From 6eb0f84e37d84caeb9db773976df5ab3a7e794d0 Mon Sep 17 00:00:00 2001
From: Damjan Marion <damarion@cisco.com>
Date: Sun, 31 Oct 2021 19:04:33 +0100
Subject: [PATCH] vppinfra: initial RISC-V support

Type: feature
Change-Id: I1314d60fc420366526efaddd1ed215cf5f8b75dd
Signed-off-by: Damjan Marion <damarion@cisco.com>
---
 src/vppinfra/longjmp.S | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/vppinfra/longjmp.h |  3 +++
 src/vppinfra/time.h    |  9 +++++++++
 src/vppinfra/types.h   |  4 +++-
 4 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/src/vppinfra/longjmp.S b/src/vppinfra/longjmp.S
index a3435ccb969..c5090877fd7 100644
--- a/src/vppinfra/longjmp.S
+++ b/src/vppinfra/longjmp.S
@@ -816,6 +816,56 @@ cdecl(clib_calljmp):
         mov     sp, x3
 	ret
 	.size	cdecl(clib_calljmp), .-cdecl(clib_calljmp)
+#elif defined(__riscv)
+#define foreach_0_to_11 _(0) _(1) _(2) _(3) _(4) _(5) _(6) _(7) _(8) _(9) _(10) _(11)
+	.global cdecl(clib_setjmp)
+	.align 1
+	.type cdecl(clib_setjmp), @function
+cdecl(clib_setjmp):
+	sd      ra, 0*8(a0)
+	sd      sp, 1*8(a0)
+#define _(x)  sd	s##x, (x + 2)*8(a0);
+	foreach_0_to_11
+#undef _
+#define _(x)  fsd	fs##x, (x + 14)*8(a0);
+	foreach_0_to_11
+#undef _
+	mv      a0,a1
+	ret
+	.size   cdecl(clib_setjmp), .-cdecl(clib_setjmp)
+
+	.global cdecl(clib_longjmp)
+	.align 1
+	.type cdecl(clib_longjmp), @function
+cdecl(clib_longjmp):
+	ld      ra, 0*8(a0)
+	ld      sp, 1*8(a0)
+#define _(x)  ld	s##x, (x + 2)*8(a0);
+	foreach_0_to_11
+#undef _
+#define _(x)  fld	fs##x, (x + 14)*8(a0);
+	foreach_0_to_11
+#undef _
+	mv      a0,a1
+	ret
+	.size   cdecl(clib_longjmp), .-cdecl(clib_longjmp)
+
+	.global cdecl(clib_calljmp)
+	.align 1
+	.type cdecl(clib_calljmp), @function
+cdecl(clib_calljmp):
+	andi	a2,a2, -16	/* Make sure stack is 16-byte aligned. */
+	addi	a2, a2, -16	/* allocate space on the new stack */
+	sd	ra, 8(a2)	/* store return address */
+	sd	sp, 0(a2)	/* store existing stack pointer */
+	mv	sp, a2		/* change stack */
+	mv	a2, a0		/* functon pointer to a2 */
+	mv	a0, a1		/* 2nd argument becomes 1st one  */
+	jalr	a2		/* function call */
+	ld	ra, 8(sp)	/* restore old return address */
+	ld	sp, 0(sp)	/* restore old stack pointer */
+	ret
+	.size   cdecl(clib_calljmp), .-cdecl(clib_calljmp)
 #else
 #error "unknown machine"
 #endif
diff --git a/src/vppinfra/longjmp.h b/src/vppinfra/longjmp.h
index 67c650a6174..62daaad59bd 100644
--- a/src/vppinfra/longjmp.h
+++ b/src/vppinfra/longjmp.h
@@ -95,6 +95,9 @@
 #define CLIB_ARCH_LONGJMP_REGS (22)
 #elif defined(_mips) && __mips == 64
 #define CLIB_ARCH_LONGJMP_REGS (12)
+#elif defined(__riscv)
+/* ra, sp, s0-s11, fs0-fs11 */
+#define CLIB_ARCH_LONGJMP_REGS (26)
 #else
 #error "unknown machine"
 #endif
diff --git a/src/vppinfra/time.h b/src/vppinfra/time.h
index 4d8997f0a9e..761dbed3fe8 100644
--- a/src/vppinfra/time.h
+++ b/src/vppinfra/time.h
@@ -192,6 +192,15 @@ clib_cpu_time_now (void)
   return result;
 }
 
+#elif defined(__riscv)
+
+always_inline u64
+clib_cpu_time_now (void)
+{
+  u64 result;
+  asm volatile("rdcycle %0\n" : "=r"(result));
+  return result;
+}
 #else
 #error "don't know how to read CPU time stamp"
 
diff --git a/src/vppinfra/types.h b/src/vppinfra/types.h
index b52d6034ae9..598061bb3e8 100644
--- a/src/vppinfra/types.h
+++ b/src/vppinfra/types.h
@@ -73,7 +73,9 @@ typedef unsigned int u32;
 typedef unsigned long long u64;
 #endif /* CLIB_AVOID_CLASH_WITH_LINUX_TYPES */
 
-#elif defined(alpha) || (defined(_mips) && __mips == 64) || defined(__x86_64__) || defined (__powerpc64__) || defined (__aarch64__)
+#elif defined(alpha) || (defined(_mips) && __mips == 64) ||                   \
+  defined(__x86_64__) || defined(__powerpc64__) || defined(__aarch64__) ||    \
+  (defined(__riscv) && __riscv_xlen == 64)
 typedef signed int i32;
 typedef signed long i64;
 
-- 
2.16.6