AArch64: Disable Secure Cycle Counter
This patch fixes an issue when secure world timing information
can be leaked because Secure Cycle Counter is not disabled.
For ARMv8.5 the counter gets disabled by setting MDCR_El3.SCCD
bit on CPU cold/warm boot.
For the earlier architectures PMCR_EL0 register is saved/restored
on secure world entry/exit from/to Non-secure state, and cycle
counting gets disabled by setting PMCR_EL0.DP bit.
'include\aarch64\arch.h' header file was tided up and new
ARMv8.5-PMU related definitions were added.
Change-Id: I6f56db6bc77504634a352388990ad925a69ebbfa
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
diff --git a/include/arch/aarch64/el3_common_macros.S b/include/arch/aarch64/el3_common_macros.S
index 22b32b4..a36b7da 100644
--- a/include/arch/aarch64/el3_common_macros.S
+++ b/include/arch/aarch64/el3_common_macros.S
@@ -116,12 +116,42 @@
* ---------------------------------------------------------------------
*/
mov_imm x0, ((MDCR_EL3_RESET_VAL | MDCR_SDD_BIT | \
- MDCR_SPD32(MDCR_SPD32_DISABLE) | MDCR_SCCD_BIT) \
- & ~(MDCR_TDOSA_BIT | MDCR_TDA_BIT | MDCR_TPM_BIT))
+ MDCR_SPD32(MDCR_SPD32_DISABLE) | MDCR_SCCD_BIT) & \
+ ~(MDCR_TDOSA_BIT | MDCR_TDA_BIT | MDCR_TPM_BIT))
msr mdcr_el3, x0
/* ---------------------------------------------------------------------
+ * Initialise PMCR_EL0 setting all fields rather than relying
+ * on hw. Some fields are architecturally UNKNOWN on reset.
+ *
+ * PMCR_EL0.LP: Set to one so that event counter overflow, that
+ * is recorded in PMOVSCLR_EL0[0-30], occurs on the increment
+ * that changes PMEVCNTR<n>_EL0[63] from 1 to 0, when ARMv8.5-PMU
+ * is implemented. This bit is RES0 in versions of the architecture
+ * earlier than ARMv8.5, setting it to 1 doesn't have any effect
+ * on them.
+ *
+ * PMCR_EL0.LC: Set to one so that cycle counter overflow, that
+ * is recorded in PMOVSCLR_EL0[31], occurs on the increment
+ * that changes PMCCNTR_EL0[63] from 1 to 0.
+ *
+ * PMCR_EL0.DP: Set to one so that the cycle counter,
+ * PMCCNTR_EL0 does not count when event counting is prohibited.
+ *
+ * PMCR_EL0.X: Set to zero to disable export of events.
+ *
+ * PMCR_EL0.D: Set to zero so that, when enabled, PMCCNTR_EL0
+ * counts on every clock cycle.
+ * ---------------------------------------------------------------------
+ */
+ mov_imm x0, ((PMCR_EL0_RESET_VAL | PMCR_EL0_LP_BIT | \
+ PMCR_EL0_LC_BIT | PMCR_EL0_DP_BIT) & \
+ ~(PMCR_EL0_X_BIT | PMCR_EL0_D_BIT))
+
+ msr pmcr_el0, x0
+
+ /* ---------------------------------------------------------------------
* Enable External Aborts and SError Interrupts now that the exception
* vectors have been setup.
* ---------------------------------------------------------------------