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