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Diffstat (limited to 'arch/s390/kernel/machine_kexec.c')
-rw-r--r--arch/s390/kernel/machine_kexec.c110
1 files changed, 61 insertions, 49 deletions
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index fb0901ec4306..2f1b7217c25c 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -35,46 +35,6 @@ extern const unsigned long long relocate_kernel_len;
#ifdef CONFIG_CRASH_DUMP
/*
- * Create ELF notes for one CPU
- */
-static void add_elf_notes(int cpu)
-{
- struct save_area *sa = (void *) 4608 + store_prefix();
- void *ptr;
-
- memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa));
- ptr = (u64 *) per_cpu_ptr(crash_notes, cpu);
- ptr = fill_cpu_elf_notes(ptr, sa, NULL);
- memset(ptr, 0, sizeof(struct elf_note));
-}
-
-/*
- * Initialize CPU ELF notes
- */
-static void setup_regs(void)
-{
- unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE;
- struct _lowcore *lc;
- int cpu, this_cpu;
-
- /* Get lowcore pointer from store status of this CPU (absolute zero) */
- lc = (struct _lowcore *)(unsigned long)S390_lowcore.prefixreg_save_area;
- this_cpu = smp_find_processor_id(stap());
- add_elf_notes(this_cpu);
- for_each_online_cpu(cpu) {
- if (cpu == this_cpu)
- continue;
- if (smp_store_status(cpu))
- continue;
- add_elf_notes(cpu);
- }
- if (MACHINE_HAS_VX)
- save_vx_regs_safe((void *) lc->vector_save_area_addr);
- /* Copy dump CPU store status info to absolute zero */
- memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area));
-}
-
-/*
* PM notifier callback for kdump
*/
static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
@@ -105,14 +65,66 @@ static int __init machine_kdump_pm_init(void)
arch_initcall(machine_kdump_pm_init);
/*
- * Start kdump: We expect here that a store status has been done on our CPU
+ * Reset the system, copy boot CPU registers to absolute zero,
+ * and jump to the kdump image
*/
static void __do_machine_kdump(void *image)
{
- int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
+ int (*start_kdump)(int);
+ unsigned long prefix;
+
+ /* store_status() saved the prefix register to lowcore */
+ prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
+
+ /* Now do the reset */
+ s390_reset_system();
+
+ /*
+ * Copy dump CPU store status info to absolute zero.
+ * This need to be done *after* s390_reset_system set the
+ * prefix register of this CPU to zero
+ */
+ memcpy((void *) __LC_FPREGS_SAVE_AREA,
+ (void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
+ start_kdump = (void *)((struct kimage *) image)->start;
start_kdump(1);
+
+ /* Die if start_kdump returns */
+ disabled_wait((unsigned long) __builtin_return_address(0));
+}
+
+/*
+ * Start kdump: create a LGR log entry, store status of all CPUs and
+ * branch to __do_machine_kdump.
+ */
+static noinline void __machine_kdump(void *image)
+{
+ int this_cpu, cpu;
+
+ lgr_info_log();
+ /* Get status of the other CPUs */
+ this_cpu = smp_find_processor_id(stap());
+ for_each_online_cpu(cpu) {
+ if (cpu == this_cpu)
+ continue;
+ if (smp_store_status(cpu))
+ continue;
+ }
+ /* Store status of the boot CPU */
+ if (MACHINE_HAS_VX)
+ save_vx_regs((void *) &S390_lowcore.vector_save_area);
+ /*
+ * To create a good backchain for this CPU in the dump store_status
+ * is passed the address of a function. The address is saved into
+ * the PSW save area of the boot CPU and the function is invoked as
+ * a tail call of store_status. The backchain in the dump will look
+ * like this:
+ * restart_int_handler -> __machine_kexec -> __do_machine_kdump
+ * The call to store_status() will not return.
+ */
+ store_status(__do_machine_kdump, image);
}
#endif
@@ -235,10 +247,14 @@ static void __do_machine_kexec(void *data)
relocate_kernel_t data_mover;
struct kimage *image = data;
+ s390_reset_system();
data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
/* Call the moving routine */
(*data_mover)(&image->head, image->start);
+
+ /* Die if kexec returns */
+ disabled_wait((unsigned long) __builtin_return_address(0));
}
/*
@@ -251,14 +267,10 @@ static void __machine_kexec(void *data)
tracing_off();
debug_locks_off();
#ifdef CONFIG_CRASH_DUMP
- if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH) {
-
- lgr_info_log();
- s390_reset_system(setup_regs, __do_machine_kdump, data);
- } else
+ if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
+ __machine_kdump(data);
#endif
- s390_reset_system(NULL, __do_machine_kexec, data);
- disabled_wait((unsigned long) __builtin_return_address(0));
+ __do_machine_kexec(data);
}
/*