[PATCH v6 00/42] powerpc/powernv: PCI hotplug suppport

Gavin Shan
2015-08-06T04:11:05Z

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 skiboot@lists.ozlabs.org
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 - 36] are
doing the related work.

The OF driver is changed to support unflattening FDT blob for sub-stree, which
is covered by PATCH[37 - 41].

The last patch is the standalone PCI hotplug driver for PowerNV platform. When
removing PCI adapter from one PCI slot, which is invoked by command in userland,
the skiboot will power off the slot to save power and remove all device-tree
nodes for all PCI devices behind the slot. Conversely, the Power to the slot
is turned on, the PCI devices behind the slot is rescanned, and the device-tree
nodes for those newly detected PCI devices will be built in skiboot. For both
of cases, one message will be sent to kernel by skiboot so that the kernel
can adjust the device-tree accordingly. At the same time, the kernel also have
to deallocate or allocate PE# and its related resources (PE# and so on) for the
removed/added PCI devices.

Changelog
=========
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 paramter 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 (42):
PCI: Add pcibios_setup_bridge()
powerpc/powernv: Drop pnv_ioda_setup_dev_PE()
powerpc/powernv: Enable M64 on P7IOC
powerpc/powernv: Reorder fields in struct pnv_phb
powerpc/powernv: Track IO/M32/M64 segments from PE
powerpc/powernv: Simplify pnv_ioda_setup_pe_seg()
powerpc/powernv: Improve IO and M32 mapping
powerpc/powernv: Calculate PHB's DMA weight dynamically
powerpc/powernv: DMA32 cleanup
powerpc/powernv: pnv_ioda_setup_dma() configure one PE only
powerpc/powernv: Trace DMA32 segments consumed by PE
powerpc/powernv: Increase PE# capacity
powerpc/pci: Cleanup on pci_controller_ops
powerpc/pci: Override pcibios_setup_bridge()
powerpc/powernv: PE oriented during configuration
powerpc/powernv: Helper function pnv_ioda_init_pe()
powerpc/powernv: Rename PE# fields in PHB
powerpc/powernv: Allocate PE# in deasending order
powerpc/powernv: Reserve PE# for root bus
powerpc/powernv: Create PEs dynamically
powerpc/powernv: Remove DMA32 list of PEs
powerpc/powernv: Move functions around
powerpc/powernv: Release PEs dynamically
powerpc/powernv: Supports slot ID
powerpc/powernv: Use PCI slot reset infrastructure
powerpc/powernv: Simplify pnv_eeh_reset()
powerpc/powernv: Don't cover root bus in pnv_pci_reset_secondary_bus()
powerpc/powernv: Fundamental reset in pnv_pci_reset_secondary_bus()
powerpc/pci: Don't scan empty slot
powerpc/pci: Move pcibios_find_pci_bus() around
powerpc/pci: Rename pcibios_{add,remove}_pci_devices
powerpc/powernv: Introduce pnv_pci_poll()
powerpc/powernv: Functions to get/reset PCI slot status
powerpc/pci: Delay creating pci_dn
powerpc/pci: Export traverse_pci_device_nodes()
powerpc/pci: Update bridge windows on PCI plugging
powerpc/powernv: Select OF_DYNAMIC
drivers/of: Unflatten subordinate nodes after specified level
drivers/of: Allow to specify root node in of_fdt_unflatten_tree()
drivers/of: Return allocated memory chunk from of_fdt_unflatten_tree()
drivers/of: Export OF changeset functions
pci/hotplug: PowerPC PowerNV PCI hotplug driver

MAINTAINERS | 6 +
arch/powerpc/include/asm/eeh.h | 2 +-
arch/powerpc/include/asm/opal-api.h | 8 +-
arch/powerpc/include/asm/opal.h | 9 +-
arch/powerpc/include/asm/pci-bridge.h | 25 +-
arch/powerpc/include/asm/pnv-pci.h | 7 +
arch/powerpc/include/asm/ppc-pci.h | 9 +-
arch/powerpc/kernel/eeh_dev.c | 19 +-
arch/powerpc/kernel/eeh_driver.c | 12 +-
arch/powerpc/kernel/pci-common.c | 16 +-
arch/powerpc/kernel/pci-hotplug.c | 48 +-
arch/powerpc/kernel/pci_dn.c | 71 +-
arch/powerpc/platforms/maple/pci.c | 34 +-
arch/powerpc/platforms/pasemi/pci.c | 3 -
arch/powerpc/platforms/powermac/pci.c | 40 +-
arch/powerpc/platforms/powernv/Kconfig | 1 +
arch/powerpc/platforms/powernv/eeh-powernv.c | 181 +--
arch/powerpc/platforms/powernv/opal-wrappers.S | 4 +
arch/powerpc/platforms/powernv/pci-ioda.c | 1661 ++++++++++++++----------
arch/powerpc/platforms/powernv/pci.c | 92 +-
arch/powerpc/platforms/powernv/pci.h | 63 +-
arch/powerpc/platforms/pseries/pci_dlpar.c | 32 -
arch/powerpc/platforms/pseries/setup.c | 9 +-
drivers/of/dynamic.c | 65 +-
drivers/of/fdt.c | 69 +-
drivers/of/overlay.c | 8 +-
drivers/of/unittest.c | 6 +-
drivers/pci/hotplug/Kconfig | 12 +
drivers/pci/hotplug/Makefile | 4 +
drivers/pci/hotplug/powernv_php.c | 140 ++
drivers/pci/hotplug/powernv_php.h | 92 ++
drivers/pci/hotplug/powernv_php_slot.c | 722 ++++++++++
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.h | 2 +
include/linux/of_fdt.h | 3 +-
include/linux/pci.h | 1 +
39 files changed, 2536 insertions(+), 961 deletions(-)
create mode 100644 drivers/pci/hotplug/powernv_php.c
create mode 100644 drivers/pci/hotplug/powernv_php.h
create mode 100644 drivers/pci/hotplug/powernv_php_slot.c

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2.1.0