1// SPDX-License-Identifier: GPL-2.0
2/*
3 * MSI[X} related functions which are available unconditionally.
4 */
5#include "../pci.h"
6
7/*
8 * Disable the MSI[X] hardware to avoid screaming interrupts during boot.
9 * This is the power on reset default so usually this should be a noop.
10 */
11
12void pci_msi_init(struct pci_dev *dev)
13{
14	u16 ctrl;
15
16	dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI);
17	if (!dev->msi_cap)
18		return;
19
20	pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &ctrl);
21	if (ctrl & PCI_MSI_FLAGS_ENABLE) {
22		pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS,
23				      ctrl & ~PCI_MSI_FLAGS_ENABLE);
24	}
25
26	if (!(ctrl & PCI_MSI_FLAGS_64BIT))
27		dev->no_64bit_msi = 1;
28}
29
30void pci_msix_init(struct pci_dev *dev)
31{
32	u16 ctrl;
33
34	dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX);
35	if (!dev->msix_cap)
36		return;
37
38	pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
39	if (ctrl & PCI_MSIX_FLAGS_ENABLE) {
40		pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS,
41				      ctrl & ~PCI_MSIX_FLAGS_ENABLE);
42	}
43}
44