Merge branch 'pci/aspm'

  - Remove unnecessary ASPM locking (Bjorn Helgaas)

  - Add support for disabling L1 PM Substates (Heiner Kallweit)

  - Allow re-enabling Clock PM after it has been disabled (Heiner Kallweit)

  - Add sysfs attributes for controlling ASPM link states (Heiner Kallweit)

  - Remove CONFIG_PCIEASPM_DEBUG, including "link_state" and "clk_ctl"
    sysfs files (Heiner Kallweit)

* pci/aspm:
  PCI/ASPM: Remove PCIEASPM_DEBUG Kconfig option and related code
  PCI/ASPM: Add sysfs attributes for controlling ASPM link states
  PCI/ASPM: Add pcie_aspm_get_link()
  PCI/ASPM: Allow re-enabling Clock PM
  PCI/ASPM: Add L1 PM substate support to pci_disable_link_state()
  PCI/ASPM: Remove pcie_aspm_enabled() unnecessary locking

4 files changed, 161 insertions, 109 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 793412954529..92bf1b1ce280 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/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 @@ err:
 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;
@@ -1588,6 +1585,9 @@ static const struct attribute_group *pci_dev_attr_groups[] = {
 #ifdef CONFIG_PCIEAER
 	&aer_stats_attr_group,
 #endif
+#ifdef CONFIG_PCIEASPM
+	&aspm_ctrl_attr_group,
+#endif
 	NULL,
 };
 
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b96988f90315..23e06feed6cb 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -542,14 +542,6 @@ 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);
@@ -668,4 +660,8 @@ static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
 }
 #endif
 
+#ifdef CONFIG_PCIEASPM
+extern const struct attribute_group aspm_ctrl_attr_group;
+#endif
+
 #endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index 362eb8cfa53b..a2e862d4ec21 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/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
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 652ef23bba35..0dcd44308228 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -64,6 +64,7 @@ struct pcie_link_state {
 	u32 clkpm_capable:1;		/* Clock PM capable? */
 	u32 clkpm_enabled:1;		/* Current Clock PM state */
 	u32 clkpm_default:1;		/* Default Clock PM state by BIOS */
+	u32 clkpm_disable:1;		/* Clock PM disabled */
 
 	/* Exit latencies */
 	struct aspm_latency latency_up;	/* Upstream direction exit latency */
@@ -161,8 +162,11 @@ static void pcie_set_clkpm_nocheck(struct pcie_link_state *link, int enable)
 
 static void pcie_set_clkpm(struct pcie_link_state *link, int enable)
 {
-	/* Don't enable Clock PM if the link is not Clock PM capable */
-	if (!link->clkpm_capable)
+	/*
+	 * Don't enable Clock PM if the link is not Clock PM capable
+	 * or Clock PM is disabled
+	 */
+	if (!link->clkpm_capable || link->clkpm_disable)
 		enable = 0;
 	/* Need nothing if the specified equals to current state */
 	if (link->clkpm_enabled == enable)
@@ -192,7 +196,8 @@ static void pcie_clkpm_cap_init(struct pcie_link_state *link, int blacklist)
 	}
 	link->clkpm_enabled = enabled;
 	link->clkpm_default = enabled;
-	link->clkpm_capable = (blacklist) ? 0 : capable;
+	link->clkpm_capable = capable;
+	link->clkpm_disable = blacklist ? 1 : 0;
 }
 
 static bool pcie_retrain_link(struct pcie_link_state *link)
@@ -894,6 +899,14 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev)
 	return link;
 }
 
+static void pcie_aspm_update_sysfs_visibility(struct pci_dev *pdev)
+{
+	struct pci_dev *child;
+
+	list_for_each_entry(child, &pdev->subordinate->devices, bus_list)
+		sysfs_update_group(&child->dev.kobj, &aspm_ctrl_attr_group);
+}
+
 /*
  * pcie_aspm_init_link_state: Initiate PCI express link state.
  * It is called after the pcie and its children devices are scanned.
@@ -955,6 +968,8 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev)
 		pcie_set_clkpm(link, policy_to_clkpm_state(link));
 	}
 
+	pcie_aspm_update_sysfs_visibility(pdev);
+
 unlock:
 	mutex_unlock(&aspm_lock);
 out:
@@ -1061,19 +1076,26 @@ void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
 	up_read(&pci_bus_sem);
 }
 
-static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
+static struct pcie_link_state *pcie_aspm_get_link(struct pci_dev *pdev)
 {
-	struct pci_dev *parent = pdev->bus->self;
-	struct pcie_link_state *link;
+	struct pci_dev *bridge;
 
 	if (!pci_is_pcie(pdev))
-		return 0;
+		return NULL;
 
-	if (pcie_downstream_port(pdev))
-		parent = pdev;
-	if (!parent || !parent->link_state)
-		return -EINVAL;
+	bridge = pci_upstream_bridge(pdev);
+	if (!bridge || !pci_is_pcie(bridge))
+		return NULL;
 
+	return bridge->link_state;
+}
+
+static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
+{
+	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
+
+	if (!link)
+		return -EINVAL;
 	/*
 	 * A driver requested that ASPM be disabled on this device, but
 	 * if we don't have permission to manage ASPM (e.g., on ACPI
@@ -1090,17 +1112,24 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem)
 	if (sem)
 		down_read(&pci_bus_sem);
 	mutex_lock(&aspm_lock);
-	link = parent->link_state;
 	if (state & PCIE_LINK_STATE_L0S)
 		link->aspm_disable |= ASPM_STATE_L0S;
 	if (state & PCIE_LINK_STATE_L1)
-		link->aspm_disable |= ASPM_STATE_L1;
+		/* L1 PM substates require L1 */
+		link->aspm_disable |= ASPM_STATE_L1 | ASPM_STATE_L1SS;
+	if (state & PCIE_LINK_STATE_L1_1)
+		link->aspm_disable |= ASPM_STATE_L1_1;
+	if (state & PCIE_LINK_STATE_L1_2)
+		link->aspm_disable |= ASPM_STATE_L1_2;
+	if (state & PCIE_LINK_STATE_L1_1_PCIPM)
+		link->aspm_disable |= ASPM_STATE_L1_1_PCIPM;
+	if (state & PCIE_LINK_STATE_L1_2_PCIPM)
+		link->aspm_disable |= ASPM_STATE_L1_2_PCIPM;
 	pcie_config_aspm_link(link, policy_to_aspm_state(link));
 
-	if (state & PCIE_LINK_STATE_CLKPM) {
-		link->clkpm_capable = 0;
-		pcie_set_clkpm(link, 0);
-	}
+	if (state & PCIE_LINK_STATE_CLKPM)
+		link->clkpm_disable = 1;
+	pcie_set_clkpm(link, policy_to_clkpm_state(link));
 	mutex_unlock(&aspm_lock);
 	if (sem)
 		up_read(&pci_bus_sem);
@@ -1172,127 +1201,161 @@ module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy,
 /**
  * pcie_aspm_enabled - Check if PCIe ASPM has been enabled for a device.
  * @pdev: Target device.
+ *
+ * Relies on the upstream bridge's link_state being valid.  The link_state
+ * is deallocated only when the last child of the bridge (i.e., @pdev or a
+ * sibling) is removed, and the caller should be holding a reference to
+ * @pdev, so this should be safe.
  */
 bool pcie_aspm_enabled(struct pci_dev *pdev)
 {
-	struct pci_dev *bridge = pci_upstream_bridge(pdev);
-	bool ret;
+	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
 
-	if (!bridge)
+	if (!link)
 		return false;
 
-	mutex_lock(&aspm_lock);
-	ret = bridge->link_state ? !!bridge->link_state->aspm_enabled : false;
-	mutex_unlock(&aspm_lock);
-
-	return ret;
+	return link->aspm_enabled;
 }
 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)
+static ssize_t aspm_attr_show_common(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf, u8 state)
 {
-	struct pci_dev *pci_device = to_pci_dev(dev);
-	struct pcie_link_state *link_state = pci_device->link_state;
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
 
-	return sprintf(buf, "%d\n", link_state->aspm_enabled);
+	return sprintf(buf, "%d\n", (link->aspm_enabled & state) ? 1 : 0);
 }
 
-static ssize_t link_state_store(struct device *dev,
-		struct device_attribute *attr,
-		const char *buf,
-		size_t n)
+static ssize_t aspm_attr_store_common(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t len, u8 state)
 {
 	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;
+	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
+	bool state_enable;
 
-	if (kstrtouint(buf, 10, &state))
-		return -EINVAL;
-	if ((state & ~ASPM_STATE_ALL) != 0)
+	if (strtobool(buf, &state_enable) < 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);
+
+	if (state_enable) {
+		link->aspm_disable &= ~state;
+		/* need to enable L1 for substates */
+		if (state & ASPM_STATE_L1SS)
+			link->aspm_disable &= ~ASPM_STATE_L1;
+	} else {
+		link->aspm_disable |= state;
 	}
+
+	pcie_config_aspm_link(link, policy_to_aspm_state(link));
+
 	mutex_unlock(&aspm_lock);
 	up_read(&pci_bus_sem);
-	return n;
+
+	return len;
 }
 
-static ssize_t clk_ctl_show(struct device *dev,
-		struct device_attribute *attr,
-		char *buf)
+#define ASPM_ATTR(_f, _s)						\
+static ssize_t _f##_show(struct device *dev,				\
+			 struct device_attribute *attr, char *buf)	\
+{ return aspm_attr_show_common(dev, attr, buf, ASPM_STATE_##_s); }	\
+									\
+static ssize_t _f##_store(struct device *dev,				\
+			  struct device_attribute *attr,		\
+			  const char *buf, size_t len)			\
+{ return aspm_attr_store_common(dev, attr, buf, len, ASPM_STATE_##_s); }
+
+ASPM_ATTR(l0s_aspm, L0S)
+ASPM_ATTR(l1_aspm, L1)
+ASPM_ATTR(l1_1_aspm, L1_1)
+ASPM_ATTR(l1_2_aspm, L1_2)
+ASPM_ATTR(l1_1_pcipm, L1_1_PCIPM)
+ASPM_ATTR(l1_2_pcipm, L1_2_PCIPM)
+
+static ssize_t clkpm_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;
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
 
-	return sprintf(buf, "%d\n", link_state->clkpm_enabled);
+	return sprintf(buf, "%d\n", link->clkpm_enabled);
 }
 
-static ssize_t clk_ctl_store(struct device *dev,
-		struct device_attribute *attr,
-		const char *buf,
-		size_t n)
+static ssize_t clkpm_store(struct device *dev,
+			   struct device_attribute *attr,
+			   const char *buf, size_t len)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
-	bool state;
+	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
+	bool state_enable;
 
-	if (strtobool(buf, &state))
+	if (strtobool(buf, &state_enable) < 0)
 		return -EINVAL;
 
 	down_read(&pci_bus_sem);
 	mutex_lock(&aspm_lock);
-	pcie_set_clkpm_nocheck(pdev->link_state, state);
+
+	link->clkpm_disable = !state_enable;
+	pcie_set_clkpm(link, policy_to_clkpm_state(link));
+
 	mutex_unlock(&aspm_lock);
 	up_read(&pci_bus_sem);
 
-	return n;
+	return len;
 }
 
-static DEVICE_ATTR_RW(link_state);
-static DEVICE_ATTR_RW(clk_ctl);
+static DEVICE_ATTR_RW(clkpm);
+static DEVICE_ATTR_RW(l0s_aspm);
+static DEVICE_ATTR_RW(l1_aspm);
+static DEVICE_ATTR_RW(l1_1_aspm);
+static DEVICE_ATTR_RW(l1_2_aspm);
+static DEVICE_ATTR_RW(l1_1_pcipm);
+static DEVICE_ATTR_RW(l1_2_pcipm);
+
+static struct attribute *aspm_ctrl_attrs[] = {
+	&dev_attr_clkpm.attr,
+	&dev_attr_l0s_aspm.attr,
+	&dev_attr_l1_aspm.attr,
+	&dev_attr_l1_1_aspm.attr,
+	&dev_attr_l1_2_aspm.attr,
+	&dev_attr_l1_1_pcipm.attr,
+	&dev_attr_l1_2_pcipm.attr,
+	NULL
+};
 
-static char power_group[] = "power";
-void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev)
+static umode_t aspm_ctrl_attrs_are_visible(struct kobject *kobj,
+					   struct attribute *a, int n)
 {
-	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);
-}
+	struct device *dev = kobj_to_dev(kobj);
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pcie_link_state *link = pcie_aspm_get_link(pdev);
+	static const u8 aspm_state_map[] = {
+		ASPM_STATE_L0S,
+		ASPM_STATE_L1,
+		ASPM_STATE_L1_1,
+		ASPM_STATE_L1_2,
+		ASPM_STATE_L1_1_PCIPM,
+		ASPM_STATE_L1_2_PCIPM,
+	};
 
-void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
-{
-	struct pcie_link_state *link_state = pdev->link_state;
+	if (aspm_disabled || !link)
+		return 0;
 
-	if (!link_state)
-		return;
+	if (n == 0)
+		return link->clkpm_capable ? a->mode : 0;
 
-	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);
+	return link->aspm_capable & aspm_state_map[n - 1] ? a->mode : 0;
 }
-#endif
+
+const struct attribute_group aspm_ctrl_attr_group = {
+	.name = "link",
+	.attrs = aspm_ctrl_attrs,
+	.is_visible = aspm_ctrl_attrs_are_visible,
+};
 
 static int __init pcie_aspm_disable(char *str)
 {