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

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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: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Alexander Gordeev 2022-09-02 10:05:08 +02:00 committed by Vasily Gorbik
parent 2187582c36
commit 14a3a26242
3 changed files with 34 additions and 35 deletions
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3
arch/s390/include/asm/smp.h
View file

@ -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);

7
arch/s390/kernel/setup.c
View file

@ -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();

59
arch/s390/kernel/smp.c
View file

@ -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)
copy_oldmem_kernel(regs, __LC_FPREGS_SAVE_AREA, 512);
else
__pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, __pa(regs));
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);
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();