Add Rust support for RISC-V arch

Signed-off-by: Gary Guo <gary@garyguo.net>
ojeda · Apr 25, 2021 · 87447f4 · 87447f4
1 parent 3e1c596
commit 87447f4
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Showing 9 changed files with 176 additions and 5 deletions.
diff --git a/Makefile b/Makefile
@@ -511,6 +511,7 @@ KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 		   -Werror=return-type -Wno-format-security \
 		   -std=gnu89
 KBUILD_CPPFLAGS := -D__KERNEL__
+KBUILD_RUSTC_TARGET := $(srctree)/arch/$(SRCARCH)/rust/target.json
 KBUILD_RUSTCFLAGS := --emit=dep-info,obj,metadata --edition=2018 \
 		     -Cpanic=abort -Cembed-bitcode=n -Clto=n -Crpath=n \
 		     -Cforce-unwind-tables=n -Ccodegen-units=1 \
@@ -542,7 +543,7 @@ export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 
 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
-export KBUILD_RUSTCFLAGS RUSTCFLAGS_KERNEL RUSTCFLAGS_MODULE
+export KBUILD_RUSTC_TARGET KBUILD_RUSTCFLAGS RUSTCFLAGS_KERNEL RUSTCFLAGS_MODULE
 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTCFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTCFLAGS_KERNEL

diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
@@ -45,6 +45,7 @@ riscv-march-$(CONFIG_FPU)		:= $(riscv-march-y)fd
 riscv-march-$(CONFIG_RISCV_ISA_C)	:= $(riscv-march-y)c
 KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
 KBUILD_AFLAGS += -march=$(riscv-march-y)
+KBUILD_RUSTC_TARGET := $(srctree)/arch/riscv/rust/$(subst fd,,$(riscv-march-y)).json
 
 KBUILD_CFLAGS += -mno-save-restore
 KBUILD_CFLAGS += -DCONFIG_PAGE_OFFSET=$(CONFIG_PAGE_OFFSET)

diff --git a/arch/riscv/rust/rv32ima.json b/arch/riscv/rust/rv32ima.json
@@ -0,0 +1,42 @@
+{
+  "arch": "riscv32",
+  "code-model": "medium",
+  "cpu": "generic-rv32",
+  "data-layout": "e-m:e-p:32:32-i64:64-n32-S128",
+  "disable-redzone": true,
+  "eliminate-frame-pointer": false,
+  "emit-debug-gdb-scripts": false,
+  "env": "gnu",
+  "features": "+m,+a",
+  "function-sections": false,
+  "is-builtin": true,
+  "linker-flavor": "gcc",
+  "linker-is-gnu": true,
+  "llvm-target": "riscv32",
+  "max-atomic-width": 32,
+  "needs-plt": true,
+  "os": "none",
+  "panic-strategy": "abort",
+  "position-independent-executables": true,
+  "pre-link-args": {
+    "gcc": [
+      "-Wl,--as-needed",
+      "-Wl,-z,noexecstack",
+      "-m32"
+    ]
+  },
+  "relocation-model": "static",
+  "relro-level": "full",
+  "stack-probes": {
+    "kind": "inline-or-call",
+    "min-llvm-version-for-inline": [
+      11,
+      0,
+      1
+    ]
+  },
+  "target-c-int-width": "32",
+  "target-endian": "little",
+  "target-pointer-width": "32",
+  "vendor": ""
+}
diff --git a/arch/riscv/rust/rv32imac.json b/arch/riscv/rust/rv32imac.json
@@ -0,0 +1,42 @@
+{
+  "arch": "riscv32",
+  "code-model": "medium",
+  "cpu": "generic-rv32",
+  "data-layout": "e-m:e-p:32:32-i64:64-n32-S128",
+  "disable-redzone": true,
+  "eliminate-frame-pointer": false,
+  "emit-debug-gdb-scripts": false,
+  "env": "gnu",
+  "features": "+m,+a,+c",
+  "function-sections": false,
+  "is-builtin": true,
+  "linker-flavor": "gcc",
+  "linker-is-gnu": true,
+  "llvm-target": "riscv32",
+  "max-atomic-width": 32,
+  "needs-plt": true,
+  "os": "none",
+  "panic-strategy": "abort",
+  "position-independent-executables": true,
+  "pre-link-args": {
+    "gcc": [
+      "-Wl,--as-needed",
+      "-Wl,-z,noexecstack",
+      "-m32"
+    ]
+  },
+  "relocation-model": "static",
+  "relro-level": "full",
+  "stack-probes": {
+    "kind": "inline-or-call",
+    "min-llvm-version-for-inline": [
+      11,
+      0,
+      1
+    ]
+  },
+  "target-c-int-width": "32",
+  "target-endian": "little",
+  "target-pointer-width": "32",
+  "vendor": ""
+}
diff --git a/arch/riscv/rust/rv64ima.json b/arch/riscv/rust/rv64ima.json
@@ -0,0 +1,42 @@
+{
+  "arch": "riscv64",
+  "code-model": "medium",
+  "cpu": "generic-rv64",
+  "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n64-S128",
+  "disable-redzone": true,
+  "eliminate-frame-pointer": false,
+  "emit-debug-gdb-scripts": false,
+  "env": "gnu",
+  "features": "+m,+a",
+  "function-sections": false,
+  "is-builtin": true,
+  "linker-flavor": "gcc",
+  "linker-is-gnu": true,
+  "llvm-target": "riscv64",
+  "max-atomic-width": 64,
+  "needs-plt": true,
+  "os": "none",
+  "panic-strategy": "abort",
+  "position-independent-executables": true,
+  "pre-link-args": {
+    "gcc": [
+      "-Wl,--as-needed",
+      "-Wl,-z,noexecstack",
+      "-m64"
+    ]
+  },
+  "relocation-model": "static",
+  "relro-level": "full",
+  "stack-probes": {
+    "kind": "inline-or-call",
+    "min-llvm-version-for-inline": [
+      11,
+      0,
+      1
+    ]
+  },
+  "target-c-int-width": "32",
+  "target-endian": "little",
+  "target-pointer-width": "64",
+  "vendor": ""
+}
diff --git a/arch/riscv/rust/rv64imac.json b/arch/riscv/rust/rv64imac.json
@@ -0,0 +1,42 @@
+{
+  "arch": "riscv64",
+  "code-model": "medium",
+  "cpu": "generic-rv64",
+  "data-layout": "e-m:e-p:64:64-i64:64-i128:128-n64-S128",
+  "disable-redzone": true,
+  "eliminate-frame-pointer": false,
+  "emit-debug-gdb-scripts": false,
+  "env": "gnu",
+  "features": "+m,+a,+c",
+  "function-sections": false,
+  "is-builtin": true,
+  "linker-flavor": "gcc",
+  "linker-is-gnu": true,
+  "llvm-target": "riscv64",
+  "max-atomic-width": 64,
+  "needs-plt": true,
+  "os": "none",
+  "panic-strategy": "abort",
+  "position-independent-executables": true,
+  "pre-link-args": {
+    "gcc": [
+      "-Wl,--as-needed",
+      "-Wl,-z,noexecstack",
+      "-m64"
+    ]
+  },
+  "relocation-model": "static",
+  "relro-level": "full",
+  "stack-probes": {
+    "kind": "inline-or-call",
+    "min-llvm-version-for-inline": [
+      11,
+      0,
+      1
+    ]
+  },
+  "target-c-int-width": "32",
+  "target-endian": "little",
+  "target-pointer-width": "64",
+  "vendor": ""
+}
diff --git a/init/Kconfig b/init/Kconfig
@@ -58,7 +58,7 @@ config LLD_VERSION
 	default 0
 
 config HAS_RUST
-	depends on ARM64 || CPU_32v6 || CPU_32v6K || (PPC64 && CPU_LITTLE_ENDIAN) || X86_64
+	depends on ARM64 || CPU_32v6 || CPU_32v6K || (PPC64 && CPU_LITTLE_ENDIAN) || X86_64 || RISCV
 	def_bool $(success,$(RUSTC) --version)
 
 config RUSTC_VERSION

diff --git a/rust/kernel/c_types.rs b/rust/kernel/c_types.rs
@@ -9,7 +9,7 @@
 
 #![allow(non_camel_case_types)]
 
-#[cfg(any(target_arch = "arm", target_arch = "x86"))]
+#[cfg(any(target_arch = "arm", target_arch = "x86", target_arch = "riscv32",))]
 mod c {
     /// C `void` type.
     pub type c_void = core::ffi::c_void;
@@ -63,7 +63,8 @@ mod c {
 #[cfg(any(
     target_arch = "aarch64",
     target_arch = "x86_64",
-    target_arch = "powerpc64"
+    target_arch = "powerpc64",
+    target_arch = "riscv64",
 ))]
 mod c {
     /// C `void` type.

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
@@ -291,7 +291,7 @@ $(obj)/%.lst: $(src)/%.c FORCE
 # Compile Rust sources (.rs)
 # ---------------------------------------------------------------------------
 
-rustc_cross_flags := --target=$(srctree)/arch/$(SRCARCH)/rust/target.json
+rustc_cross_flags := --target=$(KBUILD_RUSTC_TARGET)
 
 quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
       cmd_rustc_o_rs = \