arch/mips/include/asm/irq.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994 by Waldorf GMBH, written by Ralf Baechle
   7  * Copyright (C) 1995, 96, 97, 98, 99, 2000, 01, 02, 03 by Ralf Baechle
   8  */
   9 #ifndef _ASM_IRQ_H
  10 #define _ASM_IRQ_H
  11
  12 #include <linux/linkage.h>
  13 #include <linux/smp.h>
  14 #include <linux/irqdomain.h>
  15
  16 #include <asm/mipsmtregs.h>
  17
  18 #include <irq.h>
  19
  20 #ifdef CONFIG_I8259
  21 static inline int irq_canonicalize(int irq)
  22 {
  23         return ((irq == I8259A_IRQ_BASE + 2) ? I8259A_IRQ_BASE + 9 : irq);
  24 }
  25 #else
  26 #define irq_canonicalize(irq) (irq)     /* Sane hardware, sane code ... */
  27 #endif
  28
  29 #ifdef CONFIG_MIPS_MT_SMTC
  30
  31 struct irqaction;
  32
  33 extern unsigned long irq_hwmask[];
  34 extern int setup_irq_smtc(unsigned int irq, struct irqaction * new,
  35                           unsigned long hwmask);
  36
  37 static inline void smtc_im_ack_irq(unsigned int irq)
  38 {
  39         if (irq_hwmask[irq] & ST0_IM)
  40                 set_c0_status(irq_hwmask[irq] & ST0_IM);
  41 }
  42
  43 #else
  44
  45 static inline void smtc_im_ack_irq(unsigned int irq)
  46 {
  47 }
  48
  49 #endif /* CONFIG_MIPS_MT_SMTC */
  50
  51 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
  52 #include <linux/cpumask.h>
  53
  54 extern int plat_set_irq_affinity(struct irq_data *d,
  55                                  const struct cpumask *affinity, bool force);
  56 extern void smtc_forward_irq(struct irq_data *d);
  57
  58 /*
  59  * IRQ affinity hook invoked at the beginning of interrupt dispatch
  60  * if option is enabled.
  61  *
  62  * Up through Linux 2.6.22 (at least) cpumask operations are very
  63  * inefficient on MIPS.  Initial prototypes of SMTC IRQ affinity
  64  * used a "fast path" per-IRQ-descriptor cache of affinity information
  65  * to reduce latency.  As there is a project afoot to optimize the
  66  * cpumask implementations, this version is optimistically assuming
  67  * that cpumask.h macro overhead is reasonable during interrupt dispatch.
  68  */
  69 static inline int handle_on_other_cpu(unsigned int irq)
  70 {
  71         struct irq_data *d = irq_get_irq_data(irq);
  72
  73         if (cpumask_test_cpu(smp_processor_id(), d->affinity))
  74                 return 0;
  75         smtc_forward_irq(d);
  76         return 1;
  77 }
  78
  79 #else /* Not doing SMTC affinity */
  80
  81 static inline int handle_on_other_cpu(unsigned int irq) { return 0; }
  82
  83 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
  84
  85 #ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
  86
  87 static inline void smtc_im_backstop(unsigned int irq)
  88 {
  89         if (irq_hwmask[irq] & 0x0000ff00)
  90                 write_c0_tccontext(read_c0_tccontext() &
  91                                    ~(irq_hwmask[irq] & 0x0000ff00));
  92 }
  93
  94 /*
  95  * Clear interrupt mask handling "backstop" if irq_hwmask
  96  * entry so indicates. This implies that the ack() or end()
  97  * functions will take over re-enabling the low-level mask.
  98  * Otherwise it will be done on return from exception.
  99  */
 100 static inline int smtc_handle_on_other_cpu(unsigned int irq)
 101 {
 102         int ret = handle_on_other_cpu(irq);
 103
 104         if (!ret)
 105                 smtc_im_backstop(irq);
 106         return ret;
 107 }
 108
 109 #else
 110
 111 static inline void smtc_im_backstop(unsigned int irq) { }
 112 static inline int smtc_handle_on_other_cpu(unsigned int irq)
 113 {
 114         return handle_on_other_cpu(irq);
 115 }
 116
 117 #endif
 118
 119 extern void do_IRQ(unsigned int irq);
 120
 121 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
 122
 123 extern void do_IRQ_no_affinity(unsigned int irq);
 124
 125 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
 126
 127 extern void arch_init_irq(void);
 128 extern void spurious_interrupt(void);
 129
 130 extern int allocate_irqno(void);
 131 extern void alloc_legacy_irqno(void);
 132 extern void free_irqno(unsigned int irq);
 133
 134 /*
 135  * Before R2 the timer and performance counter interrupts were both fixed to
 136  * IE7.  Since R2 their number has to be read from the c0_intctl register.
 137  */
 138 #define CP0_LEGACY_COMPARE_IRQ 7
 139
 140 extern int cp0_compare_irq;
 141 extern int cp0_compare_irq_shift;
 142 extern int cp0_perfcount_irq;
 143
 144 #endif /* _ASM_IRQ_H */