1/*
2 * Copyright 2015, Sam Bobroff, IBM Corp.
3 * Licensed under GPLv2.
4 *
5 * Test the kernel's system call code to ensure that a system call
6 * made from within an active HTM transaction is aborted with the
7 * correct failure code.
8 * Conversely, ensure that a system call made from within a
9 * suspended transaction can succeed.
10 */
11
12#include <stdio.h>
13#include <unistd.h>
14#include <sys/syscall.h>
15#include <asm/tm.h>
16#include <asm/cputable.h>
17#include <linux/auxvec.h>
18#include <sys/time.h>
19#include <stdlib.h>
20
21#include "utils.h"
22
23extern int getppid_tm_active(void);
24extern int getppid_tm_suspended(void);
25
26unsigned retries = 0;
27
28#define TEST_DURATION 10 /* seconds */
29#define TM_RETRIES 100
30
31long failure_code(void)
32{
33	return __builtin_get_texasru() >> 24;
34}
35
36bool failure_is_persistent(void)
37{
38	return (failure_code() & TM_CAUSE_PERSISTENT) == TM_CAUSE_PERSISTENT;
39}
40
41bool failure_is_syscall(void)
42{
43	return (failure_code() & TM_CAUSE_SYSCALL) == TM_CAUSE_SYSCALL;
44}
45
46pid_t getppid_tm(bool suspend)
47{
48	int i;
49	pid_t pid;
50
51	for (i = 0; i < TM_RETRIES; i++) {
52		if (suspend)
53			pid = getppid_tm_suspended();
54		else
55			pid = getppid_tm_active();
56
57		if (pid >= 0)
58			return pid;
59
60		if (failure_is_persistent()) {
61			if (failure_is_syscall())
62				return -1;
63
64			printf("Unexpected persistent transaction failure.\n");
65			printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",
66			       __builtin_get_texasr(), __builtin_get_tfiar());
67			exit(-1);
68		}
69
70		retries++;
71	}
72
73	printf("Exceeded limit of %d temporary transaction failures.\n", TM_RETRIES);
74	printf("TEXASR 0x%016lx, TFIAR 0x%016lx.\n",
75	       __builtin_get_texasr(), __builtin_get_tfiar());
76
77	exit(-1);
78}
79
80int tm_syscall(void)
81{
82	unsigned count = 0;
83	struct timeval end, now;
84
85	SKIP_IF(!((long)get_auxv_entry(AT_HWCAP2) & PPC_FEATURE2_HTM));
86	setbuf(stdout, NULL);
87
88	printf("Testing transactional syscalls for %d seconds...\n", TEST_DURATION);
89
90	gettimeofday(&end, NULL);
91	now.tv_sec = TEST_DURATION;
92	now.tv_usec = 0;
93	timeradd(&end, &now, &end);
94
95	for (count = 0; timercmp(&now, &end, <); count++) {
96		/*
97		 * Test a syscall within a suspended transaction and verify
98		 * that it succeeds.
99		 */
100		FAIL_IF(getppid_tm(true) == -1); /* Should succeed. */
101
102		/*
103		 * Test a syscall within an active transaction and verify that
104		 * it fails with the correct failure code.
105		 */
106		FAIL_IF(getppid_tm(false) != -1);  /* Should fail... */
107		FAIL_IF(!failure_is_persistent()); /* ...persistently... */
108		FAIL_IF(!failure_is_syscall());    /* ...with code syscall. */
109		gettimeofday(&now, 0);
110	}
111
112	printf("%d active and suspended transactions behaved correctly.\n", count);
113	printf("(There were %d transaction retries.)\n", retries);
114
115	return 0;
116}
117
118int main(void)
119{
120	return test_harness(tm_syscall, "tm_syscall");
121}
122