Support for native riscv64 coroutines.

ruby · Mar 30, 2021 · b507f65 · b507f65
1 parent 3d32c21
commit b507f65
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diff --git a/configure.ac b/configure.ac
@@ -2488,6 2488,9 @@ AS_CASE([$coroutine_type], [yes|''], [
  [powerpc64le-linux*], [
  coroutine_type=ppc64le
  ],
  [riscv64-linux*], [
  rb_cv_coroutine=riscv64
  ],
  [x86_64-openbsd*], [
  coroutine_type=amd64
  ],

diff --git a/coroutine/riscv64/Context.S b/coroutine/riscv64/Context.S
@@ -0,0 1,87 @@
 #define TOKEN_PASTE(x,y) x##y
 #define PREFIXED_SYMBOL(prefix,name) TOKEN_PASTE(prefix,name)
 
 .text
 .align 2
 
 .global PREFIXED_SYMBOL(SYMBOL_PREFIX,coroutine_transfer)
 PREFIXED_SYMBOL(SYMBOL_PREFIX,coroutine_transfer):
 
  # Make space on the stack for caller registers
  addi sp, sp, -0xd0
 
  # Save caller registers
  sd s0, 0x00(sp)
  sd s1, 0x08(sp)
  sd s2, 0x10(sp)
  sd s3, 0x18(sp)
  sd s4, 0x20(sp)
  sd s5, 0x28(sp)
  sd s6, 0x30(sp)
  sd s7, 0x38(sp)
  sd s8, 0x40(sp)
  sd s9, 0x48(sp)
  sd s10, 0x50(sp)
  sd s11, 0x58(sp)
  fsd fs0, 0x60(sp)
  fsd fs1, 0x68(sp)
  fsd fs2, 0x70(sp)
  fsd fs3, 0x78(sp)
  fsd fs4, 0x80(sp)
  fsd fs5, 0x88(sp)
  fsd fs6, 0x90(sp)
  fsd fs7, 0x98(sp)
  fsd fs8, 0xa0(sp)
  fsd fs9, 0xa8(sp)
  fsd fs10, 0xb0(sp)
  fsd fs11, 0xb8(sp)
 
  # Save return address
  sd ra, 0xc0(sp)
 
  # Save stack pointer to a0 (first argument)
  mv a2, sp
  sd a2, (a0)
 
  # Load stack pointer from a1 (second argument)
  ld a3, (a1)
  mv sp, a3
 
  # Restore caller registers
  ld s0, 0x00(sp)
  ld s1, 0x08(sp)
  ld s2, 0x10(sp)
  ld s3, 0x18(sp)
  ld s4, 0x20(sp)
  ld s5, 0x28(sp)
  ld s6, 0x30(sp)
  ld s7, 0x38(sp)
  ld s8, 0x40(sp)
  ld s9, 0x48(sp)
  ld s10, 0x50(sp)
  ld s11, 0x58(sp)
  fld fs0, 0x60(sp)
  fld fs1, 0x68(sp)
  fld fs2, 0x70(sp)
  fld fs3, 0x78(sp)
  fld fs4, 0x80(sp)
  fld fs5, 0x88(sp)
  fld fs6, 0x90(sp)
  fld fs7, 0x98(sp)
  fld fs8, 0xa0(sp)
  fld fs9, 0xa8(sp)
  fld fs10, 0xb0(sp)
  fld fs11, 0xb8(sp)
 
  # Load return address
  ld ra, 0xc0(sp)
 
  # Pop stack frame
  addi sp, sp, 0xd0
 
  # Jump to return address
  ret
 
 #if defined(__linux__) && defined(__ELF__)
 .section .note.GNU-stack,"",%progbits
 #endif
diff --git a/coroutine/riscv64/Context.h b/coroutine/riscv64/Context.h
@@ -0,0 1,45 @@
 #pragma once
 
 #include <assert.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
 
 #define COROUTINE __attribute__((noreturn)) void
 
 enum {COROUTINE_REGISTERS = 0xd0 / 8};
 
 struct coroutine_context
 {
  void **stack_pointer;
 };
 
 typedef COROUTINE(* coroutine_start)(struct coroutine_context *from, struct coroutine_context *self);
 
 static inline void coroutine_initialize_main(struct coroutine_context * context) {
  context->stack_pointer = NULL;
 }
 
 static inline void coroutine_initialize(
  struct coroutine_context *context,
  coroutine_start start,
  void *stack,
  size_t size
 ) {
  assert(start && stack && size >= 1024);
 
  // Stack grows down. Force 16-byte alignment.
  char * top = (char*)stack   size;
  context->stack_pointer = (void**)((uintptr_t)top & ~0xF);
 
  context->stack_pointer -= COROUTINE_REGISTERS;
  memset(context->stack_pointer, 0, sizeof(void*) * COROUTINE_REGISTERS);
 
  context->stack_pointer[0xc0 / 8] = (void*)start;
 }
 
 struct coroutine_context * coroutine_transfer(struct coroutine_context * current, struct coroutine_context * target);
 
 static inline void coroutine_destroy(struct coroutine_context * context)
 {
 }