Commit 14a3a262 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Vasily Gorbik
Browse files

s390/dump: save IPL CPU registers once DAT is available 



Function smp_save_dump_cpus() collects CPU state of a crashed
system for secondary CPUs and for the IPL CPU very differently.
The Signal Processor stop-and-store-status orders are used for
the former while Hardware System Area requests and memcpy_real()
routine are called for the latter. In addition a system reset is
triggered, which pins smp_save_dump_cpus() function call before
CPU and device initialization.

Move the collection of IPL CPU state to a later stage when DAT
becomes available. That is needed to allow a follow-up rework of
memcpy_real() routine.

Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 2187582c

arch/s390/include/asm/smp.h

+2 −1
Original line number Diff line number Diff line
@@ -30,7 +30,8 @@ extern void smp_emergency_stop(void); 


extern int smp_find_processor_id(u16 address);

extern int smp_store_status(int cpu);

extern void smp_save_dump_cpus(void);

extern void smp_save_dump_ipl_cpu(void);

extern void smp_save_dump_secondary_cpus(void);

extern void smp_yield_cpu(int cpu);

extern void smp_cpu_set_polarization(int cpu, int val);

extern int smp_cpu_get_polarization(int cpu);

arch/s390/kernel/setup.c

+5 −2
Original line number Diff line number Diff line
@@ -1028,10 +1028,10 @@ void __init setup_arch(char **cmdline_p) 
	reserve_crashkernel();

#ifdef CONFIG_CRASH_DUMP

	/*

	 * Be aware that smp_save_dump_cpus() triggers a system reset.

	 * Be aware that smp_save_dump_secondary_cpus() triggers a system reset.

	 * Therefore CPU and device initialization should be done afterwards.

	 */

	smp_save_dump_cpus();

	smp_save_dump_secondary_cpus();

#endif



	setup_resources();
@@ -1056,6 +1056,9 @@ void __init setup_arch(char **cmdline_p) 
	 * in lowcore can now run with DAT enabled.

	 */

	setup_lowcore_dat_on();

#ifdef CONFIG_CRASH_DUMP

	smp_save_dump_ipl_cpu();

#endif



        /* Setup default console */

	conmode_default();

arch/s390/kernel/smp.c

+27 −32
Original line number Diff line number Diff line
@@ -664,35 +664,36 @@ int smp_store_status(int cpu) 
 *    This case does not exist for s390 anymore, setup_arch explicitly

 *    deactivates the elfcorehdr= kernel parameter

 */

static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,

				     bool is_boot_cpu, __vector128 *vxrs)

static bool dump_available(void)

{

	if (is_boot_cpu)

		vxrs = boot_cpu_vector_save_area;

	else

		__pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, __pa(vxrs));

	save_area_add_vxrs(sa, vxrs);

	return oldmem_data.start || is_ipl_type_dump();

}



static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,

				     bool is_boot_cpu, void *regs)

void __init smp_save_dump_ipl_cpu(void)

{

	if (is_boot_cpu)

	struct save_area *sa;

	void *regs;



	if (!dump_available())

		return;

	sa = save_area_alloc(true);

	regs = memblock_alloc(512, 8);

	if (!sa || !regs)

		panic("could not allocate memory for boot CPU save area\n");

	copy_oldmem_kernel(regs, __LC_FPREGS_SAVE_AREA, 512);

	else

		__pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, __pa(regs));

	save_area_add_regs(sa, regs);

	memblock_free(regs, 512);

	if (MACHINE_HAS_VX)

		save_area_add_vxrs(sa, boot_cpu_vector_save_area);

}



void __init smp_save_dump_cpus(void)

void __init smp_save_dump_secondary_cpus(void)

{

	int addr, boot_cpu_addr, max_cpu_addr;

	struct save_area *sa;

	bool is_boot_cpu;

	void *page;



	if (!(oldmem_data.start || is_ipl_type_dump()))

		/* No previous system present, normal boot. */

	if (!dump_available())

		return;

	/* Allocate a page as dumping area for the store status sigps */

	page = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
@@ -705,26 +706,20 @@ void __init smp_save_dump_cpus(void) 
	boot_cpu_addr = stap();

	max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;

	for (addr = 0; addr <= max_cpu_addr; addr++) {

		if (addr == boot_cpu_addr)

			continue;

		if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==

		    SIGP_CC_NOT_OPERATIONAL)

			continue;

		is_boot_cpu = (addr == boot_cpu_addr);

		/* Allocate save area */

		sa = save_area_alloc(is_boot_cpu);

		sa = save_area_alloc(false);

		if (!sa)

			panic("could not allocate memory for save area\n");

		if (MACHINE_HAS_VX)

			/* Get the vector registers */

			smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);

		/*

		 * For a zfcp/nvme dump OLDMEM_BASE == NULL and the registers

		 * of the boot CPU are stored in the HSA. To retrieve

		 * these registers an SCLP request is required which is

		 * done by drivers/s390/char/zcore.c:init_cpu_info()

		 */

		if (!is_boot_cpu || oldmem_data.start)

			/* Get the CPU registers */

			smp_save_cpu_regs(sa, addr, is_boot_cpu, page);

		__pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, __pa(page));

		save_area_add_regs(sa, page);

		if (MACHINE_HAS_VX) {

			__pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, __pa(page));

			save_area_add_vxrs(sa, page);

		}

	}

	memblock_free(page, PAGE_SIZE);

	diag_amode31_ops.diag308_reset();