From accd2dd72c8f087441d725dd916688171519e4e6 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 9 Aug 2019 10:23:57 +0200 Subject: [PATCH] PCI/ASPM: Add pcie_aspm_enabled() Add a function checking whether or not PCIe ASPM has been enabled for a given device. It will be used by the NVMe driver to decide how to handle the device during system suspend. Signed-off-by: Rafael J. Wysocki Reviewed-by: Keith Busch Acked-by: Bjorn Helgaas --- drivers/pci/pcie/aspm.c | 20 ++++++++++++++++++++ include/linux/pci.h | 2 ++ 2 files changed, 22 insertions(+) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index e44af7f4d37f..464f8f92653f 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1170,6 +1170,26 @@ static int pcie_aspm_get_policy(char *buffer, const struct kernel_param *kp) module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy, NULL, 0644); +/** + * pcie_aspm_enabled - Check if PCIe ASPM has been enabled for a device. + * @pdev: Target device. + */ +bool pcie_aspm_enabled(struct pci_dev *pdev) +{ + struct pci_dev *bridge = pci_upstream_bridge(pdev); + bool ret; + + if (!bridge) + return false; + + mutex_lock(&aspm_lock); + ret = bridge->link_state ? !!bridge->link_state->aspm_enabled : false; + mutex_unlock(&aspm_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(pcie_aspm_enabled); + #ifdef CONFIG_PCIEASPM_DEBUG static ssize_t link_state_show(struct device *dev, struct device_attribute *attr, diff --git a/include/linux/pci.h b/include/linux/pci.h index 9e700d9f9f28..82e4cd1b7ac3 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1567,8 +1567,10 @@ extern bool pcie_ports_native; #ifdef CONFIG_PCIEASPM bool pcie_aspm_support_enabled(void); +bool pcie_aspm_enabled(struct pci_dev *pdev); #else static inline bool pcie_aspm_support_enabled(void) { return false; } +static inline bool pcie_aspm_enabled(struct pci_dev *pdev) { return false; } #endif #ifdef CONFIG_PCIEAER