Subject: Re: [PATCH v8 00/45] powerpc/powernv: PCI hotplug support

From: Gavin Shan <[email-masked]>
Date: Thu, 14 Apr 2016 09:42:46 +1000

On Wed, Apr 13, 2016 at 07:14:59PM +1000, Alexey Kardashevskiy wrote:
>On 04/13/2016 05:42 PM, Gavin Shan wrote:
>>On Wed, Apr 13, 2016 at 05:28:15PM +1000, Alexey Kardashevskiy wrote:
>>>On 02/17/2016 02:43 PM, Gavin Shan wrote:
>>>>This series of patches rebases on powerpc/next branch, plus below additional
>>>>patches:
>>>>
>>>>    <This series of patches>
>>>>    <Followup 3 patches from Gavin on SRIOV EEH, which aren't posted>
>>>>    https://patchwork.ozlabs.org/patch/581315/	(PATCH[1/9] Richard's SRIOV EEH)
>>>>    https://patchwork.ozlabs.org/patch/582639/	(PATCH[1/1] Gavin's EEH fix)
>>>>    https://patchwork.ozlabs.org/patch/582093/	(PATCH[1/1] Gavin's EEH fix)
>>>>    https://patchwork.ozlabs.org/patch/580626/	(PATCH[1/4] Gavin's PCI fix)
>>>>    https://patchwork.ozlabs.org/patch/580153/	(PATCH[1/1] Andrew's EEH minor fix)
>>>>    https://patchwork.ozlabs.org/patch/566827/	(PATCH[1/1] Russell's P5IOC2 removal)
>>>>    https://patchwork.ozlabs.org/patch/534154/	(PATCH[1/7] Richard's SRIOV rework)
>>>>    commit 388f7b1 ("Linux 4.5-rc3")
>>>>
>>>>The series of patches intend to support PCI slot for PowerPC PowerNV platform,
>>>>which is running on top of skiboot firmware. The patchset requires corresponding
>>>>changes from skiboot firmware, which is sent to [email-masked]
>>>>for review. The PCI slots are exposed by skiboot with device node properties,
>>>>and kernel utilizes those properties to populated PCI slots accordingly.
>>>>
>>>>The original PCI infrastructure on PowerNV platform can't support hotplug
>>>>because the PE is assigned during PHB fixup time, which is called for once
>>>>during system boot time. For this, the PCI infrastructure on PowerNV platform
>>>>has been reworked for a lot. After that, the PE and its corresponding resources
>>>>(IODT, M32DT, M64 segments, DMA32 and bypass window) are assigned upon updating
>>>>PCI bridge's resources, which might decide PE# assigned to the PE (e.g. M64
>>>>resources, on P8 strictly speaking). Each PE will maintain a reference count,
>>>>which is (number of child PCI devices + 1). That indicates when last child PCI
>>>>device leaves the PE, the PE and its included resources will be relased and put
>>>>back into free pool again. With this design, the PE will be released when EEH PE
>>>>is released. PATCH[1 - 23] are related to this part.
>>>>
>>>> From skiboot perspective, PCI slot is providing (hot/fundamental/complete)
>>>>resets to EEH. The kernel gets to know if skiboot supports various reset on one
>>>>particular PCI slot through device-tree node. If it does, EEH will utilize the
>>>>functionality provided by skiboot. Besides, the device-tree nodes have to change
>>>>in order to support PCI hotplug. For example, when one PCI adapter inserted to
>>>>one slot, its device-tree node should be added to the system dynamically. Conversely,
>>>>the device-tree node should be removed from the system when the PCI adapter is going
>>>>to be offline. Since pci_dn and eeh_dev have same life cyle as PCI device nodes,
>>>>they should be added/removed accordingly during PCI hotplug. PATCH[24 - 39] are
>>>>doing the related work.
>>>>
>>>>The OF driver is changed to support unflattening FDT blob for sub-stree, which
>>>>is covered by PATCH[40 - 44].
>>>>
>>>>The last one, PATCH[45], is the standalone PCI hotplug driver for PowerPC PowerNV
>>>>platform.
>>>>
>>>>=======
>>>>Testing
>>>>=======
>>>>1. Unplug adapters behind non-empty slot, then plug them.
>>>>
>>>>    1.1 Check status
>>>>    # cat /sys/bus/pci/slots/C10/address
>>>>    0003:09:00
>>>>    # cat /sys/bus/pci/slots/C10/adapter
>>>>    1
>>>>    # cat /sys/bus/pci/slots/C10/power
>>>>    1
>>>>    # lspci
>>>>    0003:09:00.0 Ethernet controller: \
>>>>    Broadcom Corporation NetXtreme BCM5719 Gigabit Ethernet PCIe (rev 01)
>>>>    0003:09:00.1 Ethernet controller: \
>>>>    Broadcom Corporation NetXtreme BCM5719 Gigabit Ethernet PCIe (rev 01)
>>>>    0003:09:00.2 Ethernet controller: \
>>>>    Broadcom Corporation NetXtreme BCM5719 Gigabit Ethernet PCIe (rev 01)
>>>>    0003:09:00.3 Ethernet controller: \
>>>>    Broadcom Corporation NetXtreme BCM5719 Gigabit Ethernet PCIe (rev 01)
>>>>    # lspci -t
>>>>    # lspci -t
>>>>    -+-[0003:00]---00.0-[01-13]----00.0-[02-13]--+-01.0-[03]----00.0
>>>>     |                                           +-08.0-[04-08]--
>>>>     |                                           +-09.0-[09]--+-00.0
>>>>     |                                           |            +-00.1
>>>>     |                                           |            +-00.2
>>>>     |                                           |            \-00.3
>>>>     |                                           +-10.0-[0a-0e]--
>>>>     |                                           \-11.0-[0f-13]--
>>>>
>>>>    1.2 Unplug adapter 0003:09.00.x
>>>>    # echo 0 > /sys/bus/pci/slots/C10/power
>>>>    # lspci -t
>>>>    -+-[0003:00]---00.0-[01-13]----00.0-[02-13]--+-01.0-[03]----00.0
>>>>     |                                           +-08.0-[04-08]--
>>>>     |                                           +-09.0-[09]--
>>>>     |                                           +-10.0-[0a-0e]--
>>>>     |                                           \-11.0-[0f-13]--
>>>>
>>>>    1.3 Plug adapter 0003:09.00.x
>>>>    # echo 1 > /sys/bus/pci/slots/C10/power
>>>
>>>
>>>Do I understand correctly that the adapter was not physically moved in/out of
>>>the slot between 1.2 and 1.3?
>>>
>>
>>Correct.
>
>
>This is not right then... Someone should try it, on both P7 and P8.
>

Do you mean physically pull the adapter out and insert the same
adapter back? What's the point for the test case?

>>
>>>
>>>
>>>>    # lspci -t
>>>>    -+-[0003:00]---00.0-[01-13]----00.0-[02-13]--+-01.0-[03]----00.0
>>>>     |                                           +-08.0-[04-08]--
>>>>     |                                           +-09.0-[09]--+-00.0
>>>>     |                                           |            +-00.1
>>>>     |                                           |            +-00.2
>>>>     |                                           |            \-00.3
>>>>     |                                           +-10.0-[0a-0e]--
>>>>     |                                           \-11.0-[0f-13]--
>>>>
>>>>
>>>>    1.4 Inject EEH error to adapter 0003:09:00.x, which is recovered.
>>>
>>>I am confused - why is this needed to test hotplug?
>>>
>>
>>Without the series, the EEH reset is always done by kenrel. With the
>>series applied, the EEH reset could be done in skiboot.
>
>
>Why exactly cannot EEH reset changes go to a smaller separate patchset
>(before hotplug)?
>

As I explained before, the patchset's order is: PCI generic part,
PowerNV PCI related, EEH related, device-tree part and hotplug driver.

The EEH reset change is included in PATCH[37/45]. There is no point
to reorder the patches.

>>That's the
>>major change introduced by the series from EEH's perspective. Also,
>>the EEH code was touched.
>>
>>>>    # cat /sys/bus/pci/devices/0003:09:00.0/eeh_pe_config_addr
>>>>    0x1
>>>>    # echo 1:0:4:0:0 > /sys/kernel/debug/powerpc/PCI0003/err_injct
>>>>    # lspci -ns 0003:09:00.0
>>>>    # dmesg | grep EEH
>>>>    EEH: Frozen PHB#3-PE#1 detected
>>>>    EEH: PE location: U78C9.001.WZS00CF-P1-C10, PHB location: N/A
>>>>    EEH: Detected PCI bus error on PHB#3-PE#1
>>>>    EEH: This PCI device has failed 1 times in the last hour
>>>>    EEH: Notify device drivers to shutdown
>>>>    EEH: Collect temporary log
>>>>    EEH: Reset without hotplug activity
>>>>    EEH: Notify device drivers the completion of reset
>>>>    EEH: Notify device driver to resume
>>>>
>>>>2. Plug adapter and then unplug it. This requires hack in skiboot
>>>>    to skip probing the adapters behind the target (C12 in the
>>>>    testing) for once.
>>>>
>>>>    2.1 Check status
>>>>    # cat /sys/bus/pci/slots/C12/address
>>>>    0001:06
>>>>    # cat /sys/bus/pci/slots/C12/power
>>>>    0
>>>>    # cat /sys/bus/pci/slots/C12/adapter
>>>>    1
>>>>    # lspci -t
>>>>    +-[0001:00]---00.0-[01-0a]----00.0-[02-0a]--+-01.0-[03-04]----00.0-[04]----00.0
>>>>                                                +-08.0-[05]----00.0
>>>>                                                \-09.0-[06-0a]--
>>>>
>>>>    2.2 Plug adapter 0001:06:00.x
>>>>    # echo 1 > /sys/bus/pci/slots/C12/power
>>>>    # lspci -t
>>>>    +-[0001:00]---00.0-[01-0a]----00.0-[02-0a]--+-01.0-[03-04]----00.0-[04]----00.0
>>>>                                                +-08.0-[05]----00.0
>>>>                                                \-09.0-[06-0a]--+-00.0
>>>>                                                                \-00.1
>>>>    # lspci
>>>>    0001:06:00.0 Ethernet controller: \
>>>>    Broadcom Corporation NetXtreme II BCM57810 10 Gigabit Ethernet (rev 10)
>>>>    0001:06:00.1 Ethernet controller: \
>>>>    Broadcom Corporation NetXtreme II BCM57810 10 Gigabit Ethernet (rev 10)
>>>>
>>>>    2.3 Inject EEH error to adapter 0001:06:00.x, which is recovered
>>>>    # cat /sys/bus/pci/devices/0001:06:00.0/eeh_pe_config_addr
>>>>    0x2
>>>>    # echo 2:0:4:0:0 > /sys/kernel/debug/powerpc/PCI0001/err_injct
>>>>    # dmesg | grep EEH
>>>>    EEH: Frozen PHB#1-PE#2 detected
>>>>    EEH: PE location: U78C9.001.WZS00CF-P1-C12, PHB location: N/A
>>>>    EEH: Detected PCI bus error on PHB#1-PE#2
>>>>    EEH: This PCI device has failed 1 times in the last hour
>>>>    EEH: Notify device drivers to shutdown
>>>>    EEH: Collect temporary log
>>>>    EEH: Reset without hotplug activity
>>>>    EEH: Notify device drivers the completion of reset
>>>>    EEH: Notify device driver to resume
>>>>
>>>>    2.4 Unplug adapter 0001:06:00.x
>>>>    # echo 0 > /sys/bus/pci/slots/C12/power
>>>>    # lspci -t
>>>>    +-[0001:00]---00.0-[01-0a]----00.0-[02-0a]--+-01.0-[03-04]----00.0-[04]----00.0
>>>>                                                +-08.0-[05]----00.0
>>>>                                                \-09.0-[06-0a]--
>>>>
>>>>=========
>>>>Changelog
>>>>=========
>>>>v8:
>>>>    * Rebased to linux-powerpc next branch.
>>>>    * Resolve comments from Alexey and Daniel on PCI part
>>>>    * Resolve comments from Rob on fdt.c
>>>>    * Retested (refer to the "Testing section")
>>>>v7:
>>>>    * Reworked revision to some extent.
>>>>    * Rebased to powerpc/next repository.
>>>>    * Reorder/split/merge/drop according - Alexey.
>>>>    * Defined macros and use array to track IO/M32/M64/DMA32 segments - Alexey.
>>>>    * Merged 3 files to one for the hotplug driver - Alexey.
>>>>    * As part of OPAL API, defined macros for PCI slot power state, hotplug
>>>>      message type. Defined macros for PCI slot power confirmed state in
>>>>      hotplug driver.
>>>>    * Misc comments from Alexey.
>>>>    * Reworked unflatten_dt_node() to avoid recursive function calls.
>>>>    * Use EXPORT_SYMBOL_GPL() and document function's input/output - Rob/Frank.
>>>>v6:
>>>>    * Patch reorder, split, squash - Alexey.
>>>>    * Minor coding style - Alexey.
>>>>    * Better function names for pcibios_{add,remove}_pci_devices - Bjorn
>>>>    * Replace pr_warn() with dev_warn() in PowerNV hotplug driver - Bjorn
>>>>    * Concurrent depth as parameter passed to __unflatten_dt_node() - Grant / Alexey
>>>>    * Replace overlay with of_changeset - Grant
>>>>v5:
>>>>    * Rebased to 4.1.rc6 and some unmerged patches as below:
>>>>      Alexey's DDW patchset (v11);
>>>>      Gavin's EEH error injection support (in mpe's next branch);
>>>>      Richard's EEH cleanup patches (in mpe's next branch);
>>>>      Richard's EEH support for VF (v7);
>>>>      Gavin's misc EEH fixes for 4.2;
>>>>    * The revision bases on skiboot corresponding patches (v7):
>>>>      https://patchwork.ozlabs.org/patch/480437/
>>>>    * Utilize OF overlay to update device-tree with help of newly introduced
>>>>      OPAL API opal_get_overlay_dt().
>>>>    * Split patches for easy review according to aik's comments.
>>>>    * Fix coding style from checkpatchc.pl as pointed by aik.
>>>>    * Code cleanup and misc fixup according to aik's input.
>>>>v4:
>>>>    * Rebased to 4.1.RC1
>>>>    * Added API to unflatten FDT blob to device node sub-tree, which is attached
>>>>      the indicated parent device node. The original mechanism based on formatted
>>>>      string stream has been dropped.
>>>>    * The PATCH[v3 09/21] ("powerpc/eeh: Delay probing EEH device during hotplug")
>>>>      was picked up sent to linux-ppc@ separately for review as Richard's "VF EEH
>>>>      Support" depends on that.
>>>>v3:
>>>>    * Rebased to 4.1.RC0
>>>>    * PowerNV PCI infrasturcture is total refactored in order to support PCI
>>>>      hotplug. The PowerNV hotplug driver is also reworked a lot because of
>>>>      the changes in skiboot in order to support PCI hotplug.
>>>>
>>>>Gavin Shan (45):
>>>>   PCI: Add pcibios_setup_bridge()
>>>>   powerpc/pci: Override pcibios_setup_bridge()
>>>>   powerpc/pci: Cleanup on struct pci_controller_ops
>>>>   powerpc/powernv: Cleanup on pci_controller_ops instances
>>>>   powerpc/powernv: Drop phb->bdfn_to_pe()
>>>>   powerpc/powernv: Reorder fields in struct pnv_phb
>>>>   powerpc/powernv: Rename PE# fields in struct pnv_phb
>>>>   powerpc/powernv: Fix initial IO and M32 segmap
>>>>   powerpc/powernv: Simplify pnv_ioda_setup_pe_seg()
>>>>   powerpc/powernv: IO and M32 mapping based on PCI device resources
>>>>   powerpc/powernv: Track M64 segment consumption
>>>>   powerpc/powernv: Rename M64 related functions
>>>>   powerpc/powernv/ioda1: M64 support on P7IOC
>>>>   powerpc/powernv/ioda1: Rename pnv_pci_ioda_setup_dma_pe()
>>>>   powerpc/powernv/ioda1: Introduce PNV_IODA1_DMA32_SEGSIZE
>>>>   powerpc/powernv: Remove DMA32 PE list
>>>>   powerpc/powernv/ioda1: Improve DMA32 segment track
>>>>   powerpc/powernv: Increase PE# capacity
>>>>   powerpc/powernv: Use PE instead of number during setup and release
>>>>   powerpc/powernv: Allocate PE# in reverse order
>>>>   powerpc/powernv: Create PEs at PCI hot plugging time
>>>>   powerpc/powernv/ioda1: Support releasing IODA1 TCE table
>>>>   powerpc/powernv: Dynamically release PEs
>>>>   powerpc/pci: Rename pcibios_{add,remove}_pci_devices()
>>>>   powerpc/pci: Rename pcibios_find_pci_bus()
>>>>   powerpc/pci: Move pci_find_bus_by_node() around
>>>>   powerpc/pci: Export pci_add_device_node_info()
>>>>   powerpc/pci: Introduce pci_remove_device_node_info()
>>>>   powerpc/pci: Export pci_traverse_device_nodes()
>>>>   powerpc/pci: Delay populating pdn
>>>>   powerpc/pci: Don't scan empty slot
>>>>   powerpc/pci: Update bridge windows on PCI plug
>>>>   powerpc/powernv: Simplify pnv_eeh_reset()
>>>>   powerpc/powernv: Exclude root bus in pnv_pci_reset_secondary_bus()
>>>>   powerpc/powernv: Fundamental reset in pnv_pci_reset_secondary_bus()
>>>>   powerpc/powernv: Support PCI slot ID
>>>>   powerpc/powernv: Use firmware PCI slot reset infrastructure
>>>>   powerpc/powernv: Functions to get/set PCI slot status
>>>>   powerpc/powernv: Select OF_DYNAMIC
>>>>   drivers/of: Split unflatten_dt_node()
>>>>   drivers/of: Avoid recursively calling unflatten_dt_node()
>>>>   drivers/of: Rename unflatten_dt_node()
>>>>   drivers/of: Specify parent node in of_fdt_unflatten_tree()
>>>>   drivers/of: Return allocated memory from of_fdt_unflatten_tree()
>>>>   PCI/hotplug: PowerPC PowerNV PCI hotplug driver
>>>>
>>>>  arch/powerpc/include/asm/eeh.h                 |    2 +-
>>>>  arch/powerpc/include/asm/opal-api.h            |   17 +-
>>>>  arch/powerpc/include/asm/opal.h                |    8 +-
>>>>  arch/powerpc/include/asm/pci-bridge.h          |   25 +-
>>>>  arch/powerpc/include/asm/pnv-pci.h             |    7 +
>>>>  arch/powerpc/include/asm/ppc-pci.h             |    8 +-
>>>>  arch/powerpc/kernel/eeh_dev.c                  |   17 +-
>>>>  arch/powerpc/kernel/eeh_driver.c               |   12 +-
>>>>  arch/powerpc/kernel/pci-common.c               |   16 +-
>>>>  arch/powerpc/kernel/pci-hotplug.c              |   47 +-
>>>>  arch/powerpc/kernel/pci_dn.c                   |   89 +-
>>>>  arch/powerpc/platforms/maple/pci.c             |   34 +-
>>>>  arch/powerpc/platforms/pasemi/pci.c            |    3 -
>>>>  arch/powerpc/platforms/powermac/pci.c          |   38 +-
>>>>  arch/powerpc/platforms/powernv/Kconfig         |    1 +
>>>>  arch/powerpc/platforms/powernv/eeh-powernv.c   |  179 ++--
>>>>  arch/powerpc/platforms/powernv/opal-wrappers.S |    4 +
>>>>  arch/powerpc/platforms/powernv/pci-ioda.c      | 1243 +++++++++++++++---------
>>>>  arch/powerpc/platforms/powernv/pci.c           |   92 +-
>>>>  arch/powerpc/platforms/powernv/pci.h           |   60 +-
>>>>  arch/powerpc/platforms/pseries/msi.c           |    4 +-
>>>>  arch/powerpc/platforms/pseries/pci_dlpar.c     |   32 -
>>>>  arch/powerpc/platforms/pseries/setup.c         |    8 +-
>>>>  drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c   |    2 +-
>>>>  drivers/of/fdt.c                               |  372 ++++---
>>>>  drivers/of/unittest.c                          |    2 +-
>>>>  drivers/pci/hotplug/Kconfig                    |   12 +
>>>>  drivers/pci/hotplug/Makefile                   |    3 +
>>>>  drivers/pci/hotplug/pnv_php.c                  |  870 +++++++++++++++++
>>>>  drivers/pci/hotplug/rpadlpar_core.c            |    8 +-
>>>>  drivers/pci/hotplug/rpaphp_core.c              |    4 +-
>>>>  drivers/pci/hotplug/rpaphp_pci.c               |    4 +-
>>>>  drivers/pci/setup-bus.c                        |    5 +
>>>>  include/linux/of_fdt.h                         |    5 +-
>>>>  include/linux/pci.h                            |    1 +
>>>>  35 files changed, 2360 insertions(+), 874 deletions(-)
>>>>  create mode 100644 drivers/pci/hotplug/pnv_php.c
>>>>
>>>
>>>
>>>--
>>>Alexey
>>>
>>
>
>
>-- 
>Alexey
>