[mirror_ubuntu-zesty-kernel.git] / arch / s390 / kernel / early.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>
#include "entry.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) {
		kernel_nss_name[0] = '\0';
		return;
	}

	__cpcmd(savesys_cmd, NULL, 0, &response);

	if (response != strlen(savesys_cmd)) {
		kernel_nss_name[0] = '\0';
		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_read_info_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();
}
Commit	Line	Data
ab14de6c HC	1	/*
	2	* arch/s390/kernel/early.c
	3	*
	4	* Copyright IBM Corp. 2007
	5	* Author(s): Hongjie Yang <hongjie@us.ibm.com>,
	6	* Heiko Carstens <heiko.carstens@de.ibm.com>
	7	*/
	8
	9	#include <linux/init.h>
	10	#include <linux/errno.h>
	11	#include <linux/string.h>
	12	#include <linux/ctype.h>
	13	#include <linux/lockdep.h>
	14	#include <linux/module.h>
	15	#include <linux/pfn.h>
	16	#include <linux/uaccess.h>
46b05d26	17	#include <asm/ipl.h>
ab14de6c HC	18	#include <asm/lowcore.h>
	19	#include <asm/processor.h>
	20	#include <asm/sections.h>
	21	#include <asm/setup.h>
	22	#include <asm/cpcmd.h>
	23	#include <asm/sclp.h>
a806170e	24	#include "entry.h"
ab14de6c HC	25
	26	/*
	27	* Create a Kernel NSS if the SAVESYS= parameter is defined
	28	*/
	29	#define DEFSYS_CMD_SIZE 96
	30	#define SAVESYS_CMD_SIZE 32
	31
ab14de6c HC	32	char kernel_nss_name[NSS_NAME_SIZE + 1];
	33
	34	#ifdef CONFIG_SHARED_KERNEL
	35	static noinline __init void create_kernel_nss(void)
	36	{
	37	unsigned int i, stext_pfn, eshared_pfn, end_pfn, min_size;
	38	#ifdef CONFIG_BLK_DEV_INITRD
	39	unsigned int sinitrd_pfn, einitrd_pfn;
	40	#endif
	41	int response;
	42	char *savesys_ptr;
	43	char upper_command_line[COMMAND_LINE_SIZE];
	44	char defsys_cmd[DEFSYS_CMD_SIZE];
	45	char savesys_cmd[SAVESYS_CMD_SIZE];
	46
	47	/* Do nothing if we are not running under VM */
	48	if (!MACHINE_IS_VM)
	49	return;
	50
	51	/* Convert COMMAND_LINE to upper case */
	52	for (i = 0; i < strlen(COMMAND_LINE); i++)
	53	upper_command_line[i] = toupper(COMMAND_LINE[i]);
	54
	55	savesys_ptr = strstr(upper_command_line, "SAVESYS=");
	56
	57	if (!savesys_ptr)
	58	return;
	59
	60	savesys_ptr += 8; /* Point to the beginning of the NSS name */
	61	for (i = 0; i < NSS_NAME_SIZE; i++) {
	62	if (savesys_ptr[i] == ' ' \|\| savesys_ptr[i] == '\0')
	63	break;
	64	kernel_nss_name[i] = savesys_ptr[i];
	65	}
	66
	67	stext_pfn = PFN_DOWN(__pa(&_stext));
	68	eshared_pfn = PFN_DOWN(__pa(&_eshared));
	69	end_pfn = PFN_UP(__pa(&_end));
	70	min_size = end_pfn << 2;
	71
	72	sprintf(defsys_cmd, "DEFSYS %s 00000-%.5X EW %.5X-%.5X SR %.5X-%.5X",
	73	kernel_nss_name, stext_pfn - 1, stext_pfn, eshared_pfn - 1,
	74	eshared_pfn, end_pfn);
	75
	76	#ifdef CONFIG_BLK_DEV_INITRD
	77	if (INITRD_START && INITRD_SIZE) {
	78	sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
	79	einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
	80	min_size = einitrd_pfn << 2;
	81	sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
	82	sinitrd_pfn, einitrd_pfn);
	83	}
	84	#endif
	85
	86	sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK", defsys_cmd, min_size);
	87	sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
	88	kernel_nss_name, kernel_nss_name);
	89
	90	__cpcmd(defsys_cmd, NULL, 0, &response);
	91
583b33bc HY	92	if (response != 0) {
583b33bc HY	93	kernel_nss_name[0] = '\0';
ab14de6c	94	return;
583b33bc	95	}
ab14de6c HC	96
	97	__cpcmd(savesys_cmd, NULL, 0, &response);
	98
583b33bc HY	99	if (response != strlen(savesys_cmd)) {
583b33bc HY	100	kernel_nss_name[0] = '\0';
ab14de6c	101	return;
583b33bc	102	}
ab14de6c HC	103
	104	ipl_flags = IPL_NSS_VALID;
	105	}
	106
	107	#else /* CONFIG_SHARED_KERNEL */
	108
	109	static inline void create_kernel_nss(void) { }
	110
	111	#endif /* CONFIG_SHARED_KERNEL */
	112
	113	/*
	114	* Clear bss memory
	115	*/
	116	static noinline __init void clear_bss_section(void)
	117	{
229d9c6d	118	memset(__bss_start, 0, __bss_stop - __bss_start);
ab14de6c HC	119	}
	120
	121	/*
	122	* Initialize storage key for kernel pages
	123	*/
	124	static noinline __init void init_kernel_storage_key(void)
	125	{
	126	unsigned long end_pfn, init_pfn;
	127
	128	end_pfn = PFN_UP(__pa(&_end));
	129
	130	for (init_pfn = 0 ; init_pfn < end_pfn; init_pfn++)
	131	page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
	132	}
	133
	134	static noinline __init void detect_machine_type(void)
	135	{
	136	struct cpuinfo_S390 *cpuinfo = &S390_lowcore.cpu_data;
	137
72960a02	138	get_cpu_id(&S390_lowcore.cpu_data.cpu_id);
ab14de6c HC	139
	140	/* Running under z/VM ? */
	141	if (cpuinfo->cpu_id.version == 0xff)
	142	machine_flags \|= 1;
	143
	144	/* Running on a P/390 ? */
	145	if (cpuinfo->cpu_id.machine == 0x7490)
	146	machine_flags \|= 4;
	147	}
	148
257c6e1c	149	#ifdef CONFIG_64BIT
ab14de6c HC	150	static noinline __init int memory_fast_detect(void)
ab14de6c HC	151	{
ab14de6c HC	152	unsigned long val0 = 0;
	153	unsigned long val1 = 0xc;
	154	int ret = -ENOSYS;
	155
	156	if (ipl_flags & IPL_NSS_VALID)
	157	return -ENOSYS;
	158
	159	asm volatile(
	160	" diag %1,%2,0x260\n"
	161	"0: lhi %0,0\n"
	162	"1:\n"
	163	EX_TABLE(0b,1b)
	164	: "+d" (ret), "+d" (val0), "+d" (val1) : : "cc");
	165
	166	if (ret \|\| val0 != val1)
	167	return -ENOSYS;
	168
257c6e1c	169	memory_chunk[0].size = val0 + 1;
ab14de6c HC	170	return 0;
ab14de6c HC	171	}
257c6e1c HC	172	#else
	173	static inline int memory_fast_detect(void)
	174	{
	175	return -ENOSYS;
	176	}
	177	#endif
ab14de6c	178
ab14de6c HC	179	static inline __init unsigned long __tprot(unsigned long addr)
	180	{
	181	int cc = -1;
	182
	183	asm volatile(
	184	" tprot 0(%1),0\n"
	185	"0: ipm %0\n"
	186	" srl %0,28\n"
	187	"1:\n"
	188	EX_TABLE(0b,1b)
	189	: "+d" (cc) : "a" (addr) : "cc");
	190	return (unsigned long)cc;
	191	}
	192
	193	/* Checking memory in 128KB increments. */
	194	#define CHUNK_INCR (1UL << 17)
05dd2530	195	#define ADDR2G (1UL << 31)
ab14de6c HC	196
	197	static noinline __init void find_memory_chunks(unsigned long memsize)
	198	{
	199	unsigned long addr = 0, old_addr = 0;
	200	unsigned long old_cc = CHUNK_READ_WRITE;
	201	unsigned long cc;
	202	int chunk = 0;
	203
	204	while (chunk < MEMORY_CHUNKS) {
	205	cc = __tprot(addr);
	206	while (cc == old_cc) {
	207	addr += CHUNK_INCR;
a2cb0737	208	if (memsize && addr >= memsize)
0b8da654	209	break;
ab14de6c HC	210	#ifndef CONFIG_64BIT
	211	if (addr == ADDR2G)
	212	break;
	213	#endif
0b8da654	214	cc = __tprot(addr);
ab14de6c HC	215	}
	216
	217	if (old_addr != addr &&
	218	(old_cc == CHUNK_READ_WRITE \|\| old_cc == CHUNK_READ_ONLY)) {
	219	memory_chunk[chunk].addr = old_addr;
	220	memory_chunk[chunk].size = addr - old_addr;
	221	memory_chunk[chunk].type = old_cc;
	222	chunk++;
	223	}
	224
	225	old_addr = addr;
	226	old_cc = cc;
	227
	228	#ifndef CONFIG_64BIT
	229	if (addr == ADDR2G)
	230	break;
	231	#endif
	232	/*
29c380f5 HC	233	* Finish memory detection at the first hole
29c380f5 HC	234	* if storage size is unknown.
ab14de6c	235	*/
29c380f5	236	if (cc == -1UL && !memsize)
ab14de6c HC	237	break;
	238	if (memsize && addr >= memsize)
	239	break;
	240	}
	241	}
	242
	243	static __init void early_pgm_check_handler(void)
	244	{
	245	unsigned long addr;
	246	const struct exception_table_entry *fixup;
	247
	248	addr = S390_lowcore.program_old_psw.addr;
	249	fixup = search_exception_tables(addr & PSW_ADDR_INSN);
	250	if (!fixup)
	251	disabled_wait(0);
	252	S390_lowcore.program_old_psw.addr = fixup->fixup \| PSW_ADDR_AMODE;
	253	}
	254
	255	static noinline __init void setup_lowcore_early(void)
	256	{
	257	psw_t psw;
	258
	259	psw.mask = PSW_BASE_BITS \| PSW_DEFAULT_KEY;
	260	psw.addr = PSW_ADDR_AMODE \| (unsigned long) s390_base_ext_handler;
	261	S390_lowcore.external_new_psw = psw;
	262	psw.addr = PSW_ADDR_AMODE \| (unsigned long) s390_base_pgm_handler;
	263	S390_lowcore.program_new_psw = psw;
	264	s390_base_pgm_handler_fn = early_pgm_check_handler;
	265	}
	266
	267	/*
	268	* Save ipl parameters, clear bss memory, initialize storage keys
	269	* and create a kernel NSS at startup if the SAVESYS= parm is defined
	270	*/
	271	void __init startup_init(void)
	272	{
05dd2530	273	unsigned long long memsize;
ab14de6c HC	274
	275	ipl_save_parameters();
	276	clear_bss_section();
	277	init_kernel_storage_key();
	278	lockdep_init();
	279	lockdep_off();
	280	detect_machine_type();
	281	create_kernel_nss();
	282	sort_main_extable();
	283	setup_lowcore_early();
08d07968	284	sclp_read_info_early();
83119ad4	285	sclp_facilities_detect();
ab14de6c	286	memsize = sclp_memory_detect();
05dd2530 HC	287	#ifndef CONFIG_64BIT
	288	/*
	289	* Can't deal with more than 2G in 31 bit addressing mode, so
	290	* limit the value in order to avoid strange side effects.
	291	*/
	292	if (memsize > ADDR2G)
	293	memsize = ADDR2G;
	294	#endif
ab14de6c	295	if (memory_fast_detect() < 0)
05dd2530	296	find_memory_chunks((unsigned long) memsize);
ab14de6c HC	297	lockdep_on();
ab14de6c HC	298	}