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authorHeiko Carstens <hca@linux.ibm.com>2025-01-20 11:53:42 +0100
committerAlexander Gordeev <agordeev@linux.ibm.com>2025-01-28 17:38:46 +0100
commit3bcc8a1af581af152d43e42b53db3534018301b5 (patch)
treee1567c70de5a3317260840402e5ca865469df1eb
parent7cbae7ea3de5c17b47aeb34a770446aba1eaa904 (diff)
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s390/sclp: Initialize sclp subsystem via arch_cpu_finalize_init()
With the switch to GENERIC_CPU_DEVICES an early call to the sclp subsystem was added to smp_prepare_cpus(). This will usually succeed since the sclp subsystem is implicitly initialized early enough if an sclp based console is present. If no such console is present the initialization happens with an arch_initcall(); in such cases calls to the sclp subsystem will fail. For CPU detection this means that the fallback sigp loop will be used permanently to detect CPUs instead of the preferred READ_CPU_INFO sclp request. Fix this by adding an explicit early sclp_init() call via arch_cpu_finalize_init(). Reported-by: Sheshu Ramanandan <sheshu.ramanandan@ibm.com> Fixes: 4a39f12e753d ("s390/smp: Switch to GENERIC_CPU_DEVICES") Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/include/asm/sclp.h1
-rw-r--r--arch/s390/kernel/setup.c5
-rw-r--r--drivers/s390/char/sclp.c12
4 files changed, 9 insertions, 10 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 4e9bf698dc4d..f49ca2b485f6 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -78,6 +78,7 @@ config S390
select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
select ARCH_ENABLE_MEMORY_HOTREMOVE
select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
+ select ARCH_HAS_CPU_FINALIZE_INIT
select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DEBUG_VIRTUAL
select ARCH_HAS_DEBUG_VM_PGTABLE
diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h
index 4da3b2956285..18f37dff03c9 100644
--- a/arch/s390/include/asm/sclp.h
+++ b/arch/s390/include/asm/sclp.h
@@ -172,6 +172,7 @@ void sclp_early_printk(const char *s);
void __sclp_early_printk(const char *s, unsigned int len);
void sclp_emergency_printk(const char *s);
+int sclp_init(void);
int sclp_early_get_memsize(unsigned long *mem);
int sclp_early_get_hsa_size(unsigned long *hsa_size);
int _sclp_get_core_info(struct sclp_core_info *info);
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index f6765ea4f828..4758ad8829a2 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -1025,3 +1025,8 @@ void __init setup_arch(char **cmdline_p)
/* Add system specific data to the random pool */
setup_randomness();
}
+
+void __init arch_cpu_finalize_init(void)
+{
+ sclp_init();
+}
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index fbffd451031f..45bd001206a2 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -245,7 +245,6 @@ static void sclp_request_timeout(bool force_restart);
static void sclp_process_queue(void);
static void __sclp_make_read_req(void);
static int sclp_init_mask(int calculate);
-static int sclp_init(void);
static void
__sclp_queue_read_req(void)
@@ -1251,8 +1250,7 @@ static struct platform_driver sclp_pdrv = {
/* Initialize SCLP driver. Return zero if driver is operational, non-zero
* otherwise. */
-static int
-sclp_init(void)
+int sclp_init(void)
{
unsigned long flags;
int rc = 0;
@@ -1305,13 +1303,7 @@ fail_unlock:
static __init int sclp_initcall(void)
{
- int rc;
-
- rc = platform_driver_register(&sclp_pdrv);
- if (rc)
- return rc;
-
- return sclp_init();
+ return platform_driver_register(&sclp_pdrv);
}
arch_initcall(sclp_initcall);