[RFC] [PATCH net-next v5 1/3] PCI/ASPM: Introduce a new helper to report ASPM capability

From: Kai-Heng Feng
Date: Thu Sep 16 2021 - 11:44:44 EST


Introduce a new helper, pcie_aspm_capable(), to report ASPM capability.

The user will be introduced by next patch.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
---
v5:
- No change.

v4:
- Report aspm_capable instead.

v3:
- This is a new patch

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

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 013a47f587cea..788e7496f33b1 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_capable(struct pci_dev *pdev)
+{
+ struct pcie_link_state *link = pcie_aspm_get_link(pdev);
+
+ if (!link)
+ return false;
+
+ return link->aspm_capable;
+}
+EXPORT_SYMBOL_GPL(pcie_aspm_capable);
+
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 34d7d94ddf6dc..d77919d125af1 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1631,6 +1631,7 @@ 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_capable(struct pci_dev *pdev);
#else
static inline int pci_disable_link_state(struct pci_dev *pdev, int state)
{ return 0; }
@@ -1639,6 +1640,7 @@ 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_capable(struct pci_dev *pdev) { return false; }
#endif

#ifdef CONFIG_PCIEAER
--
2.32.0