1 /* 2 * arch/s390/kernel/early.c 3 * 4 * Copyright IBM Corp. 2007 5 * Author(s): Hongjie Yang <hongjie@us.ibm.com>, 6 * Heiko Carstens <heiko.carstens@de.ibm.com> 7 */ 8 9 #include <linux/init.h> 10 #include <linux/errno.h> 11 #include <linux/string.h> 12 #include <linux/ctype.h> 13 #include <linux/lockdep.h> 14 #include <linux/module.h> 15 #include <linux/pfn.h> 16 #include <linux/uaccess.h> 17 #include <asm/ipl.h> 18 #include <asm/lowcore.h> 19 #include <asm/processor.h> 20 #include <asm/sections.h> 21 #include <asm/setup.h> 22 #include <asm/cpcmd.h> 23 #include <asm/sclp.h> 24 25 /* 26 * Create a Kernel NSS if the SAVESYS= parameter is defined 27 */ 28 #define DEFSYS_CMD_SIZE 96 29 #define SAVESYS_CMD_SIZE 32 30 31 char kernel_nss_name[NSS_NAME_SIZE + 1]; 32 33 #ifdef CONFIG_SHARED_KERNEL 34 static noinline __init void create_kernel_nss(void) 35 { 36 unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size; 37 #ifdef CONFIG_BLK_DEV_INITRD 38 unsigned int sinitrd_pfn, einitrd_pfn; 39 #endif 40 int response; 41 char *savesys_ptr; 42 char upper_command_line[COMMAND_LINE_SIZE]; 43 char defsys_cmd[DEFSYS_CMD_SIZE]; 44 char savesys_cmd[SAVESYS_CMD_SIZE]; 45 46 /* Do nothing if we are not running under VM */ 47 if (!MACHINE_IS_VM) 48 return; 49 50 /* Convert COMMAND_LINE to upper case */ 51 for (i = 0; i < strlen(COMMAND_LINE); i++) 52 upper_command_line[i] = toupper(COMMAND_LINE[i]); 53 54 savesys_ptr = strstr(upper_command_line, "SAVESYS="); 55 56 if (!savesys_ptr) 57 return; 58 59 savesys_ptr += 8; /* Point to the beginning of the NSS name */ 60 for (i = 0; i < NSS_NAME_SIZE; i++) { 61 if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0') 62 break; 63 kernel_nss_name[i] = savesys_ptr[i]; 64 } 65 66 stext_pfn = PFN_DOWN(__pa(&_stext)); 67 eshared_pfn = PFN_DOWN(__pa(&_eshared)); 68 end_pfn = PFN_UP(__pa(&_end)); 69 min_size = end_pfn << 2; 70 71 sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X", 72 kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1, 73 eshared_pfn, end_pfn); 74 75 #ifdef CONFIG_BLK_DEV_INITRD 76 if (INITRD_START && INITRD_SIZE) { 77 sinitrd_pfn = PFN_DOWN(__pa(INITRD_START)); 78 einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE)); 79 min_size = einitrd_pfn << 2; 80 sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd, 81 sinitrd_pfn, einitrd_pfn); 82 } 83 #endif 84 85 sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK", defsys_cmd, min_size); 86 sprintf(savesys_cmd, "SAVESYS %s \n IPL %s", 87 kernel_nss_name, kernel_nss_name); 88 89 __cpcmd(defsys_cmd, NULL, 0, &response); 90 91 if (response != 0) 92 return; 93 94 __cpcmd(savesys_cmd, NULL, 0, &response); 95 96 if (response != strlen(savesys_cmd)) 97 return; 98 99 ipl_flags = IPL_NSS_VALID; 100 } 101 102 #else /* CONFIG_SHARED_KERNEL */ 103 104 static inline void create_kernel_nss(void) { } 105 106 #endif /* CONFIG_SHARED_KERNEL */ 107 108 /* 109 * Clear bss memory 110 */ 111 static noinline __init void clear_bss_section(void) 112 { 113 memset(__bss_start, 0, __bss_stop - __bss_start); 114 } 115 116 /* 117 * Initialize storage key for kernel pages 118 */ 119 static noinline __init void init_kernel_storage_key(void) 120 { 121 unsigned long end_pfn, init_pfn; 122 123 end_pfn = PFN_UP(__pa(&_end)); 124 125 for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++) 126 page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY); 127 } 128 129 static noinline __init void detect_machine_type(void) 130 { 131 struct cpuinfo_S390 *cpuinfo = &S390_lowcore.cpu_data; 132 133 get_cpu_id(&S390_lowcore.cpu_data.cpu_id); 134 135 /* Running under z/VM ? */ 136 if (cpuinfo->cpu_id.version == 0xff) 137 machine_flags |= 1; 138 139 /* Running on a P/390 ? */ 140 if (cpuinfo->cpu_id.machine == 0x7490) 141 machine_flags |= 4; 142 } 143 144 #ifdef CONFIG_64BIT 145 static noinline __init int memory_fast_detect(void) 146 { 147 unsigned long val0 = 0; 148 unsigned long val1 = 0xc; 149 int ret = -ENOSYS; 150 151 if (ipl_flags & IPL_NSS_VALID) 152 return -ENOSYS; 153 154 asm volatile( 155 " diag %1,%2,0x260\n" 156 "0: lhi %0,0\n" 157 "1:\n" 158 EX_TABLE(0b,1b) 159 : "+d" (ret), "+d" (val0), "+d" (val1) : : "cc"); 160 161 if (ret || val0 != val1) 162 return -ENOSYS; 163 164 memory_chunk[0].size = val0 + 1; 165 return 0; 166 } 167 #else 168 static inline int memory_fast_detect(void) 169 { 170 return -ENOSYS; 171 } 172 #endif 173 174 static inline __init unsigned long __tprot(unsigned long addr) 175 { 176 int cc = -1; 177 178 asm volatile( 179 " tprot 0(%1),0\n" 180 "0: ipm %0\n" 181 " srl %0,28\n" 182 "1:\n" 183 EX_TABLE(0b,1b) 184 : "+d" (cc) : "a" (addr) : "cc"); 185 return (unsigned long)cc; 186 } 187 188 /* Checking memory in 128KB increments. */ 189 #define CHUNK_INCR (1UL << 17) 190 #define ADDR2G (1UL << 31) 191 192 static noinline __init void find_memory_chunks(unsigned long memsize) 193 { 194 unsigned long addr = 0, old_addr = 0; 195 unsigned long old_cc = CHUNK_READ_WRITE; 196 unsigned long cc; 197 int chunk = 0; 198 199 while (chunk < MEMORY_CHUNKS) { 200 cc = __tprot(addr); 201 while (cc == old_cc) { 202 addr += CHUNK_INCR; 203 cc = __tprot(addr); 204 #ifndef CONFIG_64BIT 205 if (addr == ADDR2G) 206 break; 207 #endif 208 } 209 210 if (old_addr != addr && 211 (old_cc == CHUNK_READ_WRITE || old_cc == CHUNK_READ_ONLY)) { 212 memory_chunk[chunk].addr = old_addr; 213 memory_chunk[chunk].size = addr - old_addr; 214 memory_chunk[chunk].type = old_cc; 215 chunk++; 216 } 217 218 old_addr = addr; 219 old_cc = cc; 220 221 #ifndef CONFIG_64BIT 222 if (addr == ADDR2G) 223 break; 224 #endif 225 /* 226 * Finish memory detection at the first hole 227 * if storage size is unknown. 228 */ 229 if (cc == -1UL && !memsize) 230 break; 231 if (memsize && addr >= memsize) 232 break; 233 } 234 } 235 236 static __init void early_pgm_check_handler(void) 237 { 238 unsigned long addr; 239 const struct exception_table_entry *fixup; 240 241 addr = S390_lowcore.program_old_psw.addr; 242 fixup = search_exception_tables(addr & PSW_ADDR_INSN); 243 if (!fixup) 244 disabled_wait(0); 245 S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE; 246 } 247 248 static noinline __init void setup_lowcore_early(void) 249 { 250 psw_t psw; 251 252 psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY; 253 psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler; 254 S390_lowcore.external_new_psw = psw; 255 psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler; 256 S390_lowcore.program_new_psw = psw; 257 s390_base_pgm_handler_fn = early_pgm_check_handler; 258 } 259 260 /* 261 * Save ipl parameters, clear bss memory, initialize storage keys 262 * and create a kernel NSS at startup if the SAVESYS= parm is defined 263 */ 264 void __init startup_init(void) 265 { 266 unsigned long long memsize; 267 268 ipl_save_parameters(); 269 clear_bss_section(); 270 init_kernel_storage_key(); 271 lockdep_init(); 272 lockdep_off(); 273 detect_machine_type(); 274 create_kernel_nss(); 275 sort_main_extable(); 276 setup_lowcore_early(); 277 sclp_readinfo_early(); 278 sclp_facilities_detect(); 279 memsize = sclp_memory_detect(); 280 #ifndef CONFIG_64BIT 281 /* 282 * Can't deal with more than 2G in 31 bit addressing mode, so 283 * limit the value in order to avoid strange side effects. 284 */ 285 if (memsize > ADDR2G) 286 memsize = ADDR2G; 287 #endif 288 if (memory_fast_detect() < 0) 289 find_memory_chunks((unsigned long) memsize); 290 lockdep_on(); 291 } 292