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, where: dev->msi_cap + PCI_MSI_FLAGS, val: &ctrl);
21 if (ctrl & PCI_MSI_FLAGS_ENABLE) {
22 pci_write_config_word(dev, where: dev->msi_cap + PCI_MSI_FLAGS,
23 val: 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, where: dev->msix_cap + PCI_MSIX_FLAGS, val: &ctrl);
39 if (ctrl & PCI_MSIX_FLAGS_ENABLE) {
40 pci_write_config_word(dev, where: dev->msix_cap + PCI_MSIX_FLAGS,
41 val: ctrl & ~PCI_MSIX_FLAGS_ENABLE);
42 }
43}
44