[PATCH 16/20] RISC-V: add 64-bit support

[Ahmad Fatoum]

From: Rouven Czerwinski <r.czerwinski at pengutronix.de>

As our assembly routines are now written to work correctly on 32-bit as
well as 64-bit, nothing is holding us back from adding 64-bit support.

Signed-off-by: Rouven Czerwinski <r.czerwinksi at pengutronix.de>
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 arch/riscv/Kconfig             | 25 ++++++++++++++++++-------
 arch/riscv/Makefile            |  7 +++++--
 arch/riscv/include/asm/elf.h   |  1 -
 arch/riscv/include/asm/types.h |  8 +-------
 arch/riscv/lib/barebox.lds.S   |  5 +++++
 arch/riscv/lib/pbl.lds.S       |  5 +++++
 6 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 91e8546f9624..29ac95aa0f4d 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -25,6 +25,7 @@ choice
 
 config MACH_ERIZO
 	bool "erizo family"
+	select ARCH_RV32I
 	select HAS_DEBUG_LL
 	select HAS_NMON
 	select USE_COMPRESSED_DTB
@@ -42,23 +43,33 @@ config ARCH_RV32I
 	select GENERIC_LIB_ASHRDI3
 	select GENERIC_LIB_LSHRDI3
 	select HAS_ARCH_SJLJ
+	select 32BIT
+
+config ARCH_RV64I
+	bool "RV64I"
+	select CPU_SUPPORTS_64BIT_KERNEL
+	select 64BIT
 
 endchoice
 
 config CPU_SUPPORTS_32BIT_KERNEL
 	bool
 
-choice
-	prompt "barebox code model"
-	default 32BIT
+config CPU_SUPPORTS_64BIT_KERNEL
+	bool
+
+config PHYS_ADDR_T_64BIT
+	bool
 
 config 32BIT
-	bool "32-bit barebox"
+	bool
 	depends on CPU_SUPPORTS_32BIT_KERNEL
-	help
-	  Select this option to build a 32-bit barebox.
 
-endchoice
+config 64BIT
+	bool
+	depends on CPU_SUPPORTS_64BIT_KERNEL
+	select ARCH_DMA_ADDR_T_64BIT
+	select PHYS_ADDR_T_64BIT
 
 source "arch/riscv/mach-erizo/Kconfig"
 
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index f59e8b39a572..f60239fd253b 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -3,8 +3,11 @@ KBUILD_DEFCONFIG := erizo_generic_defconfig
 KBUILD_CPPFLAGS += -fno-strict-aliasing
 
 ifeq ($(CONFIG_ARCH_RV32I),y)
-	riscv-cflags-y := -march=rv32im -mabi=ilp32
-	riscv-ldflags-y := -melf32lriscv
+	riscv-cflags-y += -march=rv32im -mabi=ilp32
+	riscv-ldflags-y += -melf32lriscv
+else
+	riscv-cflags-y += -march=rv64imafd  -mabi=lp64
+	riscv-ldflags-y += -melf64lriscv
 endif
 
 riscv-cflags-y += -Wstrict-prototypes -mcmodel=medany -fpic
diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index adb8ec8f6ece..0cd27724da60 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -4,7 +4,6 @@
 
 #if __SIZEOF_POINTER__ == 8
 #define ELF_CLASS	ELFCLASS64
-#define CONFIG_PHYS_ADDR_T_64BIT
 #else
 #define ELF_CLASS	ELFCLASS32
 #endif
diff --git a/arch/riscv/include/asm/types.h b/arch/riscv/include/asm/types.h
index af37d7738c65..1ad5904f9178 100644
--- a/arch/riscv/include/asm/types.h
+++ b/arch/riscv/include/asm/types.h
@@ -3,18 +3,12 @@
 
 #include <asm-generic/int-ll64.h>
 
-#ifdef __riscv64
+#if __riscv_xlen == 64
 /*
  * This is used in dlmalloc. On RISCV64 we need it to be 64 bit
  */
 #define INTERNAL_SIZE_T unsigned long
 
-/*
- * This is a Kconfig variable in the Kernel, but we want to detect
- * this during compile time, so we set it here.
- */
-#define CONFIG_PHYS_ADDR_T_64BIT
-
 #endif
 
 #endif /* __ASM_RISCV_TYPES_H */
diff --git a/arch/riscv/lib/barebox.lds.S b/arch/riscv/lib/barebox.lds.S
index 562ad5dc6662..7856b57a5220 100644
--- a/arch/riscv/lib/barebox.lds.S
+++ b/arch/riscv/lib/barebox.lds.S
@@ -15,6 +15,11 @@
 
 OUTPUT_ARCH(riscv)
 ENTRY(start)
+#ifdef CONFIG_64BIT
+OUTPUT_FORMAT("elf64-littleriscv")
+#else
+OUTPUT_FORMAT("elf32-littleriscv")
+#endif
 SECTIONS
 {
 	. = 0x0;
diff --git a/arch/riscv/lib/pbl.lds.S b/arch/riscv/lib/pbl.lds.S
index 33caab7b1024..f1dd9aeabacc 100644
--- a/arch/riscv/lib/pbl.lds.S
+++ b/arch/riscv/lib/pbl.lds.S
@@ -6,6 +6,11 @@
 #include <asm-generic/memory_layout.h>
 
 OUTPUT_ARCH(riscv)
+#ifdef CONFIG_64BIT
+OUTPUT_FORMAT("elf64-littleriscv")
+#else
+OUTPUT_FORMAT("elf32-littleriscv")
+#endif
 SECTIONS
 {
 	. = 0x0;
-- 
2.29.2