[net-next,v3,2/3] PCI/ASPM: Introduce a new helper to report ASPM support status

Commit Message

Kai-Heng Feng Aug. 19, 2021, 5:45 a.m. UTC

Introduce a new helper, pcie_aspm_supported(), to report ASPM support
status.

The user will be introduced by next patch.

Signed-off-by: Kai-Heng Feng <[e-mail]>
---
v3:
 - This is a new patch

 drivers/pci/pcie/aspm.c | 11 +++++++++++
 include/linux/pci.h     |  2 ++
 2 files changed, 13 insertions(+)

Patch

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 013a47f587cea..eeea6a04ab0cf 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1201,6 +1201,17 @@  bool pcie_aspm_enabled(struct pci_dev *pdev)
 }
 EXPORT_SYMBOL_GPL(pcie_aspm_enabled);
 
+bool pcie_aspm_supported(struct pci_dev *pdev)
+{
+	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
+
+	if (!link)
+		return false;
+
+	return link->aspm_support;
+}
+EXPORT_SYMBOL_GPL(pcie_aspm_supported);
+
 static ssize_t aspm_attr_show_common(struct device *dev,
 				     struct device_attribute *attr,
 				     char *buf, u8 state)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 540b377ca8f61..b7b71982f2405 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1602,6 +1602,7 @@  int pci_disable_link_state_locked(struct pci_dev *pdev, int state);
 void pcie_no_aspm(void);
 bool pcie_aspm_support_enabled(void);
 bool pcie_aspm_enabled(struct pci_dev *pdev);
+bool pcie_aspm_supported(struct pci_dev *pdev);
 #else
 static inline int pci_disable_link_state(struct pci_dev *pdev, int state)
 { return 0; }
@@ -1610,6 +1611,7 @@  static inline int pci_disable_link_state_locked(struct pci_dev *pdev, int state)
 static inline void pcie_no_aspm(void) { }
 static inline bool pcie_aspm_support_enabled(void) { return false; }
 static inline bool pcie_aspm_enabled(struct pci_dev *pdev) { return false; }
+static inline bool pcie_aspm_supported(struct pci_dev *pdev) { return false; }
 #endif
 
 #ifdef CONFIG_PCIEAER