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         const struct irq_domain_ops *ops = mpic->irqhost->ops;
  36         struct device_node *np;
  37         int flags, index, i;
  38         struct of_phandle_args 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          *
  44          * This is a bit of a mix of U3 and U4 reserves but that's going
  45          * to work fine, we have plenty enugh numbers left so let's just
  46          * mark anything we don't like reserved.
  47          */
  48         for (i = 0;   i < 8;   i++)
  49                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  50
  51         for (i = 42;  i < 46;  i++)
  52                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  53
  54         for (i = 100; i < 105; i++)
  55                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  56
  57         for (i = 124; i < mpic->num_sources; i++)
  58                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  59
  60
  61         np = NULL;
  62         while ((np = of_find_all_nodes(np))) {
  63                 pr_debug("mpic: mapping hwirqs for %s\n", np->full_name);
  64
  65                 index = 0;
  66                 while (of_irq_parse_one(np, index++, &oirq) == 0) {
  67                         ops->xlate(mpic->irqhost, NULL, oirq.args,
  68                                                 oirq.args_count, &hwirq, &flags);
  69                         msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
  70                 }
  71         }
  72
  73         return 0;
  74 }
  75 #else
  76 static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
  77 {
  78         return -1;
  79 }
  80 #endif
  81
  82 int mpic_msi_init_allocator(struct mpic *mpic)
  83 {
  84         int rc;
  85
  86         rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->num_sources,
  87                               irq_domain_get_of_node(mpic->irqhost));
  88         if (rc)
  89                 return rc;
  90
  91         rc = msi_bitmap_reserve_dt_hwirqs(&mpic->msi_bitmap);
  92         if (rc > 0) {
  93                 if (mpic->flags & MPIC_U3_HT_IRQS)
  94                         rc = mpic_msi_reserve_u3_hwirqs(mpic);
  95
  96                 if (rc) {
  97                         msi_bitmap_free(&mpic->msi_bitmap);
  98                         return rc;
  99                 }
 100         }
 101
 102         return 0;
 103 }