LXR linux/arch/powerpc/sysdev/mpic

   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
  22void 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
  32static 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_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         *
  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_map_one(np, index++, &oirq) == 0) {
  67                        ops->xlate(mpic->irqhost, NULL, oirq.specifier,
  68                                                oirq.size, &hwirq, &flags);
  69                        msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
  70                }
  71        }
  72
  73        return 0;
  74}
  75#else
  76static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
  77{
  78        return -1;
  79}
  80#endif
  81
  82int mpic_msi_init_allocator(struct mpic *mpic)
  83{
  84        int rc;
  85
  86        rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->num_sources,
  87                              mpic->irqhost->of_node);
  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}
 104