case POPULATE_ONE2ONE: 104e0e0a87bSAlexander Gordeev return addr; 105e0e0a87bSAlexander Gordeev default: 106e0e0a87bSAlexander Gordeev return -1; 107e0e0a87bSAlexander Gordeev } 108e0e0a87bSAlexander Gordeev } 109e0e0a87bSAlexander Gordeev 110bb1520d5SAlexander Gordeev static bool can_large_pud(pud_t *pu_dir, unsigned long addr, unsigned long end) 111bb1520d5SAlexander Gordeev { 112bb1520d5SAlexander Gordeev return machine.has_edat2 && 113bb1520d5SAlexander Gordeev IS_ALIGNED(addr, PUD_SIZE) && (end - addr) >= PUD_SIZE; 114bb1520d5SAlexander Gordeev } 115bb1520d5SAlexander Gordeev 116bb1520d5SAlexander Gordeev static bool can_large_pmd(pmd_t *pm_dir, unsigned long addr, unsigned long end) 117bb1520d5SAlexander Gordeev { 118bb1520d5SAlexander Gordeev return machine.has_edat1 && 119bb1520d5SAlexander Gordeev IS_ALIGNED(addr, PMD_SIZE) && (end - addr) >= PMD_SIZE; 120bb1520d5SAlexander Gordeev } 121bb1520d5SAlexander Gordeev 122e0e0a87bSAlexander Gordeev static void pgtable_pte_populate(pmd_t *pmd, unsigned long addr, unsigned long end, 123e0e0a87bSAlexander Gordeev enum populate_mode mode) 124bb1520d5SAlexander Gordeev { 125bb1520d5SAlexander Gordeev unsigned long next; 126bb1520d5SAlexander Gordeev pte_t *pte, entry; 127bb1520d5SAlexander Gordeev 128bb1520d5SAlexander Gordeev pte = pte_offset_kernel(pmd, addr); 129bb1520d5SAlexander Gordeev for (; addr < end; addr += PAGE_SIZE, pte++) { 130bb1520d5SAlexander Gordeev if (pte_none(*pte)) { 131e0e0a87bSAlexander Gordeev entry = __pte(_pa(addr, mode)); 132bb1520d5SAlexander Gordeev entry = set_pte_bit(entry, PAGE_KERNEL_EXEC); 133bb1520d5SAlexander Gordeev set_pte(pte, entry); 134bb1520d5SAlexander Gordeev } 135bb1520d5SAlexander Gordeev } 136bb1520d5SAlexander Gordeev } 137bb1520d5SAlexander Gordeev 138e0e0a87bSAlexander Gordeev static void pgtable_pmd_populate(pud_t *pud, unsigned long addr, unsigned long end, 139e0e0a87bSAlexander Gordeev enum populate_mode mode) 140bb1520d5SAlexander Gordeev { 141bb1520d5SAlexander Gordeev unsigned long next; 142bb1520d5SAlexander Gordeev pmd_t *pmd, entry; 143bb1520d5SAlexander Gordeev pte_t *pte; 144bb1520d5SAlexander Gordeev 145bb1520d5SAlexander Gordeev pmd = pmd_offset(pud, addr); 146bb1520d5SAlexander Gordeev for (; addr < end; addr = next, pmd++) { 147bb1520d5SAlexander Gordeev next = pmd_addr_end(addr, end); 148bb1520d5SAlexander Gordeev if (pmd_none(*pmd)) { 149bb1520d5SAlexander Gordeev if (can_large_pmd(pmd, addr, next)) { 150e0e0a87bSAlexander Gordeev entry = __pmd(_pa(addr, mode)); 151bb1520d5SAlexander Gordeev entry = set_pmd_bit(entry, SEGMENT_KERNEL_EXEC); 152bb1520d5SAlexander Gordeev set_pmd(pmd, entry); 153bb1520d5SAlexander Gordeev continue; 154bb1520d5SAlexander Gordeev } 155bb1520d5SAlexander Gordeev pte = boot_pte_alloc(); 156bb1520d5SAlexander Gordeev pmd_populate(&init_mm, pmd, pte); 157bb1520d5SAlexander Gordeev } else if (pmd_large(*pmd)) { 158bb1520d5SAlexander Gordeev continue; 159bb1520d5SAlexander Gordeev } 160e0e0a87bSAlexander Gordeev pgtable_pte_populate(pmd, addr, next, mode); 161bb1520d5SAlexander Gordeev } 162bb1520d5SAlexander Gordeev } 163bb1520d5SAlexander Gordeev 164e0e0a87bSAlexander Gordeev static void pgtable_pud_populate(p4d_t *p4d, unsigned long addr, unsigned long end, 165e0e0a87bSAlexander Gordeev enum populate_mode mode) 166bb1520d5SAlexander Gordeev { 167bb1520d5SAlexander Gordeev unsigned long next; 168bb1520d5SAlexander Gordeev pud_t *pud, entry; 169bb1520d5SAlexander Gordeev pmd_t *pmd; 170bb1520d5SAlexander Gordeev 171bb1520d5SAlexander Gordeev pud = pud_offset(p4d, addr); 172bb1520d5SAlexander Gordeev for (; addr < end; addr = next, pud++) { 173bb1520d5SAlexander Gordeev next = pud_addr_end(addr, end); 174bb1520d5SAlexander Gordeev if (pud_none(*pud)) { 175bb1520d5SAlexander Gordeev if (can_large_pud(pud, addr, next)) { 176e0e0a87bSAlexander Gordeev entry = __pud(_pa(addr, mode)); 177bb1520d5SAlexander Gordeev entry = set_pud_bit(entry, REGION3_KERNEL_EXEC); 178bb1520d5SAlexander Gordeev set_pud(pud, entry); 179bb1520d5SAlexander Gordeev continue; 180bb1520d5SAlexander Gordeev } 181bb1520d5SAlexander Gordeev pmd = boot_crst_alloc(_SEGMENT_ENTRY_EMPTY); 182bb1520d5SAlexander Gordeev pud_populate(&init_mm, pud, pmd); 183bb1520d5SAlexander Gordeev } else if (pud_large(*pud)) { 184bb1520d5SAlexander Gordeev continue; 185bb1520d5SAlexander Gordeev } 186e0e0a87bSAlexander Gordeev pgtable_pmd_populate(pud, addr, next, mode); 187bb1520d5SAlexander Gordeev } 188bb1520d5SAlexander Gordeev } 189bb1520d5SAlexander Gordeev 190e0e0a87bSAlexander Gordeev static void pgtable_p4d_populate(pgd_t *pgd, unsigned long addr, unsigned long end, 191e0e0a87bSAlexander Gordeev enum populate_mode mode) 192bb1520d5SAlexander Gordeev { 193bb1520d5SAlexander Gordeev unsigned long next; 194bb1520d5SAlexander Gordeev p4d_t *p4d; 195bb1520d5SAlexander Gordeev pud_t *pud; 196bb1520d5SAlexander Gordeev 197bb1520d5SAlexander Gordeev p4d = p4d_offset(pgd, addr); 198bb1520d5SAlexander Gordeev for (; addr < end; addr = next, p4d++) { 199bb1520d5SAlexander Gordeev next = p4d_addr_end(addr, end); 200bb1520d5SAlexander Gordeev if (p4d_none(*p4d)) { 201bb1520d5SAlexander Gordeev pud = boot_crst_alloc(_REGION3_ENTRY_EMPTY); 202bb1520d5SAlexander Gordeev p4d_populate(&init_mm, p4d, pud); 203bb1520d5SAlexander Gordeev } 204e0e0a87bSAlexander Gordeev pgtable_pud_populate(p4d, addr, next, mode); 205bb1520d5SAlexander Gordeev } 206bb1520d5SAlexander Gordeev } 207bb1520d5SAlexander Gordeev 208e0e0a87bSAlexander Gordeev static void pgtable_populate(unsigned long addr, unsigned long end, enum populate_mode mode) 209bb1520d5SAlexander Gordeev { 210bb1520d5SAlexander Gordeev unsigned long next; 211bb1520d5SAlexander Gordeev pgd_t *pgd; 212bb1520d5SAlexander Gordeev p4d_t *p4d; 213bb1520d5SAlexander Gordeev 214bb1520d5SAlexander Gordeev pgd = pgd_offset(&init_mm, addr); 215bb1520d5SAlexander Gordeev for (; addr < end; addr = next, pgd++) { 216bb1520d5SAlexander Gordeev next = pgd_addr_end(addr, end); 217bb1520d5SAlexander Gordeev if (pgd_none(*pgd)) { 218bb1520d5SAlexander Gordeev p4d = boot_crst_alloc(_REGION2_ENTRY_EMPTY); 219bb1520d5SAlexander Gordeev pgd_populate(&init_mm, pgd, p4d); 220bb1520d5SAlexander Gordeev } 221e0e0a87bSAlexander Gordeev pgtable_p4d_populate(pgd, addr, next, mode); 222bb1520d5SAlexander Gordeev } 223bb1520d5SAlexander Gordeev } 224bb1520d5SAlexander Gordeev 225bb1520d5SAlexander Gordeev /* 226bb1520d5SAlexander Gordeev * The pgtables are located in the range [pgalloc_pos, pgalloc_end). 227bb1520d5SAlexander Gordeev * That range must stay intact and is later reserved in the memblock. 228bb1520d5SAlexander Gordeev * Therefore pgtable_populate(pgalloc_pos, pgalloc_end) is needed to 229bb1520d5SAlexander Gordeev * finalize pgalloc_pos pointer. However that call can decrease the 230bb1520d5SAlexander Gordeev * value of pgalloc_pos pointer itself. Therefore, pgtable_populate() 231bb1520d5SAlexander Gordeev * needs to be called repeatedly until pgtables are complete and 232bb1520d5SAlexander Gordeev * pgalloc_pos does not grow left anymore. 233bb1520d5SAlexander Gordeev */ 234bb1520d5SAlexander Gordeev static void pgtable_populate_end(void) 235bb1520d5SAlexander Gordeev { 236bb1520d5SAlexander Gordeev unsigned long pgalloc_end_curr = pgalloc_end; 237bb1520d5SAlexander Gordeev unsigned long pgalloc_pos_prev; 238bb1520d5SAlexander Gordeev 239bb1520d5SAlexander Gordeev do { 240bb1520d5SAlexander Gordeev pgalloc_pos_prev = pgalloc_pos; 241e0e0a87bSAlexander Gordeev pgtable_populate(pgalloc_pos, pgalloc_end_curr, POPULATE_ONE2ONE); 242bb1520d5SAlexander Gordeev pgalloc_end_curr = pgalloc_pos_prev; 243bb1520d5SAlexander Gordeev } while (pgalloc_pos < pgalloc_pos_prev); 244bb1520d5SAlexander Gordeev } 245bb1520d5SAlexander Gordeev 246bb1520d5SAlexander Gordeev void setup_vmem(unsigned long online_end, unsigned long asce_limit) 247bb1520d5SAlexander Gordeev { 248bb1520d5SAlexander Gordeev unsigned long asce_type; 249bb1520d5SAlexander Gordeev unsigned long asce_bits; 250bb1520d5SAlexander Gordeev 251bb1520d5SAlexander Gordeev if (asce_limit == _REGION1_SIZE) { 252bb1520d5SAlexander Gordeev asce_type = _REGION2_ENTRY_EMPTY; 253bb1520d5SAlexander Gordeev asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH; 254bb1520d5SAlexander Gordeev } else { 255bb1520d5SAlexander Gordeev asce_type = _REGION3_ENTRY_EMPTY; 256bb1520d5SAlexander Gordeev asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 257bb1520d5SAlexander Gordeev } 258bb1520d5SAlexander Gordeev s390_invalid_asce = invalid_pg_dir | _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH; 259bb1520d5SAlexander Gordeev 260bb1520d5SAlexander Gordeev crst_table_init((unsigned long *)swapper_pg_dir, asce_type); 261bb1520d5SAlexander Gordeev crst_table_init((unsigned long *)invalid_pg_dir, _REGION3_ENTRY_EMPTY); 262bb1520d5SAlexander Gordeev 263bb1520d5SAlexander Gordeev /* 264bb1520d5SAlexander Gordeev * To allow prefixing the lowcore must be mapped with 4KB pages. 265bb1520d5SAlexander Gordeev * To prevent creation of a large page at address 0 first map 266bb1520d5SAlexander Gordeev * the lowcore and create the identity mapping only afterwards. 267bb1520d5SAlexander Gordeev * 268bb1520d5SAlexander Gordeev * No further pgtable_populate() calls are allowed after the value 269bb1520d5SAlexander Gordeev * of pgalloc_pos finalized with a call to pgtable_populate_end(). 270bb1520d5SAlexander Gordeev */ 271bb1520d5SAlexander Gordeev pgtable_populate_begin(online_end); 272e0e0a87bSAlexander Gordeev pgtable_populate(0, sizeof(struct lowcore), POPULATE_ONE2ONE); 273e0e0a87bSAlexander Gordeev pgtable_populate(0, online_end, POPULATE_ONE2ONE); 274*8e9205d2SAlexander Gordeev pgtable_populate(__memcpy_real_area, __memcpy_real_area + PAGE_SIZE, 275*8e9205d2SAlexander Gordeev POPULATE_NONE); 276*8e9205d2SAlexander Gordeev memcpy_real_ptep = __virt_to_kpte(__memcpy_real_area); 277bb1520d5SAlexander Gordeev pgtable_populate_end(); 278bb1520d5SAlexander Gordeev 279bb1520d5SAlexander Gordeev S390_lowcore.kernel_asce = swapper_pg_dir | asce_bits; 280bb1520d5SAlexander Gordeev S390_lowcore.user_asce = s390_invalid_asce; 281bb1520d5SAlexander Gordeev 282bb1520d5SAlexander Gordeev __ctl_load(S390_lowcore.kernel_asce, 1, 1); 283bb1520d5SAlexander Gordeev __ctl_load(S390_lowcore.user_asce, 7, 7); 284bb1520d5SAlexander Gordeev __ctl_load(S390_lowcore.kernel_asce, 13, 13); 285bb1520d5SAlexander Gordeev 286bb1520d5SAlexander Gordeev init_mm.context.asce = S390_lowcore.kernel_asce; 287bb1520d5SAlexander Gordeev } 288