| Message ID | 20130130151934.GK23505@n2100.arm.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
Dear Russell King - ARM Linux, On Wed, 30 Jan 2013 15:19:34 +0000, Russell King - ARM Linux wrote: > diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h > index db9fedb..bba0cf3 100644 > --- a/arch/arm/include/asm/mach/pci.h > +++ b/arch/arm/include/asm/mach/pci.h > @@ -29,6 +29,7 @@ struct hw_pci { > void (*postinit)(void); > u8 (*swizzle)(struct pci_dev *dev, u8 *pin); > int (*map_irq)(const struct pci_dev *dev, u8 slot, u8 pin); > + resource_size_t (*window_align)(struct pci_bus *, unsigned long); > }; Didn't you say just yesterday that you would prefer a numerical value rather than a hook that could do random things? :-) Best regards, Thomas
On Wed, Jan 30, 2013 at 03:19:34PM +0000, Russell King - ARM Linux wrote: > On Wed, Jan 30, 2013 at 03:08:56PM +0000, Russell King - ARM Linux wrote: > > On Wed, Jan 30, 2013 at 01:03:44PM +0100, Thierry Reding wrote: > > > On Wed, Jan 30, 2013 at 11:32:46AM +0000, Russell King - ARM Linux wrote: > > > > On Mon, Jan 28, 2013 at 07:56:28PM +0100, Thomas Petazzoni wrote: > > > > > +static resource_size_t mvebu_pcie_align_resource(struct pci_dev *dev, > > > > > + const struct resource *res, > > > > > + resource_size_t start, > > > > > + resource_size_t size, > > > > > + resource_size_t align) > > > > > +{ > > > > > + if (!(res->flags & IORESOURCE_IO)) > > > > > + return start; > > > > > + > > > > > + /* > > > > > + * The I/O regions must be 64K aligned, because the > > > > > + * granularity of PCIe I/O address decoding windows is 64 K > > > > > + */ > > > > > + return round_up(start, SZ_64K); > > > > > +} > > > > > > > > You do realise that this will result in all PCI I/O BARs being rounded > > > > up to 64K. > > > > > > > > I've just been digging through the PCI code and have come across a > > > > function - pcibios_window_alignment() - which the PCI code allows to be > > > > overriden which allows you to increase the alignment requirement of > > > > bridge windows. It takes the PCI bus and window type as arguments. > > > > > > > > I'd suggest using that, and checking whether the bus which is passed > > > > corresponds with a bus which gives you problems, so that you don't > > > > impose the 64K requirement on downstream bridges. > > > > > > That approach isn't going to work very well with multi-platform, though, > > > since the function can only be overridden on a per-architecture basis. > > > > The same can be said of all the various other functions which the PCI > > stuff expects the arch to provide, yet we seem to cope just fine... > > And this (untested) is how it's done: > > arch/arm/include/asm/mach/pci.h | 1 + > arch/arm/kernel/bios32.c | 8 ++++++++ > 2 files changed, 9 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h > index db9fedb..bba0cf3 100644 > --- a/arch/arm/include/asm/mach/pci.h > +++ b/arch/arm/include/asm/mach/pci.h > @@ -29,6 +29,7 @@ struct hw_pci { > void (*postinit)(void); > u8 (*swizzle)(struct pci_dev *dev, u8 *pin); > int (*map_irq)(const struct pci_dev *dev, u8 slot, u8 pin); > + resource_size_t (*window_align)(struct pci_bus *, unsigned long); > }; > > /* > diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c > index 379cf32..32c3bd9 100644 > --- a/arch/arm/kernel/bios32.c > +++ b/arch/arm/kernel/bios32.c > @@ -581,6 +581,14 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, > return start; > } > > +resource_size_t pcibios_window_alignment(struct pci_bus *bus, > + unsigned long type) > +{ > + struct pci_sys_data *sys = bus->sysdata; > + > + return sys->window_alignment ? sys->window_alignment(bus, type) : 1; > +} > + > /** > * pcibios_enable_device - Enable I/O and memory. > * @dev: PCI device to be enabled Yes, something like that'll work. I had been under the impression that what you proposed was overriding pcibios_window_alignment() for Marvell only. Thierry
diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h index db9fedb..bba0cf3 100644 --- a/arch/arm/include/asm/mach/pci.h +++ b/arch/arm/include/asm/mach/pci.h @@ -29,6 +29,7 @@ struct hw_pci { void (*postinit)(void); u8 (*swizzle)(struct pci_dev *dev, u8 *pin); int (*map_irq)(const struct pci_dev *dev, u8 slot, u8 pin); + resource_size_t (*window_align)(struct pci_bus *, unsigned long); }; /* diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c index 379cf32..32c3bd9 100644 --- a/arch/arm/kernel/bios32.c +++ b/arch/arm/kernel/bios32.c @@ -581,6 +581,14 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, return start; } +resource_size_t pcibios_window_alignment(struct pci_bus *bus, + unsigned long type) +{ + struct pci_sys_data *sys = bus->sysdata; + + return sys->window_alignment ? sys->window_alignment(bus, type) : 1; +} + /** * pcibios_enable_device - Enable I/O and memory. * @dev: PCI device to be enabled