 1dad093b66
			
		
	
	
	1dad093b66
	
	
	
		
			
			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>
		
			
				
	
	
		
			149 lines
		
	
	
	
		
			3.2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			149 lines
		
	
	
	
		
			3.2 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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| 	load_runtime_instr_cb(&runtime_instr_empty_cb);
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| 
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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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| 
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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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| 	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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| 
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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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| 
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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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| 
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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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| 
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| 	if (!(param32 & CPU_MF_INT_RI_MASK))
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| 		return;
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| 
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| 	inc_irq_stat(IRQEXT_CMR);
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| 
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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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| 
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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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| 
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| 	send_sig_info(current->thread.ri_signum, &info, current);
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| }
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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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| 
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| 	if (!runtime_instr_avail())
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| 		return -EOPNOTSUPP;
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| 
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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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| 
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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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| 
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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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| 
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| 	init_runtime_instr_cb(cb);
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| 	current->thread.ri_signum = signum;
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| 
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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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| 
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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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| 
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| 	if (!runtime_instr_avail())
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| 		return 0;
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| 
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| 	irq_subclass_register(IRQ_SUBCLASS_MEASUREMENT_ALERT);
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| 	rc = register_external_irq(EXT_IRQ_MEASURE_ALERT,
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| 				   runtime_instr_int_handler);
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| 	if (rc)
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| 		irq_subclass_unregister(IRQ_SUBCLASS_MEASUREMENT_ALERT);
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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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