From 95faab6f2c0cc232c2b1d3886397c466f0d3b078 Mon Sep 17 00:00:00 2001
From: Luke Wren <wren6991@gmail.com>
Date: Wed, 22 Mar 2023 02:44:03 +0000
Subject: [PATCH] Add zcmp_irq_kill test

---
 test/sim/sw_testcases/zcmp_irq_kill.c | 128 ++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 test/sim/sw_testcases/zcmp_irq_kill.c

diff --git a/test/sim/sw_testcases/zcmp_irq_kill.c b/test/sim/sw_testcases/zcmp_irq_kill.c
new file mode 100644
index 0000000..2ec6909
--- /dev/null
+++ b/test/sim/sw_testcases/zcmp_irq_kill.c
@@ -0,0 +1,128 @@
+#include "tb_cxxrtl_io.h"
+
+// Test intent: check that killing and restarting of push/pop instructions
+// due to IRQs does not cause stack corruption
+
+volatile uint32_t results[13];
+
+void foreground_task() {
+	asm volatile (
+		// First push is an actual save of the registers
+		".hword 0xb8f6\n" // cm.push {ra,s0-s11},-80
+		"sw a0, 0(sp)\n"
+		"sw a1, 4(sp)\n"
+		"li a1, 13 * 100\n"
+		"li x1,  0xa5000000 + 1\n"
+		"li x8,  0xa5000000 + 8\n"
+		"li x9,  0xa5000000 + 9\n"
+		"li x18, 0xa5000000 + 18\n"
+		"li x19, 0xa5000000 + 19\n"
+		"li x20, 0xa5000000 + 20\n"
+		"li x21, 0xa5000000 + 21\n"
+		"li x22, 0xa5000000 + 22\n"
+		"li x23, 0xa5000000 + 23\n"
+		"li x24, 0xa5000000 + 24\n"
+		"li x25, 0xa5000000 + 25\n"
+		"li x26, 0xa5000000 + 26\n"
+		"li x27, 0xa5000000 + 27\n"
+		"1:\n"
+		".hword 0xb8f2\n" // cm.push {ra,s0-s11},-64
+		// Rotate the contents of the stack frame
+		"lw s0,  12(sp)\n"
+		"lw s1,  16(sp)\n"
+		"lw s2,  20(sp)\n"
+		"lw s3,  24(sp)\n"
+		"lw s4,  28(sp)\n"
+		"lw s5,  32(sp)\n"
+		"lw s6,  36(sp)\n"
+		"lw s7,  40(sp)\n"
+		"lw s8,  44(sp)\n"
+		"lw s9,  48(sp)\n"
+		"lw s10, 52(sp)\n"
+		"lw s11, 56(sp)\n"
+		"lw a0,  60(sp)\n"
+
+		"lw a0,  12(sp)\n"
+		"lw s0,  16(sp)\n"
+		"lw s1,  20(sp)\n"
+		"lw s2,  24(sp)\n"
+		"lw s3,  28(sp)\n"
+		"lw s4,  32(sp)\n"
+		"lw s5,  36(sp)\n"
+		"lw s6,  40(sp)\n"
+		"lw s7,  44(sp)\n"
+		"lw s8,  48(sp)\n"
+		"lw s9, 52(sp)\n"
+		"lw s10, 56(sp)\n"
+		"lw s11,  60(sp)\n"
+		// Re-pop. Doing this a multiple of 13 times will restore the original contents.
+		".hword 0xbaf2\n" // cm.pop {ra, s0-s11},64
+		"addi a1, a1, -1\n"
+		"bnez a1, 1b\n"
+		// Write out results
+		"la a1, results\n"
+		"sw x1,  4*0(a1)\n"
+		"sw x8,  4*1(a1)\n"
+		"sw x9,  4*2(a1)\n"
+		"sw x18, 4*3(a1)\n"
+		"sw x19, 4*4(a1)\n"
+		"sw x20, 4*5(a1)\n"
+		"sw x21, 4*6(a1)\n"
+		"sw x22, 4*7(a1)\n"
+		"sw x23, 4*8(a1)\n"
+		"sw x24, 4*9(a1)\n"
+		"sw x25, 4*10(a1)\n"
+		"sw x26, 4*11(a1)\n"
+		"sw x27, 4*12(a1)\n"
+		// Restore original register values
+		"lw a0, 0(sp)\n"
+		"lw a1, 4(sp)\n"
+		".hword 0xbaf6\n" // cm.pop {ra,s0-s11},80
+	);
+}
+
+// Note not using attribute interrupt due to stack corruption bug in current
+// CORE-V toolchain
+void __attribute__((naked)) isr_machine_timer() {
+	asm volatile (
+		".hword 0xb852\n"  // cm.push {ra,s0},-16
+		"li ra, %0\n"
+		"lw s0, (ra)\n"
+		"addi s0, s0, 421\n"   // Prime number
+		"sw s0, (ra)\n"
+		".hword 0xba52\n"  // cm.pop {ra,s0},16
+		"mret\n"
+		: : "i" ((uintptr_t)&mm_timer->mtimecmp)
+	);
+}
+
+int main() {
+	asm volatile ("csrw mie, %0" : : "r" (0x80));
+	mm_timer->mtime = 0;
+	// Will take first timer interrupt immediately:
+	asm volatile ("csrsi mstatus, 0x8");
+
+	foreground_task();
+	for (int i = 0; i < 13; ++i) {
+		tb_put_u32(results[i]);
+	}
+	return 0;
+}
+
+/*EXPECTED-OUTPUT***************************************************************
+
+a5000001
+a5000008
+a5000009
+a5000012
+a5000013
+a5000014
+a5000015
+a5000016
+a5000017
+a5000018
+a5000019
+a500001a
+a500001b
+
+*******************************************************************************/