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review.evervolv.com / android_kernel_oneplus_msm8996 / d1b0d842c4450e410053083db837ef16532a4139 / . / arch / s390 / kernel / runtime_instr.c
blob: 61066f6f71a590d3d35fd688e8e6715719919dc1 [file] [log] [blame]
Jan Glaubere4b8b3f2012-07-31 10:52:05 +0200[diff] [blame]1/*
2 * Copyright IBM Corp. 2012
3 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
4 */
5
6#include <linux/kernel.h>
7#include <linux/syscalls.h>
8#include <linux/signal.h>
9#include <linux/mm.h>
10#include <linux/slab.h>
11#include <linux/init.h>
12#include <linux/errno.h>
13#include <linux/kernel_stat.h>
14#include <asm/runtime_instr.h>
15#include <asm/cpu_mf.h>
16#include <asm/irq.h>
17
18/* empty control block to disable RI by loading it */
19struct runtime_instr_cb runtime_instr_empty_cb;
20
21static int runtime_instr_avail(void)
22{
23 return test_facility(64);
24}
25
26static void disable_runtime_instr(void)
27{
28 struct pt_regs *regs = task_pt_regs(current);
29
30 load_runtime_instr_cb(&runtime_instr_empty_cb);
31
32 /*
33 * Make sure the RI bit is deleted from the PSW. If the user did not
34 * switch off RI before the system call the process will get a
35 * specification exception otherwise.
36 */
37 regs->psw.mask &= ~PSW_MASK_RI;
38}
39
40static void init_runtime_instr_cb(struct runtime_instr_cb *cb)
41{
42 cb->buf_limit = 0xfff;
Heiko Carstensd1b0d842012-09-02 11:02:23 +0200[diff] [blame^]43 if (s390_user_mode == HOME_SPACE_MODE)
Jan Glaubere4b8b3f2012-07-31 10:52:05 +0200[diff] [blame]44 cb->home_space = 1;
45 cb->int_requested = 1;
46 cb->pstate = 1;
47 cb->pstate_set_buf = 1;
48 cb->pstate_sample = 1;
49 cb->pstate_collect = 1;
50 cb->key = PAGE_DEFAULT_KEY;
51 cb->valid = 1;
52}
53
54void exit_thread_runtime_instr(void)
55{
56 struct task_struct *task = current;
57
58 if (!task->thread.ri_cb)
59 return;
60 disable_runtime_instr();
61 kfree(task->thread.ri_cb);
62 task->thread.ri_signum = 0;
63 task->thread.ri_cb = NULL;
64}
65
66static void runtime_instr_int_handler(struct ext_code ext_code,
67 unsigned int param32, unsigned long param64)
68{
69 struct siginfo info;
70
71 if (!(param32 & CPU_MF_INT_RI_MASK))
72 return;
73
74 kstat_cpu(smp_processor_id()).irqs[EXTINT_CMR]++;
75
76 if (!current->thread.ri_cb)
77 return;
78 if (current->thread.ri_signum < SIGRTMIN ||
79 current->thread.ri_signum > SIGRTMAX) {
80 WARN_ON_ONCE(1);
81 return;
82 }
83
84 memset(&info, 0, sizeof(info));
85 info.si_signo = current->thread.ri_signum;
86 info.si_code = SI_QUEUE;
87 if (param32 & CPU_MF_INT_RI_BUF_FULL)
88 info.si_int = ENOBUFS;
89 else if (param32 & CPU_MF_INT_RI_HALTED)
90 info.si_int = ECANCELED;
91 else
92 return; /* unknown reason */
93
94 send_sig_info(current->thread.ri_signum, &info, current);
95}
96
97SYSCALL_DEFINE2(s390_runtime_instr, int, command, int, signum)
98{
99 struct runtime_instr_cb *cb;
100
101 if (!runtime_instr_avail())
102 return -EOPNOTSUPP;
103
104 if (command == S390_RUNTIME_INSTR_STOP) {
105 preempt_disable();
106 exit_thread_runtime_instr();
107 preempt_enable();
108 return 0;
109 }
110
111 if (command != S390_RUNTIME_INSTR_START ||
112 (signum < SIGRTMIN || signum > SIGRTMAX))
113 return -EINVAL;
114
115 if (!current->thread.ri_cb) {
116 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
117 if (!cb)
118 return -ENOMEM;
119 } else {
120 cb = current->thread.ri_cb;
121 memset(cb, 0, sizeof(*cb));
122 }
123
124 init_runtime_instr_cb(cb);
125 current->thread.ri_signum = signum;
126
127 /* now load the control block to make it available */
128 preempt_disable();
129 current->thread.ri_cb = cb;
130 load_runtime_instr_cb(cb);
131 preempt_enable();
132 return 0;
133}
134
135static int __init runtime_instr_init(void)
136{
137 int rc;
138
139 if (!runtime_instr_avail())
140 return 0;
141
142 measurement_alert_subclass_register();
143 rc = register_external_interrupt(0x1407, runtime_instr_int_handler);
144 if (rc)
145 measurement_alert_subclass_unregister();
146 else
147 pr_info("Runtime instrumentation facility initialized\n");
148 return rc;
149}
150device_initcall(runtime_instr_init);