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(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