include/asm-x86/ipi.h

   1 #ifndef __ASM_IPI_H
   2 #define __ASM_IPI_H
   3
   4 /*
   5  * Copyright 2004 James Cleverdon, IBM.
   6  * Subject to the GNU Public License, v.2
   7  *
   8  * Generic APIC InterProcessor Interrupt code.
   9  *
  10  * Moved to include file by James Cleverdon from
  11  * arch/x86-64/kernel/smp.c
  12  *
  13  * Copyrights from kernel/smp.c:
  14  *
  15  * (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
  16  * (c) 1998-99, 2000 Ingo Molnar <mingo@redhat.com>
  17  * (c) 2002,2003 Andi Kleen, SuSE Labs.
  18  * Subject to the GNU Public License, v.2
  19  */
  20
  21 #include <asm/hw_irq.h>
  22 #include <asm/apic.h>
  23
  24 /*
  25  * the following functions deal with sending IPIs between CPUs.
  26  *
  27  * We use 'broadcast', CPU->CPU IPIs and self-IPIs too.
  28  */
  29
  30 static inline unsigned int __prepare_ICR (unsigned int shortcut, int vector, unsigned int dest)
  31 {
  32         unsigned int icr = shortcut | dest;
  33
  34         switch (vector) {
  35         default:
  36                 icr |= APIC_DM_FIXED | vector;
  37                 break;
  38         case NMI_VECTOR:
  39                 icr |= APIC_DM_NMI;
  40                 break;
  41         }
  42         return icr;
  43 }
  44
  45 static inline int __prepare_ICR2 (unsigned int mask)
  46 {
  47         return SET_APIC_DEST_FIELD(mask);
  48 }
  49
  50 static inline void __send_IPI_shortcut(unsigned int shortcut, int vector, unsigned int dest)
  51 {
  52         /*
  53          * Subtle. In the case of the 'never do double writes' workaround
  54          * we have to lock out interrupts to be safe.  As we don't care
  55          * of the value read we use an atomic rmw access to avoid costly
  56          * cli/sti.  Otherwise we use an even cheaper single atomic write
  57          * to the APIC.
  58          */
  59         unsigned int cfg;
  60
  61         /*
  62          * Wait for idle.
  63          */
  64         apic_wait_icr_idle();
  65
  66         /*
  67          * No need to touch the target chip field
  68          */
  69         cfg = __prepare_ICR(shortcut, vector, dest);
  70
  71         /*
  72          * Send the IPI. The write to APIC_ICR fires this off.
  73          */
  74         apic_write(APIC_ICR, cfg);
  75 }
  76
  77 /*
  78  * This is used to send an IPI with no shorthand notation (the destination is
  79  * specified in bits 56 to 63 of the ICR).
  80  */
  81 static inline void __send_IPI_dest_field(unsigned int mask, int vector, unsigned int dest)
  82 {
  83         unsigned long cfg;
  84
  85         /*
  86          * Wait for idle.
  87          */
  88         if (unlikely(vector == NMI_VECTOR))
  89                 safe_apic_wait_icr_idle();
  90         else
  91                 apic_wait_icr_idle();
  92
  93         /*
  94          * prepare target chip field
  95          */
  96         cfg = __prepare_ICR2(mask);
  97         apic_write(APIC_ICR2, cfg);
  98
  99         /*
 100          * program the ICR
 101          */
 102         cfg = __prepare_ICR(0, vector, dest);
 103
 104         /*
 105          * Send the IPI. The write to APIC_ICR fires this off.
 106          */
 107         apic_write(APIC_ICR, cfg);
 108 }
 109
 110 static inline void send_IPI_mask_sequence(cpumask_t mask, int vector)
 111 {
 112         unsigned long flags;
 113         unsigned long query_cpu;
 114
 115         /*
 116          * Hack. The clustered APIC addressing mode doesn't allow us to send
 117          * to an arbitrary mask, so I do a unicast to each CPU instead.
 118          * - mbligh
 119          */
 120         local_irq_save(flags);
 121         for_each_cpu_mask(query_cpu, mask) {
 122                 __send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, query_cpu),
 123                                       vector, APIC_DEST_PHYSICAL);
 124         }
 125         local_irq_restore(flags);
 126 }
 127
 128 #endif /* __ASM_IPI_H */