[RFC/RFT PATCH 00/18] PCI: ARM/ARM64: remove pci_fixup_irqs() usage

[Lorenzo Pieralisi]

Current pci_fixup_irqs() usage on ARM/ARM64 host controller drivers is
flawed in that pci_fixup_irqs() allocates IRQs for all PCI devices present
in a system; those PCI devices possibly belong to different PCI bus trees
(and possibly rooted at different host bridges) and may well be enabled
(ie probed and bound to a driver) by the time pci_fixup_irqs() is called
when probing a given host bridge driver.

Furthermore, current kernel code relying on pci_fixup_irqs() to
assign legacy PCI IRQs to devices does not work at all for
hotplugged devices in that the code carrying out the IRQ fixup
is called at host bridge driver probe time, which just cannot take
into account devices hotplugged after system has booted.

By leveraging Matthew Minter's patch series (and its purpose):

http://lkml.kernel.org/r/1445576642-29624-2-git-send-email-matt@masarand.com

this series[1] adds IRQs mapping and swizzling primitives to
the struct pci_host_bridge which allows IRQs to be allocated for
for a device at probe time with host bridge specific functions,
fixing the aforementioned limitations.

Current series remove pci_fixup_irqs() usage on ARM/ARM64; removal
can be extended to other architectures provided the IRQs map/swizzle
functions are set-up properly in the respective host bridges
set-up/probe paths.

Tested on kvmtool with PCI host generic.

[1] git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git pci/pci-fixup-irqs-removal

Cc: Arnd Bergmann <arnd at arndb.de>
Cc: Will Deacon <will.deacon at arm.com>
Cc: Russell King <linux at armlinux.org.uk>
Cc: Pratyush Anand <pratyush.anand at gmail.com>
Cc: Jingoo Han <jingoohan1 at gmail.com>
Cc: Bjorn Helgaas <bhelgaas at google.com>
Cc: Rob Herring <robh at kernel.org>
Cc: Simon Horman <horms at verge.net.au>
Cc: Mingkai Hu <mingkai.hu at freescale.com>
Cc: Tanmay Inamdar <tinamdar at apm.com>
Cc: Murali Karicheri <m-karicheri2 at ti.com>
Cc: Bharat Kumar Gogada <bharat.kumar.gogada at xilinx.com>
Cc: Wenrui Li <wenrui.li at rock-chips.com>
Cc: Shawn Lin <shawn.lin at rock-chips.com>
Cc: Minghuan Lian <minghuan.Lian at freescale.com>
Cc: Matthew Minter <matt at masarand.com>
Cc: Gabriele Paoloni <gabriele.paoloni at huawei.com>
Cc: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Cc: Joao Pinto <Joao.Pinto at synopsys.com>
Cc: Thierry Reding <thierry.reding at gmail.com>
Cc: Michal Simek <michal.simek at xilinx.com>
Cc: Stanimir Varbanov <svarbanov at mm-sol.com>
Cc: Zhou Wang <wangzhou1 at hisilicon.com>
Cc: Roy Zang <tie-fei.zang at freescale.com>

Lorenzo Pieralisi (13):
  PCI: Initialize bridge release function at bridge allocation
  PCI: Add pci_free_host_bridge interface
  PCI: Introduce pci_scan_root_bus_bridge()
  ARM: PCI: bios32: Convert PCI scan API to pci_scan_root_bus_bridge()
  ARM: PCI: dove: Convert PCI scan API to pci_scan_root_bus_bridge()
  ARM: PCI: iop13xx: Convert PCI scan API to pci_scan_root_bus_bridge()
  ARM: PCI: orion5x: Convert PCI scan API to pci_scan_root_bus_bridge()
  PCI: designware: Convert PCI scan API to pci_scan_root_bus_bridge()
  PCI: aardvark: Convert PCI scan API to pci_scan_root_bus_bridge()
  PCI: rcar: Convert PCI scan API to pci_scan_root_bus_bridge()
  PCI: Remove pci_scan_root_bus_msi()
  ARM: PCI: Remove pci_fixup_irqs() call for bios32 host controllers
  ARM/ARM64: PCI: Drop pci_fixup_irqs() usage for DT based host
    controllers

Matthew Minter (5):
  PCI: Build setup-irq.o on all arches
  PCI: Add IRQ mapping function pointers to pci_host_bridge struct
  PCI: Add pci_assign_irq() function and have pci_fixup_irqs() use it
  OF/PCI: Update of_irq_parse_and_map_pci() comment
  PCI: Add a call to pci_assign_irq() in pci_device_probe()

 arch/arm/kernel/bios32.c               | 63 ++++++++++++++++++++++-----
 arch/arm/mach-dove/pcie.c              | 36 ++++++++++++----
 arch/arm/mach-iop13xx/pci.c            | 36 +++++++++++++---
 arch/arm/mach-orion5x/pci.c            | 47 ++++++++++++++------
 arch/arm64/kernel/pci.c                | 32 +++++++++++---
 drivers/of/of_pci_irq.c                |  3 +-
 drivers/pci/Makefile                   | 17 +-------
 drivers/pci/dwc/pcie-designware-host.c | 41 +++++++++---------
 drivers/pci/host/pci-aardvark.c        | 33 +++++++++++---
 drivers/pci/host/pci-host-common.c     |  4 --
 drivers/pci/host/pci-tegra.c           |  3 +-
 drivers/pci/host/pci-versatile.c       |  1 -
 drivers/pci/host/pcie-altera.c         |  1 -
 drivers/pci/host/pcie-iproc.c          | 43 ++++++++++++-------
 drivers/pci/host/pcie-rcar.c           | 28 +++++++-----
 drivers/pci/host/pcie-xilinx.c         |  3 --
 drivers/pci/pci-driver.c               |  2 +
 drivers/pci/probe.c                    | 78 ++++++++++++++++++++++------------
 drivers/pci/setup-irq.c                | 45 +++++++++++++++-----
 include/linux/pci.h                    |  9 ++--
 20 files changed, 363 insertions(+), 162 deletions(-)

-- 
2.10.0