arch/s390/kernel/early.c - maze/linux - Git at Google

 /*
  *  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, unless
 		 * - we reached the hsa -> skip it.
 		 * - we know there must be more.
 		 */
 		if (cc == -1UL && !memsize && old_addr != ADDR2G)
 			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();
 }
	/*
	* 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, unless
	* - we reached the hsa -> skip it.
	* - we know there must be more.
	*/
	if (cc == -1UL && !memsize && old_addr != ADDR2G)
	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();
	}