AArch32: Disable Secure Cycle Counter
This patch changes implementation for disabling Secure Cycle
Counter. For ARMv8.5 the counter gets disabled by setting
SDCR.SCCD bit on CPU cold/warm boot. For the earlier
architectures PMCR register is saved/restored on secure
world entry/exit from/to Non-secure state, and cycle counting
gets disabled by setting PMCR.DP bit.
In 'include\aarch32\arch.h' header file new
ARMv8.5-PMU related definitions were added.
Change-Id: Ia8845db2ebe8de940d66dff479225a5b879316f8
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
diff --git a/include/arch/aarch32/el3_common_macros.S b/include/arch/aarch32/el3_common_macros.S
index 0bd8978..c62d7d7 100644
--- a/include/arch/aarch32/el3_common_macros.S
+++ b/include/arch/aarch32/el3_common_macros.S
@@ -112,15 +112,41 @@
* SDCR.SPD: Disable AArch32 privileged debug. Debug exceptions from
* Secure EL1 are disabled.
*
- * SDCR: Set to one so that cycle counting by PMCCNTR is prohibited in
- * Secure state. This bit is RES0 in versions of the architecture
+ * SDCR.SCCD: Set to one so that cycle counting by PMCCNTR is prohibited
+ * in Secure state. This bit is RES0 in versions of the architecture
* earlier than ARMv8.5, setting it to 1 doesn't have any effect on
* them.
* ---------------------------------------------------------------------
*/
ldr r0, =(SDCR_RESET_VAL | SDCR_SPD(SDCR_SPD_DISABLE) | SDCR_SCCD_BIT)
stcopr r0, SDCR
+
+ /* ---------------------------------------------------------------------
+ * Initialise PMCR, setting all fields rather than relying
+ * on hw. Some fields are architecturally UNKNOWN on reset.
+ *
+ * PMCR.LP: Set to one so that event counter overflow, that
+ * is recorded in PMOVSCLR[0-30], occurs on the increment
+ * that changes PMEVCNTR<n>[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.
+ * This bit is Reserved, UNK/SBZP in ARMv7.
+ *
+ * PMCR.LC: Set to one so that cycle counter overflow, that
+ * is recorded in PMOVSCLR[31], occurs on the increment
+ * that changes PMCCNTR[63] from 1 to 0.
+ * This bit is Reserved, UNK/SBZP in ARMv7.
+ *
+ * PMCR.DP: Set to one to prohibit cycle counting whilst in Secure mode.
+ * ---------------------------------------------------------------------
+ */
+ ldr r0, =(PMCR_RESET_VAL | PMCR_DP_BIT | PMCR_LC_BIT | \
+ PMCR_LP_BIT)
+#else
+ ldr r0, =(PMCR_RESET_VAL | PMCR_DP_BIT)
#endif
+ stcopr r0, PMCR
/*
* If Data Independent Timing (DIT) functionality is implemented,