diff options
Diffstat (limited to 'arch/s390/kernel/early.c')
| -rw-r--r-- | arch/s390/kernel/early.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c new file mode 100644 index 000000000000..e518dd53eff5 --- /dev/null +++ b/arch/s390/kernel/early.c @@ -0,0 +1,306 @@ +/* + * arch/s390/kernel/early.c + * + * Copyright IBM Corp. 2007 + * Author(s): Hongjie Yang <hongjie@us.ibm.com>, + * Heiko Carstens <heiko.carstens@de.ibm.com> + */ + +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/lockdep.h> +#include <linux/module.h> +#include <linux/pfn.h> +#include <linux/uaccess.h> +#include <asm/lowcore.h> +#include <asm/processor.h> +#include <asm/sections.h> +#include <asm/setup.h> +#include <asm/cpcmd.h> +#include <asm/sclp.h> + +/* + * Create a Kernel NSS if the SAVESYS= parameter is defined + */ +#define DEFSYS_CMD_SIZE 96 +#define SAVESYS_CMD_SIZE 32 + +char kernel_nss_name[NSS_NAME_SIZE + 1]; + +#ifdef CONFIG_SHARED_KERNEL +static noinline __init void create_kernel_nss(void) +{ + unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size; +#ifdef CONFIG_BLK_DEV_INITRD + unsigned int sinitrd_pfn, einitrd_pfn; +#endif + int response; + char *savesys_ptr; + char upper_command_line[COMMAND_LINE_SIZE]; + char defsys_cmd[DEFSYS_CMD_SIZE]; + char savesys_cmd[SAVESYS_CMD_SIZE]; + + /* Do nothing if we are not running under VM */ + if (!MACHINE_IS_VM) + return; + + /* Convert COMMAND_LINE to upper case */ + for (i = 0; i < strlen(COMMAND_LINE); i++) + upper_command_line[i] = toupper(COMMAND_LINE[i]); + + savesys_ptr = strstr(upper_command_line, "SAVESYS="); + + if (!savesys_ptr) + return; + + savesys_ptr += 8; /* Point to the beginning of the NSS name */ + for (i = 0; i < NSS_NAME_SIZE; i++) { + if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0') + break; + kernel_nss_name[i] = savesys_ptr[i]; + } + + stext_pfn = PFN_DOWN(__pa(&_stext)); + eshared_pfn = PFN_DOWN(__pa(&_eshared)); + end_pfn = PFN_UP(__pa(&_end)); + min_size = end_pfn << 2; + + sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X", + kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1, + eshared_pfn, end_pfn); + +#ifdef CONFIG_BLK_DEV_INITRD + if (INITRD_START && INITRD_SIZE) { + sinitrd_pfn = PFN_DOWN(__pa(INITRD_START)); + einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE)); + min_size = einitrd_pfn << 2; + sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd, + sinitrd_pfn, einitrd_pfn); + } +#endif + + sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK", defsys_cmd, min_size); + sprintf(savesys_cmd, "SAVESYS %s \n IPL %s", + kernel_nss_name, kernel_nss_name); + + __cpcmd(defsys_cmd, NULL, 0, &response); + + if (response != 0) + return; + + __cpcmd(savesys_cmd, NULL, 0, &response); + + if (response != strlen(savesys_cmd)) + return; + + ipl_flags = IPL_NSS_VALID; +} + +#else /* CONFIG_SHARED_KERNEL */ + +static inline void create_kernel_nss(void) { } + +#endif /* CONFIG_SHARED_KERNEL */ + +/* + * Clear bss memory + */ +static noinline __init void clear_bss_section(void) +{ + memset(__bss_start, 0, _end - __bss_start); +} + +/* + * Initialize storage key for kernel pages + */ +static noinline __init void init_kernel_storage_key(void) +{ + unsigned long end_pfn, init_pfn; + + end_pfn = PFN_UP(__pa(&_end)); + + for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++) + page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY); +} + +static noinline __init void detect_machine_type(void) +{ + struct cpuinfo_S390 *cpuinfo = &S390_lowcore.cpu_data; + + asm volatile("stidp %0" : "=m" (S390_lowcore.cpu_data.cpu_id)); + + /* Running under z/VM ? */ + if (cpuinfo->cpu_id.version == 0xff) + machine_flags |= 1; + + /* Running on a P/390 ? */ + if (cpuinfo->cpu_id.machine == 0x7490) + machine_flags |= 4; +} + +static noinline __init int memory_fast_detect(void) +{ + + unsigned long val0 = 0; + unsigned long val1 = 0xc; + int ret = -ENOSYS; + + if (ipl_flags & IPL_NSS_VALID) + return -ENOSYS; + + asm volatile( + " diag %1,%2,0x260\n" + "0: lhi %0,0\n" + "1:\n" + EX_TABLE(0b,1b) + : "+d" (ret), "+d" (val0), "+d" (val1) : : "cc"); + + if (ret || val0 != val1) + return -ENOSYS; + + memory_chunk[0].size = val0; + return 0; +} + +#define ADDR2G (1UL << 31) + +static noinline __init unsigned long sclp_memory_detect(void) +{ + struct sclp_readinfo_sccb *sccb; + unsigned long long memsize; + + sccb = &s390_readinfo_sccb; + + if (sccb->header.response_code != 0x10) + return 0; + + if (sccb->rnsize) + memsize = sccb->rnsize << 20; + else + memsize = sccb->rnsize2 << 20; + if (sccb->rnmax) + memsize *= sccb->rnmax; + else + memsize *= sccb->rnmax2; +#ifndef CONFIG_64BIT + /* + * Can't deal with more than 2G in 31 bit addressing mode, so + * limit the value in order to avoid strange side effects. + */ + if (memsize > ADDR2G) + memsize = ADDR2G; +#endif + return (unsigned long) memsize; +} + +static inline __init unsigned long __tprot(unsigned long addr) +{ + int cc = -1; + + asm volatile( + " tprot 0(%1),0\n" + "0: ipm %0\n" + " srl %0,28\n" + "1:\n" + EX_TABLE(0b,1b) + : "+d" (cc) : "a" (addr) : "cc"); + return (unsigned long)cc; +} + +/* Checking memory in 128KB increments. */ +#define CHUNK_INCR (1UL << 17) + +static noinline __init void find_memory_chunks(unsigned long memsize) +{ + unsigned long addr = 0, old_addr = 0; + unsigned long old_cc = CHUNK_READ_WRITE; + unsigned long cc; + int chunk = 0; + + while (chunk < MEMORY_CHUNKS) { + cc = __tprot(addr); + while (cc == old_cc) { + addr += CHUNK_INCR; + cc = __tprot(addr); +#ifndef CONFIG_64BIT + if (addr == ADDR2G) + break; +#endif + } + + if (old_addr != addr && + (old_cc == CHUNK_READ_WRITE || old_cc == CHUNK_READ_ONLY)) { + memory_chunk[chunk].addr = old_addr; + memory_chunk[chunk].size = addr - old_addr; + memory_chunk[chunk].type = old_cc; + chunk++; + } + + old_addr = addr; + old_cc = cc; + +#ifndef CONFIG_64BIT + if (addr == ADDR2G) + break; +#endif + /* + * Finish memory detection at the first hole, unless + * - we reached the hsa -> skip it. + * - we know there must be more. + */ + if (cc == -1UL && !memsize && old_addr != ADDR2G) + break; + if (memsize && addr >= memsize) + break; + } +} + +static __init void early_pgm_check_handler(void) +{ + unsigned long addr; + const struct exception_table_entry *fixup; + + addr = S390_lowcore.program_old_psw.addr; + fixup = search_exception_tables(addr & PSW_ADDR_INSN); + if (!fixup) + disabled_wait(0); + S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE; +} + +static noinline __init void setup_lowcore_early(void) +{ + psw_t psw; + + psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY; + psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler; + S390_lowcore.external_new_psw = psw; + psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler; + S390_lowcore.program_new_psw = psw; + s390_base_pgm_handler_fn = early_pgm_check_handler; +} + +/* + * Save ipl parameters, clear bss memory, initialize storage keys + * and create a kernel NSS at startup if the SAVESYS= parm is defined + */ +void __init startup_init(void) +{ + unsigned long memsize; + + ipl_save_parameters(); + clear_bss_section(); + init_kernel_storage_key(); + lockdep_init(); + lockdep_off(); + detect_machine_type(); + create_kernel_nss(); + sort_main_extable(); + setup_lowcore_early(); + sclp_readinfo_early(); + memsize = sclp_memory_detect(); + if (memory_fast_detect() < 0) + find_memory_chunks(memsize); + lockdep_on(); +} |