core: riscv: Implement thread_vector_table for ABI and FIQ entries

Implement thread_vector_table which only includes entries for standard
ABI, fast ABI, and foreign interrupts. Most of code is referenced from
ARM architecture. The thread_vector_table will be registered into higher
privileged software, such as M-mode firmware. The higher privileged
software can jump(mret) to OP-TEE based on this vector table.

Signed-off-by: Alvin Chang <alvinga@andestech.com>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

core/arch/riscv/kernel/asm-defines.c

@@ -86,4 +86,8 @@ DEFINES
 	DEFINE(CORE_MMU_CONFIG_SIZE, sizeof(struct core_mmu_config));
 	DEFINE(CORE_MMU_CONFIG_SATP,
 	       offsetof(struct core_mmu_config, satp));
+
+	/* struct thread_abi_args */
+	DEFINE(THREAD_ABI_ARGS_A0, offsetof(struct thread_abi_args, a0));
+	DEFINE(THREAD_ABI_ARGS_SIZE, sizeof(struct thread_abi_args));
 }

core/arch/riscv/kernel/thread_optee_abi_rv.S

@@ -149,3 +149,67 @@ FUNC thread_rpc , :
 	addi	sp, sp, REGOFF(4)
 	ret
 END_FUNC thread_rpc
+
+LOCAL_FUNC vector_std_abi_entry, : , .identity_map
+	jal	thread_handle_std_abi
+	/*
+	 * Normally thread_handle_std_abi() should return via
+	 * thread_exit(), thread_rpc(), but if thread_handle_std_abi()
+	 * hasn't switched stack (error detected) it will do a normal "C"
+	 * return.
+	 */
+	/* Restore thread_handle_std_abi() return value */
+	mv	a1, a0
+	li	a2, 0
+	li	a3, 0
+	li	a4, 0
+	li	a0, TEEABI_OPTEED_RETURN_CALL_DONE
+
+	/* Return to untrusted domain */
+	j	thread_return_to_ree
+END_FUNC vector_std_abi_entry
+
+LOCAL_FUNC vector_fast_abi_entry , : , .identity_map
+	addi    sp, sp, -THREAD_ABI_ARGS_SIZE
+	store_xregs sp, THREAD_ABI_ARGS_A0, REG_A0, REG_A7
+	mv      a0, sp
+	jal	thread_handle_fast_abi
+	load_xregs sp, THREAD_ABI_ARGS_A0, REG_A1, REG_A7
+	addi    sp, sp, THREAD_ABI_ARGS_SIZE
+
+	li	a0, TEEABI_OPTEED_RETURN_CALL_DONE
+	/* Return to untrusted domain */
+	j	thread_return_to_ree
+END_FUNC vector_fast_abi_entry
+
+LOCAL_FUNC vector_fiq_entry , : , .identity_map
+	/* Secure Monitor received a FIQ and passed control to us. */
+	jal	interrupt_main_handler
+
+	li	a0, TEEABI_OPTEED_RETURN_FIQ_DONE
+	/* Return to untrusted domain */
+	j	thread_return_to_ree
+END_FUNC vector_fiq_entry
+
+/*
+ * Vector table supplied to M-mode secure monitor (e.g., openSBI) at
+ * initialization.
+ *
+ * Note that M-mode secure monitor depends on the layout of this vector table,
+ * any change in layout has to be synced with M-mode secure monitor.
+ */
+FUNC thread_vector_table , : , .identity_map, , nobti
+	.option push
+	.option norvc
+	j   vector_std_abi_entry
+	j   vector_fast_abi_entry
+	j   .
+	j   .
+	j   .
+	j   .
+	j   vector_fiq_entry
+	j   .
+	j   .
+	.option pop
+END_FUNC thread_vector_table
+DECLARE_KEEP_PAGER thread_vector_table