ARC: prepare for building for ARCv3 HS6x

Do basic preparations for building code for ARCv3 HS6x
* add ISA_ARCV3 and CPU_HS6X config options
* add off_t type support for __ARC64__
* use elf64-littlearc format for linking
* use arc64 mcpu for CPU_HS6X

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Evgeniy Paltsev <PaltsevEvgeniy@gmail.com>

arch/arc/Kconfig

@@ -39,6 +39,11 @@ config ISA_ARCV2
 	help
 	  v2 ISA for the ARC-HS & ARC-EM cores
 
+config ISA_ARCV3
+	bool "ARC ISA v3"
+	select USE_SWITCH
+	select USE_SWITCH_SUPPORTED
+
 endchoice
 
 if ISA_ARCV2
@@ -83,6 +88,17 @@ config CPU_HS3X
 
 endif #ISA_ARCV2
 
+if ISA_ARCV3
+
+config CPU_HS6X
+	bool
+	select CPU_ARCHS
+	select 64BIT
+	help
+	  If y, the SoC uses an ARC HS6x CPU
+
+endif #ISA_ARCV3
+
 config FP_FPU_DA
 	bool
 
@@ -123,6 +139,7 @@ config RGF_NUM_BANKS
 
 config ARC_FIRQ
 	bool "FIRQ enable"
+	depends on ISA_ARCV2
 	default y
 	help
 	  Fast interrupts are supported (FIRQ). If FIRQ enabled, for interrupts
@@ -147,6 +164,7 @@ config ARC_FIRQ_STACK_SIZE
 
 config ARC_HAS_STACK_CHECKING
 	bool "ARC has STACK_CHECKING"
+	depends on ISA_ARCV2
 	default y
 	help
 	  ARC is configured with STACK_CHECKING which is a mechanism for
@@ -233,6 +251,7 @@ config ARC_HAS_ACCL_REGS
 
 config ARC_HAS_SECURE
 	bool "ARC has SecureShield"
+	depends on ISA_ARCV2
 	select CPU_HAS_TEE
 	select ARCH_HAS_TRUSTED_EXECUTION
 	help

cmake/gcc-m-cpu.cmake

@@ -56,6 +56,8 @@ elseif("${ARCH}" STREQUAL "arc")
     set(GCC_M_CPU em4_fpuda)
   elseif(CONFIG_CPU_HS3X)
     set(GCC_M_CPU hs)
+  elseif(CONFIG_CPU_HS6X)
+    set(GCC_M_CPU arc64)
   elseif(CONFIG_CPU_EM4)
     set(GCC_M_CPU arcem)
   elseif(CONFIG_CPU_EM6)

include/linker/linker-tool-gcc.h

@@ -27,7 +27,11 @@
 #elif defined(CONFIG_ARM64)
 	OUTPUT_FORMAT("elf64-littleaarch64")
 #elif defined(CONFIG_ARC)
-	OUTPUT_FORMAT("elf32-littlearc", "elf32-bigarc", "elf32-littlearc")
+	#if defined(CONFIG_64BIT)
+		OUTPUT_FORMAT("elf64-littlearc")
+	#else
+		OUTPUT_FORMAT("elf32-littlearc", "elf32-bigarc", "elf32-littlearc")
+	#endif
 #elif defined(CONFIG_X86)
 	#if defined(CONFIG_X86_64)
 		OUTPUT_FORMAT("elf64-x86-64")

lib/libc/minimal/include/sys/types.h

@@ -25,7 +25,7 @@ typedef __SIZE_TYPE__ ssize_t;
 #if !defined(__off_t_defined)
 #define __off_t_defined
 
-#if defined(__i386) || defined(__x86_64)
+#if defined(__i386) || defined(__x86_64) || defined(__ARC64__)
 typedef long int off_t; /* "long" works for all of i386, X32 and true 64 bit */
 #elif defined(__ARM_ARCH)
 typedef int off_t;