powerpc/sysdev/mpic_msi.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
0004  */
0005
0006 #include <linux/irq.h>
0007 #include <linux/irqdomain.h>
0008 #include <linux/of_irq.h>
0009 #include <linux/bitmap.h>
0010 #include <linux/msi.h>
0011 #include <asm/mpic.h>
0012 #include <asm/hw_irq.h>
0013 #include <asm/ppc-pci.h>
0014 #include <asm/msi_bitmap.h>
0015
0016 #include <sysdev/mpic.h>
0017
0018 void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
0019 {
0020     /* The mpic calls this even when there is no allocator setup */
0021     if (!mpic->msi_bitmap.bitmap)
0022         return;
0023
0024     msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
0025 }
0026
0027 #ifdef CONFIG_MPIC_U3_HT_IRQS
0028 static int __init mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
0029 {
0030     irq_hw_number_t hwirq;
0031     const struct irq_domain_ops *ops = mpic->irqhost->ops;
0032     struct device_node *np;
0033     int flags, index, i;
0034     struct of_phandle_args oirq;
0035
0036     pr_debug("mpic: found U3, guessing msi allocator setup\n");
0037
0038     /* Reserve source numbers we know are reserved in the HW.
0039      *
0040      * This is a bit of a mix of U3 and U4 reserves but that's going
0041      * to work fine, we have plenty enough numbers left so let's just
0042      * mark anything we don't like reserved.
0043      */
0044     for (i = 0;   i < 8;   i++)
0045         msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
0046
0047     for (i = 42;  i < 46;  i++)
0048         msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
0049
0050     for (i = 100; i < 105; i++)
0051         msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
0052
0053     for (i = 124; i < mpic->num_sources; i++)
0054         msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
0055
0056
0057     np = NULL;
0058     while ((np = of_find_all_nodes(np))) {
0059         pr_debug("mpic: mapping hwirqs for %pOF\n", np);
0060
0061         index = 0;
0062         while (of_irq_parse_one(np, index++, &oirq) == 0) {
0063             ops->xlate(mpic->irqhost, NULL, oirq.args,
0064                         oirq.args_count, &hwirq, &flags);
0065             msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
0066         }
0067     }
0068
0069     return 0;
0070 }
0071 #else
0072 static int __init mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
0073 {
0074     return -1;
0075 }
0076 #endif
0077
0078 int __init mpic_msi_init_allocator(struct mpic *mpic)
0079 {
0080     int rc;
0081
0082     rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->num_sources,
0083                   irq_domain_get_of_node(mpic->irqhost));
0084     if (rc)
0085         return rc;
0086
0087     rc = msi_bitmap_reserve_dt_hwirqs(&mpic->msi_bitmap);
0088     if (rc > 0) {
0089         if (mpic->flags & MPIC_U3_HT_IRQS)
0090             rc = mpic_msi_reserve_u3_hwirqs(mpic);
0091
0092         if (rc) {
0093             msi_bitmap_free(&mpic->msi_bitmap);
0094             return rc;
0095         }
0096     }
0097
0098     return 0;
0099 }