Enable v8.6 WFE trap delays
This patch enables the v8.6 extension to add a delay before WFE traps
are taken. A weak hook plat_arm_set_twedel_scr_el3 has been added in
plat/common/aarch64/plat_common.c that disables this feature by default
but platform-specific code can override it when needed.
The only hook provided sets the TWED fields in SCR_EL3, there are similar
fields in HCR_EL2, SCTLR_EL2, and SCTLR_EL1 to control WFE trap delays in
lower ELs but these should be configured by code running at EL2 and/or EL1
depending on the platform configuration and is outside the scope of TF-A.
Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: I0a9bb814205efeab693a3d0a0623e62144abba2d
diff --git a/include/arch/aarch64/arch.h b/include/arch/aarch64/arch.h
index 81e0f27..92e6737 100644
--- a/include/arch/aarch64/arch.h
+++ b/include/arch/aarch64/arch.h
@@ -226,6 +226,12 @@
#define ID_AA64MMFR0_EL1_TGRAN16_SUPPORTED ULL(0x1)
#define ID_AA64MMFR0_EL1_TGRAN16_NOT_SUPPORTED ULL(0x0)
+/* ID_AA64MMFR1_EL1 definitions */
+#define ID_AA64MMFR1_EL1_TWED_SHIFT U(32)
+#define ID_AA64MMFR1_EL1_TWED_MASK ULL(0xf)
+#define ID_AA64MMFR1_EL1_TWED_SUPPORTED ULL(0x1)
+#define ID_AA64MMFR1_EL1_TWED_NOT_SUPPORTED ULL(0x0)
+
/* ID_AA64MMFR2_EL1 definitions */
#define ID_AA64MMFR2_EL1 S3_0_C0_C7_2
@@ -312,6 +318,9 @@
/* SCR definitions */
#define SCR_RES1_BITS ((U(1) << 4) | (U(1) << 5))
+#define SCR_TWEDEL_SHIFT U(30)
+#define SCR_TWEDEL_MASK ULL(0xf)
+#define SCR_TWEDEn_BIT (UL(1) << 29)
#define SCR_ATA_BIT (U(1) << 26)
#define SCR_FIEN_BIT (U(1) << 21)
#define SCR_EEL2_BIT (U(1) << 18)