arch/powerpc/sysdev/mpic_msi.c

   1 /*
   2  * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; version 2 of the
   7  * License.
   8  *
   9  */
  10
  11 #include <linux/irq.h>
  12 #include <linux/bitmap.h>
  13 #include <linux/msi.h>
  14 #include <asm/mpic.h>
  15 #include <asm/prom.h>
  16 #include <asm/hw_irq.h>
  17 #include <asm/ppc-pci.h>
  18 #include <asm/msi_bitmap.h>
  19
  20 #include <sysdev/mpic.h>
  21
  22 void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
  23 {
  24         /* The mpic calls this even when there is no allocator setup */
  25         if (!mpic->msi_bitmap.bitmap)
  26                 return;
  27
  28         msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
  29 }
  30
  31 #ifdef CONFIG_MPIC_U3_HT_IRQS
  32 static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
  33 {
  34         irq_hw_number_t hwirq;
  35         struct irq_host_ops *ops = mpic->irqhost->ops;
  36         struct device_node *np;
  37         int flags, index, i;
  38         struct of_irq oirq;
  39
  40         pr_debug("mpic: found U3, guessing msi allocator setup\n");
  41
  42         /* Reserve source numbers we know are reserved in the HW */
  43         for (i = 0;   i < 8;   i++)
  44                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  45
  46         for (i = 42;  i < 46;  i++)
  47                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  48
  49         for (i = 100; i < 105; i++)
  50                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  51
  52         np = NULL;
  53         while ((np = of_find_all_nodes(np))) {
  54                 pr_debug("mpic: mapping hwirqs for %s\n", np->full_name);
  55
  56                 index = 0;
  57                 while (of_irq_map_one(np, index++, &oirq) == 0) {
  58                         ops->xlate(mpic->irqhost, NULL, oirq.specifier,
  59                                                 oirq.size, &hwirq, &flags);
  60                         msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
  61                 }
  62         }
  63
  64         return 0;
  65 }
  66 #else
  67 static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
  68 {
  69         return -1;
  70 }
  71 #endif
  72
  73 int mpic_msi_init_allocator(struct mpic *mpic)
  74 {
  75         int rc;
  76
  77         rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->irq_count,
  78                               mpic->irqhost->of_node);
  79         if (rc)
  80                 return rc;
  81
  82         rc = msi_bitmap_reserve_dt_hwirqs(&mpic->msi_bitmap);
  83         if (rc > 0) {
  84                 if (mpic->flags & MPIC_U3_HT_IRQS)
  85                         rc = mpic_msi_reserve_u3_hwirqs(mpic);
  86
  87                 if (rc) {
  88                         msi_bitmap_free(&mpic->msi_bitmap);
  89                         return rc;
  90                 }
  91         }
  92
  93         return 0;
  94 }