| Message ID | 20220629153741.195789-1-seiden@linux.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC] s390: Autoload uvdevice module based on CPU feature | expand |
On Wed, Jun 29, 2022 at 05:37:41PM +0200, Steffen Eiden wrote: > With this patch the uvdevice will be automatically loaded when the > facility 158 is present. This is accomplished by using > ``module_cpu_feature_match`` and adding HWCAP_UV > connected to to facility 158. > > Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> > --- > arch/s390/include/asm/elf.h | 2 ++ > arch/s390/kernel/processor.c | 5 +++++ > drivers/s390/char/uvdevice.c | 5 ++--- > 3 files changed, 9 insertions(+), 3 deletions(-) Please split this into two patches: one which adds the hwcap bit, and one which makes use of it. Also please make sure the subject contains (nearly) always a component, which would be "s390/hwcaps: ..." in this case. > + /* IBM Secure Execution (Ultravisor) support */ > + if (test_facility(158)) { > + elf_hwcap |= HWCAP_UV; Just keep the comment short like all other one and take the PoP as reference. I would have expected something like: "ultravisor-call (secure execution)" Besides that, everything looks ok as far as I can tell.
diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h index 70a30ae258b7..3a5e89ce4fd0 100644 --- a/arch/s390/include/asm/elf.h +++ b/arch/s390/include/asm/elf.h @@ -115,6 +115,7 @@ enum { HWCAP_NR_NNPA = 20, HWCAP_NR_PCI_MIO = 21, HWCAP_NR_SIE = 22, + HWCAP_NR_UV = 23, HWCAP_NR_MAX }; @@ -142,6 +143,7 @@ enum { #define HWCAP_NNPA BIT(HWCAP_NR_NNPA) #define HWCAP_PCI_MIO BIT(HWCAP_NR_PCI_MIO) #define HWCAP_SIE BIT(HWCAP_NR_SIE) +#define HWCAP_UV BIT(HWCAP_NR_UV) /* * These are used to set parameters in the core dumps. diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c index aa0e0e7fc773..3ca528cb3819 100644 --- a/arch/s390/kernel/processor.c +++ b/arch/s390/kernel/processor.c @@ -141,6 +141,7 @@ static void show_cpu_summary(struct seq_file *m, void *v) [HWCAP_NR_NNPA] = "nnpa", [HWCAP_NR_PCI_MIO] = "pcimio", [HWCAP_NR_SIE] = "sie", + [HWCAP_NR_UV] = "uv", }; int i, cpu; @@ -249,6 +250,10 @@ static int __init setup_hwcaps(void) if (sclp.has_sief2) elf_hwcap |= HWCAP_SIE; + /* IBM Secure Execution (Ultravisor) support */ + if (test_facility(158)) { + elf_hwcap |= HWCAP_UV; + return 0; } arch_initcall(setup_hwcaps); diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c index 66505d7166a6..fddbfc1e27a2 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(UV, uvio_dev_init); module_exit(uvio_dev_exit); MODULE_AUTHOR("IBM Corporation");
With this patch the uvdevice will be automatically loaded when the facility 158 is present. This is accomplished by using ``module_cpu_feature_match`` and adding HWCAP_UV connected to to facility 158. Signed-off-by: Steffen Eiden <seiden@linux.ibm.com> --- arch/s390/include/asm/elf.h | 2 ++ arch/s390/kernel/processor.c | 5 +++++ drivers/s390/char/uvdevice.c | 5 ++--- 3 files changed, 9 insertions(+), 3 deletions(-)