ANDROID: arm64: errata: Add WORKAROUND_NXP_ERR050104 cpucaps

This is a placeholder to workaround NXP iMX8QM A53 Cache coherency issue.
The full patch is still under review upstream.

Considering the patch adds a new cpucap, which breaks KMI, and
the KMI freeze date is coming, so use a placeholder
here to update KMI before the freeze.

According to NXP errata document[1] i.MX8QuadMax SoC suffers from
serious cache coherence issue. It was also mentioned in initial
support[2] for imx8qm mek machine.

Following is excerpt from NXP IMX8_1N94W "Mask Set Errata" document
Rev. 5, 3/2023. Just in case it gets lost somehow.

"ERR050104: Arm/A53: Cache coherency issue"

Description

Some maintenance operations exchanged between the A53 and A72
core clusters, involving some Translation Look-aside Buffer
Invalidate (TLBI) and Instruction Cache (IC) instructions can
be corrupted. The upper bits, above bit-35, of ARADDR and ACADDR
buses within in Arm A53 sub-system have been incorrectly connected.
Therefore ARADDR and ACADDR address bits above bit-35 should not
be used.

Workaround

The following software instructions are required to be downgraded
to TLBI VMALLE1IS:  TLBI ASIDE1, TLBI ASIDE1IS, TLBI VAAE1,
TLBI VAAE1IS, TLBI VAALE1, TLBI VAALE1IS, TLBI VAE1, TLBI VAE1IS,
TLBI VALE1, TLBI VALE1IS

The following software instructions are required to be downgraded
to TLBI VMALLS12E1IS: TLBI IPAS2E1IS, TLBI IPAS2LE1IS

The following software instructions are required to be downgraded
to TLBI ALLE2IS: TLBI VAE2IS, TLBI VALE2IS.

The following software instructions are required to be downgraded
to TLBI ALLE3IS: TLBI VAE3IS, TLBI VALE3IS.

The following software instructions are required to be downgraded
to TLBI VMALLE1IS when the Force Broadcast (FB) bit [9] of the
Hypervisor Configuration Register (HCR_EL2) is set:
TLBI ASIDE1, TLBI VAAE1, TLBI VAALE1, TLBI VAE1, TLBI VALE1

The following software instruction is required to be downgraded
to IC IALLUIS: IC IVAU, Xt

Specifically for the IC IVAU, Xt downgrade, setting SCTLR_EL1.UCI
to 0 will disable EL0 access to this instruction. Any attempt to
execute from EL0 will generate an EL1 trap, where the downgrade to
IC ALLUIS can be implemented.

[1] https://www.nxp.com/docs/en/errata/IMX8_1N94W.pdf
[2] commit 307fd14d ("arm64: dts: imx: add imx8qm mek support")

Bug: 284762900
Link: https://lore.kernel.org/linux-arm-kernel/20230420112952.28340-1-iivanov@suse.de/


Signed-off-by: Jindong Yue <jindong.yue@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I8dd50b369412de73b608805d1b5bb8424ea23280