From 2ba24343bdb8637135bd0d9b5e249c44bd751670 Mon Sep 17 00:00:00 2001
From: Alexander Egorenkov <egorenar@linux.ibm.com>
Date: Fri, 3 Sep 2021 11:08:48 +0200
Subject: [PATCH] s390/kexec: set end-of-ipl flag in last diag308 call
If the facility IPL-complete-control is present then the last diag308
call made by kexec shall set the end-of-ipl flag in the subcode register
to signal the hypervisor that this is the last diag308 call made by Linux.
Only the diag308 calls made during a regular kexec need to set
the end-of-ipl flag, in all other cases the hypervisor will ignore it.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
arch/s390/include/asm/ipl.h | 6 ++++++
arch/s390/kernel/machine_kexec.c | 10 ++++++++--
arch/s390/kernel/relocate_kernel.S | 3 ++-
3 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/arch/s390/include/asm/ipl.h b/arch/s390/include/asm/ipl.h
index 3f8ee257f9aa..a405b6bb89fb 100644
--- a/arch/s390/include/asm/ipl.h
+++ b/arch/s390/include/asm/ipl.h
@@ -133,6 +133,8 @@ int ipl_report_add_certificate(struct ipl_report *report, void *key,
* DIAG 308 support
*/
enum diag308_subcode {
+ DIAG308_CLEAR_RESET = 0,
+ DIAG308_LOAD_NORMAL_RESET = 1,
DIAG308_REL_HSA = 2,
DIAG308_LOAD_CLEAR = 3,
DIAG308_LOAD_NORMAL_DUMP = 4,
@@ -141,6 +143,10 @@ enum diag308_subcode {
DIAG308_LOAD_NORMAL = 7,
};
+enum diag308_subcode_flags {
+ DIAG308_FLAG_EI = 1UL << 16,
+};
+
enum diag308_rc {
DIAG308_RC_OK = 0x0001,
DIAG308_RC_NOCONFIG = 0x0102,
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index 6ebf02e15c85..ab761c008f98 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -26,8 +26,10 @@
#include <asm/stacktrace.h>
#include <asm/switch_to.h>
#include <asm/nmi.h>
+#include <asm/sclp.h>
-typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
+typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long,
+ unsigned long);
extern const unsigned char relocate_kernel[];
extern const unsigned long long relocate_kernel_len;
@@ -243,6 +245,7 @@ void machine_crash_shutdown(struct pt_regs *regs)
*/
static void __do_machine_kexec(void *data)
{
+ unsigned long diag308_subcode;
relocate_kernel_t data_mover;
struct kimage *image = data;
@@ -251,7 +254,10 @@ static void __do_machine_kexec(void *data)
__arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */
/* Call the moving routine */
- (*data_mover)(&image->head, image->start);
+ diag308_subcode = DIAG308_CLEAR_RESET;
+ if (sclp.has_iplcc)
+ diag308_subcode |= DIAG308_FLAG_EI;
+ (*data_mover)(&image->head, image->start, diag308_subcode);
/* Die if kexec returns */
disabled_wait();
diff --git a/arch/s390/kernel/relocate_kernel.S b/arch/s390/kernel/relocate_kernel.S
index 9438368c3632..a9a1a6f45375 100644
--- a/arch/s390/kernel/relocate_kernel.S
+++ b/arch/s390/kernel/relocate_kernel.S
@@ -14,6 +14,7 @@
* moves the new kernel to its destination...
* %r2 = pointer to first kimage_entry_t
* %r3 = start address - where to jump to after the job is done...
+ * %r4 = subcode
*
* %r5 will be used as temp. storage
* %r6 holds the destination address
@@ -56,7 +57,7 @@ ENTRY(relocate_kernel)
jo 0b
j .base
.done:
- sgr %r0,%r0 # clear register r0
+ lgr %r0,%r4 # subcode
cghi %r3,0
je .diag
la %r4,load_psw-.base(%r13) # load psw-address into the register