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	Allocate a per-cpu irq stack for use within interrupt handlers. Also add a utility function on_irq_stack to determine if a given stack pointer is within the irq stack for that cpu. Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com> Acked-by: Jason A. Donenfeld <jason@zx2c4.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Petr Mladek <pmladek@suse.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14740/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
		
			
				
	
	
		
			109 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			109 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * This file is subject to the terms and conditions of the GNU General Public
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 * License.  See the file "COPYING" in the main directory of this archive
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 * for more details.
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 *
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 * Code to handle x86 style IRQs plus some generic interrupt stuff.
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 *
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 * Copyright (C) 1992 Linus Torvalds
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 * Copyright (C) 1994 - 2000 Ralf Baechle
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 */
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#include <linux/kernel.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/kernel_stat.h>
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#include <linux/proc_fs.h>
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#include <linux/mm.h>
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#include <linux/random.h>
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#include <linux/sched.h>
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#include <linux/seq_file.h>
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#include <linux/kallsyms.h>
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#include <linux/kgdb.h>
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#include <linux/ftrace.h>
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#include <linux/atomic.h>
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#include <linux/uaccess.h>
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void *irq_stack[NR_CPUS];
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/*
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 * 'what should we do if we get a hw irq event on an illegal vector'.
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 * each architecture has to answer this themselves.
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 */
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void ack_bad_irq(unsigned int irq)
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{
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	printk("unexpected IRQ # %d\n", irq);
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}
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atomic_t irq_err_count;
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int arch_show_interrupts(struct seq_file *p, int prec)
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{
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	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
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	return 0;
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}
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asmlinkage void spurious_interrupt(void)
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{
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	atomic_inc(&irq_err_count);
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}
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void __init init_IRQ(void)
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{
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	int i;
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	for (i = 0; i < NR_IRQS; i++)
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		irq_set_noprobe(i);
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	if (cpu_has_veic)
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		clear_c0_status(ST0_IM);
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	arch_init_irq();
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	for_each_possible_cpu(i) {
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		int irq_pages = IRQ_STACK_SIZE / PAGE_SIZE;
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		void *s = (void *)__get_free_pages(GFP_KERNEL, irq_pages);
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		irq_stack[i] = s;
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		pr_debug("CPU%d IRQ stack at 0x%p - 0x%p\n", i,
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			irq_stack[i], irq_stack[i] + IRQ_STACK_SIZE);
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	}
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}
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#ifdef CONFIG_DEBUG_STACKOVERFLOW
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static inline void check_stack_overflow(void)
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{
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	unsigned long sp;
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	__asm__ __volatile__("move %0, $sp" : "=r" (sp));
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	sp &= THREAD_MASK;
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	/*
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	 * Check for stack overflow: is there less than STACK_WARN free?
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	 * STACK_WARN is defined as 1/8 of THREAD_SIZE by default.
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	 */
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	if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
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		printk("do_IRQ: stack overflow: %ld\n",
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		       sp - sizeof(struct thread_info));
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		dump_stack();
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	}
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}
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#else
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static inline void check_stack_overflow(void) {}
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#endif
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/*
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 * do_IRQ handles all normal device IRQ's (the special
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 * SMP cross-CPU interrupts have their own specific
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 * handlers).
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 */
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void __irq_entry do_IRQ(unsigned int irq)
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{
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	irq_enter();
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	check_stack_overflow();
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	generic_handle_irq(irq);
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	irq_exit();
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}
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