Messages in this thread | | | Date | Wed, 13 Jul 2022 10:39:47 +0200 | Subject | Re: [PATCH 3/3] s390/uvdevice: autoload module based on CPU facility | From | Steffen Eiden <> |
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On 7/12/22 18:49, Claudio Imbrenda wrote: > On Tue, 12 Jul 2022 12:52:20 +0200 > Steffen Eiden <seiden@linux.ibm.com> wrote: > >> Make sure the uvdevice driver will be automatically loaded when >> facility 158 is available. >> >> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> >> --- >> 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 aa8081dad411..4b17f876ab54 100644 >> --- a/arch/s390/include/asm/cpufeature.h >> +++ b/arch/s390/include/asm/cpufeature.h >> @@ -33,6 +33,7 @@ enum { >> S390_CPU_FEATURE_NNPA, >> S390_CPU_FEATURE_PCI_MIO, >> S390_CPU_FEATURE_SIE, >> + S390_CPU_FEATURE_UV, >> MAX_CPU_FEATURES >> }; >> >> diff --git a/arch/s390/kernel/cpufeature.c b/arch/s390/kernel/cpufeature.c >> index e70b29804db4..0b854d37edcb 100644 >> --- a/arch/s390/kernel/cpufeature.c >> +++ b/arch/s390/kernel/cpufeature.c >> @@ -42,6 +42,7 @@ static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = { >> [S390_CPU_FEATURE_NNPA] = {.type = TYPE_HWCAP, .num = HWCAP_NR_NNPA}, >> [S390_CPU_FEATURE_PCI_MIO] = {.type = TYPE_HWCAP, .num = HWCAP_NR_PCI_MIO}, >> [S390_CPU_FEATURE_SIE] = {.type = TYPE_HWCAP, .num = HWCAP_NR_SIE}, >> + [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); > > does this still prevent manual loading when the feature is not present? yes.
Have a look at the macro definition at 'include/linux/cpufeature.h':
Use module_cpu_feature_match(feature, module_init_function) to
declare that
[snip] b) the module must not be loaded if CPU feature 'feature' is not present
(not even by manual insmod).
The test 'facility(158)' just moved to cpu_have_feature() in '/arch/s390/kernel/cpufeature.c'. > >> module_exit(uvio_dev_exit); >> >> MODULE_AUTHOR("IBM Corporation"); >
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