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 static noinline __init int memory_fast_detect(void) 145 { 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; 165 return 0; 166 } 167 168 #define ADDR2G (1UL << 31) 169 170 static noinline __init unsigned long sclp_memory_detect(void) 171 { 172 struct sclp_readinfo_sccb *sccb; 173 unsigned long long memsize; 174 175 sccb = &s390_readinfo_sccb; 176 177 if (sccb->header.response_code != 0x10) 178 return 0; 179 180 if (sccb->rnsize) 181 memsize = sccb->rnsize << 20; 182 else 183 memsize = sccb->rnsize2 << 20; 184 if (sccb->rnmax) 185 memsize *= sccb->rnmax; 186 else 187 memsize *= sccb->rnmax2; 188 #ifndef CONFIG_64BIT 189 /* 190 * Can't deal with more than 2G in 31 bit addressing mode, so 191 * limit the value in order to avoid strange side effects. 192 */ 193 if (memsize > ADDR2G) 194 memsize = ADDR2G; 195 #endif 196 return (unsigned long) memsize; 197 } 198 199 static inline __init unsigned long __tprot(unsigned long addr) 200 { 201 int cc = -1; 202 203 asm volatile( 204 " tprot 0(%1),0\n" 205 "0: ipm %0\n" 206 " srl %0,28\n" 207 "1:\n" 208 EX_TABLE(0b,1b) 209 : "+d" (cc) : "a" (addr) : "cc"); 210 return (unsigned long)cc; 211 } 212 213 /* Checking memory in 128KB increments. */ 214 #define CHUNK_INCR (1UL << 17) 215 216 static noinline __init void find_memory_chunks(unsigned long memsize) 217 { 218 unsigned long addr = 0, old_addr = 0; 219 unsigned long old_cc = CHUNK_READ_WRITE; 220 unsigned long cc; 221 int chunk = 0; 222 223 while (chunk < MEMORY_CHUNKS) { 224 cc = __tprot(addr); 225 while (cc == old_cc) { 226 addr += CHUNK_INCR; 227 cc = __tprot(addr); 228 #ifndef CONFIG_64BIT 229 if (addr == ADDR2G) 230 break; 231 #endif 232 } 233 234 if (old_addr != addr && 235 (old_cc == CHUNK_READ_WRITE || old_cc == CHUNK_READ_ONLY)) { 236 memory_chunk[chunk].addr = old_addr; 237 memory_chunk[chunk].size = addr - old_addr; 238 memory_chunk[chunk].type = old_cc; 239 chunk++; 240 } 241 242 old_addr = addr; 243 old_cc = cc; 244 245 #ifndef CONFIG_64BIT 246 if (addr == ADDR2G) 247 break; 248 #endif 249 /* 250 * Finish memory detection at the first hole, unless 251 * - we reached the hsa -> skip it. 252 * - we know there must be more. 253 */ 254 if (cc == -1UL && !memsize && old_addr != ADDR2G) 255 break; 256 if (memsize && addr >= memsize) 257 break; 258 } 259 } 260 261 static __init void early_pgm_check_handler(void) 262 { 263 unsigned long addr; 264 const struct exception_table_entry *fixup; 265 266 addr = S390_lowcore.program_old_psw.addr; 267 fixup = search_exception_tables(addr & PSW_ADDR_INSN); 268 if (!fixup) 269 disabled_wait(0); 270 S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE; 271 } 272 273 static noinline __init void setup_lowcore_early(void) 274 { 275 psw_t psw; 276 277 psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY; 278 psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler; 279 S390_lowcore.external_new_psw = psw; 280 psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler; 281 S390_lowcore.program_new_psw = psw; 282 s390_base_pgm_handler_fn = early_pgm_check_handler; 283 } 284 285 /* 286 * Save ipl parameters, clear bss memory, initialize storage keys 287 * and create a kernel NSS at startup if the SAVESYS= parm is defined 288 */ 289 void __init startup_init(void) 290 { 291 unsigned long memsize; 292 293 ipl_save_parameters(); 294 clear_bss_section(); 295 init_kernel_storage_key(); 296 lockdep_init(); 297 lockdep_off(); 298 detect_machine_type(); 299 create_kernel_nss(); 300 sort_main_extable(); 301 setup_lowcore_early(); 302 sclp_readinfo_early(); 303 memsize = sclp_memory_detect(); 304 if (memory_fast_detect() < 0) 305 find_memory_chunks(memsize); 306 lockdep_on(); 307 } 308