ARM: 7683/1: pci: add a align_resource hook
The PCI specifications says that an I/O region must be aligned on a 4
KB boundary, and a memory region aligned on a 1 MB boundary.
However, the Marvell PCIe interfaces rely on address decoding windows
(which allow to associate a range of physical addresses with a given
device). For PCIe memory windows, those windows are defined with a 1
MB granularity (which matches the PCI specs), but PCIe I/O windows can
only be defined with a 64 KB granularity, so they have to be 64 KB
aligned. We therefore need to tell the PCI core about this special
alignement requirement.
The PCI core already calls pcibios_align_resource() in the ARM PCI
core, specifically for such purposes. So this patch extends the ARM
PCI core so that it calls a ->align_resource() hook registered by the
PCI driver, exactly like the existing ->map_irq() and ->swizzle()
hooks.
A particular PCI driver can register a align_resource() hook, and do
its own specific alignement, depending on the specific constraints of
the underlying hardware.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index a1f73b5..b2ed73c 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -462,6 +462,7 @@
sys->busnr = busnr;
sys->swizzle = hw->swizzle;
sys->map_irq = hw->map_irq;
+ sys->align_resource = hw->align_resource;
INIT_LIST_HEAD(&sys->resources);
if (hw->private_data)
@@ -574,6 +575,8 @@
resource_size_t pcibios_align_resource(void *data, const struct resource *res,
resource_size_t size, resource_size_t align)
{
+ struct pci_dev *dev = data;
+ struct pci_sys_data *sys = dev->sysdata;
resource_size_t start = res->start;
if (res->flags & IORESOURCE_IO && start & 0x300)
@@ -581,6 +584,9 @@
start = (start + align - 1) & ~(align - 1);
+ if (sys->align_resource)
+ return sys->align_resource(dev, res, start, size, align);
+
return start;
}