// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2005-2020 IBM Corporation.
*
* Includes code from librtas (https://github.com/ibm-power-utilities/librtas/)
*/
#include <byteswap.h>
#include <stdint.h>
#include <inttypes.h>
#include <linux/limits.h>
#include <stdio.h>
#include <string.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdarg.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include "utils.h"
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
#define cpu_to_be32(x) bswap_32(x)
#define be32_to_cpu(x) bswap_32(x)
#else
#define cpu_to_be32(x) (x)
#define be32_to_cpu(x) (x)
#endif
#define RTAS_IO_ASSERT -1098 /* Unexpected I/O Error */
#define RTAS_UNKNOWN_OP -1099 /* No Firmware Implementation of Function */
#define BLOCK_SIZE 4096
#define PAGE_SIZE 4096
#define MAX_PAGES 64
static const char *ofdt_rtas_path = "/proc/device-tree/rtas";
typedef __be32 uint32_t;
struct rtas_args {
__be32 token;
__be32 nargs;
__be32 nret;
__be32 args[16];
__be32 *rets; /* Pointer to return values in args[]. */
};
struct region {
uint64_t addr;
uint32_t size;
struct region *next;
};
static int get_property(const char *prop_path, const char *prop_name,
char **prop_val, size_t *prop_len)
{
char path[PATH_MAX];
int len = snprintf(path, sizeof(path), "%s/%s", prop_path, prop_name);
if (len < 0 || len >= sizeof(path))
return -ENOMEM;
return read_file_alloc(path, prop_val, prop_len);
}
int rtas_token(const char *call_name)
{
char *prop_buf = NULL;
size_t len;
int rc;
rc = get_property(ofdt_rtas_path, call_name, &prop_buf, &len);
if (rc < 0) {
rc = RTAS_UNKNOWN_OP;
goto err;
}
rc = be32_to_cpu(*(int *)prop_buf);
err:
free(prop_buf);
return rc;
}
static int read_kregion_bounds(struct region *kregion)
{
char *buf;
int err;
err = read_file_alloc("/proc/ppc64/rtas/rmo_buffer", &buf, NULL);
if (err) {
perror("Could not open rmo_buffer file");
return RTAS_IO_ASSERT;
}
sscanf(buf, "%" SCNx64 " %x", &kregion->addr, &kregion->size);
free(buf);
if (!(kregion->size && kregion->addr) ||
(kregion->size > (PAGE_SIZE * MAX_PAGES))) {
printf("Unexpected kregion bounds\n");
return RTAS_IO_ASSERT;
}
return 0;
}
static int rtas_call(const char *name, int nargs,
int nrets, ...)
{
struct rtas_args args;
__be32 *rets[16];
int i, rc, token;
va_list ap;
va_start(ap, nrets);
token = rtas_token(name);
if (token == RTAS_UNKNOWN_OP) {
// We don't care if the call doesn't exist
printf("call '%s' not available, skipping...", name);
rc = RTAS_UNKNOWN_OP;
goto err;
}
args.token = cpu_to_be32(token);
args.nargs = cpu_to_be32(nargs);
args.nret = cpu_to_be32(nrets);
for (i = 0; i < nargs; i++)
args.args[i] = (__be32) va_arg(ap, unsigned long);
for (i = 0; i < nrets; i++)
rets[i] = (__be32 *) va_arg(ap, unsigned long);
rc = syscall(__NR_rtas, &args);
if (rc) {
rc = -errno;
goto err;
}
if (nrets) {
*(rets[0]) = be32_to_cpu(args.args[nargs]);
for (i = 1; i < nrets; i++) {
*(rets[i]) = args.args[nargs + i];
}
}
err:
va_end(ap);
return rc;
}
static int test(void)
{
struct region rmo_region;
uint32_t rmo_start;
uint32_t rmo_end;
__be32 rets[1];
int rc;
// Test a legitimate harmless call
// Expected: call succeeds
printf("Test a permitted call, no parameters... ");
rc = rtas_call("get-time-of-day", 0, 1, rets);
printf("rc: %d\n", rc);
FAIL_IF(rc != 0 && rc != RTAS_UNKNOWN_OP);
// Test a prohibited call
// Expected: call returns -EINVAL
printf("Test a prohibited call... ");
rc = rtas_call("nvram-fetch", 0, 1, rets);
printf("rc: %d\n", rc);
FAIL_IF(rc != -EINVAL && rc != RTAS_UNKNOWN_OP);
// Get RMO
rc = read_kregion_bounds(&rmo_region);
if (rc) {
printf("Couldn't read RMO region bounds, skipping remaining cases\n");
return 0;
}
rmo_start = rmo_region.addr;
rmo_end = rmo_start + rmo_region.size - 1;
printf("RMO range: %08x - %08x\n", rmo_start, rmo_end);
// Test a permitted call, user-supplied size, buffer inside RMO
// Expected: call succeeds
printf("Test a permitted call, user-supplied size, buffer inside RMO... ");
rc = rtas_call("ibm,get-system-parameter", 3, 1, 0, cpu_to_be32(rmo_start),
cpu_to_be32(rmo_end - rmo_start + 1), rets);
printf("rc: %d\n", rc);
FAIL_IF(rc != 0 && rc != RTAS_UNKNOWN_OP);
// Test a permitted call, user-supplied size, buffer start outside RMO
// Expected: call returns -EINVAL
printf("Test a permitted call, user-supplied size, buffer start outside RMO... ");
rc = rtas_call("ibm,get-system-parameter", 3, 1, 0, cpu_to_be32(rmo_end + 1),
cpu_to_be32(4000), rets);
printf("rc: %d\n", rc);
FAIL_IF(rc != -EINVAL && rc != RTAS_UNKNOWN_OP);
// Test a permitted call, user-supplied size, buffer end outside RMO
// Expected: call returns -EINVAL
printf("Test a permitted call, user-supplied size, buffer end outside RMO... ");
rc = rtas_call("ibm,get-system-parameter", 3, 1, 0, cpu_to_be32(rmo_start),
cpu_to_be32(rmo_end - rmo_start + 2), rets);
printf("rc: %d\n", rc);
FAIL_IF(rc != -EINVAL && rc != RTAS_UNKNOWN_OP);
// Test a permitted call, fixed size, buffer end outside RMO
// Expected: call returns -EINVAL
printf("Test a permitted call, fixed size, buffer end outside RMO... ");
rc = rtas_call("ibm,configure-connector", 2, 1, cpu_to_be32(rmo_end - 4000), 0, rets);
printf("rc: %d\n", rc);
FAIL_IF(rc != -EINVAL && rc != RTAS_UNKNOWN_OP);
return 0;
}
int main(int argc, char *argv[])
{
return test_harness(test, "rtas_filter");
}
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