| Message ID | 1476787939-21889-2-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 18 October 2016 at 11:52, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > Wire up the generic support for exposing CPU feature bits via the > modalias in /sys/device/system/cpu. This allows udev to automatically > load modules for things like crypto algorithms that are implemented > using optional instructions. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > arch/arm/Kconfig | 1 + > arch/arm/include/asm/cpufeature.h | 32 ++++++++++++++++++++ > 2 files changed, 33 insertions(+) > Russell, do you have any concerns regarding this patch? If not, I will drop it into the patch system. Herbert, I will resend the followup patches in this series to linux-crypto@ once this prerequisite is in place Thanks, Ard. > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index b5d529fdffab..1a0c6a486a9c 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -21,6 +21,7 @@ config ARM > select GENERIC_ALLOCATOR > select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI) > select GENERIC_CLOCKEVENTS_BROADCAST if SMP > + select GENERIC_CPU_AUTOPROBE > select GENERIC_EARLY_IOREMAP > select GENERIC_IDLE_POLL_SETUP > select GENERIC_IRQ_PROBE > diff --git a/arch/arm/include/asm/cpufeature.h b/arch/arm/include/asm/cpufeature.h > new file mode 100644 > index 000000000000..19c3dddd901a > --- /dev/null > +++ b/arch/arm/include/asm/cpufeature.h > @@ -0,0 +1,32 @@ > +/* > + * Copyright (C) 2016 Linaro Ltd. <ard.biesheuvel@linaro.org> > + * > + * 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. > + */ > + > +#ifndef __ASM_CPUFEATURE_H > +#define __ASM_CPUFEATURE_H > + > +#include <asm/hwcap.h> > + > +/* > + * Due to the fact that ELF_HWCAP is a 32-bit type on ARM, and given the number > + * of optional CPU features it defines, ARM's CPU capability bits have been > + * divided across separate elf_hwcap and elf_hwcap2 variables, each of which > + * covers a subset of the available CPU features. > + * > + * Currently, only a few of those are suitable for automatic module loading > + * (which is the primary use case of this facility) and those happen to be all > + * covered by HWCAP2. So let's only expose those via the CPU modalias for now. > + */ > +#define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap2)) > +#define cpu_feature(x) ilog2(HWCAP2_ ## x) > + > +static inline bool cpu_have_feature(unsigned int num) > +{ > + return elf_hwcap2 & (1UL << num); > +} > + > +#endif > -- > 2.7.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Oct 29, 2016 at 11:08:36AM +0100, Ard Biesheuvel wrote: > On 18 October 2016 at 11:52, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > > Wire up the generic support for exposing CPU feature bits via the > > modalias in /sys/device/system/cpu. This allows udev to automatically > > load modules for things like crypto algorithms that are implemented > > using optional instructions. > > > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > --- > > arch/arm/Kconfig | 1 + > > arch/arm/include/asm/cpufeature.h | 32 ++++++++++++++++++++ > > 2 files changed, 33 insertions(+) > > > > Russell, > > do you have any concerns regarding this patch? If not, I will drop it > into the patch system. It's still something I need to look at... I've been offline last week, and sort-of offline the previous week, so I'm catching up. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jan 02, 2017 at 09:06:04PM +0000, Ard Biesheuvel wrote: > On 31 October 2016 at 16:13, Russell King - ARM Linux > <linux@armlinux.org.uk> wrote: > > On Sat, Oct 29, 2016 at 11:08:36AM +0100, Ard Biesheuvel wrote: > >> On 18 October 2016 at 11:52, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > >> > Wire up the generic support for exposing CPU feature bits via the > >> > modalias in /sys/device/system/cpu. This allows udev to automatically > >> > load modules for things like crypto algorithms that are implemented > >> > using optional instructions. > >> > > >> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > >> > --- > >> > arch/arm/Kconfig | 1 + > >> > arch/arm/include/asm/cpufeature.h | 32 ++++++++++++++++++++ > >> > 2 files changed, 33 insertions(+) > >> > > >> > >> Russell, > >> > >> do you have any concerns regarding this patch? If not, I will drop it > >> into the patch system. > > > > It's still something I need to look at... I've been offline last week, > > and sort-of offline the previous week, so I'm catching up. > > > > Hi Russell, > > Any thoughts yet? None, and the patch is well buried now that it'll take me a while to find... back in mid-October? Yea, I'll have to drop everything and go digging through my mailboxes to find it... and I'm just catching up (again) after a week and a bit's time offline - yep, it's wonderful timing. Sorry, no time to look at it right now, you're not the only one wanting my attention at the moment. Please try again in about a week's time - don't leave it a few months, and please include the patch. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2 January 2017 at 23:40, Russell King - ARM Linux <linux@armlinux.org.uk> wrote: > On Mon, Jan 02, 2017 at 09:06:04PM +0000, Ard Biesheuvel wrote: >> On 31 October 2016 at 16:13, Russell King - ARM Linux >> <linux@armlinux.org.uk> wrote: >> > On Sat, Oct 29, 2016 at 11:08:36AM +0100, Ard Biesheuvel wrote: >> >> On 18 October 2016 at 11:52, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: >> >> > Wire up the generic support for exposing CPU feature bits via the >> >> > modalias in /sys/device/system/cpu. This allows udev to automatically >> >> > load modules for things like crypto algorithms that are implemented >> >> > using optional instructions. >> >> > >> >> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> >> >> > --- >> >> > arch/arm/Kconfig | 1 + >> >> > arch/arm/include/asm/cpufeature.h | 32 ++++++++++++++++++++ >> >> > 2 files changed, 33 insertions(+) >> >> > >> >> >> >> Russell, >> >> >> >> do you have any concerns regarding this patch? If not, I will drop it >> >> into the patch system. >> > >> > It's still something I need to look at... I've been offline last week, >> > and sort-of offline the previous week, so I'm catching up. >> > >> >> Hi Russell, >> >> Any thoughts yet? > > None, and the patch is well buried now that it'll take me a while to > find... back in mid-October? Yea, I'll have to drop everything and > go digging through my mailboxes to find it... and I'm just catching > up (again) after a week and a bit's time offline - yep, it's wonderful > timing. Sorry, no time to look at it right now, you're not the only > one wanting my attention at the moment. > No worries. It is not exactly urgent, but it is a useful enhancement nonetheless. > Please try again in about a week's time - don't leave it a few months, > and please include the patch. > OK -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index b5d529fdffab..1a0c6a486a9c 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -21,6 +21,7 @@ config ARM select GENERIC_ALLOCATOR select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI) select GENERIC_CLOCKEVENTS_BROADCAST if SMP + select GENERIC_CPU_AUTOPROBE select GENERIC_EARLY_IOREMAP select GENERIC_IDLE_POLL_SETUP select GENERIC_IRQ_PROBE diff --git a/arch/arm/include/asm/cpufeature.h b/arch/arm/include/asm/cpufeature.h new file mode 100644 index 000000000000..19c3dddd901a --- /dev/null +++ b/arch/arm/include/asm/cpufeature.h @@ -0,0 +1,32 @@ +/* + * Copyright (C) 2016 Linaro Ltd. <ard.biesheuvel@linaro.org> + * + * 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. + */ + +#ifndef __ASM_CPUFEATURE_H +#define __ASM_CPUFEATURE_H + +#include <asm/hwcap.h> + +/* + * Due to the fact that ELF_HWCAP is a 32-bit type on ARM, and given the number + * of optional CPU features it defines, ARM's CPU capability bits have been + * divided across separate elf_hwcap and elf_hwcap2 variables, each of which + * covers a subset of the available CPU features. + * + * Currently, only a few of those are suitable for automatic module loading + * (which is the primary use case of this facility) and those happen to be all + * covered by HWCAP2. So let's only expose those via the CPU modalias for now. + */ +#define MAX_CPU_FEATURES (8 * sizeof(elf_hwcap2)) +#define cpu_feature(x) ilog2(HWCAP2_ ## x) + +static inline bool cpu_have_feature(unsigned int num) +{ + return elf_hwcap2 & (1UL << num); +} + +#endif
Wire up the generic support for exposing CPU feature bits via the modalias in /sys/device/system/cpu. This allows udev to automatically load modules for things like crypto algorithms that are implemented using optional instructions. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm/Kconfig | 1 + arch/arm/include/asm/cpufeature.h | 32 ++++++++++++++++++++ 2 files changed, 33 insertions(+) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html