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