2 * Copyright IBM Corp. 2012
3 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
6 #include <linux/kernel.h>
7 #include <linux/syscalls.h>
8 #include <linux/signal.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>
18 /* empty control block to disable RI by loading it */
19 struct runtime_instr_cb runtime_instr_empty_cb;
21 static int runtime_instr_avail(void)
23 return test_facility(64);
26 static void disable_runtime_instr(void)
28 struct pt_regs *regs = task_pt_regs(current);
30 load_runtime_instr_cb(&runtime_instr_empty_cb);
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.
37 regs->psw.mask &= ~PSW_MASK_RI;
40 static void init_runtime_instr_cb(struct runtime_instr_cb *cb)
42 cb->buf_limit = 0xfff;
43 if (s390_user_mode == HOME_SPACE_MODE)
45 cb->int_requested = 1;
47 cb->pstate_set_buf = 1;
48 cb->pstate_sample = 1;
49 cb->pstate_collect = 1;
50 cb->key = PAGE_DEFAULT_KEY;
54 void exit_thread_runtime_instr(void)
56 struct task_struct *task = current;
58 if (!task->thread.ri_cb)
60 disable_runtime_instr();
61 kfree(task->thread.ri_cb);
62 task->thread.ri_signum = 0;
63 task->thread.ri_cb = NULL;
66 static void runtime_instr_int_handler(struct ext_code ext_code,
67 unsigned int param32, unsigned long param64)
71 if (!(param32 & CPU_MF_INT_RI_MASK))
74 inc_irq_stat(IRQEXT_CMR);
76 if (!current->thread.ri_cb)
78 if (current->thread.ri_signum < SIGRTMIN ||
79 current->thread.ri_signum > SIGRTMAX) {
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;
92 return; /* unknown reason */
94 send_sig_info(current->thread.ri_signum, &info, current);
97 SYSCALL_DEFINE2(s390_runtime_instr, int, command, int, signum)
99 struct runtime_instr_cb *cb;
101 if (!runtime_instr_avail())
104 if (command == S390_RUNTIME_INSTR_STOP) {
106 exit_thread_runtime_instr();
111 if (command != S390_RUNTIME_INSTR_START ||
112 (signum < SIGRTMIN || signum > SIGRTMAX))
115 if (!current->thread.ri_cb) {
116 cb = kzalloc(sizeof(*cb), GFP_KERNEL);
120 cb = current->thread.ri_cb;
121 memset(cb, 0, sizeof(*cb));
124 init_runtime_instr_cb(cb);
125 current->thread.ri_signum = signum;
127 /* now load the control block to make it available */
129 current->thread.ri_cb = cb;
130 load_runtime_instr_cb(cb);
135 static int __init runtime_instr_init(void)
139 if (!runtime_instr_avail())
142 measurement_alert_subclass_register();
143 rc = register_external_interrupt(0x1407, runtime_instr_int_handler);
145 measurement_alert_subclass_unregister();
147 pr_info("Runtime instrumentation facility initialized\n");
150 device_initcall(runtime_instr_init);