PCI/ASPM: Remove PCIEASPM_DEBUG Kconfig option and related code

BguLink: https://bugs.launchpad.net/bugs/1836030

Previously, CONFIG_PCIEASPM_DEBUG enabled "link_state" and "clk_ctl" sysfs
files that controlled ASPM.  We believe these files were rarely if ever
used.

We recently added sysfs ASPM controls that are always present, so the debug
code is no longer needed.  Removing this debug code has been discussed for
quite some time, see e.g. [0].

Remove PCIEASPM_DEBUG and the related code.

[0] https://lore.kernel.org/lkml/20180727202619.GD173328@bhelgaas-glaptop.roam.corp.google.com/
Link: https://lore.kernel.org/r/ec935d8e-c084-3938-f1d1-748617596b25@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
(cherry picked from commit 87e9028)
Signed-off-by: AceLan Kao <acelan.kao@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

Author: hkallweit

drivers/pci/pci-sysfs.c

@@ -1330,7 +1330,6 @@ static int pci_create_capabilities_sysfs(struct pci_dev *dev)
 	int retval;
 
 	pcie_vpd_create_sysfs_dev_files(dev);
-	pcie_aspm_create_sysfs_dev_files(dev);
 
 	if (dev->reset_fn) {
 		retval = device_create_file(&dev->dev, &dev_attr_reset);
@@ -1340,7 +1339,6 @@ static int pci_create_capabilities_sysfs(struct pci_dev *dev)
 	return 0;
 
 error:
-	pcie_aspm_remove_sysfs_dev_files(dev);
 	pcie_vpd_remove_sysfs_dev_files(dev);
 	return retval;
 }
@@ -1416,7 +1414,6 @@ int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
 static void pci_remove_capabilities_sysfs(struct pci_dev *dev)
 {
 	pcie_vpd_remove_sysfs_dev_files(dev);
-	pcie_aspm_remove_sysfs_dev_files(dev);
 	if (dev->reset_fn) {
 		device_remove_file(&dev->dev, &dev_attr_reset);
 		dev->reset_fn = 0;

drivers/pci/pci.h

@@ -545,14 +545,6 @@ static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { }
 static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { }
 #endif
 
-#ifdef CONFIG_PCIEASPM_DEBUG
-void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev);
-void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev);
-#else
-static inline void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev) { }
-static inline void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev) { }
-#endif
-
 #ifdef CONFIG_PCIE_ECRC
 void pcie_set_ecrc_checking(struct pci_dev *dev);
 void pcie_ecrc_get_policy(char *str);

drivers/pci/pcie/Kconfig

@@ -79,13 +79,6 @@ config PCIEASPM
 
 	  When in doubt, say Y.
 
-config PCIEASPM_DEBUG
-	bool "Debug PCI Express ASPM"
-	depends on PCIEASPM
-	help
-	  This enables PCI Express ASPM debug support. It will add per-device
-	  interface to control ASPM.
-
 choice
 	prompt "Default ASPM policy"
 	default PCIEASPM_DEFAULT

drivers/pci/pcie/aspm.c

@@ -1218,111 +1218,6 @@ bool pcie_aspm_enabled(struct pci_dev *pdev)
 }
 EXPORT_SYMBOL_GPL(pcie_aspm_enabled);
 
-#ifdef CONFIG_PCIEASPM_DEBUG
-static ssize_t link_state_show(struct device *dev,
-		struct device_attribute *attr,
-		char *buf)
-{
-	struct pci_dev *pci_device = to_pci_dev(dev);
-	struct pcie_link_state *link_state = pci_device->link_state;
-
-	return sprintf(buf, "%d\n", link_state->aspm_enabled);
-}
-
-static ssize_t link_state_store(struct device *dev,
-		struct device_attribute *attr,
-		const char *buf,
-		size_t n)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	struct pcie_link_state *link, *root = pdev->link_state->root;
-	u32 state;
-
-	if (aspm_disabled)
-		return -EPERM;
-
-	if (kstrtouint(buf, 10, &state))
-		return -EINVAL;
-	if ((state & ~ASPM_STATE_ALL) != 0)
-		return -EINVAL;
-
-	down_read(&pci_bus_sem);
-	mutex_lock(&aspm_lock);
-	list_for_each_entry(link, &link_list, sibling) {
-		if (link->root != root)
-			continue;
-		pcie_config_aspm_link(link, state);
-	}
-	mutex_unlock(&aspm_lock);
-	up_read(&pci_bus_sem);
-	return n;
-}
-
-static ssize_t clk_ctl_show(struct device *dev,
-		struct device_attribute *attr,
-		char *buf)
-{
-	struct pci_dev *pci_device = to_pci_dev(dev);
-	struct pcie_link_state *link_state = pci_device->link_state;
-
-	return sprintf(buf, "%d\n", link_state->clkpm_enabled);
-}
-
-static ssize_t clk_ctl_store(struct device *dev,
-		struct device_attribute *attr,
-		const char *buf,
-		size_t n)
-{
-	struct pci_dev *pdev = to_pci_dev(dev);
-	bool state;
-
-	if (strtobool(buf, &state))
-		return -EINVAL;
-
-	down_read(&pci_bus_sem);
-	mutex_lock(&aspm_lock);
-	pcie_set_clkpm_nocheck(pdev->link_state, state);
-	mutex_unlock(&aspm_lock);
-	up_read(&pci_bus_sem);
-
-	return n;
-}
-
-static DEVICE_ATTR_RW(link_state);
-static DEVICE_ATTR_RW(clk_ctl);
-
-static char power_group[] = "power";
-void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev)
-{
-	struct pcie_link_state *link_state = pdev->link_state;
-
-	if (!link_state)
-		return;
-
-	if (link_state->aspm_support)
-		sysfs_add_file_to_group(&pdev->dev.kobj,
-			&dev_attr_link_state.attr, power_group);
-	if (link_state->clkpm_capable)
-		sysfs_add_file_to_group(&pdev->dev.kobj,
-			&dev_attr_clk_ctl.attr, power_group);
-}
-
-void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
-{
-	struct pcie_link_state *link_state = pdev->link_state;
-
-	if (!link_state)
-		return;
-
-	if (link_state->aspm_support)
-		sysfs_remove_file_from_group(&pdev->dev.kobj,
-			&dev_attr_link_state.attr, power_group);
-	if (link_state->clkpm_capable)
-		sysfs_remove_file_from_group(&pdev->dev.kobj,
-			&dev_attr_clk_ctl.attr, power_group);
-}
-#endif
-
 static ssize_t aspm_attr_show_common(struct device *dev,
 				     struct device_attribute *attr,
 				     char *buf, u8 state)