On Sun, Jul 02, 2017 at 04:19:50PM -0500, Bjorn Helgaas wrote:
> On Sat, Jul 01, 2017 at 03:06:30PM +0100, Lorenzo Pieralisi wrote:
> > Hi Bjorn,
> >
> > On Thu, Jun 08, 2017 at 03:13:29PM +0100, Lorenzo Pieralisi wrote:
> > > Legacy PCI host controllers (ie host controllers that set-up the PCI bus
> > > through the ARM pci_common_init() API) are currently relying on
> > > pci_fixup_irqs() to assign legacy PCI irqs to devices. This is not ideal
> > > in that pci_fixup_irqs() assign IRQs for all PCI devices present in a
> > > given system some of which may well be enabled by the time
> > > pci_fixup_irqs() is called (ie a system with multiple host controllers).
> > > With the introduction of struct pci_host_bridge.(*map_irq) pointer it is
> > > possible to assign IRQs for all devices originating from a PCI host
> > > bridge at probe time; this is implemented through pci_assign_irq() that
> > > relies on the struct pci_host_bridge.map_irq pointer to map IRQ for a
> > > given device.
> > >
> > > The benefits this brings are twofold:
> > >
> > > - the IRQ for a device is assigned once at probe time
> > > - the IRQ assignment works also for hotplugged devices
> > >
> > > Remove pci_fixup_irqs() call from bios32 code and rely on
> > > pci_assign_irq() to carry out the IRQ mapping at device probe
> > > time.
> > >
> > > The map_irq() and swizzle_irq() struct pci_host_bridge callbacks are
> > > set-up in the struct pci_host_bridge created in the bios32
> > > pcibios_init_hw() function and mach-* code paths (for PCI mach
> > > implementations that require a specific struct hw_pci.(*scan) function
> > > callback).
> > >
> > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> > > Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
> > > Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> > > Cc: Russell King <linux@xxxxxxxxxxxxxxx>
> > > Cc: Andrew Lunn <andrew@xxxxxxx>
> > > ---
> > > arch/arm/kernel/bios32.c | 4 ++--
> > > arch/arm/mach-dove/pcie.c | 18 ++++++++++--------
> > > arch/arm/mach-iop13xx/pci.c | 2 ++
> > > arch/arm/mach-orion5x/pci.c | 28 +++++++++++++++-------------
> > > 4 files changed, 29 insertions(+), 23 deletions(-)
> >
> > As I mentioned to you, this patch is incomplete and needs an upgrade
> > (ie I misread how Orion and the gazillions board file that go with
> > it to map irqs - apologies but it is very hard to untangle).
> >
> > I am inlining below an incremental patch to be folded in commit:
> >
> > feaec00e757a ("ARM/PCI: Remove pci_fixup_irqs() call for bios32 host
> > controllers")
> >
> > in your pci/irq-fixups branch, or if you prefer I can send you the
> > resulting squashed-in patch to replace this one, as you prefer.
>
> Thanks, I folded this into pci/irq-fixups. The resulting patch is
> merely this:
Yes that's what I expected, we remove pci_fixup_irqs() and add the
hooks into the host bridge structure that should cover all host
bridges initialized via pci_common_init_dev().
Thanks !
Lorenzo
> commit 16508469c0f3198a63923aaec08efa1c63f5fbcc
> Author: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Date: Wed Jun 28 15:14:04 2017 -0500
>
> ARM/PCI: Remove pci_fixup_irqs() call for bios32 host controllers
>
> Legacy PCI host controllers (ie host controllers that set-up the PCI bus
> through the ARM pci_common_init() API) are currently relying on
> pci_fixup_irqs() to assign legacy PCI irqs to devices. This is not ideal
> in that pci_fixup_irqs() assigns IRQs for all PCI devices present in a given
> system some of which may well be enabled by the time pci_fixup_irqs() is
> called (ie a system with multiple host controllers). With the introduction
> of struct pci_host_bridge.(*map_irq) pointer it is possible to assign IRQs
> for all devices originating from a PCI host bridge at probe time; this is
> implemented through pci_assign_irq() that relies on the struct
> pci_host_bridge.map_irq pointer to map IRQ for a given device.
>
> The benefits this brings are twofold:
>
> - the IRQ for a device is assigned once at probe time
> - the IRQ assignment works also for hotplugged devices
>
> Remove pci_fixup_irqs() call from bios32 code and rely on pci_assign_irq()
> to carry out the IRQ mapping at device probe time.
>
> The map_irq() and swizzle_irq() struct pci_host_bridge callbacks are set-up
> in the struct pci_host_bridge created in the bios32 pcibios_init_hw()
> function and mach-* code paths (for PCI mach implementations that require a
> specific struct hw_pci.(*scan) function callback).
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> [bhelgaas: folded in fixes from Lorenzo:
> http://lkml.kernel.org/r/20170701140629.GC8977@red-moon]
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
> Cc: Russell King <linux@xxxxxxxxxxxxxxx>
> Cc: Andrew Lunn <andrew@xxxxxxx>
>
> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> index 4c7621ac389c..56dc1a3a33b4 100644
> --- a/arch/arm/kernel/bios32.c
> +++ b/arch/arm/kernel/bios32.c
> @@ -484,6 +484,9 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
> break;
> }
>
> + bridge->map_irq = pcibios_map_irq;
> + bridge->swizzle_irq = pcibios_swizzle;
> +
> if (hw->scan)
> ret = hw->scan(nr, bridge);
> else {
> @@ -530,8 +533,6 @@ void pci_common_init_dev(struct device *parent, struct hw_pci *hw)
> if (hw->postinit)
> hw->postinit();
>
> - pci_fixup_irqs(pcibios_swizzle, pcibios_map_irq);
> -
> list_for_each_entry(sys, &head, node) {
> struct pci_bus *bus = sys->bus;
>
