PCIe native hotplug shares MSI vector with native PME so the interrupt handler might get called even the hotplug interrupt is masked. In that case we should not handle any events because the interrupt was not meant for us. Modify the PCIe hotplug interrupt handler to check this accordingly and bail out if it finds out that the interrupt was not about hotplug. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Lukas Wunner <lukas@wunner.de>
When PCIe hotplug port is transitioned into D3hot, the link to the
downstream component will go down. If hotplug interrupt generation is
enabled when that happens, it will trigger immediately, waking up the
system and bringing the link back up.
To prevent this, disable hotplug interrupt generation when system suspend
is entered. This does not prevent wakeup from low power states according
to PCIe 4.0 spec section 6.7.3.4:
Software enables a hot-plug event to generate a wakeup event by
enabling software notification of the event as described in Section
6.7.3.1. Note that in order for software to disable interrupt generation
while keeping wakeup generation enabled, the Hot-Plug Interrupt Enable
bit must be cleared.
So as long as we have set the slot event mask accordingly, wakeup should
work even if slot interrupt is disabled. The port should trigger wake and
then send PME to the root port when the PCIe hierarchy is brought back up.
Limit this to systems using native PME mechanism to make sure older Apple
systems depending on commit e3354628c376 ("PCI: pciehp: Support interrupts
sent from D3hot") still continue working.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The spec has timing requirements when waiting for a link to become active after a conventional reset. Implement those hard delays when waiting for an active link so pciehp and dpc drivers don't need to duplicate this. For devices that don't support data link layer active reporting, wait the fixed time recommended by the PCIe spec. Signed-off-by: Keith Busch <keith.busch@intel.com> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Sinan Kaya <okaya@kernel.org>
When the PCI hotplug core and its first user, cpqphp, were introduced in
February 2002 with historic commit a8a2069f432c, cpqphp allocated a slot
struct for its internal use plus a hotplug_slot struct to be registered
with the hotplug core and linked the two with pointers:
https://git.kernel.org/tglx/history/c/a8a2069f432c
Nowadays, the predominant pattern in the tree is to embed ("subclass")
such structures in one another and cast to the containing struct with
container_of(). But it wasn't until July 2002 that container_of() was
introduced with historic commit ec4f214232cf:
https://git.kernel.org/tglx/history/c/ec4f214232cf
pnv_php, introduced in 2016, did the right thing and embedded struct
hotplug_slot in its internal struct pnv_php_slot, but all other drivers
cargo-culted cpqphp's design and linked separate structs with pointers.
Embedding structs is preferrable to linking them with pointers because
it requires fewer allocations, thereby reducing overhead and simplifying
error paths. Casting an embedded struct to the containing struct
becomes a cheap subtraction rather than a dereference. And having fewer
pointers reduces the risk of them pointing nowhere either accidentally
or due to an attack.
Convert all drivers to embed struct hotplug_slot in their internal slot
struct. The "private" pointer in struct hotplug_slot thereby becomes
unused, so drop it.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> # drivers/pci/hotplug/rpa*
Acked-by: Sebastian Ott <sebott@linux.ibm.com> # drivers/pci/hotplug/s390*
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # drivers/platform/x86
Cc: Len Brown <lenb@kernel.org>
Cc: Scott Murray <scott@spiteful.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Oliver OHalloran <oliveroh@au1.ibm.com>
Cc: Gavin Shan <gwshan@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Corentin Chary <corentin.chary@gmail.com>
Cc: Darren Hart <dvhart@infradead.org>
Of the members which were just moved from pciehp's slot struct to the controller struct, rename "lock" to "state_lock" and rename "work" to "button_work" for clarity. Perform the rename separately to the unification of the two structs per Sinan's request. No functional change intended. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Sinan Kaya <okaya@kernel.org>
pciehp was originally introduced together with shpchp in a single
commit, c16b4b14d980 ("PCI Hotplug: Add SHPC and PCI Express hot-plug
drivers"):
https://git.kernel.org/tglx/history/c/c16b4b14d980
shpchp supports up to 31 slots per controller, hence uses separate slot
and controller structs. pciehp has a 1:1 relationship between slot and
controller and therefore never required this separation. Nevertheless,
because much of the code had been copy-pasted between the two drivers,
pciehp likewise uses separate structs to this very day.
The artificial separation of data structures adds unnecessary complexity
and bloat to pciehp and requires constantly chasing pointers at runtime.
Simplify the driver by merging struct slot into struct controller.
Merge the slot constructor pcie_init_slot() and the destructor
pcie_cleanup_slot() into the controller counterparts.
No functional change intended.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The WiGig Bus Extension (WBE) specification allows tunneling PCIe over
IEEE 802.11. A product implementing this spec is the wil6210 from
Wilocity (now part of Qualcomm Atheros). It integrates a PCIe switch
with a wireless network adapter:
00.0-+ [1ae9:0101] Upstream Port
+-00.0-+ [1ae9:0200] Downstream Port
| +-00.0 [168c:0034] Atheros AR9462 Wireless Network Adapter
+-02.0 [1ae9:0201] Downstream Port
+-03.0 [1ae9:0201] Downstream Port
Wirelessly attached devices presumably appear below the hotplug ports
with device ID [1ae9:0201]. Oddly, the Downstream Port [1ae9:0200]
leading to the wireless network adapter is likewise Hotplug Capable,
but has its Presence Detect State bit hardwired to zero. Even if the
Link Active bit is set, Presence Detect is zero, so this cannot be
caused by in-band presence detection but only by broken hardware.
pciehp assumes an empty slot if Presence Detect State is zero,
regardless of Link Active being one. Consequently, up until v4.18 it
removes the wireless network adapter in pciehp_resume(). From v4.19 it
already does so in pciehp_probe().
Be lenient towards broken hardware and assume the slot is occupied if
Link Active is set: Introduce pciehp_card_present_or_link_active()
and use it in lieu of pciehp_get_adapter_status() everywhere, except
in pciehp_handle_presence_or_link_change() whose log messages depend
on which of Presence Detect State or Link Active is set.
Remove the Presence Detect State check from __pciehp_enable_slot()
because it is only called if either of Presence Detect State or Link
Active is set.
Caution: There is a possibility that broken hardware exists which has
working Presence Detect but hardwires Link Active to one. On such
hardware the slot will now incorrectly be considered always occupied.
If such hardware is discovered, this commit can be rolled back and a
quirk can be added which sets is_hotplug_bridge = 0 for [1ae9:0200].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200839
Reported-and-tested-by: David Yang <mmyangfl@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Rajat Jain <rajatja@google.com>
Cc: Ashok Raj <ashok.raj@intel.com>
pciehp's ->enable_slot, ->disable_slot, ->get_attention_status and ->reset_slot callbacks are currently implemented by wrapper functions that do nothing else but call down to a backend function. The backends are not called from anywhere else, so drop the wrappers and use the backends directly as callbacks, thereby shaving off a few lines of unnecessary code. No functional change intended. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Drop the following includes from pciehp source files which no longer use
any of the included symbols:
* <linux/sched/signal.h> in pciehp.h
<linux/signal.h> in pciehp_hpc.c
Added by commit de25968cc87c ("fix more missing includes") to
accommodate for a call to signal_pending().
The call was removed by commit 262303fe329a ("pciehp: fix wait command
completion").
* <linux/interrupt.h> in pciehp_core.c
Added by historic commit f308a2dfbe63 ("PCI: add PCI Express Port Bus
Driver subsystem") to accommodate for a call to free_irq():
https://git.kernel.org/tglx/history/c/f308a2dfbe63
The call was removed by commit 407f452b05f9 ("pciehp: remove
unnecessary free_irq").
* <linux/time.h> in pciehp_core.c and pciehp_hpc.c
Added by commit 34d03419f03b ("PCIEHP: Add Electro Mechanical
Interlock (EMI) support to the PCIE hotplug driver."),
which was reverted by commit bd3d99c17039 ("PCI: Remove untested
Electromechanical Interlock (EMI) support in pciehp.").
* <linux/module.h> in pciehp_ctrl.c, pciehp_hpc.c and pciehp_pci.c
Added by historic commit c16b4b14d980 ("PCI Hotplug: Add SHPC and PCI
Express hot-plug drivers"):
https://git.kernel.org/tglx/history/c/c16b4b14d980
Module-related symbols were neither used back then in those files,
nor are they used today.
* <linux/slab.h> in pciehp_ctrl.c
Added by commit 5a0e3ad6af86 ("include cleanup: Update gfp.h and
slab.h includes to prepare for breaking implicit slab.h inclusion from
percpu.h") to accommodate for calls to kmalloc().
The calls were removed by commit 0e94916e6091 ("PCI: pciehp: Handle
events synchronously").
* "../pci.h" in pciehp_ctrl.c
Added by historic commit 67f4660b72f2 ("PCI: ASPM patch for") to
accommodate for usage of the global variable pcie_mch_quirk:
https://git.kernel.org/tglx/history/c/67f4660b72f2
The global variable was removed by commit 0ba379ec0fb1 ("PCI: Simplify
hotplug mch quirk").
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
If both hot-add and power fault were observed in a single interrupt, we
handled the hot-add first, then the power fault, in this path:
pciehp_ist
if (events & (PDC | DLLSC))
pciehp_handle_presence_or_link_change
case OFF_STATE:
pciehp_enable_slot
__pciehp_enable_slot
board_added
pciehp_power_on_slot
ctrl->power_fault_detected = 0
pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_ON, PCI_EXP_SLTCTL_PCC)
pciehp_green_led_on(p_slot) # power LED on
pciehp_set_attention_status(p_slot, 0) # attention LED off
if ((events & PFD) && !ctrl->power_fault_detected)
ctrl->power_fault_detected = 1
pciehp_set_attention_status(1) # attention LED on
pciehp_green_led_off(slot) # power LED off
This left the attention indicator on (even though the hot-add succeeded)
and the power indicator off (even though the slot power was on).
Fix this by checking for power faults before checking for new devices.
Prior to 0e94916e6091, this was successful because everything was chained
through work queues and the order was:
INT_PRESENCE_ON -> INT_POWER_FAULT -> ENABLE_REQ
The ENABLE_REQ cleared the power fault at the end, but now everything is
handled inline with the interrupt thread, such that the work ENABLE_REQ was
doing happens before power fault handling now.
Fixes: 0e94916e6091 ("PCI: pciehp: Handle events synchronously")
Signed-off-by: Keith Busch <keith.busch@intel.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>