[PATCH V6 1/5] PCI/ASPM: introduce pci_aspm_init() and add to pci_init_capabilities()

[Sinan Kaya]

We need a callback from pci_init_capabilities function for every
single new PCI device that is currently being added.

pci_aspm_init() will be used to save the power on state of the HW.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=194895
Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
---
 drivers/pci/pcie/aspm.c | 10 ++++++++++
 drivers/pci/probe.c     |  3 +++
 include/linux/pci.h     |  2 ++
 3 files changed, 15 insertions(+)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 1dfa10c..dc36717 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -827,6 +827,16 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev)
 }
 
 /*
+ * pci_aspm_init: Initiate PCI express link state.
+ * It is called from device_add for every single pci device.
+ * @pdev: all pci devices
+ */
+int pci_aspm_init(struct pci_dev *pdev)
+{
+	return 0;
+}
+
+/*
  * pcie_aspm_init_link_state: Initiate PCI express link state.
  * It is called after the pcie and its children devices are scanned.
  * @pdev: the root port or switch downstream port
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index dfc9a27..1e19364 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1847,6 +1847,9 @@ static void pci_init_capabilities(struct pci_dev *dev)
 
 	/* Advanced Error Reporting */
 	pci_aer_init(dev);
+
+	/* Active State Power Management */
+	pci_aspm_init(dev);
 }
 
 /*
diff --git a/include/linux/pci.h b/include/linux/pci.h
index eb3da1a..8828dd7 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1396,8 +1396,10 @@ static inline int pci_irq_get_node(struct pci_dev *pdev, int vec)
 
 #ifdef CONFIG_PCIEASPM
 bool pcie_aspm_support_enabled(void);
+int pci_aspm_init(struct pci_dev *pdev);
 #else
 static inline bool pcie_aspm_support_enabled(void) { return false; }
+static inline int pci_aspm_init(struct pci_dev *pdev) { return -ENODEV; }
 #endif
 
 #ifdef CONFIG_PCIEAER
-- 
1.9.1