src/system/kernel/arch/x86/msi.cpp

   1 /*
   2  * Copyright 2010-2011, Michael Lotz, mmlr@mlotz.ch. All Rights Reserved.
   3  * Distributed under the terms of the MIT license.
   4  */
   5
   6 #include <arch/x86/apic.h>
   7 #include <arch/x86/msi.h>
   8 #include <arch/x86/arch_smp.h>
   9
  10 #include <debug.h>
  11 #include <int.h>
  12 #include <lock.h>
  13
  14
  15 struct MSIConfiguration {
  16         uint64* fAddress;
  17         uint16* fData;
  18 };
  19
  20 static MSIConfiguration sMSIConfigurations[NUM_IO_VECTORS];
  21
  22 static bool sMSISupported = false;
  23 static uint32 sBootCPUAPICId = 0;
  24
  25
  26 void
  27 msi_init(kernel_args* args)
  28 {
  29         if (!apic_available()) {
  30                 dprintf("disabling msi due to missing apic\n");
  31                 return;
  32         }
  33
  34         dprintf("msi support enabled\n");
  35         sMSISupported = true;
  36         sBootCPUAPICId = args->arch_args.cpu_apic_id[0];
  37 }
  38
  39
  40 bool
  41 msi_supported()
  42 {
  43         return sMSISupported;
  44 }
  45
  46
  47 status_t
  48 msi_allocate_vectors(uint8 count, uint8 *startVector, uint64 *address,
  49         uint16 *data)
  50 {
  51         if (!sMSISupported)
  52                 return B_UNSUPPORTED;
  53
  54         long vector;
  55         status_t result = allocate_io_interrupt_vectors(count, &vector,
  56                 INTERRUPT_TYPE_IRQ);
  57         if (result != B_OK)
  58                 return result;
  59
  60         if (vector >= NUM_IO_VECTORS) {
  61                 free_io_interrupt_vectors(count, vector);
  62                 return B_NO_MEMORY;
  63         }
  64
  65         sMSIConfigurations[vector].fAddress = address;
  66         sMSIConfigurations[vector].fData = data;
  67         x86_set_irq_source(vector, IRQ_SOURCE_MSI);
  68
  69         *startVector = (uint8)vector;
  70         *address = MSI_ADDRESS_BASE | (sBootCPUAPICId << MSI_DESTINATION_ID_SHIFT)
  71                 | MSI_NO_REDIRECTION | MSI_DESTINATION_MODE_PHYSICAL;
  72         *data = MSI_TRIGGER_MODE_EDGE | MSI_DELIVERY_MODE_FIXED
  73                 | ((uint16)vector + ARCH_INTERRUPT_BASE);
  74
  75         dprintf("msi_allocate_vectors: allocated %u vectors starting from %u\n",
  76                 count, *startVector);
  77         return B_OK;
  78 }
  79
  80
  81 void
  82 msi_free_vectors(uint8 count, uint8 startVector)
  83 {
  84         if (!sMSISupported) {
  85                 panic("trying to free msi vectors but msi not supported\n");
  86                 return;
  87         }
  88
  89         dprintf("msi_free_vectors: freeing %u vectors starting from %u\n", count,
  90                 startVector);
  91
  92         free_io_interrupt_vectors(count, startVector);
  93 }
  94
  95
  96 void
  97 msi_assign_interrupt_to_cpu(uint8 irq, int32 cpu)
  98 {
  99         uint32 apic_id = x86_get_cpu_apic_id(cpu);
 100
 101         uint64* address = sMSIConfigurations[irq].fAddress;
 102         *address = MSI_ADDRESS_BASE | (apic_id << MSI_DESTINATION_ID_SHIFT)
 103                 | MSI_NO_REDIRECTION | MSI_DESTINATION_MODE_PHYSICAL;
 104 }
 105