Move common macros and structures from drivers/pci/doe.c to
drivers/pci/pci.h to allow reuse across root complex and
endpoint DOE implementations.

PCI_DOE_MAX_LENGTH macro can be used outside the PCI core as well,
hence move the macro to include/linux/pci-doe.h.

These changes prepare the groundwork for the DOE endpoint implementation
that will reuse these common definitions.

Co-developed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: Aksh Garg <a-garg7@ti.com>
---

Changes since v1:
- Moved the common macros that need not be visible outside the PCI core
  to drivers/pci/pci.h instead to include/linux/pci-doe.h as suggested
  by Lukas Wunner
- Removed the redundant empty inlines guarded with CONFIG_PCI_DOE in
  include/linux/pci-doe.h.

v1: https://lore.kernel.org/all/20260213123603.420941-3-a-garg7@ti.com/

 drivers/pci/doe.c       | 11 -----------
 drivers/pci/pci.h       |  9 +++++++++
 include/linux/pci-doe.h |  3 +++
 3 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/doe.c b/drivers/pci/doe.c
index 7b41da4ec11a..e8d9e95644b3 100644
--- a/drivers/pci/doe.c
+++ b/drivers/pci/doe.c
@@ -28,12 +28,6 @@
 #define PCI_DOE_TIMEOUT HZ
 #define PCI_DOE_POLL_INTERVAL	(PCI_DOE_TIMEOUT / 128)
 
-#define PCI_DOE_FLAG_CANCEL	0
-#define PCI_DOE_FLAG_DEAD	1
-
-/* Max data object length is 2^18 dwords */
-#define PCI_DOE_MAX_LENGTH	(1 << 18)
-
 /**
  * struct pci_doe_mb - State for a single DOE mailbox
  *
@@ -63,11 +57,6 @@ struct pci_doe_mb {
 #endif
 };
 
-struct pci_doe_feature {
-	u16 vid;
-	u8 type;
-};
-
 /**
  * struct pci_doe_task - represents a single query/response
  *
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 13d998fbacce..66b7ec80f46f 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -681,6 +681,15 @@ struct pci_sriov {
 	bool		drivers_autoprobe; /* Auto probing of VFs by driver */
 };
 
+/* DOE Mailbox state flags */
+#define PCI_DOE_FLAG_CANCEL	0
+#define PCI_DOE_FLAG_DEAD	1
+
+struct pci_doe_feature {
+	u16 vid;
+	u8 type;
+};
+
 #ifdef CONFIG_PCI_DOE
 void pci_doe_init(struct pci_dev *pdev);
 void pci_doe_destroy(struct pci_dev *pdev);
diff --git a/include/linux/pci-doe.h b/include/linux/pci-doe.h
index bd4346a7c4e7..abb9b7ae8029 100644
--- a/include/linux/pci-doe.h
+++ b/include/linux/pci-doe.h
@@ -19,6 +19,9 @@ struct pci_doe_mb;
 #define PCI_DOE_FEATURE_CMA 1
 #define PCI_DOE_FEATURE_SSESSION 2
 
+/* Max data object length is 2^18 dwords */
+#define PCI_DOE_MAX_LENGTH		(1 << 18)
+
 struct pci_doe_mb *pci_find_doe_mailbox(struct pci_dev *pdev, u16 vendor,
 					u8 type);
 
-- 
2.34.1