Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 979 insertions, 0 deletions

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
new file mode 100644
index 000000000..279544523
--- /dev/null
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -0,0 +1,979 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCI Express PCI Hot Plug Driver
+ *
+ * Copyright (C) 1995,2001 Compaq Computer Corporation
+ * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 2001 IBM Corp.
+ * Copyright (C) 2003-2004 Intel Corporation
+ *
+ * All rights reserved.
+ *
+ * Send feedback to <greg@kroah.com>,<kristen.c.accardi@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/signal.h>
+#include <linux/jiffies.h>
+#include <linux/kthread.h>
+#include <linux/pci.h>
+#include <linux/pm_runtime.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/slab.h>
+
+#include "../pci.h"
+#include "pciehp.h"
+
+static inline struct pci_dev *ctrl_dev(struct controller *ctrl)
+{
+	return ctrl->pcie->port;
+}
+
+static irqreturn_t pciehp_isr(int irq, void *dev_id);
+static irqreturn_t pciehp_ist(int irq, void *dev_id);
+static int pciehp_poll(void *data);
+
+static inline int pciehp_request_irq(struct controller *ctrl)
+{
+	int retval, irq = ctrl->pcie->irq;
+
+	if (pciehp_poll_mode) {
+		ctrl->poll_thread = kthread_run(&pciehp_poll, ctrl,
+						"pciehp_poll-%s",
+						slot_name(ctrl->slot));
+		return PTR_ERR_OR_ZERO(ctrl->poll_thread);
+	}
+
+	/* Installs the interrupt handler */
+	retval = request_threaded_irq(irq, pciehp_isr, pciehp_ist,
+				      IRQF_SHARED, MY_NAME, ctrl);
+	if (retval)
+		ctrl_err(ctrl, "Cannot get irq %d for the hotplug controller\n",
+			 irq);
+	return retval;
+}
+
+static inline void pciehp_free_irq(struct controller *ctrl)
+{
+	if (pciehp_poll_mode)
+		kthread_stop(ctrl->poll_thread);
+	else
+		free_irq(ctrl->pcie->irq, ctrl);
+}
+
+static int pcie_poll_cmd(struct controller *ctrl, int timeout)
+{
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	u16 slot_status;
+
+	while (true) {
+		pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
+		if (slot_status == (u16) ~0) {
+			ctrl_info(ctrl, "%s: no response from device\n",
+				  __func__);
+			return 0;
+		}
+
+		if (slot_status & PCI_EXP_SLTSTA_CC) {
+			pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
+						   PCI_EXP_SLTSTA_CC);
+			ctrl->cmd_busy = 0;
+			smp_mb();
+			return 1;
+		}
+		if (timeout < 0)
+			break;
+		msleep(10);
+		timeout -= 10;
+	}
+	return 0;	/* timeout */
+}
+
+static void pcie_wait_cmd(struct controller *ctrl)
+{
+	unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
+	unsigned long duration = msecs_to_jiffies(msecs);
+	unsigned long cmd_timeout = ctrl->cmd_started + duration;
+	unsigned long now, timeout;
+	int rc;
+
+	/*
+	 * If the controller does not generate notifications for command
+	 * completions, we never need to wait between writes.
+	 */
+	if (NO_CMD_CMPL(ctrl))
+		return;
+
+	if (!ctrl->cmd_busy)
+		return;
+
+	/*
+	 * Even if the command has already timed out, we want to call
+	 * pcie_poll_cmd() so it can clear PCI_EXP_SLTSTA_CC.
+	 */
+	now = jiffies;
+	if (time_before_eq(cmd_timeout, now))
+		timeout = 1;
+	else
+		timeout = cmd_timeout - now;
+
+	if (ctrl->slot_ctrl & PCI_EXP_SLTCTL_HPIE &&
+	    ctrl->slot_ctrl & PCI_EXP_SLTCTL_CCIE)
+		rc = wait_event_timeout(ctrl->queue, !ctrl->cmd_busy, timeout);
+	else
+		rc = pcie_poll_cmd(ctrl, jiffies_to_msecs(timeout));
+
+	if (!rc)
+		ctrl_info(ctrl, "Timeout on hotplug command %#06x (issued %u msec ago)\n",
+			  ctrl->slot_ctrl,
+			  jiffies_to_msecs(jiffies - ctrl->cmd_started));
+}
+
+#define CC_ERRATUM_MASK		(PCI_EXP_SLTCTL_PCC |	\
+				 PCI_EXP_SLTCTL_PIC |	\
+				 PCI_EXP_SLTCTL_AIC |	\
+				 PCI_EXP_SLTCTL_EIC)
+
+static void pcie_do_write_cmd(struct controller *ctrl, u16 cmd,
+			      u16 mask, bool wait)
+{
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	u16 slot_ctrl_orig, slot_ctrl;
+
+	mutex_lock(&ctrl->ctrl_lock);
+
+	/*
+	 * Always wait for any previous command that might still be in progress
+	 */
+	pcie_wait_cmd(ctrl);
+
+	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
+	if (slot_ctrl == (u16) ~0) {
+		ctrl_info(ctrl, "%s: no response from device\n", __func__);
+		goto out;
+	}
+
+	slot_ctrl_orig = slot_ctrl;
+	slot_ctrl &= ~mask;
+	slot_ctrl |= (cmd & mask);
+	ctrl->cmd_busy = 1;
+	smp_mb();
+	pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, slot_ctrl);
+	ctrl->cmd_started = jiffies;
+	ctrl->slot_ctrl = slot_ctrl;
+
+	/*
+	 * Controllers with the Intel CF118 and similar errata advertise
+	 * Command Completed support, but they only set Command Completed
+	 * if we change the "Control" bits for power, power indicator,
+	 * attention indicator, or interlock.  If we only change the
+	 * "Enable" bits, they never set the Command Completed bit.
+	 */
+	if (pdev->broken_cmd_compl &&
+	    (slot_ctrl_orig & CC_ERRATUM_MASK) == (slot_ctrl & CC_ERRATUM_MASK))
+		ctrl->cmd_busy = 0;
+
+	/*
+	 * Optionally wait for the hardware to be ready for a new command,
+	 * indicating completion of the above issued command.
+	 */
+	if (wait)
+		pcie_wait_cmd(ctrl);
+
+out:
+	mutex_unlock(&ctrl->ctrl_lock);
+}
+
+/**
+ * pcie_write_cmd - Issue controller command
+ * @ctrl: controller to which the command is issued
+ * @cmd:  command value written to slot control register
+ * @mask: bitmask of slot control register to be modified
+ */
+static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
+{
+	pcie_do_write_cmd(ctrl, cmd, mask, true);
+}
+
+/* Same as above without waiting for the hardware to latch */
+static void pcie_write_cmd_nowait(struct controller *ctrl, u16 cmd, u16 mask)
+{
+	pcie_do_write_cmd(ctrl, cmd, mask, false);
+}
+
+bool pciehp_check_link_active(struct controller *ctrl)
+{
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	u16 lnk_status;
+	bool ret;
+
+	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
+	ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
+
+	if (ret)
+		ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
+
+	return ret;
+}
+
+static void pcie_wait_link_active(struct controller *ctrl)
+{
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+
+	pcie_wait_for_link(pdev, true);
+}
+
+static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)
+{
+	u32 l;
+	int count = 0;
+	int delay = 1000, step = 20;
+	bool found = false;
+
+	do {
+		found = pci_bus_read_dev_vendor_id(bus, devfn, &l, 0);
+		count++;
+
+		if (found)
+			break;
+
+		msleep(step);
+		delay -= step;
+	} while (delay > 0);
+
+	if (count > 1 && pciehp_debug)
+		printk(KERN_DEBUG "pci %04x:%02x:%02x.%d id reading try %d times with interval %d ms to get %08x\n",
+			pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
+			PCI_FUNC(devfn), count, step, l);
+
+	return found;
+}
+
+int pciehp_check_link_status(struct controller *ctrl)
+{
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	bool found;
+	u16 lnk_status;
+
+	/*
+	 * Data Link Layer Link Active Reporting must be capable for
+	 * hot-plug capable downstream port. But old controller might
+	 * not implement it. In this case, we wait for 1000 ms.
+	*/
+	if (ctrl->link_active_reporting)
+		pcie_wait_link_active(ctrl);
+	else
+		msleep(1000);
+
+	/* wait 100ms before read pci conf, and try in 1s */
+	msleep(100);
+	found = pci_bus_check_dev(ctrl->pcie->port->subordinate,
+					PCI_DEVFN(0, 0));
+
+	/* ignore link or presence changes up to this point */
+	if (found)
+		atomic_and(~(PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC),
+			   &ctrl->pending_events);
+
+	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
+	ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
+	if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
+	    !(lnk_status & PCI_EXP_LNKSTA_NLW)) {
+		ctrl_err(ctrl, "link training error: status %#06x\n",
+			 lnk_status);
+		return -1;
+	}
+
+	pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status);
+
+	if (!found)
+		return -1;
+
+	return 0;
+}
+
+static int __pciehp_link_set(struct controller *ctrl, bool enable)
+{
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	u16 lnk_ctrl;
+
+	pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &lnk_ctrl);
+
+	if (enable)
+		lnk_ctrl &= ~PCI_EXP_LNKCTL_LD;
+	else
+		lnk_ctrl |= PCI_EXP_LNKCTL_LD;
+
+	pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, lnk_ctrl);
+	ctrl_dbg(ctrl, "%s: lnk_ctrl = %x\n", __func__, lnk_ctrl);
+	return 0;
+}
+
+static int pciehp_link_enable(struct controller *ctrl)
+{
+	return __pciehp_link_set(ctrl, true);
+}
+
+int pciehp_get_raw_indicator_status(struct hotplug_slot *hotplug_slot,
+				    u8 *status)
+{
+	struct slot *slot = hotplug_slot->private;
+	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
+	u16 slot_ctrl;
+
+	pci_config_pm_runtime_get(pdev);
+	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
+	pci_config_pm_runtime_put(pdev);
+	*status = (slot_ctrl & (PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC)) >> 6;
+	return 0;
+}
+
+void pciehp_get_attention_status(struct slot *slot, u8 *status)
+{
+	struct controller *ctrl = slot->ctrl;
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	u16 slot_ctrl;
+
+	pci_config_pm_runtime_get(pdev);
+	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
+	pci_config_pm_runtime_put(pdev);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x, value read %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
+
+	switch (slot_ctrl & PCI_EXP_SLTCTL_AIC) {
+	case PCI_EXP_SLTCTL_ATTN_IND_ON:
+		*status = 1;	/* On */
+		break;
+	case PCI_EXP_SLTCTL_ATTN_IND_BLINK:
+		*status = 2;	/* Blink */
+		break;
+	case PCI_EXP_SLTCTL_ATTN_IND_OFF:
+		*status = 0;	/* Off */
+		break;
+	default:
+		*status = 0xFF;
+		break;
+	}
+}
+
+void pciehp_get_power_status(struct slot *slot, u8 *status)
+{
+	struct controller *ctrl = slot->ctrl;
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	u16 slot_ctrl;
+
+	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x value read %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_ctrl);
+
+	switch (slot_ctrl & PCI_EXP_SLTCTL_PCC) {
+	case PCI_EXP_SLTCTL_PWR_ON:
+		*status = 1;	/* On */
+		break;
+	case PCI_EXP_SLTCTL_PWR_OFF:
+		*status = 0;	/* Off */
+		break;
+	default:
+		*status = 0xFF;
+		break;
+	}
+}
+
+void pciehp_get_latch_status(struct slot *slot, u8 *status)
+{
+	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
+	u16 slot_status;
+
+	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
+	*status = !!(slot_status & PCI_EXP_SLTSTA_MRLSS);
+}
+
+void pciehp_get_adapter_status(struct slot *slot, u8 *status)
+{
+	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
+	u16 slot_status;
+
+	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
+	*status = !!(slot_status & PCI_EXP_SLTSTA_PDS);
+}
+
+int pciehp_query_power_fault(struct slot *slot)
+{
+	struct pci_dev *pdev = ctrl_dev(slot->ctrl);
+	u16 slot_status;
+
+	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
+	return !!(slot_status & PCI_EXP_SLTSTA_PFD);
+}
+
+int pciehp_set_raw_indicator_status(struct hotplug_slot *hotplug_slot,
+				    u8 status)
+{
+	struct slot *slot = hotplug_slot->private;
+	struct controller *ctrl = slot->ctrl;
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+
+	pci_config_pm_runtime_get(pdev);
+	pcie_write_cmd_nowait(ctrl, status << 6,
+			      PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC);
+	pci_config_pm_runtime_put(pdev);
+	return 0;
+}
+
+void pciehp_set_attention_status(struct slot *slot, u8 value)
+{
+	struct controller *ctrl = slot->ctrl;
+	u16 slot_cmd;
+
+	if (!ATTN_LED(ctrl))
+		return;
+
+	switch (value) {
+	case 0:		/* turn off */
+		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_OFF;
+		break;
+	case 1:		/* turn on */
+		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_ON;
+		break;
+	case 2:		/* turn blink */
+		slot_cmd = PCI_EXP_SLTCTL_ATTN_IND_BLINK;
+		break;
+	default:
+		return;
+	}
+	pcie_write_cmd_nowait(ctrl, slot_cmd, PCI_EXP_SLTCTL_AIC);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, slot_cmd);
+}
+
+void pciehp_green_led_on(struct slot *slot)
+{
+	struct controller *ctrl = slot->ctrl;
+
+	if (!PWR_LED(ctrl))
+		return;
+
+	pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
+			      PCI_EXP_SLTCTL_PIC);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
+		 PCI_EXP_SLTCTL_PWR_IND_ON);
+}
+
+void pciehp_green_led_off(struct slot *slot)
+{
+	struct controller *ctrl = slot->ctrl;
+
+	if (!PWR_LED(ctrl))
+		return;
+
+	pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
+			      PCI_EXP_SLTCTL_PIC);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
+		 PCI_EXP_SLTCTL_PWR_IND_OFF);
+}
+
+void pciehp_green_led_blink(struct slot *slot)
+{
+	struct controller *ctrl = slot->ctrl;
+
+	if (!PWR_LED(ctrl))
+		return;
+
+	pcie_write_cmd_nowait(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
+			      PCI_EXP_SLTCTL_PIC);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
+		 PCI_EXP_SLTCTL_PWR_IND_BLINK);
+}
+
+int pciehp_power_on_slot(struct slot *slot)
+{
+	struct controller *ctrl = slot->ctrl;
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	u16 slot_status;
+	int retval;
+
+	/* Clear power-fault bit from previous power failures */
+	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &slot_status);
+	if (slot_status & PCI_EXP_SLTSTA_PFD)
+		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
+					   PCI_EXP_SLTSTA_PFD);
+	ctrl->power_fault_detected = 0;
+
+	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
+		 PCI_EXP_SLTCTL_PWR_ON);
+
+	retval = pciehp_link_enable(ctrl);
+	if (retval)
+		ctrl_err(ctrl, "%s: Can not enable the link!\n", __func__);
+
+	return retval;
+}
+
+void pciehp_power_off_slot(struct slot *slot)
+{
+	struct controller *ctrl = slot->ctrl;
+
+	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
+		 PCI_EXP_SLTCTL_PWR_OFF);
+}
+
+static irqreturn_t pciehp_isr(int irq, void *dev_id)
+{
+	struct controller *ctrl = (struct controller *)dev_id;
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	struct device *parent = pdev->dev.parent;
+	u16 status, events = 0;
+
+	/*
+	 * Interrupts only occur in D3hot or shallower (PCIe r4.0, sec 6.7.3.4).
+	 */
+	if (pdev->current_state == PCI_D3cold)
+		return IRQ_NONE;
+
+	/*
+	 * Keep the port accessible by holding a runtime PM ref on its parent.
+	 * Defer resume of the parent to the IRQ thread if it's suspended.
+	 * Mask the interrupt until then.
+	 */
+	if (parent) {
+		pm_runtime_get_noresume(parent);
+		if (!pm_runtime_active(parent)) {
+			pm_runtime_put(parent);
+			disable_irq_nosync(irq);
+			atomic_or(RERUN_ISR, &ctrl->pending_events);
+			return IRQ_WAKE_THREAD;
+		}
+	}
+
+read_status:
+	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
+	if (status == (u16) ~0) {
+		ctrl_info(ctrl, "%s: no response from device\n", __func__);
+		if (parent)
+			pm_runtime_put(parent);
+		return IRQ_NONE;
+	}
+
+	/*
+	 * Slot Status contains plain status bits as well as event
+	 * notification bits; right now we only want the event bits.
+	 */
+	status &= PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
+		  PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_CC |
+		  PCI_EXP_SLTSTA_DLLSC;
+
+	/*
+	 * If we've already reported a power fault, don't report it again
+	 * until we've done something to handle it.
+	 */
+	if (ctrl->power_fault_detected)
+		status &= ~PCI_EXP_SLTSTA_PFD;
+	else if (status & PCI_EXP_SLTSTA_PFD)
+		ctrl->power_fault_detected = true;
+
+	events |= status;
+	if (!events) {
+		if (parent)
+			pm_runtime_put(parent);
+		return IRQ_NONE;
+	}
+
+	if (status) {
+		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, status);
+
+		/*
+		 * In MSI mode, all event bits must be zero before the port
+		 * will send a new interrupt (PCIe Base Spec r5.0 sec 6.7.3.4).
+		 * So re-read the Slot Status register in case a bit was set
+		 * between read and write.
+		 */
+		if (pci_dev_msi_enabled(pdev) && !pciehp_poll_mode)
+			goto read_status;
+	}
+
+	ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events);
+	if (parent)
+		pm_runtime_put(parent);
+
+	/*
+	 * Command Completed notifications are not deferred to the
+	 * IRQ thread because it may be waiting for their arrival.
+	 */
+	if (events & PCI_EXP_SLTSTA_CC) {
+		ctrl->cmd_busy = 0;
+		smp_mb();
+		wake_up(&ctrl->queue);
+
+		if (events == PCI_EXP_SLTSTA_CC)
+			return IRQ_HANDLED;
+
+		events &= ~PCI_EXP_SLTSTA_CC;
+	}
+
+	if (pdev->ignore_hotplug) {
+		ctrl_dbg(ctrl, "ignoring hotplug event %#06x\n", events);
+		return IRQ_HANDLED;
+	}
+
+	/* Save pending events for consumption by IRQ thread. */
+	atomic_or(events, &ctrl->pending_events);
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t pciehp_ist(int irq, void *dev_id)
+{
+	struct controller *ctrl = (struct controller *)dev_id;
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	struct slot *slot = ctrl->slot;
+	irqreturn_t ret;
+	u32 events;
+
+	ctrl->ist_running = true;
+	pci_config_pm_runtime_get(pdev);
+
+	/* rerun pciehp_isr() if the port was inaccessible on interrupt */
+	if (atomic_fetch_and(~RERUN_ISR, &ctrl->pending_events) & RERUN_ISR) {
+		ret = pciehp_isr(irq, dev_id);
+		enable_irq(irq);
+		if (ret != IRQ_WAKE_THREAD)
+			goto out;
+	}
+
+	synchronize_hardirq(irq);
+	events = atomic_xchg(&ctrl->pending_events, 0);
+	if (!events) {
+		ret = IRQ_NONE;
+		goto out;
+	}
+
+	/* Check Attention Button Pressed */
+	if (events & PCI_EXP_SLTSTA_ABP) {
+		ctrl_info(ctrl, "Slot(%s): Attention button pressed\n",
+			  slot_name(slot));
+		pciehp_handle_button_press(slot);
+	}
+
+	/* Check Power Fault Detected */
+	if (events & PCI_EXP_SLTSTA_PFD) {
+		ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(slot));
+		pciehp_set_attention_status(slot, 1);
+		pciehp_green_led_off(slot);
+	}
+
+	/*
+	 * Disable requests have higher priority than Presence Detect Changed
+	 * or Data Link Layer State Changed events.
+	 */
+	down_read(&ctrl->reset_lock);
+	if (events & DISABLE_SLOT)
+		pciehp_handle_disable_request(slot);
+	else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC))
+		pciehp_handle_presence_or_link_change(slot, events);
+	up_read(&ctrl->reset_lock);
+
+	ret = IRQ_HANDLED;
+out:
+	pci_config_pm_runtime_put(pdev);
+	ctrl->ist_running = false;
+	wake_up(&ctrl->requester);
+	return ret;
+}
+
+static int pciehp_poll(void *data)
+{
+	struct controller *ctrl = data;
+
+	schedule_timeout_idle(10 * HZ); /* start with 10 sec delay */
+
+	while (!kthread_should_stop()) {
+		/* poll for interrupt events or user requests */
+		while (pciehp_isr(IRQ_NOTCONNECTED, ctrl) == IRQ_WAKE_THREAD ||
+		       atomic_read(&ctrl->pending_events))
+			pciehp_ist(IRQ_NOTCONNECTED, ctrl);
+
+		if (pciehp_poll_time <= 0 || pciehp_poll_time > 60)
+			pciehp_poll_time = 2; /* clamp to sane value */
+
+		schedule_timeout_idle(pciehp_poll_time * HZ);
+	}
+
+	return 0;
+}
+
+static void pcie_enable_notification(struct controller *ctrl)
+{
+	u16 cmd, mask;
+
+	/*
+	 * TBD: Power fault detected software notification support.
+	 *
+	 * Power fault detected software notification is not enabled
+	 * now, because it caused power fault detected interrupt storm
+	 * on some machines. On those machines, power fault detected
+	 * bit in the slot status register was set again immediately
+	 * when it is cleared in the interrupt service routine, and
+	 * next power fault detected interrupt was notified again.
+	 */
+
+	/*
+	 * Always enable link events: thus link-up and link-down shall
+	 * always be treated as hotplug and unplug respectively. Enable
+	 * presence detect only if Attention Button is not present.
+	 */
+	cmd = PCI_EXP_SLTCTL_DLLSCE;
+	if (ATTN_BUTTN(ctrl))
+		cmd |= PCI_EXP_SLTCTL_ABPE;
+	else
+		cmd |= PCI_EXP_SLTCTL_PDCE;
+	if (!pciehp_poll_mode)
+		cmd |= PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE;
+
+	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
+		PCI_EXP_SLTCTL_PFDE |
+		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
+		PCI_EXP_SLTCTL_DLLSCE);
+
+	pcie_write_cmd_nowait(ctrl, cmd, mask);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, cmd);
+}
+
+static void pcie_disable_notification(struct controller *ctrl)
+{
+	u16 mask;
+
+	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
+		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
+		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
+		PCI_EXP_SLTCTL_DLLSCE);
+	pcie_write_cmd(ctrl, 0, mask);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
+}
+
+void pcie_clear_hotplug_events(struct controller *ctrl)
+{
+	pcie_capability_write_word(ctrl_dev(ctrl), PCI_EXP_SLTSTA,
+				   PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
+}
+
+/*
+ * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
+ * bus reset of the bridge, but at the same time we want to ensure that it is
+ * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
+ * disable link state notification and presence detection change notification
+ * momentarily, if we see that they could interfere. Also, clear any spurious
+ * events after.
+ */
+int pciehp_reset_slot(struct slot *slot, int probe)
+{
+	struct controller *ctrl = slot->ctrl;
+	struct pci_dev *pdev = ctrl_dev(ctrl);
+	u16 stat_mask = 0, ctrl_mask = 0;
+	int rc;
+
+	if (probe)
+		return 0;
+
+	down_write(&ctrl->reset_lock);
+
+	if (!ATTN_BUTTN(ctrl)) {
+		ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
+		stat_mask |= PCI_EXP_SLTSTA_PDC;
+	}
+	ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE;
+	stat_mask |= PCI_EXP_SLTSTA_DLLSC;
+
+	pcie_write_cmd(ctrl, 0, ctrl_mask);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, 0);
+
+	rc = pci_bridge_secondary_bus_reset(ctrl->pcie->port);
+
+	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
+	pcie_write_cmd_nowait(ctrl, ctrl_mask, ctrl_mask);
+	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
+		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, ctrl_mask);
+
+	up_write(&ctrl->reset_lock);
+	return rc;
+}
+
+int pcie_init_notification(struct controller *ctrl)
+{
+	if (pciehp_request_irq(ctrl))
+		return -1;
+	pcie_enable_notification(ctrl);
+	ctrl->notification_enabled = 1;
+	return 0;
+}
+
+void pcie_shutdown_notification(struct controller *ctrl)
+{
+	if (ctrl->notification_enabled) {
+		pcie_disable_notification(ctrl);
+		pciehp_free_irq(ctrl);
+		ctrl->notification_enabled = 0;
+	}
+}
+
+static int pcie_init_slot(struct controller *ctrl)
+{
+	struct pci_bus *subordinate = ctrl_dev(ctrl)->subordinate;
+	struct slot *slot;
+
+	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
+	if (!slot)
+		return -ENOMEM;
+
+	down_read(&pci_bus_sem);
+	slot->state = list_empty(&subordinate->devices) ? OFF_STATE : ON_STATE;
+	up_read(&pci_bus_sem);
+
+	slot->ctrl = ctrl;
+	mutex_init(&slot->lock);
+	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
+	ctrl->slot = slot;
+	return 0;
+}
+
+static void pcie_cleanup_slot(struct controller *ctrl)
+{
+	struct slot *slot = ctrl->slot;
+
+	cancel_delayed_work_sync(&slot->work);
+	kfree(slot);
+}
+
+static inline void dbg_ctrl(struct controller *ctrl)
+{
+	struct pci_dev *pdev = ctrl->pcie->port;
+	u16 reg16;
+
+	if (!pciehp_debug)
+		return;
+
+	ctrl_info(ctrl, "Slot Capabilities      : 0x%08x\n", ctrl->slot_cap);
+	pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &reg16);
+	ctrl_info(ctrl, "Slot Status            : 0x%04x\n", reg16);
+	pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &reg16);
+	ctrl_info(ctrl, "Slot Control           : 0x%04x\n", reg16);
+}
+
+#define FLAG(x, y)	(((x) & (y)) ? '+' : '-')
+
+struct controller *pcie_init(struct pcie_device *dev)
+{
+	struct controller *ctrl;
+	u32 slot_cap, link_cap;
+	u8 occupied, poweron;
+	struct pci_dev *pdev = dev->port;
+
+	ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		goto abort;
+
+	ctrl->pcie = dev;
+	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
+
+	if (pdev->hotplug_user_indicators)
+		slot_cap &= ~(PCI_EXP_SLTCAP_AIP | PCI_EXP_SLTCAP_PIP);
+
+	/*
+	 * We assume no Thunderbolt controllers support Command Complete events,
+	 * but some controllers falsely claim they do.
+	 */
+	if (pdev->is_thunderbolt)
+		slot_cap |= PCI_EXP_SLTCAP_NCCS;
+
+	ctrl->slot_cap = slot_cap;
+	mutex_init(&ctrl->ctrl_lock);
+	init_rwsem(&ctrl->reset_lock);
+	init_waitqueue_head(&ctrl->requester);
+	init_waitqueue_head(&ctrl->queue);
+	dbg_ctrl(ctrl);
+
+	/* Check if Data Link Layer Link Active Reporting is implemented */
+	pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, &link_cap);
+	if (link_cap & PCI_EXP_LNKCAP_DLLLARC)
+		ctrl->link_active_reporting = 1;
+
+	/* Clear all remaining event bits in Slot Status register. */
+	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
+		PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
+		PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_CC |
+		PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC);
+
+	ctrl_info(ctrl, "Slot #%d AttnBtn%c PwrCtrl%c MRL%c AttnInd%c PwrInd%c HotPlug%c Surprise%c Interlock%c NoCompl%c LLActRep%c%s\n",
+		(slot_cap & PCI_EXP_SLTCAP_PSN) >> 19,
+		FLAG(slot_cap, PCI_EXP_SLTCAP_ABP),
+		FLAG(slot_cap, PCI_EXP_SLTCAP_PCP),
+		FLAG(slot_cap, PCI_EXP_SLTCAP_MRLSP),
+		FLAG(slot_cap, PCI_EXP_SLTCAP_AIP),
+		FLAG(slot_cap, PCI_EXP_SLTCAP_PIP),
+		FLAG(slot_cap, PCI_EXP_SLTCAP_HPC),
+		FLAG(slot_cap, PCI_EXP_SLTCAP_HPS),
+		FLAG(slot_cap, PCI_EXP_SLTCAP_EIP),
+		FLAG(slot_cap, PCI_EXP_SLTCAP_NCCS),
+		FLAG(link_cap, PCI_EXP_LNKCAP_DLLLARC),
+		pdev->broken_cmd_compl ? " (with Cmd Compl erratum)" : "");
+
+	if (pcie_init_slot(ctrl))
+		goto abort_ctrl;
+
+	/*
+	 * If empty slot's power status is on, turn power off.  The IRQ isn't
+	 * requested yet, so avoid triggering a notification with this command.
+	 */
+	if (POWER_CTRL(ctrl)) {
+		pciehp_get_adapter_status(ctrl->slot, &occupied);
+		pciehp_get_power_status(ctrl->slot, &poweron);
+		if (!occupied && poweron) {
+			pcie_disable_notification(ctrl);
+			pciehp_power_off_slot(ctrl->slot);
+		}
+	}
+
+	return ctrl;
+
+abort_ctrl:
+	kfree(ctrl);
+abort:
+	return NULL;
+}
+
+void pciehp_release_ctrl(struct controller *ctrl)
+{
+	pcie_cleanup_slot(ctrl);
+	kfree(ctrl);
+}
+
+static void quirk_cmd_compl(struct pci_dev *pdev)
+{
+	u32 slot_cap;
+
+	if (pci_is_pcie(pdev)) {
+		pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
+		if (slot_cap & PCI_EXP_SLTCAP_HPC &&
+		    !(slot_cap & PCI_EXP_SLTCAP_NCCS))
+			pdev->broken_cmd_compl = 1;
+	}
+}
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
+			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0110,
+			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0400,
+			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0401,
+			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);