ARC: add TLS support for ARCv3

For ARCv3 the register is fixed to r30, so we don't need to
configure it at compile-time.

Signed-off-by: Eugeniy Paltsev <[email protected]>
Signed-off-by: Evgeniy Paltsev <[email protected]>

Author: evgeniy-paltsev

arch/arc/CMakeLists.txt

@@ -12,8 +12,11 @@ zephyr_cc_option(-fno-delete-null-pointer-checks)
 
 zephyr_cc_option_ifdef(CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS -munaligned-access)
 
-# Instruct compiler to use register R26 as thread pointer
-# for thread local storage.
-zephyr_cc_option_ifdef(CONFIG_THREAD_LOCAL_STORAGE -mtp-regno=26)
+if(CONFIG_ISA_ARCV2)
+  # Instruct compiler to use register R26 as thread pointer
+  # for thread local storage.
+  # For ARCv3 the register is fixed to r30, so we don't need to specify it
+  zephyr_cc_option_ifdef(CONFIG_THREAD_LOCAL_STORAGE -mtp-regno=26)
+endif()
 
 add_subdirectory(core)

arch/arc/core/thread.c

@@ -122,8 +122,13 @@ static inline void arch_setup_callee_saved_regs(struct k_thread *thread,
 	ARG_UNUSED(regs);
 
 #ifdef CONFIG_THREAD_LOCAL_STORAGE
-	/* R26 is used for thread pointer */
+#ifdef CONFIG_ISA_ARCV2
+	/* R26 is used for thread pointer for ARCv2 */
 	regs->r26 = thread->tls;
+#else
+	/* R30 is used for thread pointer for ARCv3 */
+	regs->r30 = thread->tls;
+#endif /* CONFIG_ISA_ARCV2 */
 #endif
 }