linux/arch/arm64
Mark Brown d158a0608e arm64/sme: More sensibly define the size for the ZA register set
Since the vector length configuration mechanism is identical between SVE
and SME we share large elements of the code including the definition for
the maximum vector length. Unfortunately when we were defining the ABI
for SVE we included not only the actual maximum vector length of 2048
bits but also the value possible if all the bits reserved in the
architecture for expansion of the LEN field were used, 16384 bits.

This starts creating problems if we try to allocate anything for the ZA
matrix based on the maximum possible vector length, as we do for the
regset used with ptrace during the process of generating a core dump.
While the maximum potential size for ZA with the current architecture is
a reasonably managable 64K with the higher reserved limit ZA would be
64M which leads to entirely reasonable complaints from the memory
management code when we try to allocate a buffer of that size. Avoid
these issues by defining the actual maximum vector length for the
architecture and using it for the SME regsets.

Also use the full ZA_PT_SIZE() with the header rather than just the
actual register payload when specifying the size, fixing support for the
largest vector lengths now that we have this new, lower define. With the
SVE maximum this did not cause problems due to the extra headroom we
had.

While we're at it add a comment clarifying why even though ZA is a
single register we tell the regset code that it is a multi-register
regset.

Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/r/20220505221517.1642014-1-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-05-06 18:24:19 +01:00
..
boot arm64: dts: qcom/sdm845-shift-axolotl: Fix boolean properties with values 2022-04-14 22:52:17 +02:00
configs ARM: DT updates for 5.18 2022-03-23 18:37:22 -07:00
crypto crypto: arm64 - cleanup comments 2022-03-09 15:12:32 +12:00
hyperv arm64: hyperv: Initialize hypervisor on boot 2021-08-04 16:54:36 +00:00
include arm64/sme: More sensibly define the size for the ZA register set 2022-05-06 18:24:19 +01:00
kernel arm64/sme: More sensibly define the size for the ZA register set 2022-05-06 18:24:19 +01:00
kvm KVM: arm64: Handle SME host state when running guests 2022-04-22 18:51:23 +01:00
lib Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2022-03-21 16:02:36 -07:00
mm arm64: fix typos in comments 2022-04-04 10:32:50 +01:00
net kasan, arm64: don't tag executable vmalloc allocations 2022-03-24 19:06:48 -07:00
tools arm64/sme: Basic enumeration support 2022-04-22 18:50:49 +01:00
xen xen: allow pv-only hypercalls only with CONFIG_XEN_PV 2021-11-02 08:11:01 -05:00
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig arm64/sme: Provide Kconfig for SME 2022-04-22 18:51:23 +01:00
Kconfig.debug
Kconfig.platforms ARM: DT updates for 5.18 2022-03-23 18:37:22 -07:00
Makefile arm64/xor: use EOR3 instructions when available 2021-12-14 12:14:26 +00:00