refactor(dice): save parent context handle
Improve the restart handling of DPE. In the case of a restart
scenario where only that core is restarted which executes
the DPE client, but the core executes the DPE service
remains up and running. In this case, client needs to save
a valid context handle to be able to send commands again
to the DPE service during the new boot sequence.
BL1 saves a valid parent context handle to SDS
before passing the execution to BL2. This handle
can be used in case of a restart scenario when AP
is restarted but RSE is not. Because in that case
RSE does not save an initial context handle to SDS,
which meant to be used by AP during the boot process.
By then the very first initial context handle is
invalidated because it was already used in the
previous boot cycle by BL1.
BL2 does not need to do this, because the cold
boot starts with BL1.
Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Change-Id: Id14eefd2ec758f89f672af176e4f5386a397fa35
diff --git a/plat/arm/board/tc/tc_bl1_dpe.c b/plat/arm/board/tc/tc_bl1_dpe.c
index 432a163..a073dc3 100644
--- a/plat/arm/board/tc/tc_bl1_dpe.c
+++ b/plat/arm/board/tc/tc_bl1_dpe.c
@@ -45,7 +45,7 @@
.signer_id_size = SIGNER_ID_MIN_SIZE,
.sw_type = MBOOT_BL2_IMAGE_STRING,
.allow_new_context_to_derive = true,
- .retain_parent_context = false,
+ .retain_parent_context = true, /* To handle restart */
.create_certificate = false,
.pk_oid = ZERO_OID },
{
@@ -58,10 +58,15 @@
/* Context handle is meant to be used by BL2. Sharing it via TB_FW_CONFIG */
static int new_ctx_handle;
+/* Save a valid parent context handle to be able to send commands to DPE service
+ * in case of an AP cold restart.
+ */
+static int new_parent_ctx_handle;
-void plat_dpe_share_context_handle(int *ctx_handle)
+void plat_dpe_share_context_handle(int *ctx_handle, int *parent_ctx_handle)
{
new_ctx_handle = *ctx_handle;
+ new_parent_ctx_handle = *parent_ctx_handle;
}
void plat_dpe_get_context_handle(int *ctx_handle)
@@ -135,4 +140,16 @@
*/
plat_panic_handler();
}
+
+ VERBOSE("Save parent context handle: 0x%x\n", new_parent_ctx_handle);
+ rc = sds_struct_write(SDS_RSE_AP_REGION_ID,
+ TC2_SDS_DPE_CTX_HANDLE_STRUCT_ID,
+ 0,
+ &new_parent_ctx_handle,
+ sizeof(new_parent_ctx_handle),
+ SDS_ACCESS_MODE_NON_CACHED);
+ if (rc != SDS_OK) {
+ ERROR("Unable to save DPE parent context handle to SDS area\n");
+ plat_panic_handler();
+ }
}
diff --git a/plat/arm/board/tc/tc_bl2_dpe.c b/plat/arm/board/tc/tc_bl2_dpe.c
index 50cdbf8..fb70fef 100644
--- a/plat/arm/board/tc/tc_bl2_dpe.c
+++ b/plat/arm/board/tc/tc_bl2_dpe.c
@@ -186,9 +186,12 @@
/* Context handle is meant to be used by BL33. Sharing it via NT_FW_CONFIG */
static int new_ctx_handle;
-void plat_dpe_share_context_handle(int *ctx_handle)
+void plat_dpe_share_context_handle(int *ctx_handle, int *parent_ctx_handle)
{
new_ctx_handle = *ctx_handle;
+
+ /* Irrelevant in BL2 because cold restart resumes CPU in BL1 */
+ (void)parent_ctx_handle;
}
void plat_dpe_get_context_handle(int *ctx_handle)