xref: /openbmc/linux/arch/powerpc/sysdev/mpic_msi.c (revision 9a29f5fc)
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 
18 void 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
28 static 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
72 static int __init mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
73 {
74 	return -1;
75 }
76 #endif
77 
78 int __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