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linux/arch/s390/kernel/early.c
Heiko Carstens df1bd59c5c s390/mem_detect: limit memory detection loop to "mem=" parameter 
The current memory detection loop will detect all present memory of
a machine. This is true even if the user specified the "mem=" parameter
on the kernel command line.
This can be a problem since the memory detection may cause a fully
populated host page table for the guest, even for those parts of the
memory that the guest will never use afterwards.

So fix this and only detect memory up to a user supplied "mem=" limit
if specified.

Reported-by: Michael Johanssen <johanssn@de.ibm.com>
Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-05-02 15:50:26 +02:00

490 lines
12 KiB
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/*
* Copyright IBM Corp. 2007, 2009
* Author(s): Hongjie Yang <hongjie@us.ibm.com>,
* Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#define KMSG_COMPONENT "setup"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/ftrace.h>
#include <linux/lockdep.h>
#include <linux/module.h>
#include <linux/pfn.h>
#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <asm/ebcdic.h>
#include <asm/ipl.h>
#include <asm/lowcore.h>
#include <asm/processor.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sysinfo.h>
#include <asm/cpcmd.h>
#include <asm/sclp.h>
#include <asm/facility.h>
#include "entry.h"
/*
* Create a Kernel NSS if the SAVESYS= parameter is defined
*/
#define DEFSYS_CMD_SIZE 128
#define SAVESYS_CMD_SIZE 32
char kernel_nss_name[NSS_NAME_SIZE + 1];
static void __init setup_boot_command_line(void);
/*
* Get the TOD clock running.
*/
static void __init reset_tod_clock(void)
{
u64 time;
if (store_tod_clock(&time) == 0)
return;
/* TOD clock not running. Set the clock to Unix Epoch. */
if (set_tod_clock(TOD_UNIX_EPOCH) != 0 || store_tod_clock(&time) != 0)
disabled_wait(0);
sched_clock_base_cc = TOD_UNIX_EPOCH;
S390_lowcore.last_update_clock = sched_clock_base_cc;
}
#ifdef CONFIG_SHARED_KERNEL
int __init savesys_ipl_nss(char *cmd, const int cmdlen);
asm(
" .section .init.text,\"ax\",@progbits\n"
" .align 4\n"
" .type savesys_ipl_nss, @function\n"
"savesys_ipl_nss:\n"
#ifdef CONFIG_64BIT
" stmg 6,15,48(15)\n"
" lgr 14,3\n"
" sam31\n"
" diag 2,14,0x8\n"
" sam64\n"
" lgr 2,14\n"
" lmg 6,15,48(15)\n"
#else
" stm 6,15,24(15)\n"
" lr 14,3\n"
" diag 2,14,0x8\n"
" lr 2,14\n"
" lm 6,15,24(15)\n"
#endif
" br 14\n"
" .size savesys_ipl_nss, .-savesys_ipl_nss\n"
" .previous\n");
static __initdata char upper_command_line[COMMAND_LINE_SIZE];
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;
int hlen;
size_t len;
char *savesys_ptr;
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(boot_command_line); i++)
upper_command_line[i] = toupper(boot_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;
hlen = snprintf(defsys_cmd, DEFSYS_CMD_SIZE,
"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;
hlen += snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
" EW %.5X-%.5X", sinitrd_pfn, einitrd_pfn);
}
#endif
snprintf(defsys_cmd + hlen, DEFSYS_CMD_SIZE - hlen,
" EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
defsys_cmd[DEFSYS_CMD_SIZE - 1] = '\0';
snprintf(savesys_cmd, SAVESYS_CMD_SIZE, "SAVESYS %s \n IPL %s",
kernel_nss_name, kernel_nss_name);
savesys_cmd[SAVESYS_CMD_SIZE - 1] = '\0';
__cpcmd(defsys_cmd, NULL, 0, &response);
if (response != 0) {
pr_err("Defining the Linux kernel NSS failed with rc=%d\n",
response);
kernel_nss_name[0] = '\0';
return;
}
len = strlen(savesys_cmd);
ASCEBC(savesys_cmd, len);
response = savesys_ipl_nss(savesys_cmd, len);
/* On success: response is equal to the command size,
* max SAVESYS_CMD_SIZE
* On error: response contains the numeric portion of cp error message.
* for SAVESYS it will be >= 263
* for missing privilege class, it will be 1
*/
if (response > SAVESYS_CMD_SIZE || response == 1) {
pr_err("Saving the Linux kernel NSS failed with rc=%d\n",
response);
kernel_nss_name[0] = '\0';
return;
}
/* re-initialize cputime accounting. */
sched_clock_base_cc = get_tod_clock();
S390_lowcore.last_update_clock = sched_clock_base_cc;
S390_lowcore.last_update_timer = 0x7fffffffffffffffULL;
S390_lowcore.user_timer = 0;
S390_lowcore.system_timer = 0;
asm volatile("SPT 0(%0)" : : "a" (&S390_lowcore.last_update_timer));
/* re-setup boot command line with new ipl vm parms */
ipl_update_parameters();
setup_boot_command_line();
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, 0);
}
static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
static noinline __init void detect_machine_type(void)
{
struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
/* Check current-configuration-level */
if (stsi(NULL, 0, 0, 0) <= 2) {
S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
return;
}
/* Get virtual-machine cpu information. */
if (stsi(vmms, 3, 2, 2) || !vmms->count)
return;
/* Running under KVM? If not we assume z/VM */
if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
else
S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
}
static __init void setup_topology(void)
{
#ifdef CONFIG_64BIT
int max_mnest;
if (!test_facility(11))
return;
S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
for (max_mnest = 6; max_mnest > 1; max_mnest--) {
if (stsi(&sysinfo_page, 15, 1, max_mnest) == 0)
break;
}
topology_max_mnest = max_mnest;
#endif
}
static void early_pgm_check_handler(void)
{
const struct exception_table_entry *fixup;
unsigned long addr;
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 = extable_fixup(fixup)|PSW_ADDR_AMODE;
}
static noinline __init void setup_lowcore_early(void)
{
psw_t psw;
psw.mask = PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA;
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;
}
static noinline __init void setup_facility_list(void)
{
stfle(S390_lowcore.stfle_fac_list,
ARRAY_SIZE(S390_lowcore.stfle_fac_list));
}
static __init void detect_mvpg(void)
{
#ifndef CONFIG_64BIT
int rc;
asm volatile(
" la 0,0\n"
" mvpg %2,%2\n"
"0: la %0,0\n"
"1:\n"
EX_TABLE(0b,1b)
: "=d" (rc) : "0" (-EOPNOTSUPP), "a" (0) : "memory", "cc", "0");
if (!rc)
S390_lowcore.machine_flags |= MACHINE_FLAG_MVPG;
#endif
}
static __init void detect_ieee(void)
{
#ifndef CONFIG_64BIT
int rc, tmp;
asm volatile(
" efpc %1,0\n"
"0: la %0,0\n"
"1:\n"
EX_TABLE(0b,1b)
: "=d" (rc), "=d" (tmp): "0" (-EOPNOTSUPP) : "cc");
if (!rc)
S390_lowcore.machine_flags |= MACHINE_FLAG_IEEE;
#endif
}
static __init void detect_csp(void)
{
#ifndef CONFIG_64BIT
int rc;
asm volatile(
" la 0,0\n"
" la 1,0\n"
" la 2,4\n"
" csp 0,2\n"
"0: la %0,0\n"
"1:\n"
EX_TABLE(0b,1b)
: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc", "0", "1", "2");
if (!rc)
S390_lowcore.machine_flags |= MACHINE_FLAG_CSP;
#endif
}
static __init void detect_diag9c(void)
{
unsigned int cpu_address;
int rc;
cpu_address = stap();
asm volatile(
" diag %2,0,0x9c\n"
"0: la %0,0\n"
"1:\n"
EX_TABLE(0b,1b)
: "=d" (rc) : "0" (-EOPNOTSUPP), "d" (cpu_address) : "cc");
if (!rc)
S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG9C;
}
static __init void detect_diag44(void)
{
#ifdef CONFIG_64BIT
int rc;
asm volatile(
" diag 0,0,0x44\n"
"0: la %0,0\n"
"1:\n"
EX_TABLE(0b,1b)
: "=d" (rc) : "0" (-EOPNOTSUPP) : "cc");
if (!rc)
S390_lowcore.machine_flags |= MACHINE_FLAG_DIAG44;
#endif
}
static __init void detect_machine_facilities(void)
{
#ifdef CONFIG_64BIT
if (test_facility(8)) {
S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT1;
__ctl_set_bit(0, 23);
}
if (test_facility(78))
S390_lowcore.machine_flags |= MACHINE_FLAG_EDAT2;
if (test_facility(3))
S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
if (test_facility(27))
S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
if (test_facility(40))
S390_lowcore.machine_flags |= MACHINE_FLAG_LPP;
if (test_facility(50) && test_facility(73))
S390_lowcore.machine_flags |= MACHINE_FLAG_TE;
if (test_facility(66))
S390_lowcore.machine_flags |= MACHINE_FLAG_RRBM;
#endif
}
static __init void rescue_initrd(void)
{
#ifdef CONFIG_BLK_DEV_INITRD
unsigned long min_initrd_addr = (unsigned long) _end + (4UL << 20);
/*
* Just like in case of IPL from VM reader we make sure there is a
* gap of 4MB between end of kernel and start of initrd.
* That way we can also be sure that saving an NSS will succeed,
* which however only requires different segments.
*/
if (!INITRD_START || !INITRD_SIZE)
return;
if (INITRD_START >= min_initrd_addr)
return;
memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
INITRD_START = min_initrd_addr;
#endif
}
/* Set up boot command line */
static void __init append_to_cmdline(size_t (*ipl_data)(char *, size_t))
{
char *parm, *delim;
size_t rc, len;
len = strlen(boot_command_line);
delim = boot_command_line + len; /* '\0' character position */
parm = boot_command_line + len + 1; /* append right after '\0' */
rc = ipl_data(parm, COMMAND_LINE_SIZE - len - 1);
if (rc) {
if (*parm == '=')
memmove(boot_command_line, parm + 1, rc);
else
*delim = ' '; /* replace '\0' with space */
}
}
static inline int has_ebcdic_char(const char *str)
{
int i;
for (i = 0; str[i]; i++)
if (str[i] & 0x80)
return 1;
return 0;
}
static void __init setup_boot_command_line(void)
{
COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
/* convert arch command line to ascii if necessary */
if (has_ebcdic_char(COMMAND_LINE))
EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
/* copy arch command line */
strlcpy(boot_command_line, strstrip(COMMAND_LINE),
ARCH_COMMAND_LINE_SIZE);
/* append IPL PARM data to the boot command line */
if (MACHINE_IS_VM)
append_to_cmdline(append_ipl_vmparm);
append_to_cmdline(append_ipl_scpdata);
}
/*
* 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)
{
reset_tod_clock();
ipl_save_parameters();
rescue_initrd();
clear_bss_section();
init_kernel_storage_key();
lockdep_init();
lockdep_off();
setup_lowcore_early();
setup_facility_list();
detect_machine_type();
ipl_update_parameters();
setup_boot_command_line();
create_kernel_nss();
detect_mvpg();
detect_ieee();
detect_csp();
detect_diag9c();
detect_diag44();
detect_machine_facilities();
setup_topology();
sclp_facilities_detect();
#ifdef CONFIG_DYNAMIC_FTRACE
S390_lowcore.ftrace_func = (unsigned long)ftrace_caller;
#endif
lockdep_on();
}
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