Preempt/Resume standard function ID calls
This patch allows servicing of the non-secure world IRQs when the
CPU is in the secure world. Once the interrupt is handled, the
non-secure world issues the Resume FID to allow the secure payload
complete the preempted standard FID.
Change-Id: Ia52c41adf45014ab51d8447bed6605ca2f935587
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/include/bl32/payloads/tlk.h b/include/bl32/payloads/tlk.h
index 0ad1ac0..65fd333 100644
--- a/include/bl32/payloads/tlk.h
+++ b/include/bl32/payloads/tlk.h
@@ -41,12 +41,14 @@
*/
#define TLK_REGISTER_LOGBUF TLK_TOS_STD_FID(0x1)
#define TLK_REGISTER_REQBUF TLK_TOS_STD_FID(0x2)
+#define TLK_RESUME_FID TLK_TOS_STD_FID(0x100)
/*
* SMC function IDs that TLK uses to signal various forms of completions
* to the secure payload dispatcher.
*/
#define TLK_REQUEST_DONE (0x32000001 | (1 << 31))
+#define TLK_PREEMPTED (0x32000002 | (1 << 31))
#define TLK_ENTRY_DONE (0x32000003 | (1 << 31))
#define TLK_VA_TRANSLATE (0x32000004 | (1 << 31))
#define TLK_FID_SHARED_MEMBUF (0x32000005 | (1 << 31))
diff --git a/services/spd/tlkd/tlkd_main.c b/services/spd/tlkd/tlkd_main.c
index eb6b89d..bea4c48 100644
--- a/services/spd/tlkd/tlkd_main.c
+++ b/services/spd/tlkd/tlkd_main.c
@@ -199,6 +199,67 @@
switch (smc_fid) {
/*
+ * This function ID is used by SP to indicate that it was
+ * preempted by a non-secure world IRQ.
+ */
+ case TLK_PREEMPTED:
+
+ if (ns)
+ SMC_RET1(handle, SMC_UNK);
+
+ assert(handle == cm_get_context(SECURE));
+ cm_el1_sysregs_context_save(SECURE);
+
+ /* Get a reference to the non-secure context */
+ ns_cpu_context = cm_get_context(NON_SECURE);
+ assert(ns_cpu_context);
+
+ /*
+ * Restore non-secure state. There is no need to save the
+ * secure system register context since the SP was supposed
+ * to preserve it during S-EL1 interrupt handling.
+ */
+ cm_el1_sysregs_context_restore(NON_SECURE);
+ cm_set_next_eret_context(NON_SECURE);
+
+ SMC_RET1(ns_cpu_context, tlk_args_results_buf->args[0]);
+
+ /*
+ * Request from non secure world to resume the preempted
+ * Standard SMC call.
+ */
+ case TLK_RESUME_FID:
+
+ /* RESUME should be invoked only by normal world */
+ if (!ns)
+ SMC_RET1(handle, SMC_UNK);
+
+ /*
+ * This is a resume request from the non-secure client.
+ * save the non-secure state and send the request to
+ * the secure payload.
+ */
+ assert(handle == cm_get_context(NON_SECURE));
+
+ /* Check if we are already preempted before resume */
+ if (!get_std_smc_active_flag(tlk_ctx.state))
+ SMC_RET1(handle, SMC_UNK);
+
+ cm_el1_sysregs_context_save(NON_SECURE);
+
+ /*
+ * We are done stashing the non-secure context. Ask the
+ * secure payload to do the work now.
+ */
+
+ /* We just need to return to the preempted point in
+ * SP and the execution will resume as normal.
+ */
+ cm_el1_sysregs_context_restore(SECURE);
+ cm_set_next_eret_context(SECURE);
+ SMC_RET0(handle);
+
+ /*
* This is a request from the non-secure context to:
*
* a. register shared memory with the SP for storing it's