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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/pci/hotplug/pciehp_ctrl.c | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/pci/hotplug/pciehp_ctrl.c')
-rw-r--r-- | drivers/pci/hotplug/pciehp_ctrl.c | 439 |
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; +} |