linux_dsm_epyc7002/arch/s390/kernel/runtime_instr.c
Thomas Huth 1dad093b66 s390/irq: Use defines for external interruption codes
Use the new defines for external interruption codes to get rid
of "magic" numbers in the s390 source code. And while we're at it,
also rename the (un-)register_external_interrupt function to
something shorter so that this patch does not exceed the 80
columns all over the place.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-04-03 14:30:52 +02:00

150 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_irq(EXT_IRQ_MEASURE_ALERT,
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);