[S390] Convert memory detection into C code.
Hopefully this will make it more maintainable and less error prone. Code makes use of search_exception_tables(). Since it calls this function before the kernel exeception table is sorted, there is an early call to sort_main_extable(). This way it's easy to use the already present infrastructure of fixup sections. Also this would allows to easily convert the rest of head[31|64].S into C code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens
committed by
Martin Schwidefsky
Martin Schwidefsky
parent
31ee4b2f40
commit
ab14de6c37
307
arch/s390/kernel/early.c
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307
arch/s390/kernel/early.c
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/*
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* arch/s390/kernel/early.c
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*
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* Copyright IBM Corp. 2007
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* Author(s): Hongjie Yang <hongjie@us.ibm.com>,
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* Heiko Carstens <heiko.carstens@de.ibm.com>
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*/
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/ctype.h>
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#include <linux/lockdep.h>
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#include <linux/module.h>
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#include <linux/pfn.h>
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#include <linux/uaccess.h>
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#include <asm/lowcore.h>
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#include <asm/processor.h>
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#include <asm/sections.h>
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#include <asm/setup.h>
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#include <asm/cpcmd.h>
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#include <asm/sclp.h>
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/*
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* Create a Kernel NSS if the SAVESYS= parameter is defined
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*/
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#define DEFSYS_CMD_SIZE 96
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#define SAVESYS_CMD_SIZE 32
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extern int _eshared;
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char kernel_nss_name[NSS_NAME_SIZE + 1];
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#ifdef CONFIG_SHARED_KERNEL
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static noinline __init void create_kernel_nss(void)
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{
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unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
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#ifdef CONFIG_BLK_DEV_INITRD
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unsigned int sinitrd_pfn, einitrd_pfn;
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#endif
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int response;
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char *savesys_ptr;
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char upper_command_line[COMMAND_LINE_SIZE];
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char defsys_cmd[DEFSYS_CMD_SIZE];
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char savesys_cmd[SAVESYS_CMD_SIZE];
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/* Do nothing if we are not running under VM */
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if (!MACHINE_IS_VM)
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return;
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/* Convert COMMAND_LINE to upper case */
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for (i = 0; i < strlen(COMMAND_LINE); i++)
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upper_command_line[i] = toupper(COMMAND_LINE[i]);
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savesys_ptr = strstr(upper_command_line, "SAVESYS=");
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if (!savesys_ptr)
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return;
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savesys_ptr += 8; /* Point to the beginning of the NSS name */
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for (i = 0; i < NSS_NAME_SIZE; i++) {
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if (savesys_ptr[i] == ' ' || savesys_ptr[i] == '\0')
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break;
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kernel_nss_name[i] = savesys_ptr[i];
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}
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stext_pfn = PFN_DOWN(__pa(&_stext));
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eshared_pfn = PFN_DOWN(__pa(&_eshared));
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end_pfn = PFN_UP(__pa(&_end));
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min_size = end_pfn << 2;
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sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
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kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
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eshared_pfn, end_pfn);
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#ifdef CONFIG_BLK_DEV_INITRD
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if (INITRD_START && INITRD_SIZE) {
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sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
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einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
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min_size = einitrd_pfn << 2;
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sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
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sinitrd_pfn, einitrd_pfn);
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}
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#endif
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sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK", defsys_cmd, min_size);
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sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
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kernel_nss_name, kernel_nss_name);
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__cpcmd(defsys_cmd, NULL, 0, &response);
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if (response != 0)
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return;
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__cpcmd(savesys_cmd, NULL, 0, &response);
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if (response != strlen(savesys_cmd))
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return;
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ipl_flags = IPL_NSS_VALID;
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}
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#else /* CONFIG_SHARED_KERNEL */
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static inline void create_kernel_nss(void) { }
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#endif /* CONFIG_SHARED_KERNEL */
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/*
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* Clear bss memory
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*/
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static noinline __init void clear_bss_section(void)
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{
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memset(__bss_start, 0, _end - __bss_start);
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}
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/*
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* Initialize storage key for kernel pages
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*/
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static noinline __init void init_kernel_storage_key(void)
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{
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unsigned long end_pfn, init_pfn;
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end_pfn = PFN_UP(__pa(&_end));
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for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
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page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
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}
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static noinline __init void detect_machine_type(void)
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{
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struct cpuinfo_S390 *cpuinfo = &S390_lowcore.cpu_data;
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asm volatile("stidp %0" : "=m" (S390_lowcore.cpu_data.cpu_id));
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/* Running under z/VM ? */
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if (cpuinfo->cpu_id.version == 0xff)
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machine_flags |= 1;
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/* Running on a P/390 ? */
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if (cpuinfo->cpu_id.machine == 0x7490)
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machine_flags |= 4;
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}
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static noinline __init int memory_fast_detect(void)
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{
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unsigned long val0 = 0;
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unsigned long val1 = 0xc;
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int ret = -ENOSYS;
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if (ipl_flags & IPL_NSS_VALID)
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return -ENOSYS;
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asm volatile(
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" diag %1,%2,0x260\n"
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"0: lhi %0,0\n"
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"1:\n"
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EX_TABLE(0b,1b)
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: "+d" (ret), "+d" (val0), "+d" (val1) : : "cc");
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if (ret || val0 != val1)
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return -ENOSYS;
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memory_chunk[0].size = val0;
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return 0;
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}
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#define ADDR2G (1UL << 31)
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static noinline __init unsigned long sclp_memory_detect(void)
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{
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struct sclp_readinfo_sccb *sccb;
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unsigned long long memsize;
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sccb = &s390_readinfo_sccb;
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if (sccb->header.response_code != 0x10)
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return 0;
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if (sccb->rnsize)
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memsize = sccb->rnsize << 20;
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else
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memsize = sccb->rnsize2 << 20;
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if (sccb->rnmax)
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memsize *= sccb->rnmax;
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else
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memsize *= sccb->rnmax2;
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#ifndef CONFIG_64BIT
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/*
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* Can't deal with more than 2G in 31 bit addressing mode, so
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* limit the value in order to avoid strange side effects.
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*/
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if (memsize > ADDR2G)
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memsize = ADDR2G;
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#endif
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return (unsigned long) memsize;
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}
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static inline __init unsigned long __tprot(unsigned long addr)
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{
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int cc = -1;
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asm volatile(
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" tprot 0(%1),0\n"
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"0: ipm %0\n"
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" srl %0,28\n"
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"1:\n"
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EX_TABLE(0b,1b)
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: "+d" (cc) : "a" (addr) : "cc");
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return (unsigned long)cc;
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}
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/* Checking memory in 128KB increments. */
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#define CHUNK_INCR (1UL << 17)
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static noinline __init void find_memory_chunks(unsigned long memsize)
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{
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unsigned long addr = 0, old_addr = 0;
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unsigned long old_cc = CHUNK_READ_WRITE;
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unsigned long cc;
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int chunk = 0;
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while (chunk < MEMORY_CHUNKS) {
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cc = __tprot(addr);
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while (cc == old_cc) {
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addr += CHUNK_INCR;
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cc = __tprot(addr);
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#ifndef CONFIG_64BIT
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if (addr == ADDR2G)
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break;
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#endif
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}
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if (old_addr != addr &&
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(old_cc == CHUNK_READ_WRITE || old_cc == CHUNK_READ_ONLY)) {
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memory_chunk[chunk].addr = old_addr;
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memory_chunk[chunk].size = addr - old_addr;
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memory_chunk[chunk].type = old_cc;
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chunk++;
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}
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old_addr = addr;
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old_cc = cc;
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#ifndef CONFIG_64BIT
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if (addr == ADDR2G)
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break;
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#endif
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/*
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* Finish memory detection at the first hole, unless
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* - we reached the hsa -> skip it.
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* - we know there must be more.
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*/
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if (cc == -1UL && !memsize && old_addr != ADDR2G)
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break;
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if (memsize && addr >= memsize)
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break;
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}
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}
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static __init void early_pgm_check_handler(void)
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{
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unsigned long addr;
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const struct exception_table_entry *fixup;
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addr = S390_lowcore.program_old_psw.addr;
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fixup = search_exception_tables(addr & PSW_ADDR_INSN);
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if (!fixup)
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disabled_wait(0);
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S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
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}
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static noinline __init void setup_lowcore_early(void)
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{
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psw_t psw;
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psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
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psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_ext_handler;
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S390_lowcore.external_new_psw = psw;
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psw.addr = PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
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S390_lowcore.program_new_psw = psw;
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s390_base_pgm_handler_fn = early_pgm_check_handler;
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}
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/*
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* Save ipl parameters, clear bss memory, initialize storage keys
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* and create a kernel NSS at startup if the SAVESYS= parm is defined
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*/
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void __init startup_init(void)
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{
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unsigned long memsize;
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ipl_save_parameters();
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clear_bss_section();
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init_kernel_storage_key();
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lockdep_init();
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lockdep_off();
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detect_machine_type();
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create_kernel_nss();
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sort_main_extable();
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setup_lowcore_early();
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sclp_readinfo_early();
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memsize = sclp_memory_detect();
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if (memory_fast_detect() < 0)
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find_memory_chunks(memsize);
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lockdep_on();
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}
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