refactor(cm): reset the cptr_el3 before perworld context setup
Currently, the registers which are maintained per-world, does not
take into account the reset value while configuring the context for
the respective world.
This leads to an issue, wherein the register retains the same value
across world switch, which is an error.
This patch addresses this problem, by configuring the register
(cptr_el3) precisely according to the world, the cpu is in
execution via resetting it before initializing the world specific context.
Change-Id: I592d82af373155fca67eed109c199341c305f0b9
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c
index fdd1388..a0212c6 100644
--- a/lib/el3_runtime/aarch64/context_mgmt.c
+++ b/lib/el3_runtime/aarch64/context_mgmt.c
@@ -600,6 +600,28 @@
}
#endif /* IMAGE_BL31 */
+/******************************************************************************
+ * Function to initialise the registers with the RESET values in the context
+ * memory, which are maintained per world.
+ ******************************************************************************/
+#if IMAGE_BL31
+void cm_el3_arch_init_per_world(per_world_context_t *per_world_ctx)
+{
+ /*
+ * Initialise CPTR_EL3, setting all fields rather than relying on hw.
+ *
+ * CPTR_EL3.TFP: Set to zero so that accesses to the V- or Z- registers
+ * by Advanced SIMD, floating-point or SVE instructions (if
+ * implemented) do not trap to EL3.
+ *
+ * CPTR_EL3.TCPAC: Set to zero so that accesses to CPACR_EL1,
+ * CPTR_EL2,CPACR, or HCPTR do not trap to EL3.
+ */
+ uint64_t cptr_el3 = CPTR_EL3_RESET_VAL & ~(TCPAC_BIT | TFP_BIT);
+ per_world_ctx->ctx_cptr_el3 = cptr_el3;
+}
+#endif /* IMAGE_BL31 */
+
/*******************************************************************************
* Initialise per_world_context for Non-Secure world.
* This function enables the architecture extensions, which have same value
@@ -608,6 +630,8 @@
#if IMAGE_BL31
void manage_extensions_nonsecure_per_world(void)
{
+ cm_el3_arch_init_per_world(&per_world_context[CPU_CONTEXT_NS]);
+
if (is_feat_sme_supported()) {
sme_enable_per_world(&per_world_context[CPU_CONTEXT_NS]);
}
@@ -631,10 +655,11 @@
* This function enables the architecture extensions, which have same value
* across the cores for the secure world.
******************************************************************************/
-
static void manage_extensions_secure_per_world(void)
{
#if IMAGE_BL31
+ cm_el3_arch_init_per_world(&per_world_context[CPU_CONTEXT_SECURE]);
+
if (is_feat_sme_supported()) {
if (ENABLE_SME_FOR_SWD) {