| Message ID | 1462466065-30212-6-git-send-email-julien.grall@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 5 May 2016, Julien Grall wrote: > This will be used to know if a feature, which Xen cares, is available accross > all the CPUs. > > This code is a light version of arch/arm64/kernel/cpufeature.c from > Linux v4.6-rc3. > > Signed-off-by: Julien Grall <julien.grall@arm.com> > --- > xen/arch/arm/Makefile | 1 + > xen/arch/arm/cpufeature.c | 34 ++++++++++++++++++++++++++++++++++ > xen/include/asm-arm/cpufeature.h | 29 +++++++++++++++++++++++++++++ > 3 files changed, 64 insertions(+) > create mode 100644 xen/arch/arm/cpufeature.c > > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile > index 8e0d2f6..9122f78 100644 > --- a/xen/arch/arm/Makefile > +++ b/xen/arch/arm/Makefile > @@ -6,6 +6,7 @@ subdir-$(CONFIG_ACPI) += acpi > > obj-y += bootfdt.o > obj-y += cpu.o > +obj-y += cpufeature.o > obj-y += decode.o > obj-y += device.o > obj-y += domain.o > diff --git a/xen/arch/arm/cpufeature.c b/xen/arch/arm/cpufeature.c > new file mode 100644 > index 0000000..7a1b56b > --- /dev/null > +++ b/xen/arch/arm/cpufeature.c > @@ -0,0 +1,34 @@ > +/* > + * Contains CPU feature definitions > + * > + * Copyright (C) 2015 ARM Ltd. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <xen/config.h> > +#include <xen/types.h> > +#include <xen/init.h> > +#include <xen/smp.h> > +#include <asm/cpufeature.h> > + > +DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS); > + > +/* > + * Local variables: > + * mode: C > + * c-file-style: "BSD" > + * c-basic-offset: 4 > + * indent-tabs-mode: nil > + * End: > + */ > diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h > index 7b519cd..2bebad1 100644 > --- a/xen/include/asm-arm/cpufeature.h > +++ b/xen/include/asm-arm/cpufeature.h > @@ -35,6 +35,35 @@ > #endif > #define cpu_has_security (boot_cpu_feature32(security) > 0) > > +#define ARM_NCAPS 0 > + > +#ifndef __ASSEMBLY__ > + > +#include <xen/types.h> > +#include <xen/lib.h> > +#include <xen/bitops.h> > + > +extern DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS); > + > +static inline bool_t cpus_have_cap(unsigned int num) > +{ > + if ( num >= ARM_NCAPS ) > + return 0; > + > + return test_bit(num, cpu_hwcaps); > +} > + > +static inline void cpus_set_cap(unsigned int num) > +{ > + if (num >= ARM_NCAPS) > + printk(XENLOG_WARNING "Attempt to set an illegal CPU capability (%d >= %d)\n", > + num, ARM_NCAPS); > + else > + __set_bit(num, cpu_hwcaps); > +} > + > +#endif /* __ASSEMBLY__ */ Why everything static line? Wouldn't it better to add the functions to cpufeature.c? They are not going to be called too many times, right? > #endif > /* > * Local variables: > -- > 1.9.1 >
Hi Stefano, On 09/05/2016 10:53, Stefano Stabellini wrote: > On Thu, 5 May 2016, Julien Grall wrote: >> diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h >> index 7b519cd..2bebad1 100644 >> --- a/xen/include/asm-arm/cpufeature.h >> +++ b/xen/include/asm-arm/cpufeature.h >> @@ -35,6 +35,35 @@ >> #endif >> #define cpu_has_security (boot_cpu_feature32(security) > 0) >> >> +#define ARM_NCAPS 0 >> + >> +#ifndef __ASSEMBLY__ >> + >> +#include <xen/types.h> >> +#include <xen/lib.h> >> +#include <xen/bitops.h> >> + >> +extern DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS); >> + >> +static inline bool_t cpus_have_cap(unsigned int num) >> +{ >> + if ( num >= ARM_NCAPS ) >> + return 0; >> + >> + return test_bit(num, cpu_hwcaps); >> +} >> + >> +static inline void cpus_set_cap(unsigned int num) >> +{ >> + if (num >= ARM_NCAPS) >> + printk(XENLOG_WARNING "Attempt to set an illegal CPU capability (%d >= %d)\n", >> + num, ARM_NCAPS); >> + else >> + __set_bit(num, cpu_hwcaps); >> +} >> + >> +#endif /* __ASSEMBLY__ */ > > Why everything static line? Wouldn't it better to add the functions to > cpufeature.c? They are not going to be called too many times, right? This code is based on Linux where the 2 functions were already static inline. I agree that cpus_set_cap won't be called often (mostly CPU bring up), however cpus_have_cap could be used at runtime to check whether the AArch32 mode is present... But I think those 2 functions should be kept together. Note that today, we always use the boot CPU data to know if a feature exists (see include/asm-arm/cpufeatures.h). Regards,
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile index 8e0d2f6..9122f78 100644 --- a/xen/arch/arm/Makefile +++ b/xen/arch/arm/Makefile @@ -6,6 +6,7 @@ subdir-$(CONFIG_ACPI) += acpi obj-y += bootfdt.o obj-y += cpu.o +obj-y += cpufeature.o obj-y += decode.o obj-y += device.o obj-y += domain.o diff --git a/xen/arch/arm/cpufeature.c b/xen/arch/arm/cpufeature.c new file mode 100644 index 0000000..7a1b56b --- /dev/null +++ b/xen/arch/arm/cpufeature.c @@ -0,0 +1,34 @@ +/* + * Contains CPU feature definitions + * + * Copyright (C) 2015 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <xen/config.h> +#include <xen/types.h> +#include <xen/init.h> +#include <xen/smp.h> +#include <asm/cpufeature.h> + +DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS); + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h index 7b519cd..2bebad1 100644 --- a/xen/include/asm-arm/cpufeature.h +++ b/xen/include/asm-arm/cpufeature.h @@ -35,6 +35,35 @@ #endif #define cpu_has_security (boot_cpu_feature32(security) > 0) +#define ARM_NCAPS 0 + +#ifndef __ASSEMBLY__ + +#include <xen/types.h> +#include <xen/lib.h> +#include <xen/bitops.h> + +extern DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS); + +static inline bool_t cpus_have_cap(unsigned int num) +{ + if ( num >= ARM_NCAPS ) + return 0; + + return test_bit(num, cpu_hwcaps); +} + +static inline void cpus_set_cap(unsigned int num) +{ + if (num >= ARM_NCAPS) + printk(XENLOG_WARNING "Attempt to set an illegal CPU capability (%d >= %d)\n", + num, ARM_NCAPS); + else + __set_bit(num, cpu_hwcaps); +} + +#endif /* __ASSEMBLY__ */ + #endif /* * Local variables:
This will be used to know if a feature, which Xen cares, is available accross all the CPUs. This code is a light version of arch/arm64/kernel/cpufeature.c from Linux v4.6-rc3. Signed-off-by: Julien Grall <julien.grall@arm.com> --- xen/arch/arm/Makefile | 1 + xen/arch/arm/cpufeature.c | 34 ++++++++++++++++++++++++++++++++++ xen/include/asm-arm/cpufeature.h | 29 +++++++++++++++++++++++++++++ 3 files changed, 64 insertions(+) create mode 100644 xen/arch/arm/cpufeature.c