Unverified Commit 5c93c4c7 authored by Andy Chiu's avatar Andy Chiu Committed by Palmer Dabbelt
Browse files

selftests: Test RISC-V Vector's first-use handler 



This add a test to check if the kernel zero-initializes all V registers
after the first-use trap handler returns.

If V registers are not zero-initialized, then the test should fail one
out of several runs:

```
 root@sifive-fpga:~# ./v_initval_nolibc
 # vl = 256
 not ok 1 detect stale values on v-regesters
 0 0 0 0 0 0 0 0   0 0 0 0 0 0 0 0
 0 4c 41 4e 47 3d 43 0   50 41 54 48 3d 2f 75 73
 72 2f 6c 6f 63 61 6c 2f   73 62 69 6e 3a 2f 75 73
 72 2f 6c 6f 63 61 6c 2f   62 69 6e 3a 2f 75 73 72
 ff ff 81 0 0 0 0 0   0 0 0 0 0 0 0 0
```

Otherwise, the test passes without errors each run.

Signed-off-by: default avatarAndy Chiu <andy.chiu@sifive.com>
Reviewed-by: default avatarBjörn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230627015556.12329-3-andy.chiu@sifive.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 75b59f2a

tools/testing/selftests/riscv/vector/.gitignore

+1 −0
Original line number Diff line number Diff line 
vstate_exec_nolibc

vstate_prctl

v_initval_nolibc

tools/testing/selftests/riscv/vector/Makefile

+5 −1
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
# Copyright (C) 2021 ARM Limited

# Originally tools/testing/arm64/abi/Makefile



TEST_GEN_PROGS := vstate_prctl

TEST_GEN_PROGS := vstate_prctl v_initval_nolibc

TEST_GEN_PROGS_EXTENDED := vstate_exec_nolibc



include ../../lib.mk
@@ -13,3 +13,7 @@ $(OUTPUT)/vstate_prctl: vstate_prctl.c ../hwprobe/sys_hwprobe.S 
$(OUTPUT)/vstate_exec_nolibc: vstate_exec_nolibc.c

	$(CC) -nostdlib -static -include ../../../../include/nolibc/nolibc.h \

		-Wall $(CFLAGS) $(LDFLAGS) $^ -o $@ -lgcc



$(OUTPUT)/v_initval_nolibc: v_initval_nolibc.c

	$(CC) -nostdlib -static -include ../../../../include/nolibc/nolibc.h \

		-Wall $(CFLAGS) $(LDFLAGS) $^ -o $@ -lgcc

tools/testing/selftests/riscv/vector/v_initval_nolibc.c

0 → 100644
+68 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only



#include "../../kselftest.h"

#define MAX_VSIZE	(8192 * 32)



void dump(char *ptr, int size)

{

	int i = 0;



	for (i = 0; i < size; i++) {

		if (i != 0) {

			if (i % 16 == 0)

				printf("\n");

			else if (i % 8 == 0)

				printf("  ");

		}

		printf("%02x ", ptr[i]);

	}

	printf("\n");

}



int main(void)

{

	int i;

	unsigned long vl;

	char *datap, *tmp;



	datap = malloc(MAX_VSIZE);

	if (!datap) {

		ksft_test_result_fail("fail to allocate memory for size = %lu\n", MAX_VSIZE);

		exit(-1);

	}



	tmp = datap;

	asm volatile (

		".option push\n\t"

		".option arch, +v\n\t"

		"vsetvli	%0, x0, e8, m8, ta, ma\n\t"

		"vse8.v		v0, (%2)\n\t"

		"add		%1, %2, %0\n\t"

		"vse8.v		v8, (%1)\n\t"

		"add		%1, %1, %0\n\t"

		"vse8.v		v16, (%1)\n\t"

		"add		%1, %1, %0\n\t"

		"vse8.v		v24, (%1)\n\t"

		".option pop\n\t"

		: "=&r" (vl), "=r" (tmp) : "r" (datap) : "memory");



	ksft_print_msg("vl = %lu\n", vl);



	if (datap[0] != 0x00 && datap[0] != 0xff) {

		ksft_test_result_fail("v-regesters are not properly initialized\n");

		dump(datap, vl * 4);

		exit(-1);

	}



	for (i = 1; i < vl * 4; i++) {

		if (datap[i] != datap[0]) {

			ksft_test_result_fail("detect stale values on v-regesters\n");

			dump(datap, vl * 4);

			exit(-2);

		}

	}



	free(datap);

	ksft_exit_pass();

	return 0;

}