s390/dump: rework CPU register dump code

To collect the CPU registers of the crashed system allocated a single
page with memblock_alloc_base and use it as a copy buffer. Replace the
stop-and-store-status sigp with a store-status-at-address sigp in
smp_save_dump_cpus() and smp_store_status(). In both cases the target
CPU is already stopped and store-status-at-address avoids the detour
via the absolute zero page.

For kexec simplify s390_reset_system and call store_status() before
the prefix register of the boot CPU has been set to zero. Use STPX
to store the prefix register and remove dump_prefix_page.

Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky
2015-10-29 10:28:26 +01:00
parent f08b841463
commit 1a36a39e22
12 changed files with 158 additions and 145 deletions

View File

@@ -18,6 +18,7 @@
extern struct mutex smp_cpu_state_mutex;
extern unsigned int smp_cpu_mt_shift;
extern unsigned int smp_cpu_mtid;
extern __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
extern int __cpu_up(unsigned int cpu, struct task_struct *tidle);
@@ -55,7 +56,6 @@ static inline int smp_store_status(int cpu) { return 0; }
static inline int smp_vcpu_scheduled(int cpu) { return 1; }
static inline void smp_yield_cpu(int cpu) { }
static inline void smp_fill_possible_mask(void) { }
static inline void smp_save_dump_cpus(void) { }
#endif /* CONFIG_SMP */