Skip to content
Commit a8d4636f authored by Will Deacon's avatar Will Deacon Committed by Catalin Marinas
Browse files

arm64: cacheinfo: Remove CCSIDR-based cache information probing



The CCSIDR_EL1.{NumSets,Associativity,LineSize} fields are only for use
in conjunction with set/way cache maintenance and are not guaranteed to
represent the actual microarchitectural features of a design.

The architecture explicitly states:

| You cannot make any inference about the actual sizes of caches based
| on these parameters.

Furthermore, CCSIDR_EL1.{WT,WB,RA,WA} have been removed retrospectively
from ARMv8 and are now considered to be UNKNOWN.

Since the kernel doesn't make use of set/way cache maintenance and it is
not possible for userspace to execute these instructions, we have no
need for the CCSIDR information in the kernel.

This patch removes the accessors, along with the related portions of the
cacheinfo support, which should instead be reintroduced when firmware has
a mechanism to provide us with reliable information.

Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 3689c75a
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment