diff options
Diffstat (limited to 'drivers/pci/setup-bus.c')
| -rw-r--r-- | drivers/pci/setup-bus.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index fb506137aaee..896f06e3e793 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -697,6 +697,38 @@ static resource_size_t calculate_memsize(resource_size_t size, return size; } +resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus, + unsigned long type) +{ + return 1; +} + +#define PCI_P2P_DEFAULT_MEM_ALIGN 0x100000 /* 1MiB */ +#define PCI_P2P_DEFAULT_IO_ALIGN 0x1000 /* 4KiB */ +#define PCI_P2P_DEFAULT_IO_ALIGN_1K 0x400 /* 1KiB */ + +static resource_size_t window_alignment(struct pci_bus *bus, + unsigned long type) +{ + resource_size_t align = 1, arch_align; + + if (type & IORESOURCE_MEM) + align = PCI_P2P_DEFAULT_MEM_ALIGN; + else if (type & IORESOURCE_IO) { + /* + * Per spec, I/O windows are 4K-aligned, but some + * bridges have an extension to support 1K alignment. + */ + if (bus->self->io_window_1k) + align = PCI_P2P_DEFAULT_IO_ALIGN_1K; + else + align = PCI_P2P_DEFAULT_IO_ALIGN; + } + + arch_align = pcibios_window_alignment(bus, type); + return max(align, arch_align); +} + /** * pbus_size_io() - size the io window of a given bus * |