From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Joey Gouly <joey.gouly@arm.com>,
Will Deacon <will@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
Marc Zyngier <maz@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>
Subject: [PATCH 5.16 16/53] arm64: cpufeature: add HWCAP for FEAT_RPRES
Date: Thu, 10 Mar 2022 15:09:21 +0100 [thread overview]
Message-ID: <20220310140812.302496501@linuxfoundation.org> (raw)
In-Reply-To: <20220310140811.832630727@linuxfoundation.org>
From: Joey Gouly <joey.gouly@arm.com>
commit 1175011a7d0030d49dc9c10bde36f08f26d0a8ee upstream.
Add a new HWCAP to detect the Increased precision of Reciprocal Estimate
and Reciprocal Square Root Estimate feature (FEAT_RPRES), introduced in Armv8.7.
Also expose this to userspace in the ID_AA64ISAR2_EL1 feature register.
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211210165432.8106-4-joey.gouly@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
Documentation/arm64/cpu-feature-registers.rst | 8 ++++++++
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 | 2 ++
arch/arm64/kernel/cpuinfo.c | 1 +
6 files changed, 17 insertions(+)
--- a/Documentation/arm64/cpu-feature-registers.rst
+++ b/Documentation/arm64/cpu-feature-registers.rst
@@ -283,6 +283,14 @@ infrastructure:
| AFP | [47-44] | y |
+------------------------------+---------+---------+
+ 9) ID_AA64ISAR2_EL1 - Instruction set attribute register 2
+
+ +------------------------------+---------+---------+
+ | Name | bits | visible |
+ +------------------------------+---------+---------+
+ | RPRES | [7-4] | y |
+ +------------------------------+---------+---------+
+
Appendix I: Example
-------------------
--- a/Documentation/arm64/elf_hwcaps.rst
+++ b/Documentation/arm64/elf_hwcaps.rst
@@ -255,6 +255,10 @@ HWCAP2_AFP
Functionality implied by ID_AA64MFR1_EL1.AFP == 0b0001.
+HWCAP2_RPRES
+
+ Functionality implied by ID_AA64ISAR2_EL1.RPRES == 0b0001.
+
4. Unused AT_HWCAP bits
-----------------------
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h
@@ -107,6 +107,7 @@
#define KERNEL_HWCAP_MTE __khwcap2_feature(MTE)
#define KERNEL_HWCAP_ECV __khwcap2_feature(ECV)
#define KERNEL_HWCAP_AFP __khwcap2_feature(AFP)
+#define KERNEL_HWCAP_RPRES __khwcap2_feature(RPRES)
/*
* This yields a mask that user programs can use to figure out what
--- a/arch/arm64/include/uapi/asm/hwcap.h
+++ b/arch/arm64/include/uapi/asm/hwcap.h
@@ -77,5 +77,6 @@
#define HWCAP2_MTE (1 << 18)
#define HWCAP2_ECV (1 << 19)
#define HWCAP2_AFP (1 << 20)
+#define HWCAP2_RPRES (1 << 21)
#endif /* _UAPI__ASM_HWCAP_H */
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -226,6 +226,7 @@ static const struct arm64_ftr_bits ftr_i
};
static const struct arm64_ftr_bits ftr_id_aa64isar2[] = {
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_RPRES_SHIFT, 4, 0),
ARM64_FTR_END,
};
@@ -2490,6 +2491,7 @@ static const struct arm64_cpu_capabiliti
#endif /* CONFIG_ARM64_MTE */
HWCAP_CAP(SYS_ID_AA64MMFR0_EL1, ID_AA64MMFR0_ECV_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ECV),
HWCAP_CAP(SYS_ID_AA64MMFR1_EL1, ID_AA64MMFR1_AFP_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AFP),
+ HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_RPRES_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RPRES),
{},
};
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -96,6 +96,7 @@ static const char *const hwcap_str[] = {
[KERNEL_HWCAP_MTE] = "mte",
[KERNEL_HWCAP_ECV] = "ecv",
[KERNEL_HWCAP_AFP] = "afp",
+ [KERNEL_HWCAP_RPRES] = "rpres",
};
#ifdef CONFIG_COMPAT
next prev parent reply other threads:[~2022-03-10 14:16 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-10 14:09 [PATCH 5.16 00/53] 5.16.14-rc2 review Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 01/53] x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 02/53] x86/speculation: Add eIBRS + Retpoline options Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 03/53] Documentation/hw-vuln: Update spectre doc Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 04/53] x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 05/53] x86/speculation: Use generic retpoline by default on AMD Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 06/53] x86/speculation: Update link to AMD speculation whitepaper Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 07/53] x86/speculation: Warn about Spectre v2 LFENCE mitigation Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 08/53] x86/speculation: Warn about eIBRS + LFENCE + Unprivileged eBPF + SMT Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 09/53] ARM: report Spectre v2 status through sysfs Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 10/53] ARM: early traps initialisation Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 11/53] ARM: use LOADADDR() to get load address of sections Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 12/53] ARM: Spectre-BHB workaround Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 13/53] ARM: include unprivileged BPF status in Spectre V2 reporting Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 14/53] arm64: add ID_AA64ISAR2_EL1 sys register Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 15/53] arm64: cpufeature: add HWCAP for FEAT_AFP Greg Kroah-Hartman
2022-03-10 14:09 ` Greg Kroah-Hartman [this message]
2022-03-10 14:09 ` [PATCH 5.16 17/53] arm64: entry.S: Add ventry overflow sanity checks Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 18/53] arm64: spectre: Rename spectre_v4_patch_fw_mitigation_conduit Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 19/53] KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 20/53] arm64: entry: Make the trampoline cleanup optional Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 21/53] arm64: entry: Free up another register on kptis tramp_exit path Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 22/53] arm64: entry: Move the trampoline data page before the text page Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 23/53] arm64: entry: Allow tramp_alias to access symbols after the 4K boundary Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 24/53] arm64: entry: Dont assume tramp_vectors is the start of the vectors Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 25/53] arm64: entry: Move trampoline macros out of ifdefd section Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 26/53] arm64: entry: Make the kpti trampolines kpti sequence optional Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 27/53] arm64: entry: Allow the trampoline text to occupy multiple pages Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 28/53] arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 29/53] arm64: entry: Add vectors that have the bhb mitigation sequences Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 30/53] arm64: entry: Add macro for reading symbol addresses from the trampoline Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 31/53] arm64: Add percpu vectors for EL1 Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 32/53] arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2 Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 33/53] arm64: Mitigate spectre style branch history side channels Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 34/53] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 35/53] arm64: Use the clearbhb instruction in mitigations Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 36/53] arm64: proton-pack: Include unprivileged eBPF status in Spectre v2 mitigation reporting Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 37/53] ARM: fix build error when BPF_SYSCALL is disabled Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 38/53] ARM: fix co-processor register typo Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 39/53] ARM: Do not use NOCROSSREFS directive with ld.lld Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 40/53] arm64: Do not include __READ_ONCE() block in assembly files Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 41/53] ARM: fix build warning in proc-v7-bugs.c Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 42/53] xen/xenbus: dont let xenbus_grant_ring() remove grants in error case Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 43/53] xen/grant-table: add gnttab_try_end_foreign_access() Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 44/53] xen/blkfront: dont use gnttab_query_foreign_access() for mapped status Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 45/53] xen/netfront: " Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 46/53] xen/scsifront: " Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 47/53] xen/gntalloc: dont use gnttab_query_foreign_access() Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 48/53] xen: remove gnttab_query_foreign_access() Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 49/53] xen/9p: use alloc/free_pages_exact() Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 50/53] xen/pvcalls: " Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 51/53] xen/gnttab: fix gnttab_end_foreign_access() without page specified Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 52/53] xen/netfront: react properly to failing gnttab_end_foreign_access_ref() Greg Kroah-Hartman
2022-03-10 14:09 ` [PATCH 5.16 53/53] Revert "ACPI: PM: s2idle: Cancel wakeup before dispatching EC GPE" Greg Kroah-Hartman
2022-03-10 18:48 ` [PATCH 5.16 00/53] 5.16.14-rc2 review Jon Hunter
2022-03-10 19:32 ` Shuah Khan
2022-03-10 21:30 ` Justin Forbes
2022-03-10 21:53 ` Naresh Kamboju
2022-03-10 23:20 ` Ron Economos
2022-03-10 23:20 ` Florian Fainelli
2022-03-11 0:14 ` Fox Chen
2022-03-11 1:03 ` Guenter Roeck
2022-03-11 3:11 ` Zan Aziz
2022-03-11 8:14 ` Rudi Heitbaum
2022-03-11 10:55 ` Bagas Sanjaya
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