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path: root/drivers/pci/hotplug/pciehp_ctrl.c
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Diffstat (limited to 'drivers/pci/hotplug/pciehp_ctrl.c')
-rw-r--r--drivers/pci/hotplug/pciehp_ctrl.c439
1 files changed, 439 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c
new file mode 100644
index 000000000..32baba1b7
--- /dev/null
+++ b/drivers/pci/hotplug/pciehp_ctrl.c
@@ -0,0 +1,439 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCI Express Hot Plug Controller 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>
+ *
+ */
+
+#define dev_fmt(fmt) "pciehp: " fmt
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/pm_runtime.h>
+#include <linux/pci.h>
+#include "pciehp.h"
+
+/* The following routines constitute the bulk of the
+ hotplug controller logic
+ */
+
+#define SAFE_REMOVAL true
+#define SURPRISE_REMOVAL false
+
+static void set_slot_off(struct controller *ctrl)
+{
+ /*
+ * Turn off slot, turn on attention indicator, turn off power
+ * indicator
+ */
+ if (POWER_CTRL(ctrl)) {
+ pciehp_power_off_slot(ctrl);
+
+ /*
+ * After turning power off, we must wait for at least 1 second
+ * before taking any action that relies on power having been
+ * removed from the slot/adapter.
+ */
+ msleep(1000);
+ }
+
+ pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
+ PCI_EXP_SLTCTL_ATTN_IND_ON);
+}
+
+/**
+ * board_added - Called after a board has been added to the system.
+ * @ctrl: PCIe hotplug controller where board is added
+ *
+ * Turns power on for the board.
+ * Configures board.
+ */
+static int board_added(struct controller *ctrl)
+{
+ int retval = 0;
+ struct pci_bus *parent = ctrl->pcie->port->subordinate;
+
+ if (POWER_CTRL(ctrl)) {
+ /* Power on slot */
+ retval = pciehp_power_on_slot(ctrl);
+ if (retval)
+ return retval;
+ }
+
+ pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
+ INDICATOR_NOOP);
+
+ /* Check link training status */
+ retval = pciehp_check_link_status(ctrl);
+ if (retval)
+ goto err_exit;
+
+ /* Check for a power fault */
+ if (ctrl->power_fault_detected || pciehp_query_power_fault(ctrl)) {
+ ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl));
+ retval = -EIO;
+ goto err_exit;
+ }
+
+ retval = pciehp_configure_device(ctrl);
+ if (retval) {
+ if (retval != -EEXIST) {
+ ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
+ pci_domain_nr(parent), parent->number);
+ goto err_exit;
+ }
+ }
+
+ pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
+ PCI_EXP_SLTCTL_ATTN_IND_OFF);
+ return 0;
+
+err_exit:
+ set_slot_off(ctrl);
+ return retval;
+}
+
+/**
+ * remove_board - Turn off slot and Power Indicator
+ * @ctrl: PCIe hotplug controller where board is being removed
+ * @safe_removal: whether the board is safely removed (versus surprise removed)
+ */
+static void remove_board(struct controller *ctrl, bool safe_removal)
+{
+ pciehp_unconfigure_device(ctrl, safe_removal);
+
+ if (POWER_CTRL(ctrl)) {
+ pciehp_power_off_slot(ctrl);
+
+ /*
+ * After turning power off, we must wait for at least 1 second
+ * before taking any action that relies on power having been
+ * removed from the slot/adapter.
+ */
+ msleep(1000);
+
+ /* Ignore link or presence changes caused by power off */
+ atomic_and(~(PCI_EXP_SLTSTA_DLLSC | PCI_EXP_SLTSTA_PDC),
+ &ctrl->pending_events);
+ }
+
+ pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
+ INDICATOR_NOOP);
+}
+
+static int pciehp_enable_slot(struct controller *ctrl);
+static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal);
+
+void pciehp_request(struct controller *ctrl, int action)
+{
+ atomic_or(action, &ctrl->pending_events);
+ if (!pciehp_poll_mode)
+ irq_wake_thread(ctrl->pcie->irq, ctrl);
+}
+
+void pciehp_queue_pushbutton_work(struct work_struct *work)
+{
+ struct controller *ctrl = container_of(work, struct controller,
+ button_work.work);
+
+ mutex_lock(&ctrl->state_lock);
+ switch (ctrl->state) {
+ case BLINKINGOFF_STATE:
+ pciehp_request(ctrl, DISABLE_SLOT);
+ break;
+ case BLINKINGON_STATE:
+ pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
+ break;
+ default:
+ break;
+ }
+ mutex_unlock(&ctrl->state_lock);
+}
+
+void pciehp_handle_button_press(struct controller *ctrl)
+{
+ mutex_lock(&ctrl->state_lock);
+ switch (ctrl->state) {
+ case OFF_STATE:
+ case ON_STATE:
+ if (ctrl->state == ON_STATE) {
+ ctrl->state = BLINKINGOFF_STATE;
+ ctrl_info(ctrl, "Slot(%s): Powering off due to button press\n",
+ slot_name(ctrl));
+ } else {
+ ctrl->state = BLINKINGON_STATE;
+ ctrl_info(ctrl, "Slot(%s) Powering on due to button press\n",
+ slot_name(ctrl));
+ }
+ /* blink power indicator and turn off attention */
+ pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_BLINK,
+ PCI_EXP_SLTCTL_ATTN_IND_OFF);
+ schedule_delayed_work(&ctrl->button_work, 5 * HZ);
+ break;
+ case BLINKINGOFF_STATE:
+ case BLINKINGON_STATE:
+ /*
+ * Cancel if we are still blinking; this means that we
+ * press the attention again before the 5 sec. limit
+ * expires to cancel hot-add or hot-remove
+ */
+ ctrl_info(ctrl, "Slot(%s): Button cancel\n", slot_name(ctrl));
+ cancel_delayed_work(&ctrl->button_work);
+ if (ctrl->state == BLINKINGOFF_STATE) {
+ ctrl->state = ON_STATE;
+ pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_ON,
+ PCI_EXP_SLTCTL_ATTN_IND_OFF);
+ } else {
+ ctrl->state = OFF_STATE;
+ pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
+ PCI_EXP_SLTCTL_ATTN_IND_OFF);
+ }
+ ctrl_info(ctrl, "Slot(%s): Action canceled due to button press\n",
+ slot_name(ctrl));
+ break;
+ default:
+ ctrl_err(ctrl, "Slot(%s): Ignoring invalid state %#x\n",
+ slot_name(ctrl), ctrl->state);
+ break;
+ }
+ mutex_unlock(&ctrl->state_lock);
+}
+
+void pciehp_handle_disable_request(struct controller *ctrl)
+{
+ mutex_lock(&ctrl->state_lock);
+ switch (ctrl->state) {
+ case BLINKINGON_STATE:
+ case BLINKINGOFF_STATE:
+ cancel_delayed_work(&ctrl->button_work);
+ break;
+ }
+ ctrl->state = POWEROFF_STATE;
+ mutex_unlock(&ctrl->state_lock);
+
+ ctrl->request_result = pciehp_disable_slot(ctrl, SAFE_REMOVAL);
+}
+
+void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events)
+{
+ int present, link_active;
+
+ /*
+ * If the slot is on and presence or link has changed, turn it off.
+ * Even if it's occupied again, we cannot assume the card is the same.
+ */
+ mutex_lock(&ctrl->state_lock);
+ switch (ctrl->state) {
+ case BLINKINGOFF_STATE:
+ cancel_delayed_work(&ctrl->button_work);
+ fallthrough;
+ case ON_STATE:
+ ctrl->state = POWEROFF_STATE;
+ mutex_unlock(&ctrl->state_lock);
+ if (events & PCI_EXP_SLTSTA_DLLSC)
+ ctrl_info(ctrl, "Slot(%s): Link Down\n",
+ slot_name(ctrl));
+ if (events & PCI_EXP_SLTSTA_PDC)
+ ctrl_info(ctrl, "Slot(%s): Card not present\n",
+ slot_name(ctrl));
+ pciehp_disable_slot(ctrl, SURPRISE_REMOVAL);
+ break;
+ default:
+ mutex_unlock(&ctrl->state_lock);
+ break;
+ }
+
+ /* Turn the slot on if it's occupied or link is up */
+ mutex_lock(&ctrl->state_lock);
+ present = pciehp_card_present(ctrl);
+ link_active = pciehp_check_link_active(ctrl);
+ if (present <= 0 && link_active <= 0) {
+ if (ctrl->state == BLINKINGON_STATE) {
+ ctrl->state = OFF_STATE;
+ cancel_delayed_work(&ctrl->button_work);
+ pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
+ INDICATOR_NOOP);
+ ctrl_info(ctrl, "Slot(%s): Card not present\n",
+ slot_name(ctrl));
+ }
+ mutex_unlock(&ctrl->state_lock);
+ return;
+ }
+
+ switch (ctrl->state) {
+ case BLINKINGON_STATE:
+ cancel_delayed_work(&ctrl->button_work);
+ fallthrough;
+ case OFF_STATE:
+ ctrl->state = POWERON_STATE;
+ mutex_unlock(&ctrl->state_lock);
+ if (present)
+ ctrl_info(ctrl, "Slot(%s): Card present\n",
+ slot_name(ctrl));
+ if (link_active)
+ ctrl_info(ctrl, "Slot(%s): Link Up\n",
+ slot_name(ctrl));
+ ctrl->request_result = pciehp_enable_slot(ctrl);
+ break;
+ default:
+ mutex_unlock(&ctrl->state_lock);
+ break;
+ }
+}
+
+static int __pciehp_enable_slot(struct controller *ctrl)
+{
+ u8 getstatus = 0;
+
+ if (MRL_SENS(ctrl)) {
+ pciehp_get_latch_status(ctrl, &getstatus);
+ if (getstatus) {
+ ctrl_info(ctrl, "Slot(%s): Latch open\n",
+ slot_name(ctrl));
+ return -ENODEV;
+ }
+ }
+
+ if (POWER_CTRL(ctrl)) {
+ pciehp_get_power_status(ctrl, &getstatus);
+ if (getstatus) {
+ ctrl_info(ctrl, "Slot(%s): Already enabled\n",
+ slot_name(ctrl));
+ return 0;
+ }
+ }
+
+ return board_added(ctrl);
+}
+
+static int pciehp_enable_slot(struct controller *ctrl)
+{
+ int ret;
+
+ pm_runtime_get_sync(&ctrl->pcie->port->dev);
+ ret = __pciehp_enable_slot(ctrl);
+ if (ret && ATTN_BUTTN(ctrl))
+ /* may be blinking */
+ pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
+ INDICATOR_NOOP);
+ pm_runtime_put(&ctrl->pcie->port->dev);
+
+ mutex_lock(&ctrl->state_lock);
+ ctrl->state = ret ? OFF_STATE : ON_STATE;
+ mutex_unlock(&ctrl->state_lock);
+
+ return ret;
+}
+
+static int __pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
+{
+ u8 getstatus = 0;
+
+ if (POWER_CTRL(ctrl)) {
+ pciehp_get_power_status(ctrl, &getstatus);
+ if (!getstatus) {
+ ctrl_info(ctrl, "Slot(%s): Already disabled\n",
+ slot_name(ctrl));
+ return -EINVAL;
+ }
+ }
+
+ remove_board(ctrl, safe_removal);
+ return 0;
+}
+
+static int pciehp_disable_slot(struct controller *ctrl, bool safe_removal)
+{
+ int ret;
+
+ pm_runtime_get_sync(&ctrl->pcie->port->dev);
+ ret = __pciehp_disable_slot(ctrl, safe_removal);
+ pm_runtime_put(&ctrl->pcie->port->dev);
+
+ mutex_lock(&ctrl->state_lock);
+ ctrl->state = OFF_STATE;
+ mutex_unlock(&ctrl->state_lock);
+
+ return ret;
+}
+
+int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot)
+{
+ struct controller *ctrl = to_ctrl(hotplug_slot);
+
+ mutex_lock(&ctrl->state_lock);
+ switch (ctrl->state) {
+ case BLINKINGON_STATE:
+ case OFF_STATE:
+ mutex_unlock(&ctrl->state_lock);
+ /*
+ * The IRQ thread becomes a no-op if the user pulls out the
+ * card before the thread wakes up, so initialize to -ENODEV.
+ */
+ ctrl->request_result = -ENODEV;
+ pciehp_request(ctrl, PCI_EXP_SLTSTA_PDC);
+ wait_event(ctrl->requester,
+ !atomic_read(&ctrl->pending_events) &&
+ !ctrl->ist_running);
+ return ctrl->request_result;
+ case POWERON_STATE:
+ ctrl_info(ctrl, "Slot(%s): Already in powering on state\n",
+ slot_name(ctrl));
+ break;
+ case BLINKINGOFF_STATE:
+ case ON_STATE:
+ case POWEROFF_STATE:
+ ctrl_info(ctrl, "Slot(%s): Already enabled\n",
+ slot_name(ctrl));
+ break;
+ default:
+ ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
+ slot_name(ctrl), ctrl->state);
+ break;
+ }
+ mutex_unlock(&ctrl->state_lock);
+
+ return -ENODEV;
+}
+
+int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot)
+{
+ struct controller *ctrl = to_ctrl(hotplug_slot);
+
+ mutex_lock(&ctrl->state_lock);
+ switch (ctrl->state) {
+ case BLINKINGOFF_STATE:
+ case ON_STATE:
+ mutex_unlock(&ctrl->state_lock);
+ pciehp_request(ctrl, DISABLE_SLOT);
+ wait_event(ctrl->requester,
+ !atomic_read(&ctrl->pending_events) &&
+ !ctrl->ist_running);
+ return ctrl->request_result;
+ case POWEROFF_STATE:
+ ctrl_info(ctrl, "Slot(%s): Already in powering off state\n",
+ slot_name(ctrl));
+ break;
+ case BLINKINGON_STATE:
+ case OFF_STATE:
+ case POWERON_STATE:
+ ctrl_info(ctrl, "Slot(%s): Already disabled\n",
+ slot_name(ctrl));
+ break;
+ default:
+ ctrl_err(ctrl, "Slot(%s): Invalid state %#x\n",
+ slot_name(ctrl), ctrl->state);
+ break;
+ }
+ mutex_unlock(&ctrl->state_lock);
+
+ return -ENODEV;
+}