linux-stable.git/drivers/pci/hotplug/pnv_php.c, branch linux-4.9.y

drivers/pci/hotplug: Fix initial state for empty slot

2017-03-15T02:02:46+00:00

commit d0c424971f70501ec0a0364117b9934db039c9cc upstream.

In PowerNV PCI hotplug driver, the initial PCI slot's state is set
to PNV_PHP_STATE_POPULATED if no PCI devices are connected to the
slot. The PCI devices that are hot added to the slot won't be probed
and populated because of the check in pnv_php_enable():

        /* Check if the slot has been configured */
        if (php_slot->state != PNV_PHP_STATE_REGISTERED)
                return 0;

This fixes the issue by leaving the slot in PNV_PHP_STATE_REGISTERED
state initially if nothing is connected to the slot.

Fixes: 360aebd85a4 ("drivers/pci/hotplug: Support surprise hotplug in powernv driver")
Reported-by: Hank Chang 
Signed-off-by: Gavin Shan 
Tested-by: Willie Liauw 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

drivers/pci/hotplug: Handle presence detection change properly

2017-03-15T02:02:46+00:00

commit d7d55536c6cd1f80295b6d7483ad0587b148bde4 upstream.

The surprise hotplug is driven by interrupt in PowerNV PCI hotplug
driver. In the interrupt handler, pnv_php_interrupt(), we bail when
pnv_pci_get_presence_state() returns zero wrongly. It causes the
presence change event is always ignored incorrectly.

This fixes the issue by bailing on error (non-zero value) returned
from pnv_pci_get_presence_state().

Fixes: 360aebd85a4 ("drivers/pci/hotplug: Support surprise hotplug in powernv driver")
Reported-by: Hank Chang 
Signed-off-by: Gavin Shan 
Tested-by: Willie Liauw 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

pci/hotplug/pnv-php: Disable surprise hotplug capability on conflicts

2017-03-15T02:02:45+00:00

commit 303529d6ef1293513c2c73c9ab86489eebb37d08 upstream.

The root port or PCIe switch downstream port might have been associated
with driver other than pnv-php. The MSI or MSIx might also have been
enabled by that driver (e.g. pcieport_drv). Attempt to enable MSI incurs
below backtrace:

 PowerPC PowerNV PCI Hotplug Driver version: 0.1
 ------------[ cut here ]------------
 WARNING: CPU: 19 PID: 1004 at drivers/pci/msi.c:1071 \
                              __pci_enable_msi_range+0x84/0x4e0
 NIP [c000000000665c34] __pci_enable_msi_range+0x84/0x4e0
 LR [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0
 Call Trace:
 [c000000384d67600] [c000000000665c24] __pci_enable_msi_range+0x74/0x4e0
 [c000000384d676e0] [d00000000aa31b04] pnv_php_register+0x564/0x5a0 [pnv_php]
 [c000000384d677c0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php]
 [c000000384d678a0] [d00000000aa31658] pnv_php_register+0xb8/0x5a0 [pnv_php]
 [c000000384d67980] [d00000000aa31dfc] pnv_php_init+0x60/0x98 [pnv_php]
 [c000000384d679f0] [c00000000000cfdc] do_one_initcall+0x6c/0x1d0
 [c000000384d67ab0] [c000000000b92354] do_init_module+0x94/0x254
 [c000000384d67b40] [c00000000019719c] load_module+0x258c/0x2c60
 [c000000384d67d30] [c000000000197bb0] SyS_finit_module+0xf0/0x170
 [c000000384d67e30] [c00000000000b184] system_call+0x38/0xe0

This fixes the issue by skipping enabling the surprise hotplug
capability if the MSI or MSIx on the PCI slot's upstream port has
been enabled by other driver.

Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver")
Signed-off-by: Gavin Shan 
Reviewed-by: Andrew Donnellan 
Tested-by: Vaibhav Jain 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

pci/hotplug/pnv-php: Remove WARN_ON() in pnv_php_put_slot()

2017-03-15T02:02:45+00:00

commit 36c7c9da40c408a71e5e6bfe12e57dcf549a296d upstream.

The WARN_ON() causes unnecessary backtrace when putting the parent
slot, which is likely to be NULL.

 WARNING: CPU: 2 PID: 1071 at drivers/pci/hotplug/pnv_php.c:85 \
                              pnv_php_release+0xcc/0x150 [pnv_php]
    :
 Call Trace:
 [c0000003bc007c10] [d00000000ad613c4] pnv_php_release+0x144/0x150 [pnv_php]
 [c0000003bc007c40] [c0000000006641d8] pci_hp_deregister+0x238/0x330
 [c0000003bc007cd0] [d00000000ad61440] pnv_php_unregister_one+0x70/0xa0 [pnv_php]
 [c0000003bc007d10] [d00000000ad614c0] pnv_php_unregister+0x50/0x80 [pnv_php]
 [c0000003bc007d40] [d00000000ad61e84] pnv_php_exit+0x50/0xcb4 [pnv_php]
 [c0000003bc007d70] [c00000000019499c] SyS_delete_module+0x1fc/0x2a0
 [c0000003bc007e30] [c00000000000b184] system_call+0x38/0xe0

Fixes: 66725152fb9f ("PCI/hotplug: PowerPC PowerNV PCI hotplug driver")
Signed-off-by: Gavin Shan 
Reviewed-by: Andrew Donnellan 
Tested-by: Vaibhav Jain 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

pci/hotplug/pnv-php: Disable MSI and PCI device properly

2017-03-12T05:41:47+00:00

commit 49f4b08e61547a5ccd2db551d994c4503efe5666 upstream.

pnv_php_disable_irq() can be called in two paths: Bailing path in
pnv_php_enable_irq() or releasing slot. The MSI (or MSIx) interrupts
is disabled unconditionally in pnv_php_disable_irq(). It's wrong
because that might be enabled by drivers other than pnv-php.

This disables MSI (or MSIx) interrupts and the PCI device only if
it was enabled by pnv-php. In the error path of pnv_php_enable_irq(),
we rely on the newly added parameter @disable_device. In the path
of releasing slot, @pnv_php->irq is checked.

Fixes: 360aebd85a4c ("drivers/pci/hotplug: Support surprise hotplug in powernv driver")
Signed-off-by: Gavin Shan 
Reviewed-by: Andrew Donnellan 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

drivers/pci/hotplug: Use of_property_read_u32() in powernv driver

2016-10-04T05:22:47+00:00

This replaces of_get_property() with of_property_read_u32() or
of_property_read_string() so that we needn't consider the endian
issue, the returned value always is in CPU-endian.

Signed-off-by: Gavin Shan 
[mpe: Fold in the change to the "ibm,slot-surprise-pluggable" case]
Signed-off-by: Michael Ellerman

drivers/pci/hotplug: Support surprise hotplug in powernv driver

2016-09-29T05:02:28+00:00

This supports PCI surprise hotplug. The design is highlighted as
below:

   * The PCI slot's surprise hotplug capability is exposed through
     device node property "ibm,slot-surprise-pluggable", meaning
     PCI surprise hotplug will be disabled if skiboot doesn't support
     it yet.
   * The interrupt because of presence or link state change is raised
     on surprise hotplug event. One event is allocated and queued to
     the PCI slot for workqueue to pick it up and process in serialized
     fashion. The code flow for surprise hotplug is same to that for
     managed hotplug except: the affected PEs are put into frozen state
     to avoid unexpected EEH error reporting in surprise hot remove path.

Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman

drivers/pci/hotplug: Remove likely() and unlikely() in powernv driver

2016-09-29T05:01:55+00:00

This removes likely() and unlikely() in pnv_php.c as the code isn't
running in hot path. Those macros to affect CPU's branch stream don't
help a lot for performance. I used them to identify the cases are
likely or unlikely to happen. No logical changes introduced.

Signed-off-by: Gavin Shan 
Signed-off-by: Michael Ellerman

PCI/hotplug: pnv_php: handle OPAL_PCI_SLOT_OFFLINE power state

2016-07-14T10:28:10+00:00

When calling pnv_php_set_slot_power_state() with state ==
OPAL_PCI_SLOT_OFFLINE, remove devices from the device tree as if we're
dealing with OPAL_PCI_SLOT_POWER_OFF.

Cc: Gavin Shan 
Cc: linux-pci@vger.kernel.org
Cc: Bjorn Helgaas 
Signed-off-by: Andrew Donnellan 
Signed-off-by: Ian Munsie 
Acked-by: Gavin Shan 
Signed-off-by: Michael Ellerman

PCI/hotplug: pnv_php: export symbols and move struct types needed by cxl

2016-07-14T10:28:08+00:00

The cxl driver will use infrastructure from pnv_php to handle device tree
updates when switching bi-modal CAPI cards into CAPI mode.

To enable this, export pnv_php_find_slot() and
pnv_php_set_slot_power_state(), and add corresponding declarations, as well
as the definition of struct pnv_php_slot, to asm/pnv-pci.h.

Cc: Gavin Shan 
Cc: linux-pci@vger.kernel.org
Cc: Bjorn Helgaas 
Signed-off-by: Andrew Donnellan 
Signed-off-by: Ian Munsie 
Acked-by: Gavin Shan 
Signed-off-by: Michael Ellerman