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
18void 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
28static 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
72static int __init mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
73{
74 return -1;
75}
76#endif
77
78int __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(d: 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}
100

source code of linux/arch/powerpc/sysdev/mpic_msi.c