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
  15 #include <asm/mipsmtregs.h>
  16
  17 #include <irq.h>
  18
  19 #ifdef CONFIG_I8259
  20 static inline int irq_canonicalize(int irq)
  21 {
  22         return ((irq == I8259A_IRQ_BASE + 2) ? I8259A_IRQ_BASE + 9 : irq);
  23 }
  24 #else
  25 #define irq_canonicalize(irq) (irq)     /* Sane hardware, sane code ... */
  26 #endif
  27
  28 #ifdef CONFIG_MIPS_MT_SMTC
  29
  30 struct irqaction;
  31
  32 extern unsigned long irq_hwmask[];
  33 extern int setup_irq_smtc(unsigned int irq, struct irqaction * new,
  34                           unsigned long hwmask);
  35
  36 static inline void smtc_im_ack_irq(unsigned int irq)
  37 {
  38         if (irq_hwmask[irq] & ST0_IM)
  39                 set_c0_status(irq_hwmask[irq] & ST0_IM);
  40 }
  41
  42 #else
  43
  44 static inline void smtc_im_ack_irq(unsigned int irq)
  45 {
  46 }
  47
  48 #endif /* CONFIG_MIPS_MT_SMTC */
  49
  50 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
  51 #include <linux/cpumask.h>
  52
  53 extern int plat_set_irq_affinity(unsigned int irq,
  54                                   const struct cpumask *affinity);
  55 extern void smtc_forward_irq(unsigned int irq);
  56
  57 /*
  58  * IRQ affinity hook invoked at the beginning of interrupt dispatch
  59  * if option is enabled.
  60  *
  61  * Up through Linux 2.6.22 (at least) cpumask operations are very
  62  * inefficient on MIPS.  Initial prototypes of SMTC IRQ affinity
  63  * used a "fast path" per-IRQ-descriptor cache of affinity information
  64  * to reduce latency.  As there is a project afoot to optimize the
  65  * cpumask implementations, this version is optimistically assuming
  66  * that cpumask.h macro overhead is reasonable during interrupt dispatch.
  67  */
  68 #define IRQ_AFFINITY_HOOK(irq)                                          \
  69 do {                                                                    \
  70     if (!cpumask_test_cpu(smp_processor_id(), irq_desc[irq].affinity)) {\
  71         smtc_forward_irq(irq);                                          \
  72         irq_exit();                                                     \
  73         return;                                                         \
  74     }                                                                   \
  75 } while (0)
  76
  77 #else /* Not doing SMTC affinity */
  78
  79 #define IRQ_AFFINITY_HOOK(irq) do { } while (0)
  80
  81 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
  82
  83 #ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
  84
  85 /*
  86  * Clear interrupt mask handling "backstop" if irq_hwmask
  87  * entry so indicates. This implies that the ack() or end()
  88  * functions will take over re-enabling the low-level mask.
  89  * Otherwise it will be done on return from exception.
  90  */
  91 #define __DO_IRQ_SMTC_HOOK(irq)                                         \
  92 do {                                                                    \
  93         IRQ_AFFINITY_HOOK(irq);                                         \
  94         if (irq_hwmask[irq] & 0x0000ff00)                               \
  95                 write_c0_tccontext(read_c0_tccontext() &                \
  96                                    ~(irq_hwmask[irq] & 0x0000ff00));    \
  97 } while (0)
  98
  99 #define __NO_AFFINITY_IRQ_SMTC_HOOK(irq)                                \
 100 do {                                                                    \
 101         if (irq_hwmask[irq] & 0x0000ff00)                               \
 102                 write_c0_tccontext(read_c0_tccontext() &                \
 103                                    ~(irq_hwmask[irq] & 0x0000ff00));    \
 104 } while (0)
 105
 106 #else
 107
 108 #define __DO_IRQ_SMTC_HOOK(irq)                                         \
 109 do {                                                                    \
 110         IRQ_AFFINITY_HOOK(irq);                                         \
 111 } while (0)
 112 #define __NO_AFFINITY_IRQ_SMTC_HOOK(irq) do { } while (0)
 113
 114 #endif
 115
 116 /*
 117  * do_IRQ handles all normal device IRQ's (the special
 118  * SMP cross-CPU interrupts have their own specific
 119  * handlers).
 120  *
 121  * Ideally there should be away to get this into kernel/irq/handle.c to
 122  * avoid the overhead of a call for just a tiny function ...
 123  */
 124 #define do_IRQ(irq)                                                     \
 125 do {                                                                    \
 126         irq_enter();                                                    \
 127         __DO_IRQ_SMTC_HOOK(irq);                                        \
 128         generic_handle_irq(irq);                                        \
 129         irq_exit();                                                     \
 130 } while (0)
 131
 132 #ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
 133 /*
 134  * To avoid inefficient and in some cases pathological re-checking of
 135  * IRQ affinity, we have this variant that skips the affinity check.
 136  */
 137
 138
 139 #define do_IRQ_no_affinity(irq)                                         \
 140 do {                                                                    \
 141         irq_enter();                                                    \
 142         __NO_AFFINITY_IRQ_SMTC_HOOK(irq);                               \
 143         generic_handle_irq(irq);                                        \
 144         irq_exit();                                                     \
 145 } while (0)
 146
 147 #endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
 148
 149 extern void arch_init_irq(void);
 150 extern void spurious_interrupt(void);
 151
 152 extern int allocate_irqno(void);
 153 extern void alloc_legacy_irqno(void);
 154 extern void free_irqno(unsigned int irq);
 155
 156 /*
 157  * Before R2 the timer and performance counter interrupts were both fixed to
 158  * IE7.  Since R2 their number has to be read from the c0_intctl register.
 159  */
 160 #define CP0_LEGACY_COMPARE_IRQ 7
 161
 162 extern int cp0_compare_irq;
 163 extern int cp0_perfcount_irq;
 164
 165 #endif /* _ASM_IRQ_H */