Preliminary support for RV64G

This adds basic support for RISC-V, specifically RV64G.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Romain Dolbeau <romain.dolbeau@european-processor-initiative.eu>
Closes #9540

module/lua/ldo.c

@@ -63,6 +63,8 @@
 #define JMP_BUF_CNT	12
 #elif defined(__s390x__)
 #define JMP_BUF_CNT	18
+#elif defined(__riscv)
+#define JMP_BUF_CNT     64
 #else
 #define	JMP_BUF_CNT	1
 #endif

module/lua/setjmp/setjmp.S

@@ -14,4 +14,6 @@
 #include "setjmp_mips.S"
 #elif defined(__s390x__)
 #include "setjmp_s390x.S"
+#elif defined(__riscv)
+#include "setjmp_rv64g.S"
 #endif

module/lua/setjmp/setjmp_rv64g.S

@@ -0,0 +1,91 @@
+/*-
+ * Copyright (c) 2015-2016 Ruslan Bukin <br@bsdpad.com>
+ * All rights reserved.
+ *
+ * Portions of this software were developed by SRI International and the
+ * University of Cambridge Computer Laboratory under DARPA/AFRL contract
+ * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
+ *
+ * Portions of this software were developed by the University of Cambridge
+ * Computer Laboratory as part of the CTSRD Project, with support from the
+ * UK Higher Education Innovation Fund (HEIF).
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#define ENTRY(sym)                                              \
+        .text; .globl sym; .type sym,@function; sym:
+#define END(sym) .size sym, . - sym
+
+
+ENTRY(setjmp)
+	/* Store the stack pointer */
+	sd	sp, (0 * 8)(a0)
+	addi	a0, a0, (1 * 8)
+
+	/* Store the general purpose registers and ra */
+	sd	s0, (0 * 8)(a0)
+	sd	s1, (1 * 8)(a0)
+	sd	s2, (2 * 8)(a0)
+	sd	s3, (3 * 8)(a0)
+	sd	s4, (4 * 8)(a0)
+	sd	s5, (5 * 8)(a0)
+	sd	s6, (6 * 8)(a0)
+	sd	s7, (7 * 8)(a0)
+	sd	s8, (8 * 8)(a0)
+	sd	s9, (9 * 8)(a0)
+	sd	s10, (10 * 8)(a0)
+	sd	s11, (11 * 8)(a0)
+	sd	ra, (12 * 8)(a0)
+	addi	a0, a0, (13 * 8)
+
+	/* Return value */
+	li	a0, 0
+	ret
+END(setjmp)
+
+ENTRY(longjmp)
+	/* Restore the stack pointer */
+	ld	t0, 0(a0)
+	mv	sp, t0
+	addi	a0, a0, (1 * 8)
+
+	/* Restore the general purpose registers and ra */
+	ld	s0, (0 * 8)(a0)
+	ld	s1, (1 * 8)(a0)
+	ld	s2, (2 * 8)(a0)
+	ld	s3, (3 * 8)(a0)
+	ld	s4, (4 * 8)(a0)
+	ld	s5, (5 * 8)(a0)
+	ld	s6, (6 * 8)(a0)
+	ld	s7, (7 * 8)(a0)
+	ld	s8, (8 * 8)(a0)
+	ld	s9, (9 * 8)(a0)
+	ld	s10, (10 * 8)(a0)
+	ld	s11, (11 * 8)(a0)
+	ld	ra, (12 * 8)(a0)
+	addi	a0, a0, (13 * 8)
+
+	/* Load the return value */
+	mv	a0, a1
+	ret
+END(longjmp)