[PATCH v2 3/3] s390/uvdevice: autoload module based on CPU facility

From: Steffen Eiden
Date: Wed Jul 13 2022 - 08:57:09 EST


Make sure the uvdevice driver will be automatically loaded when
facility 158 is available.

Signed-off-by: Steffen Eiden <seiden@xxxxxxxxxxxxx>
Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
arch/s390/include/asm/cpufeature.h | 1 +
arch/s390/kernel/cpufeature.c | 1 +
drivers/s390/char/uvdevice.c | 5 ++---
3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/s390/include/asm/cpufeature.h b/arch/s390/include/asm/cpufeature.h
index 771caf5281e5..931204613753 100644
--- a/arch/s390/include/asm/cpufeature.h
+++ b/arch/s390/include/asm/cpufeature.h
@@ -12,6 +12,7 @@
enum {
S390_CPU_FEATURE_MSA,
S390_CPU_FEATURE_VXRS,
+ S390_CPU_FEATURE_UV,
MAX_CPU_FEATURES
};

diff --git a/arch/s390/kernel/cpufeature.c b/arch/s390/kernel/cpufeature.c
index 170894730fcc..5c69be58a057 100644
--- a/arch/s390/kernel/cpufeature.c
+++ b/arch/s390/kernel/cpufeature.c
@@ -19,6 +19,7 @@ struct s390_cpu_feature {
static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = {
[S390_CPU_FEATURE_MSA] = {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA},
[S390_CPU_FEATURE_VXRS] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS},
+ [S390_CPU_FEATURE_UV] = {.type = TYPE_FACILITY, .num = 158},
};

/*
diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c
index 66505d7166a6..1d40457c7b10 100644
--- a/drivers/s390/char/uvdevice.c
+++ b/drivers/s390/char/uvdevice.c
@@ -27,6 +27,7 @@
#include <linux/stddef.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
+#include <linux/cpufeature.h>

#include <asm/uvdevice.h>
#include <asm/uv.h>
@@ -244,12 +245,10 @@ static void __exit uvio_dev_exit(void)

static int __init uvio_dev_init(void)
{
- if (!test_facility(158))
- return -ENXIO;
return misc_register(&uvio_dev_miscdev);
}

-module_init(uvio_dev_init);
+module_cpu_feature_match(S390_CPU_FEATURE_UV, uvio_dev_init);
module_exit(uvio_dev_exit);

MODULE_AUTHOR("IBM Corporation");
--
2.35.3