Enable ARMv8.6-ECV Self-Synch when booting to EL2
Enhanced Counter Virtualization, ECV, is an architecture extension introduced
in ARMv8.6. This extension allows the hypervisor, at EL2, to setup
self-synchronizing views of the timers for it's EL1 Guests. This patch pokes the
control register to enable this extension when booting a hypervisor at EL2.
Change-Id: I4e929ecdf400cea17eff1de5cf8704aa7e40973d
Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>
diff --git a/include/arch/aarch64/arch.h b/include/arch/aarch64/arch.h
index c7cf9f4..10fe926 100644
--- a/include/arch/aarch64/arch.h
+++ b/include/arch/aarch64/arch.h
@@ -211,6 +211,12 @@
#define PARANGE_0101 U(48)
#define PARANGE_0110 U(52)
+#define ID_AA64MMFR0_EL1_ECV_SHIFT U(60)
+#define ID_AA64MMFR0_EL1_ECV_MASK ULL(0xf)
+#define ID_AA64MMFR0_EL1_ECV_NOT_SUPPORTED ULL(0x0)
+#define ID_AA64MMFR0_EL1_ECV_SUPPORTED ULL(0x1)
+#define ID_AA64MMFR0_EL1_ECV_SELF_SYNCH ULL(0x2)
+
#define ID_AA64MMFR0_EL1_FGT_SHIFT U(56)
#define ID_AA64MMFR0_EL1_FGT_MASK ULL(0xf)
#define ID_AA64MMFR0_EL1_FGT_SUPPORTED ULL(0x1)
@@ -329,6 +335,7 @@
#define SCR_TWEDEL_SHIFT U(30)
#define SCR_TWEDEL_MASK ULL(0xf)
#define SCR_TWEDEn_BIT (UL(1) << 29)
+#define SCR_ECVEN_BIT (U(1) << 28)
#define SCR_FGTEN_BIT (U(1) << 27)
#define SCR_ATA_BIT (U(1) << 26)
#define SCR_FIEN_BIT (U(1) << 21)
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index 9bcf305..6b5d326 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -70,6 +70,12 @@
ID_AA64MMFR0_EL1_FGT_MASK) == ID_AA64MMFR0_EL1_FGT_SUPPORTED;
}
+static inline unsigned long int get_armv8_6_ecv_support(void)
+{
+ return ((read_id_aa64mmfr0_el1() >> ID_AA64MMFR0_EL1_ECV_SHIFT) &
+ ID_AA64MMFR0_EL1_ECV_MASK);
+}
+
/*
* Return MPAM version:
*
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c
index 1c5ba36..53b4ea3 100644
--- a/lib/el3_runtime/aarch64/context_mgmt.c
+++ b/lib/el3_runtime/aarch64/context_mgmt.c
@@ -176,6 +176,9 @@
* SCR_EL3.FGTEn: Enable Fine Grained Virtualization Traps under the
* same conditions as HVC instructions and when the processor supports
* ARMv8.6-FGT.
+ * SCR_EL3.ECVEn: Enable Enhanced Counter Virtualization (ECV)
+ * CNTPOFF_EL2 register under the same conditions as HVC instructions
+ * and when the processor supports ECV.
*/
if (((GET_RW(ep->spsr) == MODE_RW_64) && (GET_EL(ep->spsr) == MODE_EL2))
|| ((GET_RW(ep->spsr) != MODE_RW_64)
@@ -185,6 +188,11 @@
if (is_armv8_6_fgt_present()) {
scr_el3 |= SCR_FGTEN_BIT;
}
+
+ if (get_armv8_6_ecv_support()
+ == ID_AA64MMFR0_EL1_ECV_SELF_SYNCH) {
+ scr_el3 |= SCR_ECVEN_BIT;
+ }
}
/* Enable S-EL2 if the next EL is EL2 and security state is secure */