[pci] Add generic configuration space backup/restore facility

Some devices can only be reset via a mechanism that also resets the
card's PCI core, thus necessitating a backup and restore of all or
part of the PCI configuration space across a reset.

1 files changed, 33 insertions, 0 deletions

diff --git a/src/include/gpxe/pcibackup.h b/src/include/gpxe/pcibackup.h
new file mode 100644
index 000000000..3d295c0fc
--- /dev/null
+++ b/src/include/gpxe/pcibackup.h
@@ -0,0 +1,33 @@
+#ifndef _GPXE_PCIBACKUP_H
+#define _GPXE_PCIBACKUP_H
+
+/** @file
+ *
+ * PCI configuration space backup and restoration
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+
+/** A PCI configuration space backup */
+struct pci_config_backup {
+	uint32_t dwords[64];
+};
+
+/** PCI configuration space backup exclusion list end marker */
+#define PCI_CONFIG_BACKUP_EXCLUDE_END 0xff
+
+/** Define a PCI configuration space backup exclusion list */
+#define PCI_CONFIG_BACKUP_EXCLUDE(...) \
+	{ __VA_ARGS__, PCI_CONFIG_BACKUP_EXCLUDE_END }
+
+extern void pci_backup ( struct pci_device *pci,
+			 struct pci_config_backup *backup,
+			 const uint8_t *exclude );
+extern void pci_restore ( struct pci_device *pci,
+			  struct pci_config_backup *backup,
+			  const uint8_t *exclude );
+
+#endif /* _GPXE_PCIBACKUP_H */