1 files changed, 275 insertions, 0 deletions
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
new file mode 100644
index 000000000..fb0901ec4
--- /dev/null
+++ b/arch/s390/kernel/machine_kexec.c
@@ -0,0 +1,275 @@
+/*
+ * Copyright IBM Corp. 2005, 2011
+ *
+ * Author(s): Rolf Adelsberger,
+ *	      Heiko Carstens <heiko.carstens@de.ibm.com>
+ *	      Michael Holzheu <holzheu@linux.vnet.ibm.com>
+ */
+
+#include <linux/device.h>
+#include <linux/mm.h>
+#include <linux/kexec.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/ftrace.h>
+#include <linux/debug_locks.h>
+#include <linux/suspend.h>
+#include <asm/cio.h>
+#include <asm/setup.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/smp.h>
+#include <asm/reset.h>
+#include <asm/ipl.h>
+#include <asm/diag.h>
+#include <asm/elf.h>
+#include <asm/asm-offsets.h>
+#include <asm/os_info.h>
+#include <asm/switch_to.h>
+
+typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
+
+extern const unsigned char relocate_kernel[];
+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,
+			       void *ptr)
+{
+	switch (action) {
+	case PM_SUSPEND_PREPARE:
+	case PM_HIBERNATION_PREPARE:
+		if (crashk_res.start)
+			crash_map_reserved_pages();
+		break;
+	case PM_POST_SUSPEND:
+	case PM_POST_HIBERNATION:
+		if (crashk_res.start)
+			crash_unmap_reserved_pages();
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+	return NOTIFY_OK;
+}
+
+static int __init machine_kdump_pm_init(void)
+{
+	pm_notifier(machine_kdump_pm_cb, 0);
+	return 0;
+}
+arch_initcall(machine_kdump_pm_init);
+
+/*
+ * Start kdump: We expect here that a store status has been done on our CPU
+ */
+static void __do_machine_kdump(void *image)
+{
+	int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
+
+	__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
+	start_kdump(1);
+}
+#endif
+
+/*
+ * Check if kdump checksums are valid: We call purgatory with parameter "0"
+ */
+static int kdump_csum_valid(struct kimage *image)
+{
+#ifdef CONFIG_CRASH_DUMP
+	int (*start_kdump)(int) = (void *)image->start;
+	int rc;
+
+	__arch_local_irq_stnsm(0xfb); /* disable DAT */
+	rc = start_kdump(0);
+	__arch_local_irq_stosm(0x04); /* enable DAT */
+	return rc ? 0 : -EINVAL;
+#else
+	return -EINVAL;
+#endif
+}
+
+/*
+ * Map or unmap crashkernel memory
+ */
+static void crash_map_pages(int enable)
+{
+	unsigned long size = resource_size(&crashk_res);
+
+	BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||
+	       size % KEXEC_CRASH_MEM_ALIGN);
+	if (enable)
+		vmem_add_mapping(crashk_res.start, size);
+	else {
+		vmem_remove_mapping(crashk_res.start, size);
+		if (size)
+			os_info_crashkernel_add(crashk_res.start, size);
+		else
+			os_info_crashkernel_add(0, 0);
+	}
+}
+
+/*
+ * Map crashkernel memory
+ */
+void crash_map_reserved_pages(void)
+{
+	crash_map_pages(1);
+}
+
+/*
+ * Unmap crashkernel memory
+ */
+void crash_unmap_reserved_pages(void)
+{
+	crash_map_pages(0);
+}
+
+/*
+ * Give back memory to hypervisor before new kdump is loaded
+ */
+static int machine_kexec_prepare_kdump(void)
+{
+#ifdef CONFIG_CRASH_DUMP
+	if (MACHINE_IS_VM)
+		diag10_range(PFN_DOWN(crashk_res.start),
+			     PFN_DOWN(crashk_res.end - crashk_res.start + 1));
+	return 0;
+#else
+	return -EINVAL;
+#endif
+}
+
+int machine_kexec_prepare(struct kimage *image)
+{
+	void *reboot_code_buffer;
+
+	/* Can't replace kernel image since it is read-only. */
+	if (ipl_flags & IPL_NSS_VALID)
+		return -EOPNOTSUPP;
+
+	if (image->type == KEXEC_TYPE_CRASH)
+		return machine_kexec_prepare_kdump();
+
+	/* We don't support anything but the default image type for now. */
+	if (image->type != KEXEC_TYPE_DEFAULT)
+		return -EINVAL;
+
+	/* Get the destination where the assembler code should be copied to.*/
+	reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
+
+	/* Then copy it */
+	memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
+	return 0;
+}
+
+void machine_kexec_cleanup(struct kimage *image)
+{
+}
+
+void arch_crash_save_vmcoreinfo(void)
+{
+	VMCOREINFO_SYMBOL(lowcore_ptr);
+	VMCOREINFO_SYMBOL(high_memory);
+	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
+}
+
+void machine_shutdown(void)
+{
+}
+
+void machine_crash_shutdown(struct pt_regs *regs)
+{
+}
+
+/*
+ * Do normal kexec
+ */
+static void __do_machine_kexec(void *data)
+{
+	relocate_kernel_t data_mover;
+	struct kimage *image = data;
+
+	data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
+
+	/* Call the moving routine */
+	(*data_mover)(&image->head, image->start);
+}
+
+/*
+ * Reset system and call either kdump or normal kexec
+ */
+static void __machine_kexec(void *data)
+{
+	__arch_local_irq_stosm(0x04); /* enable DAT */
+	pfault_fini();
+	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
+#endif
+		s390_reset_system(NULL, __do_machine_kexec, data);
+	disabled_wait((unsigned long) __builtin_return_address(0));
+}
+
+/*
+ * Do either kdump or normal kexec. In case of kdump we first ask
+ * purgatory, if kdump checksums are valid.
+ */
+void machine_kexec(struct kimage *image)
+{
+	if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
+		return;
+	tracer_disable();
+	smp_send_stop();
+	smp_call_ipl_cpu(__machine_kexec, image);
+}