core: riscv: Update thread core local flags for native interrupts

Record the type of stack and the type of interrupt into thread core
local flags before handling the native interrupts. Once we finish the
handling of the native interrupts, we clear the previous flags.

Signed-off-by: Alvin Chang <alvinga@andestech.com>
Reviewed-by: Yu Chien Peter Lin <peterlin@andestech.com>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

core/arch/riscv/kernel/thread_rv.S

@@ -125,13 +125,24 @@ foreign_interrupt_from_kernel:
 	tail	thread_foreign_interrupt_handler
 
 native_interrupt_from_kernel:
+	/* Update 32-bit core local flags */
+	lw	a2, THREAD_CORE_LOCAL_FLAGS(tp)
+	slli	a2, a2, THREAD_CLF_SAVED_SHIFT
+	ori	a2, a2, (THREAD_CLF_TMP | THREAD_CLF_IRQ)
+	sw	a2, THREAD_CORE_LOCAL_FLAGS(tp)
+
 	/*
 	 * a0 = struct thread_ctx_regs *regs
 	 * a1 = cause
 	 * Call thread_native_interrupt_handler(regs, cause)
 	 */
 	call	thread_native_interrupt_handler
 
+	/* Update 32-bit core local flags */
+	lw	a2, THREAD_CORE_LOCAL_FLAGS(tp)
+	srli	a2, a2, THREAD_CLF_SAVED_SHIFT
+	sw	a2, THREAD_CORE_LOCAL_FLAGS(tp)
+
 	/* Get thread context as sp */
 	get_thread_ctx sp, t0
 	/* Restore XEPC */
@@ -351,13 +362,24 @@ foreign_interrupt_from_user:
 	tail	thread_foreign_interrupt_handler
 
 native_interrupt_from_user:
+	/* Update 32-bit core local flags */
+	lw	a2, THREAD_CORE_LOCAL_FLAGS(tp)
+	slli	a2, a2, THREAD_CLF_SAVED_SHIFT
+	ori	a2, a2, (THREAD_CLF_TMP | THREAD_CLF_IRQ)
+	sw	a2, THREAD_CORE_LOCAL_FLAGS(tp)
+
 	/*
 	 * a0 = struct thread_ctx_regs *regs
 	 * a1 = cause
 	 * Call thread_native_interrupt_handler(regs, cause)
 	 */
 	call	thread_native_interrupt_handler
 
+	/* Update 32-bit core local flags */
+	lw	a2, THREAD_CORE_LOCAL_FLAGS(tp)
+	srli	a2, a2, THREAD_CLF_SAVED_SHIFT
+	sw	a2, THREAD_CORE_LOCAL_FLAGS(tp)
+
 	/* Get thread context as sp */
 	get_thread_ctx sp, t0
 	/* Restore XEPC */