149 lines
3.2 KiB
C
149 lines
3.2 KiB
C
/*
|
|
* Copyright IBM Corp. 2012
|
|
* Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/signal.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/init.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <asm/runtime_instr.h>
|
|
#include <asm/cpu_mf.h>
|
|
#include <asm/irq.h>
|
|
|
|
/* empty control block to disable RI by loading it */
|
|
struct runtime_instr_cb runtime_instr_empty_cb;
|
|
|
|
static int runtime_instr_avail(void)
|
|
{
|
|
return test_facility(64);
|
|
}
|
|
|
|
static void disable_runtime_instr(void)
|
|
{
|
|
struct pt_regs *regs = task_pt_regs(current);
|
|
|
|
load_runtime_instr_cb(&runtime_instr_empty_cb);
|
|
|
|
/*
|
|
* Make sure the RI bit is deleted from the PSW. If the user did not
|
|
* switch off RI before the system call the process will get a
|
|
* specification exception otherwise.
|
|
*/
|
|
regs->psw.mask &= ~PSW_MASK_RI;
|
|
}
|
|
|
|
static void init_runtime_instr_cb(struct runtime_instr_cb *cb)
|
|
{
|
|
cb->buf_limit = 0xfff;
|
|
cb->int_requested = 1;
|
|
cb->pstate = 1;
|
|
cb->pstate_set_buf = 1;
|
|
cb->pstate_sample = 1;
|
|
cb->pstate_collect = 1;
|
|
cb->key = PAGE_DEFAULT_KEY;
|
|
cb->valid = 1;
|
|
}
|
|
|
|
void exit_thread_runtime_instr(void)
|
|
{
|
|
struct task_struct *task = current;
|
|
|
|
if (!task->thread.ri_cb)
|
|
return;
|
|
disable_runtime_instr();
|
|
kfree(task->thread.ri_cb);
|
|
task->thread.ri_signum = 0;
|
|
task->thread.ri_cb = NULL;
|
|
}
|
|
|
|
static void runtime_instr_int_handler(struct ext_code ext_code,
|
|
unsigned int param32, unsigned long param64)
|
|
{
|
|
struct siginfo info;
|
|
|
|
if (!(param32 & CPU_MF_INT_RI_MASK))
|
|
return;
|
|
|
|
inc_irq_stat(IRQEXT_CMR);
|
|
|
|
if (!current->thread.ri_cb)
|
|
return;
|
|
if (current->thread.ri_signum < SIGRTMIN ||
|
|
current->thread.ri_signum > SIGRTMAX) {
|
|
WARN_ON_ONCE(1);
|
|
return;
|
|
}
|
|
|
|
memset(&info, 0, sizeof(info));
|
|
info.si_signo = current->thread.ri_signum;
|
|
info.si_code = SI_QUEUE;
|
|
if (param32 & CPU_MF_INT_RI_BUF_FULL)
|
|
info.si_int = ENOBUFS;
|
|
else if (param32 & CPU_MF_INT_RI_HALTED)
|
|
info.si_int = ECANCELED;
|
|
else
|
|
return; /* unknown reason */
|
|
|
|
send_sig_info(current->thread.ri_signum, &info, current);
|
|
}
|
|
|
|
SYSCALL_DEFINE2(s390_runtime_instr, int, command, int, signum)
|
|
{
|
|
struct runtime_instr_cb *cb;
|
|
|
|
if (!runtime_instr_avail())
|
|
return -EOPNOTSUPP;
|
|
|
|
if (command == S390_RUNTIME_INSTR_STOP) {
|
|
preempt_disable();
|
|
exit_thread_runtime_instr();
|
|
preempt_enable();
|
|
return 0;
|
|
}
|
|
|
|
if (command != S390_RUNTIME_INSTR_START ||
|
|
(signum < SIGRTMIN || signum > SIGRTMAX))
|
|
return -EINVAL;
|
|
|
|
if (!current->thread.ri_cb) {
|
|
cb = kzalloc(sizeof(*cb), GFP_KERNEL);
|
|
if (!cb)
|
|
return -ENOMEM;
|
|
} else {
|
|
cb = current->thread.ri_cb;
|
|
memset(cb, 0, sizeof(*cb));
|
|
}
|
|
|
|
init_runtime_instr_cb(cb);
|
|
current->thread.ri_signum = signum;
|
|
|
|
/* now load the control block to make it available */
|
|
preempt_disable();
|
|
current->thread.ri_cb = cb;
|
|
load_runtime_instr_cb(cb);
|
|
preempt_enable();
|
|
return 0;
|
|
}
|
|
|
|
static int __init runtime_instr_init(void)
|
|
{
|
|
int rc;
|
|
|
|
if (!runtime_instr_avail())
|
|
return 0;
|
|
|
|
irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT);
|
|
rc = register_external_interrupt(0x1407, runtime_instr_int_handler);
|
|
if (rc)
|
|
irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
|
|
else
|
|
pr_info("Runtime instrumentation facility initialized\n");
|
|
return rc;
|
|
}
|
|
device_initcall(runtime_instr_init);
|