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fix(pmu): make MDCR_EL3.MTPME=1 out of reset

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Make the default value for MTPME always be 1 to preserve the reset
behaviour on newer revisions and on older revisions where the bit is
RES0 it doesn't matter.

Before its introduction MDCR_EL3.MTPME was RES0. Upon its introduction
the field resets to 1, making the MTPMU architecturally "enabled". As
such, the logical action on TF-A's part is to "disable" it, which led to
the introduction of DISABLE_MTPMU.

This hinges on the assumption that MDCR_EL3.MTPME will always be 1
unless the above flag is set. Unfortunately this is not the case, as the
reset value is overwritten at reset with a macro that sets this bit to
0.

Signed-off-by: Boyan Karatotev <boyan.karatotev@arm.com>
Change-Id: Ie570774972f246b3aa41dc016ecbcc6fc2f581f6
This commit is contained in:
Boyan Karatotev 2023-06-15 14:46:20 +01:00 • committed by Jayanth Dodderi Chidanand
parent 24a70738b2
commit 33815eb719
1 changed files with 1 additions and 1 deletions
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2
include/arch/aarch64/arch.h
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@ -595,7 +595,7 @@
#define MDCR_TDOSA_BIT (ULL(1) << 10)
#define MDCR_TDA_BIT (ULL(1) << 9)
#define MDCR_TPM_BIT (ULL(1) << 6)
#define MDCR_EL3_RESET_VAL ULL(0x0)
#define MDCR_EL3_RESET_VAL MDCR_MTPME_BIT
/* MDCR_EL2 definitions */
#define MDCR_EL2_MTPME (U(1) << 28)