ARMv8.5 introduces a DC CVADP instruction which cleans the data cache to
the point of deep persistence. This series makes the instruction
available to userspace and advertises the presence of this CPU feature.
At present when CONFIG_ARM64_PMEM is enabled and the CVAP feature is
present (ARMv8.2) the CVAP instruction is used (from memcpy_flushcache
and arch_wb_cache_pmem). No changes have been made to use CVADP in
these functions or similar.
As we have moved beyond 32 capabilities we now begin using AT_HWCAP2
for userspace.
Tested as follows:
$ dmesg | grep "Deep"
[ 0.166496] CPU features: detected: Data cache clean to Point of Deep Persistence
$ LD_SHOW_AUXV=1 sleep 2>&1 | grep AT_HWCAP
AT_HWCAP: ef91ff87
AT_HWCAP2: 0x1
Changes since v2:
- Rebased onto v5.1-rc2
- Renamed cpu_{have,set}_feature_name to cpu_{have,set}_named_feature
- Add additional comments and update kernel Documentation
Changes since v1:
- Rebased onto v5.0-rc7
- Introduced cpu_{have,set}_feature_name to eliminate use of
KERNEL_HWCAP prefix
- Hard coded MAX_CPU_FEATURES and added a WARN_ON
- Minor comment and tab/spacing changes
- Use elf_hwcap for all 64 caps in the kernel instead of
a new elf_hwcap2
Andrew Murray (7):
arm64: Handle trapped DC CVADP
arm64: HWCAP: add support for AT_HWCAP2
arm64: HWCAP: encapsulate elf_hwcap
arm64: Expose DC CVADP to userspace
arm64: add CVADP support to the cache maintenance helper
arm64: Advertise ARM64_HAS_DCPODP cpu feature
arm64: docs: document AT_HWCAP2 and unused AT_HWCAP bits
Documentation/arm64/elf_hwcaps.txt | 18 +++-
arch/arm64/crypto/aes-ce-ccm-glue.c | 2 +-
arch/arm64/crypto/aes-neonbs-glue.c | 2 +-
arch/arm64/crypto/chacha-neon-glue.c | 2 +-
arch/arm64/crypto/crct10dif-ce-glue.c | 4 +-
arch/arm64/crypto/ghash-ce-glue.c | 8 +-
arch/arm64/crypto/nhpoly1305-neon-glue.c | 2 +-
arch/arm64/crypto/sha256-glue.c | 4 +-
arch/arm64/include/asm/assembler.h | 4 +
arch/arm64/include/asm/cpucaps.h | 3 +-
arch/arm64/include/asm/cpufeature.h | 21 ++---
arch/arm64/include/asm/esr.h | 3 +-
arch/arm64/include/asm/hwcap.h | 50 ++++++++++-
arch/arm64/include/uapi/asm/hwcap.h | 7 +-
arch/arm64/kernel/cpufeature.c | 108 +++++++++++++++--------
arch/arm64/kernel/cpuinfo.c | 3 +-
arch/arm64/kernel/fpsimd.c | 4 +-
arch/arm64/kernel/traps.c | 3 +
drivers/clocksource/arm_arch_timer.c | 8 ++
19 files changed, 185 insertions(+), 71 deletions(-)
--
2.21.0
