linux/arch/s390/kernel/early.c
Heiko Carstens a2cb07376e [S390] Fix memory detection.
Before we're getting short on memory detection fixes here is the next
one: if neither sclp nor diag260 report the storage size the detection
loop will return immediately without detecting anything. Fix this by
breaking the detection loop only if the memory end is known.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20 11:13:48 +01:00

294 lines
6.6 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
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)
#define ADDR2G (1UL << 31)
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;
if (memsize && addr >= memsize)
break;
#ifndef CONFIG_64BIT
if (addr == ADDR2G)
break;
#endif
cc = __tprot(addr);
}
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 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();
sclp_facilities_detect();
memsize = sclp_memory_detect();
#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
if (memory_fast_detect() < 0)
find_memory_chunks((unsigned long) memsize);
lockdep_on();
}