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authorDave Martin <Dave.Martin@arm.com>2017-10-31 15:51:19 +0000
committerWill Deacon <will.deacon@arm.com>2017-11-03 15:24:21 +0000
commit43994d824e8443263dc98b151e6326bf677be52e (patch)
treeef769d01442f52999428d241b02b0c849489842b /Documentation/arm64
parent07d79fe7c22364de34618e58b92a8f091bd7e03d (diff)
downloadlinux-43994d824e8443263dc98b151e6326bf677be52e.tar.bz2
arm64/sve: Detect SVE and activate runtime support
This patch enables detection of hardware SVE support via the cpufeatures framework, and reports its presence to the kernel and userspace via the new ARM64_SVE cpucap and HWCAP_SVE hwcap respectively. Userspace can also detect SVE using ID_AA64PFR0_EL1, using the cpufeatures MRS emulation. When running on hardware that supports SVE, this enables runtime kernel support for SVE, and allows user tasks to execute SVE instructions and make of the of the SVE-specific user/kernel interface extensions implemented by this series. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'Documentation/arm64')
-rw-r--r--Documentation/arm64/cpu-feature-registers.txt6
-rw-r--r--Documentation/arm64/elf_hwcaps.txt4
2 files changed, 9 insertions, 1 deletions
diff --git a/Documentation/arm64/cpu-feature-registers.txt b/Documentation/arm64/cpu-feature-registers.txt
index 011ddfc1e570..bd9b3faab2c4 100644
--- a/Documentation/arm64/cpu-feature-registers.txt
+++ b/Documentation/arm64/cpu-feature-registers.txt
@@ -142,7 +142,11 @@ infrastructure:
x--------------------------------------------------x
| Name | bits | visible |
|--------------------------------------------------|
- | RES0 | [63-28] | n |
+ | RES0 | [63-36] | n |
+ |--------------------------------------------------|
+ | SVE | [35-32] | y |
+ |--------------------------------------------------|
+ | RES0 | [31-28] | n |
|--------------------------------------------------|
| GIC | [27-24] | n |
|--------------------------------------------------|
diff --git a/Documentation/arm64/elf_hwcaps.txt b/Documentation/arm64/elf_hwcaps.txt
index 0ba180522e3c..89edba12a9e0 100644
--- a/Documentation/arm64/elf_hwcaps.txt
+++ b/Documentation/arm64/elf_hwcaps.txt
@@ -154,3 +154,7 @@ HWCAP_ASIMDDP
HWCAP_SHA512
Functionality implied by ID_AA64ISAR0_EL1.SHA2 == 0b0002.
+
+HWCAP_SVE
+
+ Functionality implied by ID_AA64PFR0_EL1.SVE == 0b0001.