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path: root/drivers/pci/msi/pcidev_msi.c
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Diffstat (limited to 'drivers/pci/msi/pcidev_msi.c')
-rw-r--r--drivers/pci/msi/pcidev_msi.c43
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 0000000000..5520aff53b
--- /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);
+ }
+}