kernel-ark/arch/s390/kernel/early.c
Heiko Carstens 29c380f5f0 [S390] memory detection: stop at first memory hole.
If both sclp and diag memory detection don't work stop at the first
memory hole. Otherwise the code might loop forever...

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2007-04-27 16:01:12 +02:00

313 lines
6.9 KiB
C

/*
* 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/ipl.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, __bss_stop - __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;
get_cpu_id(&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;
}
#ifdef CONFIG_64BIT
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 + 1;
return 0;
}
#else
static inline int memory_fast_detect(void)
{
return -ENOSYS;
}
#endif
#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
* if storage size is unknown.
*/
if (cc == -1UL && !memsize)
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();
}