core: arm: virt-aware FF-A thread_foreign_intr_exit()

thread_foreign_intr_exit() is called after the thread state has been
saved and the thread is suspended. With virtualization enabled
(CFG_NS_VIRTUALIZATION=y) the virt_unset_guest() is also called. After
this, the guests thread contexts aren't available any longer. For FF-A
thread_foreign_intr_exit() needs a few fields from the suspend threads
context so extract those before suspending the thread and pass them as
parameters for thread_foreign_intr_exit().

Signed-off-by: Jens Wiklander <[email protected]>
Reviewed-by: Etienne Carriere <[email protected]>

core/arch/arm/kernel/thread_a64.S

@@ -1153,6 +1153,15 @@ END_FUNC el0_sync_abort
 	write_apiakeylo	x2
 	isb
 #endif
+
+#ifdef CFG_CORE_FFA
+	/* x0 is still pointing to the current thread_ctx */
+	/* load curr_thread_ctx->tsd.rpc_target_info into w19 */
+	ldr	w19, [x0, #THREAD_CTX_TSD_RPC_TARGET_INFO]
+	/* load curr_thread_ctx->flags into w19 */
+	ldr	w20, [x0, #THREAD_CTX_FLAGS]
+#endif
+
 	/* load tmp_stack_va_end */
 	ldr	x1, [sp, #THREAD_CORE_LOCAL_TMP_STACK_VA_END]
 	/* Switch to SP_EL0 */
@@ -1193,6 +1202,10 @@ END_FUNC el0_sync_abort
 	 */
 
 	/* Passing thread index in w0 */
+#ifdef CFG_CORE_FFA
+	mov	w1, w19		/* rpc_target_info */
+	mov	w2, w20		/* flags */
+#endif
 	b	thread_foreign_intr_exit
 .endm
 

core/arch/arm/kernel/thread_spmc_a64.S

@@ -192,7 +192,8 @@ FUNC thread_rpc_spsr , :
 END_FUNC thread_rpc_spsr
 
 /*
- * void thread_foreign_intr_exit(uint32_t thread_index)
+ * void thread_foreign_intr_exit(uint32_t thread_index,
+ *				 uint32_t rpc_target_info, uint32_t flags);
  *
  * This function is jumped to at the end of macro foreign_intr_handler().
  * The current thread as indicated by @thread_index has just been
@@ -209,14 +210,7 @@ END_FUNC thread_rpc_spsr
  * in threads[w0].flags. This is only set for the thread which handles SPs.
  */
 FUNC thread_foreign_intr_exit , :
-	/* load threads[w0].tsd.rpc_target_info into w1 */
-	mov	x1, #THREAD_CTX_SIZE
-	adr_l	x2, threads
-	madd	x2, x1, x0, x2
-	ldr	w1, [x2, #THREAD_CTX_TSD_RPC_TARGET_INFO]
 #ifdef CFG_SECURE_PARTITION
-	/* load threads[w0].flags into w2 */
-	ldr	w2, [x2, #THREAD_CTX_FLAGS]
 	and     w2, w2, #THREAD_FLAGS_FFA_ONLY
 	cbnz	w2, thread_ffa_interrupt
 #endif /* CFG_SECURE_PARTITION */