1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * PCI Message Signaled Interrupt (MSI).
 4 *
 5 * Legacy architecture specific setup and teardown mechanism.
 6 */
 7#include "msi.h"
 8
 9/* Arch hooks */
10int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
11{
12	return -EINVAL;
13}
14
15void __weak arch_teardown_msi_irq(unsigned int irq)
16{
17}
18
19int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
20{
21	struct msi_desc *desc;
22	int ret;
23
24	/*
25	 * If an architecture wants to support multiple MSI, it needs to
26	 * override arch_setup_msi_irqs()
27	 */
28	if (type == PCI_CAP_ID_MSI && nvec > 1)
29		return 1;
30
31	msi_for_each_desc(desc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
32		ret = arch_setup_msi_irq(dev, desc);
33		if (ret)
34			return ret < 0 ? ret : -ENOSPC;
35	}
36
37	return 0;
38}
39
40void __weak arch_teardown_msi_irqs(struct pci_dev *dev)
41{
42	struct msi_desc *desc;
43	int i;
44
45	msi_for_each_desc(desc, &dev->dev, MSI_DESC_ASSOCIATED) {
46		for (i = 0; i < desc->nvec_used; i++)
47			arch_teardown_msi_irq(desc->irq + i);
48	}
49}
50
51static int pci_msi_setup_check_result(struct pci_dev *dev, int type, int ret)
52{
53	struct msi_desc *desc;
54	int avail = 0;
55
56	if (type != PCI_CAP_ID_MSIX || ret >= 0)
57		return ret;
58
59	/* Scan the MSI descriptors for successfully allocated ones. */
60	msi_for_each_desc(desc, &dev->dev, MSI_DESC_ASSOCIATED)
61		avail++;
62
63	return avail ? avail : ret;
64}
65
66int pci_msi_legacy_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
67{
68	int ret = arch_setup_msi_irqs(dev, nvec, type);
69
70	ret = pci_msi_setup_check_result(dev, type, ret);
71	if (!ret)
72		ret = msi_device_populate_sysfs(&dev->dev);
73	return ret;
74}
75
76void pci_msi_legacy_teardown_msi_irqs(struct pci_dev *dev)
77{
78	msi_device_destroy_sysfs(&dev->dev);
79	arch_teardown_msi_irqs(dev);
80}