* [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2
@ 2022-07-07 10:36 Mark Brown
2022-07-07 10:36 ` [PATCH v5 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP Mark Brown
` (3 more replies)
0 siblings, 4 replies; 10+ messages in thread
From: Mark Brown @ 2022-07-07 10:36 UTC (permalink / raw)
To: Catalin Marinas, Will Deacon
Cc: Suzuki K Poulose, Szabolcs Nagy, linux-arm-kernel, Mark Brown
Currently for arm64 we expose hwcaps to userspace using the low 32 bits
of AT_HWCAP and AT_HWCAP2. Due to the ever expanding capabilties of the
architecture we have now allocated all the available bits in this scheme
so we need to expand, either using the higher bits or adding a new
AT_HWCAP3. Discussions suggest that the favoured approach for now is to
start allocating the upper bits of AT_HWCAP2.
The final patch starts allocating from the upper bits of AT_HWCAP2,
reporting the presence of FEAT_EBF16, this will conflict with my series
converting ID_AA64ISAR1_EL1 to be generated. I've got a version based on
top of that which I can send if that's convenient.
v5:
- Correct bit ranges for glibc reservation.
v4:
- Document status of upper bits in AT_HWCAP.
- Instead of creating AT_HWCAP3 just convert elf_hwcap to a bitmask and
start allocating the upper bits of AT_HWCAP2.
v3:
- Expand comment on CPU_FEATURES_PER_HWCAP.
v2:
- Rebase onto v5.19-rc3.
Mark Brown (3):
arm64/hwcap: Document allocation of upper bits of AT_HWCAP
arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned
long
arm64/hwcap: Support FEAT_EBF16
Documentation/arm64/elf_hwcaps.rst | 4 ++++
arch/arm64/include/asm/cpufeature.h | 2 +-
arch/arm64/include/asm/hwcap.h | 3 ++-
arch/arm64/include/uapi/asm/hwcap.h | 4 ++++
arch/arm64/kernel/cpufeature.c | 13 ++++++-------
arch/arm64/kernel/cpuinfo.c | 1 +
6 files changed, 18 insertions(+), 9 deletions(-)
base-commit: a111daf0c53ae91e71fd2bfe7497862d14132e3e
--
2.30.2
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^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH v5 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP 2022-07-07 10:36 [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2 Mark Brown @ 2022-07-07 10:36 ` Mark Brown 2022-07-07 11:21 ` Szabolcs Nagy 2022-07-07 11:38 ` Catalin Marinas 2022-07-07 10:36 ` [PATCH v5 2/3] arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long Mark Brown ` (2 subsequent siblings) 3 siblings, 2 replies; 10+ messages in thread From: Mark Brown @ 2022-07-07 10:36 UTC (permalink / raw) To: Catalin Marinas, Will Deacon Cc: Suzuki K Poulose, Szabolcs Nagy, linux-arm-kernel, Mark Brown The top two bits of AT_HWCAP are reserved for use by glibc and the rest of the top 32 bits are being kept unallocated for potential use by glibc. Document this in the header. Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/include/uapi/asm/hwcap.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index 4bb2cc8ac446..fd7577cf8e77 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -19,6 +19,9 @@ /* * HWCAP flags - for AT_HWCAP + * + * Bits 62 and 63 are reserved for use by libc. + * Bits 32-61 are unallocated for potential use by libc. */ #define HWCAP_FP (1 << 0) #define HWCAP_ASIMD (1 << 1) -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v5 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP 2022-07-07 10:36 ` [PATCH v5 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP Mark Brown @ 2022-07-07 11:21 ` Szabolcs Nagy 2022-07-07 11:38 ` Catalin Marinas 1 sibling, 0 replies; 10+ messages in thread From: Szabolcs Nagy @ 2022-07-07 11:21 UTC (permalink / raw) To: Mark Brown Cc: Catalin Marinas, Will Deacon, Suzuki K Poulose, linux-arm-kernel The 07/07/2022 11:36, Mark Brown wrote: > The top two bits of AT_HWCAP are reserved for use by glibc and the rest of > the top 32 bits are being kept unallocated for potential use by glibc. > Document this in the header. > > Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Szabolcs Nagy <szabolcs.nagy@arm.com> > --- > arch/arm64/include/uapi/asm/hwcap.h | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h > index 4bb2cc8ac446..fd7577cf8e77 100644 > --- a/arch/arm64/include/uapi/asm/hwcap.h > +++ b/arch/arm64/include/uapi/asm/hwcap.h > @@ -19,6 +19,9 @@ > > /* > * HWCAP flags - for AT_HWCAP > + * > + * Bits 62 and 63 are reserved for use by libc. > + * Bits 32-61 are unallocated for potential use by libc. > */ > #define HWCAP_FP (1 << 0) > #define HWCAP_ASIMD (1 << 1) > -- > 2.30.2 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v5 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP 2022-07-07 10:36 ` [PATCH v5 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP Mark Brown 2022-07-07 11:21 ` Szabolcs Nagy @ 2022-07-07 11:38 ` Catalin Marinas 1 sibling, 0 replies; 10+ messages in thread From: Catalin Marinas @ 2022-07-07 11:38 UTC (permalink / raw) To: Mark Brown; +Cc: Will Deacon, Suzuki K Poulose, Szabolcs Nagy, linux-arm-kernel On Thu, Jul 07, 2022 at 11:36:30AM +0100, Mark Brown wrote: > The top two bits of AT_HWCAP are reserved for use by glibc and the rest of > the top 32 bits are being kept unallocated for potential use by glibc. > Document this in the header. > > Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v5 2/3] arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long 2022-07-07 10:36 [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2 Mark Brown 2022-07-07 10:36 ` [PATCH v5 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP Mark Brown @ 2022-07-07 10:36 ` Mark Brown 2022-07-07 11:37 ` Catalin Marinas 2022-07-07 10:36 ` [PATCH v5 3/3] arm64/hwcap: Support FEAT_EBF16 Mark Brown 2022-07-20 12:29 ` [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2 Will Deacon 3 siblings, 1 reply; 10+ messages in thread From: Mark Brown @ 2022-07-07 10:36 UTC (permalink / raw) To: Catalin Marinas, Will Deacon Cc: Suzuki K Poulose, Szabolcs Nagy, linux-arm-kernel, Mark Brown When we added support for AT_HWCAP2 we took advantage of the fact that we have limited hwcaps to the low 32 bits and stored it along with AT_HWCAP in a single unsigned integer. Thanks to the ever expanding capabilities of the architecture we have now allocated all 64 of the bits in an unsigned long so in preparation for adding more hwcaps convert elf_hwcap to be a bitmap instead, with 64 bits allocated to each AT_HWCAP. There should be no functional change from this patch. Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/include/asm/cpufeature.h | 2 +- arch/arm64/include/asm/hwcap.h | 2 +- arch/arm64/kernel/cpufeature.c | 12 +++++------- 3 files changed, 7 insertions(+), 9 deletions(-) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 14a8f3d93add..7abd6c0fa53d 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -11,7 +11,7 @@ #include <asm/hwcap.h> #include <asm/sysreg.h> -#define MAX_CPU_FEATURES 64 +#define MAX_CPU_FEATURES 128 #define cpu_feature(x) KERNEL_HWCAP_ ## x #ifndef __ASSEMBLY__ diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index aa443d8f8cfb..9b5fdc114f8c 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -85,7 +85,7 @@ #define KERNEL_HWCAP_PACA __khwcap_feature(PACA) #define KERNEL_HWCAP_PACG __khwcap_feature(PACG) -#define __khwcap2_feature(x) (const_ilog2(HWCAP2_ ## x) + 32) +#define __khwcap2_feature(x) (const_ilog2(HWCAP2_ ## x) + 64) #define KERNEL_HWCAP_DCPODP __khwcap2_feature(DCPODP) #define KERNEL_HWCAP_SVE2 __khwcap2_feature(SVE2) #define KERNEL_HWCAP_SVEAES __khwcap2_feature(SVEAES) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 8d88433de81d..5ba226f3721c 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -91,7 +91,7 @@ #include <asm/virt.h> /* Kernel representation of AT_HWCAP and AT_HWCAP2 */ -static unsigned long elf_hwcap __read_mostly; +static DECLARE_BITMAP(elf_hwcap, MAX_CPU_FEATURES) __read_mostly; #ifdef CONFIG_COMPAT #define COMPAT_ELF_HWCAP_DEFAULT \ @@ -3098,14 +3098,12 @@ static bool __maybe_unused __system_matches_cap(unsigned int n) void cpu_set_feature(unsigned int num) { - WARN_ON(num >= MAX_CPU_FEATURES); - elf_hwcap |= BIT(num); + set_bit(num, elf_hwcap); } bool cpu_have_feature(unsigned int num) { - WARN_ON(num >= MAX_CPU_FEATURES); - return elf_hwcap & BIT(num); + return test_bit(num, elf_hwcap); } EXPORT_SYMBOL_GPL(cpu_have_feature); @@ -3116,12 +3114,12 @@ unsigned long cpu_get_elf_hwcap(void) * note that for userspace compatibility we guarantee that bits 62 * and 63 will always be returned as 0. */ - return lower_32_bits(elf_hwcap); + return elf_hwcap[0]; } unsigned long cpu_get_elf_hwcap2(void) { - return upper_32_bits(elf_hwcap); + return elf_hwcap[1]; } static void __init setup_system_capabilities(void) -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v5 2/3] arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long 2022-07-07 10:36 ` [PATCH v5 2/3] arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long Mark Brown @ 2022-07-07 11:37 ` Catalin Marinas 2022-07-07 11:52 ` Mark Brown 0 siblings, 1 reply; 10+ messages in thread From: Catalin Marinas @ 2022-07-07 11:37 UTC (permalink / raw) To: Mark Brown; +Cc: Will Deacon, Suzuki K Poulose, Szabolcs Nagy, linux-arm-kernel On Thu, Jul 07, 2022 at 11:36:31AM +0100, Mark Brown wrote: > When we added support for AT_HWCAP2 we took advantage of the fact that we > have limited hwcaps to the low 32 bits and stored it along with AT_HWCAP > in a single unsigned integer. Thanks to the ever expanding capabilities of > the architecture we have now allocated all 64 of the bits in an unsigned > long so in preparation for adding more hwcaps convert elf_hwcap to be a > bitmap instead, with 64 bits allocated to each AT_HWCAP. > > There should be no functional change from this patch. > > Signed-off-by: Mark Brown <broonie@kernel.org> > --- > arch/arm64/include/asm/cpufeature.h | 2 +- > arch/arm64/include/asm/hwcap.h | 2 +- > arch/arm64/kernel/cpufeature.c | 12 +++++------- > 3 files changed, 7 insertions(+), 9 deletions(-) > > diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h > index 14a8f3d93add..7abd6c0fa53d 100644 > --- a/arch/arm64/include/asm/cpufeature.h > +++ b/arch/arm64/include/asm/cpufeature.h > @@ -11,7 +11,7 @@ > #include <asm/hwcap.h> > #include <asm/sysreg.h> > > -#define MAX_CPU_FEATURES 64 > +#define MAX_CPU_FEATURES 128 Should this be (32 + 64)? I guess it's easier as you did since we have 128 bits in total, only that we reserved the top 32 in ELF_HWCAP. > #define cpu_feature(x) KERNEL_HWCAP_ ## x > > #ifndef __ASSEMBLY__ > diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h > index aa443d8f8cfb..9b5fdc114f8c 100644 > --- a/arch/arm64/include/asm/hwcap.h > +++ b/arch/arm64/include/asm/hwcap.h > @@ -85,7 +85,7 @@ > #define KERNEL_HWCAP_PACA __khwcap_feature(PACA) > #define KERNEL_HWCAP_PACG __khwcap_feature(PACG) > > -#define __khwcap2_feature(x) (const_ilog2(HWCAP2_ ## x) + 32) > +#define __khwcap2_feature(x) (const_ilog2(HWCAP2_ ## x) + 64) > #define KERNEL_HWCAP_DCPODP __khwcap2_feature(DCPODP) > #define KERNEL_HWCAP_SVE2 __khwcap2_feature(SVE2) > #define KERNEL_HWCAP_SVEAES __khwcap2_feature(SVEAES) > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 8d88433de81d..5ba226f3721c 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -91,7 +91,7 @@ > #include <asm/virt.h> > > /* Kernel representation of AT_HWCAP and AT_HWCAP2 */ > -static unsigned long elf_hwcap __read_mostly; > +static DECLARE_BITMAP(elf_hwcap, MAX_CPU_FEATURES) __read_mostly; > > #ifdef CONFIG_COMPAT > #define COMPAT_ELF_HWCAP_DEFAULT \ > @@ -3098,14 +3098,12 @@ static bool __maybe_unused __system_matches_cap(unsigned int n) > > void cpu_set_feature(unsigned int num) > { > - WARN_ON(num >= MAX_CPU_FEATURES); > - elf_hwcap |= BIT(num); > + set_bit(num, elf_hwcap); > } > > bool cpu_have_feature(unsigned int num) > { > - WARN_ON(num >= MAX_CPU_FEATURES); > - return elf_hwcap & BIT(num); > + return test_bit(num, elf_hwcap); > } > EXPORT_SYMBOL_GPL(cpu_have_feature); > > @@ -3116,12 +3114,12 @@ unsigned long cpu_get_elf_hwcap(void) > * note that for userspace compatibility we guarantee that bits 62 > * and 63 will always be returned as 0. > */ > - return lower_32_bits(elf_hwcap); > + return elf_hwcap[0]; > } > > unsigned long cpu_get_elf_hwcap2(void) > { > - return upper_32_bits(elf_hwcap); > + return elf_hwcap[1]; > } This is fine on the assumption that DECLARE_BITMAP is always an array of longs. I couldn't see any documentation on this but at least the set_bit() etc. API only works on 'long *' pointers. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v5 2/3] arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long 2022-07-07 11:37 ` Catalin Marinas @ 2022-07-07 11:52 ` Mark Brown 0 siblings, 0 replies; 10+ messages in thread From: Mark Brown @ 2022-07-07 11:52 UTC (permalink / raw) To: Catalin Marinas Cc: Will Deacon, Suzuki K Poulose, Szabolcs Nagy, linux-arm-kernel [-- Attachment #1.1: Type: text/plain, Size: 1016 bytes --] On Thu, Jul 07, 2022 at 12:37:58PM +0100, Catalin Marinas wrote: > On Thu, Jul 07, 2022 at 11:36:31AM +0100, Mark Brown wrote: > > -#define MAX_CPU_FEATURES 64 > > +#define MAX_CPU_FEATURES 128 > Should this be (32 + 64)? I guess it's easier as you did since we have > 128 bits in total, only that we reserved the top 32 in ELF_HWCAP. We need to have the full 64 bits allocated for AT_HWCAP storage even if nothing uses the top 32 so that we can return the elements in the array, otherwise we need logic for fishing variably sized silces of bits out of the bitmap which seems more trouble than it's worth. > > unsigned long cpu_get_elf_hwcap2(void) > > { > > - return upper_32_bits(elf_hwcap); > > + return elf_hwcap[1]; > > } > This is fine on the assumption that DECLARE_BITMAP is always an array of > longs. I couldn't see any documentation on this but at least the > set_bit() etc. API only works on 'long *' pointers. If someone changes DECLARE_BITMAP() they're going to have to be very, very careful. [-- Attachment #1.2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] [-- Attachment #2: Type: text/plain, Size: 176 bytes --] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v5 3/3] arm64/hwcap: Support FEAT_EBF16 2022-07-07 10:36 [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2 Mark Brown 2022-07-07 10:36 ` [PATCH v5 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP Mark Brown 2022-07-07 10:36 ` [PATCH v5 2/3] arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long Mark Brown @ 2022-07-07 10:36 ` Mark Brown 2022-07-07 11:40 ` Catalin Marinas 2022-07-20 12:29 ` [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2 Will Deacon 3 siblings, 1 reply; 10+ messages in thread From: Mark Brown @ 2022-07-07 10:36 UTC (permalink / raw) To: Catalin Marinas, Will Deacon Cc: Suzuki K Poulose, Szabolcs Nagy, linux-arm-kernel, Mark Brown The v9.2 feature FEAT_EBF16 provides support for an extended BFloat16 mode. Allow userspace to discover system support for this feature by adding a hwcap for it. Signed-off-by: Mark Brown <broonie@kernel.org> --- Documentation/arm64/elf_hwcaps.rst | 4 ++++ arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/kernel/cpufeature.c | 1 + arch/arm64/kernel/cpuinfo.c | 1 + 5 files changed, 8 insertions(+) diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst index 3d116fb536c5..31fc10b833dd 100644 --- a/Documentation/arm64/elf_hwcaps.rst +++ b/Documentation/arm64/elf_hwcaps.rst @@ -301,6 +301,10 @@ HWCAP2_WFXT Functionality implied by ID_AA64ISAR2_EL1.WFXT == 0b0010. +HWCAP2_EBF16 + + Functionality implied by ID_AA64ISAR1_EL1.BF16 == 0b0010. + 4. Unused AT_HWCAP bits ----------------------- diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 9b5fdc114f8c..cef4ae7a3d8b 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -118,6 +118,7 @@ #define KERNEL_HWCAP_SME_F32F32 __khwcap2_feature(SME_F32F32) #define KERNEL_HWCAP_SME_FA64 __khwcap2_feature(SME_FA64) #define KERNEL_HWCAP_WFXT __khwcap2_feature(WFXT) +#define KERNEL_HWCAP_EBF16 __khwcap2_feature(EBF16) /* * This yields a mask that user programs can use to figure out what diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index fd7577cf8e77..1ad2568a2569 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -91,5 +91,6 @@ #define HWCAP2_SME_F32F32 (1 << 29) #define HWCAP2_SME_FA64 (1 << 30) #define HWCAP2_WFXT (1UL << 31) +#define HWCAP2_EBF16 (1UL << 32) #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 5ba226f3721c..c84f97797985 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2623,6 +2623,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_FRINTTS_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_FRINT), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_SB_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_SB), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_BF16), + HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_BF16_SHIFT, 4, FTR_UNSIGNED, 2, CAP_HWCAP, KERNEL_HWCAP_EBF16), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_DGH_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_DGH), HWCAP_CAP(SYS_ID_AA64ISAR1_EL1, ID_AA64ISAR1_I8MM_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_I8MM), HWCAP_CAP(SYS_ID_AA64MMFR2_EL1, ID_AA64MMFR2_AT_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_USCAT), diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 8eff0a34ffd4..2ca131243c30 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -107,6 +107,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_SME_F32F32] = "smef32f32", [KERNEL_HWCAP_SME_FA64] = "smefa64", [KERNEL_HWCAP_WFXT] = "wfxt", + [KERNEL_HWCAP_EBF16] = "ebf16", }; #ifdef CONFIG_COMPAT -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v5 3/3] arm64/hwcap: Support FEAT_EBF16 2022-07-07 10:36 ` [PATCH v5 3/3] arm64/hwcap: Support FEAT_EBF16 Mark Brown @ 2022-07-07 11:40 ` Catalin Marinas 0 siblings, 0 replies; 10+ messages in thread From: Catalin Marinas @ 2022-07-07 11:40 UTC (permalink / raw) To: Mark Brown; +Cc: Will Deacon, Suzuki K Poulose, Szabolcs Nagy, linux-arm-kernel On Thu, Jul 07, 2022 at 11:36:32AM +0100, Mark Brown wrote: > diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h > index fd7577cf8e77..1ad2568a2569 100644 > --- a/arch/arm64/include/uapi/asm/hwcap.h > +++ b/arch/arm64/include/uapi/asm/hwcap.h > @@ -91,5 +91,6 @@ > #define HWCAP2_SME_F32F32 (1 << 29) > #define HWCAP2_SME_FA64 (1 << 30) > #define HWCAP2_WFXT (1UL << 31) > +#define HWCAP2_EBF16 (1UL << 32) This works for me: Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2 2022-07-07 10:36 [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2 Mark Brown ` (2 preceding siblings ...) 2022-07-07 10:36 ` [PATCH v5 3/3] arm64/hwcap: Support FEAT_EBF16 Mark Brown @ 2022-07-20 12:29 ` Will Deacon 3 siblings, 0 replies; 10+ messages in thread From: Will Deacon @ 2022-07-20 12:29 UTC (permalink / raw) To: Mark Brown, Catalin Marinas Cc: kernel-team, Will Deacon, linux-arm-kernel, Szabolcs Nagy, Suzuki K Poulose On Thu, 7 Jul 2022 11:36:29 +0100, Mark Brown wrote: > Currently for arm64 we expose hwcaps to userspace using the low 32 bits > of AT_HWCAP and AT_HWCAP2. Due to the ever expanding capabilties of the > architecture we have now allocated all the available bits in this scheme > so we need to expand, either using the higher bits or adding a new > AT_HWCAP3. Discussions suggest that the favoured approach for now is to > start allocating the upper bits of AT_HWCAP2. > > [...] Applied to arm64 (for-next/cpufeature), thanks! [1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP https://git.kernel.org/arm64/c/d3e4a9d30804 [2/3] arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long https://git.kernel.org/arm64/c/60c868eff2bc [3/3] arm64/hwcap: Support FEAT_EBF16 https://git.kernel.org/arm64/c/a6a468f50d6a Cheers, -- Will https://fixes.arm64.dev https://next.arm64.dev https://will.arm64.dev _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2022-07-20 12:30 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2022-07-07 10:36 [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2 Mark Brown 2022-07-07 10:36 ` [PATCH v5 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP Mark Brown 2022-07-07 11:21 ` Szabolcs Nagy 2022-07-07 11:38 ` Catalin Marinas 2022-07-07 10:36 ` [PATCH v5 2/3] arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long Mark Brown 2022-07-07 11:37 ` Catalin Marinas 2022-07-07 11:52 ` Mark Brown 2022-07-07 10:36 ` [PATCH v5 3/3] arm64/hwcap: Support FEAT_EBF16 Mark Brown 2022-07-07 11:40 ` Catalin Marinas 2022-07-20 12:29 ` [PATCH v5 0/3] arm64: Start allocating upper bits of AT_HWCAP2 Will Deacon
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