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linux/drivers/pci/hotplug/pciehp_hpc.c
Bjorn Helgaas d22b362184 PCI: pciehp: Add quirk for Command Completed errata 
Several PCIe hotplug controllers have errata that mean they do not set the
Command Completed bit unless writes to the Slot Command register change
"Control" bits.  Command Completed is never set for writes that only change
software notification "Enable" bits.  This results in timeouts like this:

  pciehp 0000:00:1c.0:pcie004: Timeout on hotplug command 0x1038 (issued 65284 msec ago)

When this erratum is present, avoid these timeouts by marking commands
"completed" immediately unless they change the "Control" bits.

Here's the text of the Intel erratum CF118.  We assume this applies to all
Intel parts:

  CF118        PCIe Slot Status Register Command Completed bit not always
               updated on any configuration write to the Slot Control
               Register

  Problem:     For PCIe root ports (devices 0 - 10) supporting hot-plug,
               the Slot Status Register (offset AAh) Command Completed
               (bit[4]) status is updated under the following condition:
               IOH will set Command Completed bit after delivering the new
               commands written in the Slot Controller register (offset
               A8h) to VPP. The IOH detects new commands written in Slot
               Control register by checking the change of value for Power
               Controller Control (bit[10]), Power Indicator Control
               (bits[9:8]), Attention Indicator Control (bits[7:6]), or
               Electromechanical Interlock Control (bit[11]) fields. Any
               other configuration writes to the Slot Control register
               without changing the values of these fields will not cause
               Command Completed bit to be set.

               The PCIe Base Specification Revision 2.0 or later describes
               the “Slot Control Register” in section 7.8.10, as follows
               (Reference section 7.8.10, Slot Control Register, Offset
               18h). In hot-plug capable Downstream Ports, a write to the
               Slot Control register must cause a hot-plug command to be
               generated (see Section 6.7.3.2 for details on hot-plug
               commands). A write to the Slot Control register in a
               Downstream Port that is not hotplug capable must not cause a
               hot-plug command to be executed.

               The PCIe Spec intended that every write to the Slot Control
               Register is a command and expected a command complete status
               to abstract the VPP implementation specific nuances from the
               OS software. IOH PCIe Slot Control Register implementation
               is not fully conforming to the PCIe Specification in this
               respect.

  Implication: Software checking on the Command Completed status after
               writing to the Slot Control register may time out.

  Workaround:  Software can read the Slot Control register and compare the
               existing and new values to determine if it should check the
               Command Completed status after writing to the Slot Control
               register.

Per Sinan, the Qualcomm QDF2400 controller also does not set the Command
Completed bit unless writes to the Slot Command register change "Control"
bits.

Link: http://www.intel.com/content/www/us/en/processors/xeon/xeon-e7-v2-spec-update.html
Link: https://lkml.kernel.org/r/8770820b-85a0-172b-7230-3a44524e6c9f@molgen.mpg.de
Reported-by: Paul Menzel <pmenzel+linux-pci@molgen.mpg.de>	# Lenovo X60
Tested-by: Paul Menzel <pmenzel+linux-pci@molgen.mpg.de>	# Lenovo X60
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>		# Qcom quirk
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2018-05-07 16:25:08 -05:00

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// 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/timer.h>
#include <linux/pci.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 pcie_isr(int irq, void *dev_id);
static void start_int_poll_timer(struct controller *ctrl, int sec);
/* This is the interrupt polling timeout function. */
static void int_poll_timeout(struct timer_list *t)
{
struct controller *ctrl = from_timer(ctrl, t, poll_timer);
/* Poll for interrupt events. regs == NULL => polling */
pcie_isr(0, ctrl);
if (!pciehp_poll_time)
pciehp_poll_time = 2; /* default polling interval is 2 sec */
start_int_poll_timer(ctrl, pciehp_poll_time);
}
/* This function starts the interrupt polling timer. */
static void start_int_poll_timer(struct controller *ctrl, int sec)
{
/* Clamp to sane value */
if ((sec <= 0) || (sec > 60))
sec = 2;
ctrl->poll_timer.expires = jiffies + sec * HZ;
add_timer(&ctrl->poll_timer);
}
static inline int pciehp_request_irq(struct controller *ctrl)
{
int retval, irq = ctrl->pcie->irq;
/* Install interrupt polling timer. Start with 10 sec delay */
if (pciehp_poll_mode) {
timer_setup(&ctrl->poll_timer, int_poll_timeout, 0);
start_int_poll_timer(ctrl, 10);
return 0;
}
/* Installs the interrupt handler */
retval = request_irq(irq, pcie_isr, 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)
del_timer_sync(&ctrl->poll_timer);
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);
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, bool active)
{
int timeout = 1000;
if (pciehp_check_link_active(ctrl) == active)
return;
while (timeout > 0) {
msleep(10);
timeout -= 10;
if (pciehp_check_link_active(ctrl) == active)
return;
}
ctrl_dbg(ctrl, "Data Link Layer Link Active not %s in 1000 msec\n",
active ? "set" : "cleared");
}
static void pcie_wait_link_active(struct controller *ctrl)
{
__pcie_wait_link_active(ctrl, 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));
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;
pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &slot_ctrl);
*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;
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_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;
pcie_write_cmd_nowait(ctrl, status << 6,
PCI_EXP_SLTCTL_AIC | PCI_EXP_SLTCTL_PIC);
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 sticky 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 pci_bus *subordinate = pdev->subordinate;
struct pci_dev *dev;
struct slot *slot = ctrl->slot;
u16 status, events;
u8 present;
bool link;
/* Interrupts cannot originate from a controller that's asleep */
if (pdev->current_state == PCI_D3cold)
return IRQ_NONE;
pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &status);
if (status == (u16) ~0) {
ctrl_info(ctrl, "%s: no response from device\n", __func__);
return IRQ_NONE;
}
/*
* Slot Status contains plain status bits as well as event
* notification bits; right now we only want the event bits.
*/
events = 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)
events &= ~PCI_EXP_SLTSTA_PFD;
if (!events)
return IRQ_NONE;
/* Capture link status before clearing interrupts */
if (events & PCI_EXP_SLTSTA_DLLSC)
link = pciehp_check_link_active(ctrl);
pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events);
ctrl_dbg(ctrl, "pending interrupts %#06x from Slot Status\n", events);
/* Check Command Complete Interrupt Pending */
if (events & PCI_EXP_SLTSTA_CC) {
ctrl->cmd_busy = 0;
smp_mb();
wake_up(&ctrl->queue);
}
if (subordinate) {
list_for_each_entry(dev, &subordinate->devices, bus_list) {
if (dev->ignore_hotplug) {
ctrl_dbg(ctrl, "ignoring hotplug event %#06x (%s requested no hotplug)\n",
events, pci_name(dev));
return IRQ_HANDLED;
}
}
}
/* Check Attention Button Pressed */
if (events & PCI_EXP_SLTSTA_ABP) {
ctrl_info(ctrl, "Slot(%s): Attention button pressed\n",
slot_name(slot));
pciehp_queue_interrupt_event(slot, INT_BUTTON_PRESS);
}
/*
* Check Link Status Changed at higher precedence than Presence
* Detect Changed. The PDS value may be set to "card present" from
* out-of-band detection, which may be in conflict with a Link Down
* and cause the wrong event to queue.
*/
if (events & PCI_EXP_SLTSTA_DLLSC) {
ctrl_info(ctrl, "Slot(%s): Link %s\n", slot_name(slot),
link ? "Up" : "Down");
pciehp_queue_interrupt_event(slot, link ? INT_LINK_UP :
INT_LINK_DOWN);
} else if (events & PCI_EXP_SLTSTA_PDC) {
present = !!(status & PCI_EXP_SLTSTA_PDS);
ctrl_info(ctrl, "Slot(%s): Card %spresent\n", slot_name(slot),
present ? "" : "not ");
pciehp_queue_interrupt_event(slot, present ? INT_PRESENCE_ON :
INT_PRESENCE_OFF);
}
/* Check Power Fault Detected */
if ((events & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
ctrl->power_fault_detected = 1;
ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(slot));
pciehp_queue_interrupt_event(slot, INT_POWER_FAULT);
}
return IRQ_HANDLED;
}
static irqreturn_t pcie_isr(int irq, void *dev_id)
{
irqreturn_t rc, handled = IRQ_NONE;
/*
* To guarantee that all interrupt events are serviced, we need to
* re-inspect Slot Status register after clearing what is presumed
* to be the last pending interrupt.
*/
do {
rc = pciehp_isr(irq, dev_id);
if (rc == IRQ_HANDLED)
handled = IRQ_HANDLED;
} while (rc == IRQ_HANDLED);
/* Return IRQ_HANDLED if we handled one or more events */
return handled;
}
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);
}
/*
* 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;
if (probe)
return 0;
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);
if (pciehp_poll_mode)
del_timer_sync(&ctrl->poll_timer);
pci_reset_bridge_secondary_bus(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);
if (pciehp_poll_mode)
int_poll_timeout(&ctrl->poll_timer);
return 0;
}
int pcie_init_notification(struct controller *ctrl)
{
if (pciehp_request_irq(ctrl))
return -1;
pcie_enable_notification(ctrl);
ctrl->notification_enabled = 1;
return 0;
}
static 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 slot *slot;
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
if (!slot)
return -ENOMEM;
slot->wq = alloc_ordered_workqueue("pciehp-%u", 0, PSN(ctrl));
if (!slot->wq)
goto abort;
slot->ctrl = ctrl;
mutex_init(&slot->lock);
mutex_init(&slot->hotplug_lock);
INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
ctrl->slot = slot;
return 0;
abort:
kfree(slot);
return -ENOMEM;
}
static void pcie_cleanup_slot(struct controller *ctrl)
{
struct slot *slot = ctrl->slot;
cancel_delayed_work(&slot->work);
destroy_workqueue(slot->wq);
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;
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_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 except
* Presence Detect Changed. We want to make sure possible
* hotplug event is triggered when the interrupt is unmasked so
* that we don't lose that event.
*/
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);
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;
return ctrl;
abort_ctrl:
kfree(ctrl);
abort:
return NULL;
}
void pciehp_release_ctrl(struct controller *ctrl)
{
pcie_shutdown_notification(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, 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);
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