1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2007, Olof Johansson, PA Semi
4 *
5 * Based on arch/powerpc/sysdev/mpic_u3msi.c:
6 *
7 * Copyright 2006, Segher Boessenkool, IBM Corporation.
8 * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
9 */
10
11#include <linux/irq.h>
12#include <linux/irqdomain.h>
13#include <linux/msi.h>
14#include <asm/mpic.h>
15#include <asm/hw_irq.h>
16#include <asm/ppc-pci.h>
17#include <asm/msi_bitmap.h>
18
19#include <sysdev/mpic.h>
20
21/* Allocate 16 interrupts per device, to give an alignment of 16,
22 * since that's the size of the grouping w.r.t. affinity. If someone
23 * needs more than 32 MSI's down the road we'll have to rethink this,
24 * but it should be OK for now.
25 */
26#define ALLOC_CHUNK 16
27
28#define PASEMI_MSI_ADDR 0xfc080000
29
30/* A bit ugly, can we get this from the pci_dev somehow? */
31static struct mpic *msi_mpic;
32
33
34static void mpic_pasemi_msi_mask_irq(struct irq_data *data)
35{
36 pr_debug("mpic_pasemi_msi_mask_irq %d\n", data->irq);
37 pci_msi_mask_irq(data);
38 mpic_mask_irq(data);
39}
40
41static void mpic_pasemi_msi_unmask_irq(struct irq_data *data)
42{
43 pr_debug("mpic_pasemi_msi_unmask_irq %d\n", data->irq);
44 mpic_unmask_irq(data);
45 pci_msi_unmask_irq(data);
46}
47
48static struct irq_chip mpic_pasemi_msi_chip = {
49 .irq_shutdown = mpic_pasemi_msi_mask_irq,
50 .irq_mask = mpic_pasemi_msi_mask_irq,
51 .irq_unmask = mpic_pasemi_msi_unmask_irq,
52 .irq_eoi = mpic_end_irq,
53 .irq_set_type = mpic_set_irq_type,
54 .irq_set_affinity = mpic_set_affinity,
55 .name = "PASEMI-MSI",
56};
57
58static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev)
59{
60 struct msi_desc *entry;
61 irq_hw_number_t hwirq;
62
63 pr_debug("pasemi_msi_teardown_msi_irqs, pdev %p\n", pdev);
64
65 msi_for_each_desc(entry, &pdev->dev, MSI_DESC_ASSOCIATED) {
66 hwirq = virq_to_hw(entry->irq);
67 irq_set_msi_desc(irq: entry->irq, NULL);
68 irq_dispose_mapping(virq: entry->irq);
69 entry->irq = 0;
70 msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, ALLOC_CHUNK);
71 }
72}
73
74static int pasemi_msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
75{
76 unsigned int virq;
77 struct msi_desc *entry;
78 struct msi_msg msg;
79 int hwirq;
80
81 if (type == PCI_CAP_ID_MSIX)
82 pr_debug("pasemi_msi: MSI-X untested, trying anyway\n");
83 pr_debug("pasemi_msi_setup_msi_irqs, pdev %p nvec %d type %d\n",
84 pdev, nvec, type);
85
86 msg.address_hi = 0;
87 msg.address_lo = PASEMI_MSI_ADDR;
88
89 msi_for_each_desc(entry, &pdev->dev, MSI_DESC_NOTASSOCIATED) {
90 /* Allocate 16 interrupts for now, since that's the grouping for
91 * affinity. This can be changed later if it turns out 32 is too
92 * few MSIs for someone, but restrictions will apply to how the
93 * sources can be changed independently.
94 */
95 hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap,
96 ALLOC_CHUNK);
97 if (hwirq < 0) {
98 pr_debug("pasemi_msi: failed allocating hwirq\n");
99 return hwirq;
100 }
101
102 virq = irq_create_mapping(domain: msi_mpic->irqhost, hwirq);
103 if (!virq) {
104 pr_debug("pasemi_msi: failed mapping hwirq 0x%x\n",
105 hwirq);
106 msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq,
107 ALLOC_CHUNK);
108 return -ENOSPC;
109 }
110
111 /* Vector on MSI is really an offset, the hardware adds
112 * it to the value written at the magic address. So set
113 * it to 0 to remain sane.
114 */
115 mpic_set_vector(virq, 0);
116
117 irq_set_msi_desc(irq: virq, entry);
118 irq_set_chip(irq: virq, chip: &mpic_pasemi_msi_chip);
119 irq_set_irq_type(irq: virq, type: IRQ_TYPE_EDGE_RISING);
120
121 pr_debug("pasemi_msi: allocated virq 0x%x (hw 0x%x) " \
122 "addr 0x%x\n", virq, hwirq, msg.address_lo);
123
124 /* Likewise, the device writes [0...511] into the target
125 * register to generate MSI [512...1023]
126 */
127 msg.data = hwirq-0x200;
128 pci_write_msi_msg(irq: virq, msg: &msg);
129 }
130
131 return 0;
132}
133
134int __init mpic_pasemi_msi_init(struct mpic *mpic)
135{
136 int rc;
137 struct pci_controller *phb;
138 struct device_node *of_node;
139
140 of_node = irq_domain_get_of_node(d: mpic->irqhost);
141 if (!of_node ||
142 !of_device_is_compatible(device: of_node,
143 "pasemi,pwrficient-openpic"))
144 return -ENODEV;
145
146 rc = mpic_msi_init_allocator(mpic);
147 if (rc) {
148 pr_debug("pasemi_msi: Error allocating bitmap!\n");
149 return rc;
150 }
151
152 pr_debug("pasemi_msi: Registering PA Semi MPIC MSI callbacks\n");
153
154 msi_mpic = mpic;
155 list_for_each_entry(phb, &hose_list, list_node) {
156 WARN_ON(phb->controller_ops.setup_msi_irqs);
157 phb->controller_ops.setup_msi_irqs = pasemi_msi_setup_msi_irqs;
158 phb->controller_ops.teardown_msi_irqs = pasemi_msi_teardown_msi_irqs;
159 }
160
161 return 0;
162}
163

source code of linux/arch/powerpc/platforms/pasemi/msi.c