arch/powerpc/sysdev/mpic_msi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
   4  */
   5
   6 #include <linux/irq.h>
   7 #include <linux/irqdomain.h>
   8 #include <linux/of_irq.h>
   9 #include <linux/bitmap.h>
  10 #include <linux/msi.h>
  11 #include <asm/mpic.h>
  12 #include <asm/hw_irq.h>
  13 #include <asm/ppc-pci.h>
  14 #include <asm/msi_bitmap.h>
  15
  16 #include <sysdev/mpic.h>
  17
  18 void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
  19 {
  20         /* The mpic calls this even when there is no allocator setup */
  21         if (!mpic->msi_bitmap.bitmap)
  22                 return;
  23
  24         msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
  25 }
  26
  27 #ifdef CONFIG_MPIC_U3_HT_IRQS
  28 static int __init mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
  29 {
  30         irq_hw_number_t hwirq;
  31         const struct irq_domain_ops *ops = mpic->irqhost->ops;
  32         struct device_node *np;
  33         int flags, index, i;
  34         struct of_phandle_args oirq;
  35
  36         pr_debug("mpic: found U3, guessing msi allocator setup\n");
  37
  38         /* Reserve source numbers we know are reserved in the HW.
  39          *
  40          * This is a bit of a mix of U3 and U4 reserves but that's going
  41          * to work fine, we have plenty enough numbers left so let's just
  42          * mark anything we don't like reserved.
  43          */
  44         for (i = 0;   i < 8;   i++)
  45                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  46
  47         for (i = 42;  i < 46;  i++)
  48                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  49
  50         for (i = 100; i < 105; i++)
  51                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  52
  53         for (i = 124; i < mpic->num_sources; i++)
  54                 msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
  55
  56
  57         np = NULL;
  58         while ((np = of_find_all_nodes(np))) {
  59                 pr_debug("mpic: mapping hwirqs for %pOF\n", np);
  60
  61                 index = 0;
  62                 while (of_irq_parse_one(np, index++, &oirq) == 0) {
  63                         ops->xlate(mpic->irqhost, NULL, oirq.args,
  64                                                 oirq.args_count, &hwirq, &flags);
  65                         msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
  66                 }
  67         }
  68
  69         return 0;
  70 }
  71 #else
  72 static int __init mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
  73 {
  74         return -1;
  75 }
  76 #endif
  77
  78 int __init mpic_msi_init_allocator(struct mpic *mpic)
  79 {
  80         int rc;
  81
  82         rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->num_sources,
  83                               irq_domain_get_of_node(mpic->irqhost));
  84         if (rc)
  85                 return rc;
  86
  87         rc = msi_bitmap_reserve_dt_hwirqs(&mpic->msi_bitmap);
  88         if (rc > 0) {
  89                 if (mpic->flags & MPIC_U3_HT_IRQS)
  90                         rc = mpic_msi_reserve_u3_hwirqs(mpic);
  91
  92                 if (rc) {
  93                         msi_bitmap_free(&mpic->msi_bitmap);
  94                         return rc;
  95                 }
  96         }
  97
  98         return 0;
  99 }