Commit Graph

9 Commits

Author SHA1 Message Date
Keith Busch
0c27e28f77 PCI/DPC: Defer event handling to work queue
Move all event handling to the existing work queue, which will
make it simpler to pass event information to the handler.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
2018-07-19 16:21:01 -05:00
Keith Busch
f8d46c89c8 PCI/DPC: Leave interrupts enabled while handling event
Now that the DPC driver clears the interrupt status before exiting the
IRQ handler, we don't need to abuse the DPC control register to know if
a shared interrupt is for a new DPC event: a DPC port can not trigger
a second interrupt until the host clears the trigger status later in the
work queue handler.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
Reviewed-by: Oza Pawandeep <poza@codeaurora.org>
2018-07-19 16:20:59 -05:00
Bjorn Helgaas
0544b04b79 PCI/AER: Move pcie_aer_get_firmware_first() to portdrv.h
Move pcie_aer_get_firmware_first() to portdrv.h, where it can be more
easily shared between AER and DPC.  Then DPC no longer needs to include
aer/aerdrv.h.  No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
2018-06-11 08:11:11 -05:00
Bjorn Helgaas
8e069da28d Merge branch 'pci/dpc'
- clear interrupt status in top half to avoid interrupt storm (Oza
    Pawandeep)

* pci/dpc:
  PCI/DPC: Clear interrupt status in interrupt handler top half
2018-06-06 16:10:06 -05:00
Oza Pawandeep
b09803b5e5 PCI/DPC: Use the generic pcie_do_fatal_recovery() path
Our goal is to handle ERR_FATAL errors similarly, whether they are reported
via AER or via DPC.  A previous commit changed AER so it handles ERR_FATAL
by calling driver .remove() methods and resetting the Link.  DPC already
does that (although the Link reset is done automatically by hardware and
happens before we call the driver .remove() methods).

Restructure the DPC code so it calls the same pcie_do_fatal_recovery()
interface used by AER.  This makes it clearer that we want to use the same
path.

Implement the .reset_link() method used by pcie_do_fatal_recovery().  For
DPC, the actual reset is done automatically by hardware, so we really only
have to wait for the Link to be inactive, then release the Port from DPC.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
[bhelgaas: changelog, DPC_FATAL is not a bitfield, can be sequential]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-06-02 19:29:27 -05:00
Oza Pawandeep
6927868e7a PCI/DPC: Disable ERR_NONFATAL handling by DPC
PCIe ERR_NONFATAL errors mean a particular transaction is unreliable but
the Link is otherwise fully functional (PCIe r4.0, sec 6.2.2).

The AER driver handles these by logging the error details and calling
driver-supplied pci_error_handlers callbacks.  It does not reset downstream
devices, does not remove them from the PCI subsystem, does not re-enumerate
them, and does not call their driver .remove() or .probe() methods.

But DPC driver previously enabled DPC on ERR_NONFATAL, so if the hardware
supports DPC, these errors caused a Link reset (performed automatically by
the hardware), followed by the DPC driver removing affected devices (which
calls their .remove() methods), bringing the Link back up, and
re-enumerating (which calls driver .probe() methods).

Disable ERR_NONFATAL DPC triggering so these errors will only be handled by
AER.  This means drivers won't have to deal with different usage of their
pci_error_handlers callbacks and .probe() and .remove() methods based on
whether the platform has DPC support.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-06-02 19:29:25 -05:00
Oza Pawandeep
9f5a70f18c PCI: Add generic pcie_wait_for_link() interface
Clients such as hotplug and Downstream Port Containment (DPC) both need to
wait until a link becomes active or inactive.

Add a generic pcie_wait_link_active() interface and use it instead of
duplicating the code.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
2018-05-17 16:44:11 -05:00
Oza Pawandeep
56abbf8ad7 PCI/DPC: Clear interrupt status in interrupt handler top half
The generic IRQ handling code ensures that an interrupt handler runs with
its interrupt masked or disabled.  If the interrupt is level-triggered, the
interrupt handler must tell its device to stop asserting the interrupt
before returning.  If it doesn't, we will immediately take the interrupt
again when the handler returns and the generic code unmasks the interrupt.

The driver doesn't know whether its interrupt is edge- or level-triggered,
so it must clear its interrupt source directly in its interrupt handler.

Previously we cleared the DPC interrupt status in the bottom half, i.e., in
deferred work, which can cause an interrupt storm if the DPC interrupt
happens to be level-triggered, e.g., if we're using INTx instead of MSI.

Clear the DPC interrupt status bit in the interrupt handler, not in the
deferred work.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Reviewed-by: Keith Busch <keith.busch@intel.com>
2018-05-16 15:59:35 -05:00
Bjorn Helgaas
e02602bd76 PCI/DPC: Rename from pcie-dpc.c to dpc.c
Rename pcie-dpc.c to dpc.c.  The path "drivers/pci/pcie/pcie-dpc.c" has
more occurrences of "pci" than necessary.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2018-03-31 17:48:57 -05:00