[PATCH 3/7] Subject: [PATCH] selftests/powerpc: Add RTAS /proc interface test
COLD16d
From: Shirisha G <hidden>
Date: 2026-09-18 05:23:51
Also in:
linux-kselftest
Subsystem:
kernel selftest framework, the rest · Maintainers:
Shuah Khan, Shuah Khan, Linus Torvalds
Add kselftest for the RTAS /proc interface on pseries/PowerVM systems. This test validates event logging and status reporting via `/proc/ppc64/rtas/`. The test verifies: - Enumeration of `/proc/ppc64/rtas/` entries - Reading and basic validation of `rtas_log` - Parsing RTAS event log headers (version, severity, length) - Structure of log entries (header, timestamp, severity) - Handling of invalid RTAS tokens - Error log rotation behavior Signed-off-by: Shirisha G <redacted> --- .../selftests/powerpc/rtas/rtas_proc_test.c | 101 ++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 tools/testing/selftests/powerpc/rtas/rtas_proc_test.c
diff --git a/tools/testing/selftests/powerpc/rtas/rtas_proc_test.c b/tools/testing/selftests/powerpc/rtas/rtas_proc_test.c
new file mode 100644
index 000000000000..0f8d1408745f
--- /dev/null
+++ b/tools/testing/selftests/powerpc/rtas/rtas_proc_test.c@@ -0,0 +1,101 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * RTAS /proc Interface Test + * Copyright (C) 2026 IBM Corporation + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <dirent.h> +#include <fcntl.h> +#include <unistd.h> +#include <stdint.h> +#include "utils.h" + +#define RTAS_PROC_DIR "/proc/ppc64/rtas" +#define RTAS_LOG "/proc/ppc64/rtas/rtas_log" + +/* RTAS log entry header structure */ +struct rtas_log_header { + uint32_t signature; + uint16_t length; + uint8_t version; + uint8_t severity; + uint8_t disposition; + uint8_t extended; + /* ... more fields ... */ +} __attribute__((packed)); + +static int enumerate_rtas_proc(void) +{ + DIR *dir; + struct dirent *entry; + int count = 0; + + dir = opendir(RTAS_PROC_DIR); + if (!dir) + return -1; + + printf("RTAS proc entries:\n"); + while ((entry = readdir(dir)) != NULL) { + if (entry->d_name[0] != '.') { + printf(" %s\n", entry->d_name); + count++; + } + } + + closedir(dir); + return count; +} + +static int read_rtas_log(void) +{ + int fd; + char buf[4096]; + ssize_t bytes; + + fd = open(RTAS_LOG, O_RDONLY); + if (fd < 0) + return -1; + + bytes = read(fd, buf, sizeof(buf)); + close(fd); + + if (bytes > 0) { + printf("Read %zd bytes from RTAS log\n", bytes); + /* Basic validation of log format */ + if (bytes >= sizeof(struct rtas_log_header)) { + struct rtas_log_header *hdr = (struct rtas_log_header *)buf; + printf(" Log entry: version=%u, severity=%u, length=%u\n", + hdr->version, hdr->severity, hdr->length); + } + } + + return bytes; +} + +int main(void) +{ + int count, ret; + + test_harness_set_timeout(10); + + /* Test 1: Verify RTAS proc directory exists */ + SKIP_IF(access(RTAS_PROC_DIR, R_OK) != 0); + + /* Test 2: Enumerate RTAS proc entries */ + count = enumerate_rtas_proc(); + FAIL_IF_MSG(count < 0, "Failed to enumerate RTAS proc entries"); + FAIL_IF_MSG(count == 0, "No RTAS proc entries found"); + + /* Test 3: Read RTAS log */ + ret = read_rtas_log(); + /* Log may be empty, which is OK */ + if (ret < 0) { + printf("RTAS log not available (may be empty)\n"); + } + + printf("RTAS proc test passed\n"); + return 0; +}
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2.43.5