forked from Minki/linux
420f42ecf4
Now that irq sum accounting for /proc/stat's "intr" line works again we
have the oddity that the sum field (first field) contains only the sum
of the second (external irqs) and third field (I/O interrupts).
The reason for that is that these two fields are already sums of all other
fields. So if we would sum up everything we would count every interrupt
twice.
This is broken since the split interrupt accounting was merged two years
ago: 052ff461c8 "[S390] irq: have detailed
statistics for interrupt types".
To fix this remove the split interrupt fields from /proc/stat's "intr"
line again and only have them in /proc/interrupts.
This restores the old behaviour, seems to be the only sane fix and mimics
a behaviour from other architectures where /proc/interrupts also contains
more than /proc/stat's "intr" line does.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
151 lines
3.3 KiB
C
151 lines
3.3 KiB
C
/*
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* Copyright IBM Corp. 2012
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* Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
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*/
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#include <linux/kernel.h>
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#include <linux/syscalls.h>
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#include <linux/signal.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/kernel_stat.h>
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#include <asm/runtime_instr.h>
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#include <asm/cpu_mf.h>
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#include <asm/irq.h>
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/* empty control block to disable RI by loading it */
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struct runtime_instr_cb runtime_instr_empty_cb;
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static int runtime_instr_avail(void)
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{
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return test_facility(64);
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}
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static void disable_runtime_instr(void)
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{
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struct pt_regs *regs = task_pt_regs(current);
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load_runtime_instr_cb(&runtime_instr_empty_cb);
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/*
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* Make sure the RI bit is deleted from the PSW. If the user did not
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* switch off RI before the system call the process will get a
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* specification exception otherwise.
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*/
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regs->psw.mask &= ~PSW_MASK_RI;
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}
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static void init_runtime_instr_cb(struct runtime_instr_cb *cb)
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{
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cb->buf_limit = 0xfff;
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if (s390_user_mode == HOME_SPACE_MODE)
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cb->home_space = 1;
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cb->int_requested = 1;
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cb->pstate = 1;
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cb->pstate_set_buf = 1;
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cb->pstate_sample = 1;
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cb->pstate_collect = 1;
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cb->key = PAGE_DEFAULT_KEY;
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cb->valid = 1;
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}
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void exit_thread_runtime_instr(void)
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{
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struct task_struct *task = current;
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if (!task->thread.ri_cb)
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return;
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disable_runtime_instr();
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kfree(task->thread.ri_cb);
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task->thread.ri_signum = 0;
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task->thread.ri_cb = NULL;
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}
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static void runtime_instr_int_handler(struct ext_code ext_code,
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unsigned int param32, unsigned long param64)
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{
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struct siginfo info;
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if (!(param32 & CPU_MF_INT_RI_MASK))
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return;
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inc_irq_stat(IRQEXT_CMR);
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if (!current->thread.ri_cb)
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return;
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if (current->thread.ri_signum < SIGRTMIN ||
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current->thread.ri_signum > SIGRTMAX) {
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WARN_ON_ONCE(1);
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return;
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}
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memset(&info, 0, sizeof(info));
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info.si_signo = current->thread.ri_signum;
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info.si_code = SI_QUEUE;
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if (param32 & CPU_MF_INT_RI_BUF_FULL)
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info.si_int = ENOBUFS;
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else if (param32 & CPU_MF_INT_RI_HALTED)
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info.si_int = ECANCELED;
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else
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return; /* unknown reason */
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send_sig_info(current->thread.ri_signum, &info, current);
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}
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SYSCALL_DEFINE2(s390_runtime_instr, int, command, int, signum)
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{
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struct runtime_instr_cb *cb;
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if (!runtime_instr_avail())
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return -EOPNOTSUPP;
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if (command == S390_RUNTIME_INSTR_STOP) {
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preempt_disable();
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exit_thread_runtime_instr();
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preempt_enable();
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return 0;
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}
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if (command != S390_RUNTIME_INSTR_START ||
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(signum < SIGRTMIN || signum > SIGRTMAX))
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return -EINVAL;
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if (!current->thread.ri_cb) {
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cb = kzalloc(sizeof(*cb), GFP_KERNEL);
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if (!cb)
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return -ENOMEM;
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} else {
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cb = current->thread.ri_cb;
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memset(cb, 0, sizeof(*cb));
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}
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init_runtime_instr_cb(cb);
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current->thread.ri_signum = signum;
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/* now load the control block to make it available */
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preempt_disable();
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current->thread.ri_cb = cb;
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load_runtime_instr_cb(cb);
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preempt_enable();
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return 0;
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}
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static int __init runtime_instr_init(void)
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{
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int rc;
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if (!runtime_instr_avail())
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return 0;
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measurement_alert_subclass_register();
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rc = register_external_interrupt(0x1407, runtime_instr_int_handler);
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if (rc)
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measurement_alert_subclass_unregister();
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else
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pr_info("Runtime instrumentation facility initialized\n");
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return rc;
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}
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device_initcall(runtime_instr_init);
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