diff options
Diffstat (limited to 'drivers/pci/msi/pcidev_msi.c')
| -rw-r--r-- | drivers/pci/msi/pcidev_msi.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/drivers/pci/msi/pcidev_msi.c b/drivers/pci/msi/pcidev_msi.c new file mode 100644 index 000000000..5520aff53 --- /dev/null +++ b/drivers/pci/msi/pcidev_msi.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MSI[X} related functions which are available unconditionally. + */ +#include "../pci.h" + +/* + * Disable the MSI[X] hardware to avoid screaming interrupts during boot. + * This is the power on reset default so usually this should be a noop. + */ + +void pci_msi_init(struct pci_dev *dev) +{ + u16 ctrl; + + dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI); + if (!dev->msi_cap) + return; + + pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &ctrl); + if (ctrl & PCI_MSI_FLAGS_ENABLE) { + pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, + ctrl & ~PCI_MSI_FLAGS_ENABLE); + } + + if (!(ctrl & PCI_MSI_FLAGS_64BIT)) + dev->no_64bit_msi = 1; +} + +void pci_msix_init(struct pci_dev *dev) +{ + u16 ctrl; + + dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX); + if (!dev->msix_cap) + return; + + pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl); + if (ctrl & PCI_MSIX_FLAGS_ENABLE) { + pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, + ctrl & ~PCI_MSIX_FLAGS_ENABLE); + } +} |