linux-stable.git/drivers/pci/hotplug/shpchp_ctrl.c, branch linux-5.4.y

PCI: hotplug: Drop hotplug_slot_info

2018-09-18T22:52:15+00:00

Ever since the PCI hotplug core was introduced in 2002, drivers had to
allocate and register a struct hotplug_slot_info for every slot:
https://git.kernel.org/tglx/history/c/a8a2069f432c

Apparently the idea was that drivers furnish the hotplug core with an
up-to-date card presence status, power status, latch status and
attention indicator status as well as notify the hotplug core of changes
thereof.  However only 4 out of 12 hotplug drivers bother to notify the
hotplug core with pci_hp_change_slot_info() and the hotplug core never
made any use of the information:  There is just a single macro in
pci_hotplug_core.c, GET_STATUS(), which uses the hotplug_slot_info if
the driver lacks the corresponding callback in hotplug_slot_ops.  The
macro is called when the user reads the attribute via sysfs.

Now, if the callback isn't defined, the attribute isn't exposed in sysfs
in the first place (see e.g. has_power_file()).  There are only two
situations when the hotplug_slot_info would actually be accessed:

* If the driver defines ->enable_slot or ->disable_slot but not
  ->get_power_status.

* If the driver defines ->set_attention_status but not
  ->get_attention_status.

There is no driver doing the former and just a single driver doing the
latter, namely pnv_php.c.  Amend it with a ->get_attention_status
callback.  With that, the hotplug_slot_info becomes completely unused by
the PCI hotplug core.  But a few drivers use it internally as a cache:

cpcihp uses it to cache the latch_status and adapter_status.
cpqhp uses it to cache the adapter_status.
pnv_php and rpaphp use it to cache the attention_status.
shpchp uses it to cache all four values.

Amend these drivers to cache the information in their private slot
struct.  shpchp's slot struct already contains members to cache the
power_status and adapter_status, so additional members are only needed
for the other two values.  In the case of cpqphp, the cached value is
only accessed in a single place, so instead of caching it, read the
current value from the hardware.

Caution:  acpiphp, cpci, cpqhp, shpchp, asus-wmi and eeepc-laptop
populate the hotplug_slot_info with initial values on probe.  That code
is herewith removed.  There is a theoretical chance that the code has
side effects without which the driver fails to function, e.g. if the
ACPI method to read the adapter status needs to be executed at least
once on probe.  That seems unlikely to me, still maintainers should
review the changes carefully for this possibility.

Rafael adds: "I'm not aware of any case in which it will break anything,
[...] but if that happens, it may be necessary to add the execution of
the control methods in question directly to the initialization part."

Signed-off-by: Lukas Wunner 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Rafael J. Wysocki 
Acked-by: Tyrel Datwyler   # drivers/pci/hotplug/rpa*
Acked-by: Sebastian Ott         # drivers/pci/hotplug/s390*
Acked-by: Andy Shevchenko  # drivers/platform/x86
Cc: Len Brown 
Cc: Scott Murray 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Oliver OHalloran 
Cc: Gavin Shan 
Cc: Gerald Schaefer 
Cc: Corentin Chary 
Cc: Darren Hart

PCI: Mark fall-through switch cases before enabling -Wimplicit-fallthrough

2018-07-12T21:55:57+00:00

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where
we are expecting to fall through.

Warning level 2 was used: -Wimplicit-fallthrough=2

Signed-off-by: Gustavo A. R. Silva 
Signed-off-by: Bjorn Helgaas

PCI: shpchp: Fix AMD POGO identification

2018-06-04T17:07:31+00:00

The fix for an AMD POGO erratum related to SHPC incorrectly identified the
device.  The workaround should be applied only for AMD POGO devices, but it
was instead applied to:

  - all AMD bridges, and
  - all devices from any vendor with device ID 0x7458

Fixes: 53044f357448 ("[PATCH] PCI Hotplug: shpchp: AMD POGO errata fix")
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Mika Westerberg 
Reviewed-by: Rafael J. Wysocki

PCI: Add SPDX GPL-2.0+ to replace GPL v2 or later boilerplate

2018-01-28T21:49:06+00:00

Add SPDX GPL-2.0+ to all PCI files that specified the GPL and allowed
either GPL version 2 or any later version.

Remove the boilerplate GPL version 2 or later language, relying on the
assertion in b24413180f56 ("License cleanup: add SPDX GPL-2.0 license
identifier to files with no license") that the SPDX identifier may be used
instead of the full boilerplate text.

Signed-off-by: Bjorn Helgaas 
Reviewed-by: Greg Kroah-Hartman

PCI: Remove assignment from "if" conditions

2014-09-24T13:50:53+00:00

The following Coccinelle semantic patch was used to find and correct cases
of assignments in "if" conditions:

@@
expression var, expr;
statement S;
@@

+ var = expr;
  if(
- (var = expr)
+ var
  ) S

Signed-off-by: Quentin Lambert 
Signed-off-by: Bjorn Helgaas

PCI: Add space before open parenthesis

2014-09-24T13:43:03+00:00

Add space before open parenthesis as is conventional.

No functional change.

[bhelgaas: fix a few more in ibmphp, shpchp]
Signed-off-by: Quentin Lambert 
Signed-off-by: Bjorn Helgaas

Merge tag 'pci-v3.16-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2014-06-12T20:20:24+00:00

Pull more PCI updates from Bjorn Helgaas:
 "Here are some more things I'd like to see in v3.16-rc1:

   - DMA alias iterator, part of some work to fix IOMMU issues
   - MVEBU, Tegra, DesignWare changes that I forgot to include before
   - Some whitespace code cleanup

  Details:

  IOMMU
    - Add DMA alias iterator (Alex Williamson)
    - Add DMA alias quirks for ASMedia, ITE, Tundra bridges (Alex Williamson)
    - Add DMA alias quirks for Marvell, Ricoh devices (Alex Williamson)
    - Add DMA alias quirk for HighPoint devices (Jérôme Carretero)

  MSI
    - Fix leak in free_msi_irqs() (Alexei Starovoitov)

  Marvell MVEBU
    - Remove unnecessary use of 'conf_lock' spinlock (Andrew Murray)
    - Avoid setting an undefined window size (Jason Gunthorpe)
    - Allow several windows with the same target/attribute (Thomas Petazzoni)
    - Split PCIe BARs into multiple MBus windows when needed (Thomas Petazzoni)
    - Fix off-by-one in the computed size of the mbus windows (Willy Tarreau)

  NVIDIA Tegra
    - Use new OF interrupt mapping when possible (Lucas Stach)

  Synopsys DesignWare
    - Remove unnecessary use of 'conf_lock' spinlock (Andrew Murray)
    - Use new OF interrupt mapping when possible (Lucas Stach)
    - Split Exynos and i.MX bindings (Lucas Stach)
    - Fix comment for setting number of lanes (Mohit Kumar)
    - Fix iATU programming for cfg1, io and mem viewport (Mohit Kumar)

  Miscellaneous
    - EXPORT_SYMBOL cleanup (Ryan Desfosses)
    - Whitespace cleanup (Ryan Desfosses)
    - Merge multi-line quoted strings (Ryan Desfosses)"

* tag 'pci-v3.16-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (21 commits)
  PCI: Add function 1 DMA alias quirk for HighPoint RocketRaid 642L
  PCI/MSI: Fix memory leak in free_msi_irqs()
  PCI: Merge multi-line quoted strings
  PCI: Whitespace cleanup
  PCI: Move EXPORT_SYMBOL so it immediately follows function/variable
  PCI: Add bridge DMA alias quirk for ITE bridge
  PCI: designware: Split Exynos and i.MX bindings
  PCI: Add bridge DMA alias quirk for ASMedia and Tundra bridges
  PCI: Add support for PCIe-to-PCI bridge DMA alias quirks
  PCI: Add function 1 DMA alias quirk for Marvell devices
  PCI: Add function 0 DMA alias quirk for Ricoh devices
  PCI: Add support for DMA alias quirks
  PCI: Convert pci_dev_flags definitions to bit shifts
  PCI: Add DMA alias iterator
  PCI: mvebu: Use '%pa' for printing 'phys_addr_t' type
  PCI: mvebu: Remove unnecessary use of 'conf_lock' spinlock
  PCI: designware: Remove unnecessary use of 'conf_lock' spinlock
  PCI: designware: Use new OF interrupt mapping when possible
  PCI: designware: Fix iATU programming for cfg1, io and mem viewport
  PCI: designware: Fix comment for setting number of lanes
  ...

PCI: Merge multi-line quoted strings

2014-06-11T02:20:42+00:00

Merge quoted strings that are broken across lines into a single entity.
The compiler merges them anyway, but checkpatch complains about it, and
merging them makes it easier to grep for strings.

No functional change.

[bhelgaas: changelog, do the same for everything under drivers/pci]
Signed-off-by: Ryan Desfosses 
Signed-off-by: Bjorn Helgaas

PCI: Whitespace cleanup

2014-06-11T02:20:19+00:00

Fix various whitespace errors.

No functional change.

[bhelgaas: fix other similar problems]
Signed-off-by: Ryan Desfosses 
Signed-off-by: Bjorn Helgaas

PCI: shpchp: Check bridge's secondary (not primary) bus speed

2014-05-15T18:42:49+00:00

When a new device is added below a hotplug bridge, the bridge's secondary
bus speed and the device's bus speed must match.  The shpchp driver
previously checked the bridge's *primary* bus speed, not the secondary bus
speed.

This caused hot-add errors like:

  shpchp 0000:00:03.0: Speed of bus ff and adapter 0 mismatch

Check the secondary bus speed instead.

[bhelgaas: changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=75251
Fixes: 3749c51ac6c1 ("PCI: Make current and maximum bus speeds part of the PCI core")
Signed-off-by: Marcel Apfelbaum 
Signed-off-by: Bjorn Helgaas 
Acked-by: Michael S. Tsirkin 
CC: stable@vger.kernel.org	# v2.6.34+